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| Electronic Schematics (alt.binaries.schematics.electronic) A place to show and share your electronics schematic drawings. |
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#1
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
Okay, I haven't had time to get by the candy store, so I still don't have
the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave |
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#2
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
Dave wrote:
Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). |
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#3
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
"Robert Baer" wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave |
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#4
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On Tue, 11 Oct 2011 12:57:11 -0500, "Dave" wrote:
"Robert Baer" wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice  480)460-2350 Fax: Available upon request | Brass Rat || E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
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#5
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
"Jim Thompson" wrote in message ... On Tue, 11 Oct 2011 12:57:11 -0500, "Dave" wrote: "Robert Baer" wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- Umm, I *think* I see a problem with this solution. If I'm correct, it will spend it's daytime hours conducting *instead* of Q1, which will drain my batteries rather than allowing them to charge. Then when the lights go out, they will not be able to support conduction of Q1 or the LED. Please correct me if I'm wrong. It doesnt' look like a real solution though... But thanks, Dave |
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#6
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On 10/11/2011 04:38 PM, Dave wrote:
"Jim wrote in message ... On Tue, 11 Oct 2011 12:57:11 -0500, wrote: "Robert wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- Umm, I *think* I see a problem with this solution. If I'm correct, it will spend it's daytime hours conducting *instead* of Q1, which will drain my batteries rather than allowing them to charge. Then when the lights go out, they will not be able to support conduction of Q1 or the LED. Please correct me if I'm wrong. It doesnt' look like a real solution though... But thanks, Dave So order some MOSFETs from Digikey for 42 cents apiece in quantity 1 (or 5 cents in quantity 2000), and get on with it. Even Radio Shack has IRF510 MOSFETs for two bucks. It really isn't this hard! Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net |
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#7
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
"Phil Hobbs" wrote in message ... On 10/11/2011 04:38 PM, Dave wrote: "Jim wrote in message ... On Tue, 11 Oct 2011 12:57:11 -0500, wrote: "Robert wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- Umm, I *think* I see a problem with this solution. If I'm correct, it will spend it's daytime hours conducting *instead* of Q1, which will drain my batteries rather than allowing them to charge. Then when the lights go out, they will not be able to support conduction of Q1 or the LED. Please correct me if I'm wrong. It doesnt' look like a real solution though... But thanks, Dave So order some MOSFETs from Digikey for 42 cents apiece in quantity 1 (or 5 cents in quantity 2000), and get on with it. Even Radio Shack has IRF510 MOSFETs for two bucks. It really isn't this hard! Cheers Phil Hobbs Well, I could only find the surface mount devices at Digikey, and my local Radio Shack doens't stock anything more than standard general purpose NPN and PNP transistors. I know where to get what I need, I just have to get by there (severely limited in my potential for getting about town.) But you're right, it's not that hard, I just have to pick up what I need. Could have done it today, but I spent my time putting a new wax seal on the toilet and doing laundry.  Will try to get it Thursday. In the meantime I keep fiddling with junk box paraphernailia. Thought I had it with the mini photocell. Still can't figure out why that one doesn't work. sigh Dave |
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#8
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On 10/11/2011 05:32 PM, Dave wrote:
"Phil wrote in message ... On 10/11/2011 04:38 PM, Dave wrote: "Jim wrote in message ... On Tue, 11 Oct 2011 12:57:11 -0500, wrote: "Robert wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- Umm, I *think* I see a problem with this solution. If I'm correct, it will spend it's daytime hours conducting *instead* of Q1, which will drain my batteries rather than allowing them to charge. Then when the lights go out, they will not be able to support conduction of Q1 or the LED. Please correct me if I'm wrong. It doesnt' look like a real solution though... But thanks, Dave So order some MOSFETs from Digikey for 42 cents apiece in quantity 1 (or 5 cents in quantity 2000), and get on with it. Even Radio Shack has IRF510 MOSFETs for two bucks. It really isn't this hard! Cheers Phil Hobbs Well, I could only find the surface mount devices at Digikey, and my local Radio Shack doens't stock anything more than standard general purpose NPN and PNP transistors. I know where to get what I need, I just have to get by there (severely limited in my potential for getting about town.) But you're right, it's not that hard, I just have to pick up what I need. Could have done it today, but I spent my time putting a new wax seal on the toilet and doing laundry. Will try to get it Thursday. In the meantime I keepfiddling with junk box paraphernailia. Thought I had it with the mini photocell. Still can't figure out why that one doesn't work. sigh Dave 2N7000. TO92, a nickel in quantity. http://search.digikey.com/scripts/Dk...eywords=2N7000 Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net |
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#9
Posted to alt.binaries.schematics.electronic
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Damned, I am.
"Dave" wrote in message ica... "Phil Hobbs" wrote in message ... On 10/11/2011 04:38 PM, Dave wrote: "Jim wrote in message ... On Tue, 11 Oct 2011 12:57:11 -0500, wrote: "Robert wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- Umm, I *think* I see a problem with this solution. If I'm correct, it will spend it's daytime hours conducting *instead* of Q1, which will drain my batteries rather than allowing them to charge. Then when the lights go out, they will not be able to support conduction of Q1 or the LED. Please correct me if I'm wrong. It doesnt' look like a real solution though... But thanks, Dave So order some MOSFETs from Digikey for 42 cents apiece in quantity 1 (or 5 cents in quantity 2000), and get on with it. Even Radio Shack has IRF510 MOSFETs for two bucks. It really isn't this hard! Cheers Phil Hobbs Well, I could only find the surface mount devices at Digikey, and my local Radio Shack doens't stock anything more than standard general purpose NPN and PNP transistors. I know where to get what I need, I just have to get by there (severely limited in my potential for getting about town.) But you're right, it's not that hard, I just have to pick up what I need. Could have done it today, but I spent my time putting a new wax seal on the toilet and doing laundry. Will try to get it Thursday. In the meantime I keep fiddling with junk box paraphernailia. Thought I had it with the mini photocell. Still can't figure out why that one doesn't work. sigh Dave Well Phil, I owe you an apology. My local Radio Shack DOES stock that MOSFET. They have two of them, and I am going to walk down and get them. Thank you. It was knowing what to search for that apparently made the difference. This place has been such a frustration to me in the past I almost didn't give them a chance. But they do have two. Thank you for clueing me in to what to look for. Dave |
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#10
Posted to alt.binaries.schematics.electronic
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Damned, I am.
On 10/11/2011 05:46 PM, Dave wrote:
wrote in message ica... "Phil wrote in message ... On 10/11/2011 04:38 PM, Dave wrote: "Jim wrote in message ... On Tue, 11 Oct 2011 12:57:11 -0500, wrote: "Robert wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- Umm, I *think* I see a problem with this solution. If I'm correct, it will spend it's daytime hours conducting *instead* of Q1, which will drain my batteries rather than allowing them to charge. Then when the lights go out, they will not be able to support conduction of Q1 or the LED. Please correct me if I'm wrong. It doesnt' look like a real solution though... But thanks, Dave So order some MOSFETs from Digikey for 42 cents apiece in quantity 1 (or 5 cents in quantity 2000), and get on with it. Even Radio Shack has IRF510 MOSFETs for two bucks. It really isn't this hard! Cheers Phil Hobbs Well, I could only find the surface mount devices at Digikey, and my local Radio Shack doens't stock anything more than standard general purpose NPN and PNP transistors. I know where to get what I need, I just have to get by there (severely limited in my potential for getting about town.) But you're right, it's not that hard, I just have to pick up what I need. Could have done it today, but I spent my time putting a new wax seal on the toilet and doing laundry. Will try to get it Thursday. In themeantime I keep fiddling with junk box paraphernailia. Thought I had it with the mini photocell. Still can't figure out why that one doesn't work. sigh Dave Well Phil, I owe you an apology. My local Radio Shack DOES stock that MOSFET. They have two of them, and I am going to walk down and get them. Thank you. It was knowing what to search for that apparently made the difference. This place has been such a frustration to me in the past I almost didn't give them a chance. But they do have two. Thank you for clueing me in to what to look for. Dave No worries--I'm just in favour of forward motion! Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net |
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#11
Posted to alt.binaries.schematics.electronic
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Damned, I am.
"Phil Hobbs" wrote in message ... On 10/11/2011 05:46 PM, Dave wrote: wrote in message ica... "Phil wrote in message ... On 10/11/2011 04:38 PM, Dave wrote: "Jim wrote in message ... On Tue, 11 Oct 2011 12:57:11 -0500, wrote: "Robert wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- Umm, I *think* I see a problem with this solution. If I'm correct, it will spend it's daytime hours conducting *instead* of Q1, which will drain my batteries rather than allowing them to charge. Then when the lights go out, they will not be able to support conduction of Q1 or the LED. Please correct me if I'm wrong. It doesnt' look like a real solution though... But thanks, Dave So order some MOSFETs from Digikey for 42 cents apiece in quantity 1 (or 5 cents in quantity 2000), and get on with it. Even Radio Shack has IRF510 MOSFETs for two bucks. It really isn't this hard! Cheers Phil Hobbs Well, I could only find the surface mount devices at Digikey, and my local Radio Shack doens't stock anything more than standard general purpose NPN and PNP transistors. I know where to get what I need, I just have to get by there (severely limited in my potential for getting about town.) But you're right, it's not that hard, I just have to pick up what I need. Could have done it today, but I spent my time putting a new wax seal on the toilet and doing laundry. Will try to get it Thursday. In themeantime I keep fiddling with junk box paraphernailia. Thought I had it with the mini photocell. Still can't figure out why that one doesn't work. sigh Dave Well Phil, I owe you an apology. My local Radio Shack DOES stock that MOSFET. They have two of them, and I am going to walk down and get them. Thank you. It was knowing what to search for that apparently made the difference. This place has been such a frustration to me in the past I almost didn't give them a chance. But they do have two. Thank you for clueing me in to what to look for. Dave No worries--I'm just in favour of forward motion! Cheers Phil Hobbs And I thank you for your spurring.  And I can hardly believe you found the 2N7000 at Digikey in a TO-92 package. I think I know why I didn't see it though. I was looking for the 2N7002, and I *think* THAT only comes in SMD. Or I could be full of crap. Either way, I couldn't find it, but you pointed directely at it. Thank you. I appreciate your help. Take it easy... Dave |
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#12
Posted to alt.binaries.schematics.electronic
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Damned, I am.
On 10/11/2011 06:07 PM, Dave wrote:
"Phil wrote in message ... On 10/11/2011 05:46 PM, Dave wrote: wrote in message ica... "Phil wrote in message ... On 10/11/2011 04:38 PM, Dave wrote: "Jim wrote in message ... On Tue, 11 Oct 2011 12:57:11 -0500, wrote: "Robert wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- Umm, I *think* I see a problem with this solution. If I'm correct, it will spend it's daytime hours conducting *instead* of Q1, which will drain my batteries rather than allowing them to charge. Then when the lights go out, they will not be able to support conduction of Q1 or the LED. Please correct me if I'm wrong. It doesnt' look like a real solution though... But thanks, Dave So order some MOSFETs from Digikey for 42 cents apiece in quantity 1 (or 5 cents in quantity 2000), and get on with it. Even Radio Shack has IRF510 MOSFETs for two bucks. It really isn't this hard! Cheers Phil Hobbs Well, I could only find the surface mount devices at Digikey, and my local Radio Shack doens't stock anything more than standard general purpose NPN and PNP transistors. I know where to get what I need, I just have to get by there (severely limited in my potential for getting about town.) But you're right, it's not that hard, I just have to pick up what I need. Could have done it today, but I spent my time putting a new wax seal on the toilet and doing laundry. Will try to get it Thursday. In themeantime I keep fiddling with junk box paraphernailia. Thought I had it with the mini photocell. Still can't figure out why that one doesn't work. sigh Dave Well Phil, I owe you an apology. My local Radio Shack DOES stock that MOSFET. They have two of them, and I am going to walk down and get them. Thank you. It was knowing what to search for that apparently made the difference. This place has been such a frustration to me in the past I almost didn't give them a chance. But they do have two. Thank you for clueing me in to what to look for. Dave No worries--I'm just in favour of forward motion! Cheers Phil Hobbs And I thank you for your spurring. And I can hardly believe you foundthe 2N7000 at Digikey in a TO-92 package. I think I know why I didn't see it though. I was looking for the 2N7002, and I *think* THAT only comes in SMD. Or I could be full of crap. Either way, I couldn't find it, butyou pointed directely at it. Thank you. I appreciate your help. Take it easy... Dave Yes, my first post mentioned the 2N7002 in the text but the 2N7000 in the schematic. The 7002 is the SOT23 version of the 7000--which is by far the most popular jellybean small-signal switching MOSFET, and if you don't cook them, they're good for practically everything. John L. makes Godzilla pulsers out of them, for instance. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net |
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#13
Posted to alt.binaries.schematics.electronic
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Damned, I am.
Yes, my first post mentioned the 2N7002 in the text but the 2N7000 in the schematic. The 7002 is the SOT23 version of the 7000--which is by far the most popular jellybean small-signal switching MOSFET, and if you don't cook them, they're good for practically everything. John L. makes Godzilla pulsers out of them, for instance. Cheers Phil Hobbs And I have a question about that schematic. I see drain and source, but where I expect to see the gate indicated it has a letter J. Is that the gate? If not, what is it actually? Many thanks, Dave |
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#14
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On Tue, 11 Oct 2011 15:38:06 -0500, "Dave" wrote:
"Jim Thompson" wrote in message ... On Tue, 11 Oct 2011 12:57:11 -0500, "Dave" wrote: "Robert Baer" wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave Put the photo-resistor across the base emitter junction of the transistor. Then a bias resistor to plus (NPN assumed). Twiddle bias resistor value as you try from dark-to-light until you get the value right. Strong light will keep the Vbe below 0.7V, and the transistor will not conduct. ...Jim Thompson -- Umm, I *think* I see a problem with this solution. If I'm correct, it will spend it's daytime hours conducting *instead* of Q1, which will drain my batteries rather than allowing them to charge. Then when the lights go out, they will not be able to support conduction of Q1 or the LED. Please correct me if I'm wrong. It doesnt' look like a real solution though... But thanks, Dave Nope! Light make low valued photo-resistor, dark make high valued photo-resistor, thus transistor OFF in daylight. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice 480)460-2350 Fax: Available upon request | Brass Rat || E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
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#15
Posted to alt.binaries.schematics.electronic
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Damned, I am.
On 10/11/2011 06:38 PM, Dave wrote:
Yes, my first post mentioned the 2N7002 in the text but the 2N7000 in the schematic. The 7002 is the SOT23 version of the 7000--which is by far the most popular jellybean small-signal switching MOSFET, and if you don't cook them, they're good for practically everything. John L. makes Godzilla pulsers out of them, for instance. Cheers Phil Hobbs And I have a question about that schematic. I see drain and source, butwhere I expect to see the gate indicated it has a letter J. Is that the gate? If not, what is it actually? Many thanks, Dave It's the ASCII art. A J is the nearest thing to a backwards L. If you recognize the drain and source, and it's a 3-lead device..... Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net |
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#16
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
Dave wrote:
"Robert Baer" wrote in message ... Dave wrote: Okay, I haven't had time to get by the candy store, so I still don't have the MOSFET recommended, and am still tinkering with this project out of my junkbox. Problem is, it's not working right, and I can't figure out why. Details a the photoresistor (and every photoresistor I have) DROPS it's resistance in sunlight, rather than raising it, so the transistor conducts when exposed to sunlight only. I replaced the photoresistor with a device that seems to be a tiny photocell behind a window (with leads, and sized similarly to the photoresistor) which provides .4VDC in normally bright light, installed in polarity opposite to that which would assist Q1 in conducting. My calculations (obviously flawed, but I can't figure out where) tell me that it should counteract some of the voltage resulting form the 4.2K/680 voltage divider, and keep Q1 from conducting in normal sunlight. My numbers say there should be -.7VDC from the voltage divider, and the photocell shouldmake that -.3VDC, which should turn Q1 off. Only it doesn't seem to work that way. Q1 conducts regardless. What am I doing wrong? I have verified the actual voltages at the base of Q1 (the juncture of the voltage divider) and coming from the tiny photocell. Only nothing changes. Could the problem be the miniscule current coming from the tiny photocell? I somehow thought voltage was voltage, and current didn't matter... Attached is my schematic of the current configuration. Haven't bothered to convert it to LTSpice, as I have no idea how to incorporate a solar cell, sunlight, or the photocell on the PC board. Ignorantly yours... Dave WELL!!! It is a known fact, a result via the laws of physics, that photo resistors increase their conductivity when illuminated; to expect otherwise is not exactly sane or an educated "deduction". Just use a voltage divider to the gate / base, placed in an appropiate position (i sure ain't gonna do that "work" fer yah). Okay, so please explain to me how a voltage divider will change it's values according to whether it is day or night, and turn the transistor on at night while turning it off during the day. Look at the schematic. I've biased the transistor properly I believe, it's getting things to respond to daylight I am having trouble with. Thanks, Dave NOPE! Figgr 'tout yerself. Use that magnificent computer that was given to you when you were born.. |
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#17
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On Tue, 11 Oct 2011 16:32:09 -0500, "Dave" wrote:
.. .. .. Thought I had it with the mini photocell. Still can't figure out why that one doesn't work. sigh Dave --- Seems to work nicely after a few resistor value changes. Also, I guessed at the PV's output voltage as 8V with a 50mA load and fiddled with R1 (its internal resistance) to get 50mA into D1. Do you have the open circuit voltage and short circuit current spec's for the PV? Here's the sim: Version 4 SHEET 1 880 680 WIRE -144 -112 -192 -112 WIRE -48 -112 -80 -112 WIRE 64 -112 -48 -112 WIRE 144 -112 64 -112 WIRE 320 -112 224 -112 WIRE 320 -80 320 -112 WIRE 64 -64 64 -112 WIRE -192 -16 -192 -112 WIRE -48 -16 -48 -112 WIRE 320 16 320 -16 WIRE 64 64 64 16 WIRE 144 64 64 64 WIRE 256 64 224 64 WIRE -192 112 -192 64 WIRE -48 112 -48 64 WIRE 64 112 64 64 WIRE -192 240 -192 192 WIRE -48 240 -48 192 WIRE -48 240 -192 240 WIRE 64 240 64 192 WIRE 64 240 -48 240 WIRE 320 240 320 112 WIRE 320 240 64 240 WIRE -192 304 -192 240 FLAG -192 304 0 SYMBOL res 48 -80 R0 SYMATTR InstName R3 SYMATTR Value 4700 SYMBOL npn 256 16 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904 SYMBOL LED 304 -80 R0 SYMATTR InstName D2 SYMATTR Value NSCW100 SYMBOL schottky -144 -96 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D1 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL res 48 96 R0 SYMATTR InstName R4 SYMATTR Value 10K SYMBOL res 240 -128 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R5 SYMATTR Value 56 SYMBOL voltage -48 96 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value 4.8 SYMBOL voltage 128 64 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 -32 56 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V3 SYMATTR Value PULSE(0 4 0 12 12 0 0 1) SYMBOL voltage -192 96 R0 WINDOW 3 24 96 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value PULSE(0 8 0 12 12 0 24 1) SYMBOL res -64 -32 R0 SYMATTR InstName R2 SYMATTR Value .1 SYMBOL res -208 -32 R0 SYMATTR InstName R1 SYMATTR Value 58 TEXT -162 272 Left 2 !.tran 24 startup uic -- JF |
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#18
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
Hey John. No, I don't have any data on the PV (I'm guessing that is
"PhotoVoataic".) It's something I pulled out of my junkbox... BTW, I'm trying to run this sim in LTSpice, and can't figure out how to make it work. This is a netlist, right? How can I import it to my version of LTSpice and give it a test run. I'm really interested in seeing your changes. Thanks! Dave "John Fields" wrote in message ... On Tue, 11 Oct 2011 16:32:09 -0500, "Dave" wrote: . . . Thought I had it with the mini photocell. Still can't figure out why that one doesn't work. sigh Dave --- Seems to work nicely after a few resistor value changes. Also, I guessed at the PV's output voltage as 8V with a 50mA load and fiddled with R1 (its internal resistance) to get 50mA into D1. Do you have the open circuit voltage and short circuit current spec's for the PV? Here's the sim: Version 4 SHEET 1 880 680 WIRE -144 -112 -192 -112 WIRE -48 -112 -80 -112 WIRE 64 -112 -48 -112 WIRE 144 -112 64 -112 WIRE 320 -112 224 -112 WIRE 320 -80 320 -112 WIRE 64 -64 64 -112 WIRE -192 -16 -192 -112 WIRE -48 -16 -48 -112 WIRE 320 16 320 -16 WIRE 64 64 64 16 WIRE 144 64 64 64 WIRE 256 64 224 64 WIRE -192 112 -192 64 WIRE -48 112 -48 64 WIRE 64 112 64 64 WIRE -192 240 -192 192 WIRE -48 240 -48 192 WIRE -48 240 -192 240 WIRE 64 240 64 192 WIRE 64 240 -48 240 WIRE 320 240 320 112 WIRE 320 240 64 240 WIRE -192 304 -192 240 FLAG -192 304 0 SYMBOL res 48 -80 R0 SYMATTR InstName R3 SYMATTR Value 4700 SYMBOL npn 256 16 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904 SYMBOL LED 304 -80 R0 SYMATTR InstName D2 SYMATTR Value NSCW100 SYMBOL schottky -144 -96 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D1 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL res 48 96 R0 SYMATTR InstName R4 SYMATTR Value 10K SYMBOL res 240 -128 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R5 SYMATTR Value 56 SYMBOL voltage -48 96 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value 4.8 SYMBOL voltage 128 64 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 -32 56 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V3 SYMATTR Value PULSE(0 4 0 12 12 0 0 1) SYMBOL voltage -192 96 R0 WINDOW 3 24 96 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value PULSE(0 8 0 12 12 0 24 1) SYMBOL res -64 -32 R0 SYMATTR InstName R2 SYMATTR Value .1 SYMBOL res -208 -32 R0 SYMATTR InstName R1 SYMATTR Value 58 TEXT -162 272 Left 2 !.tran 24 startup uic -- JF |
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#19
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On Wed, 12 Oct 2011 16:44:41 -0500, "Dave" wrote:
Hey John. No, I don't have any data on the PV (I'm guessing that is "PhotoVoataic".) It's something I pulled out of my junkbox... --- PhotoVoltaic. :-) ^ --- BTW, I'm trying to run this sim in LTSpice, and can't figure out how to make it work. This is a netlist, right? --- No. It's an ASCII circuit description, and LTspice generates the needed netlist from it. --- How can I import it to my version of LTSpice and give it a test run. I'm really interested in seeing your changes. Thanks! --- OK. Save the list to a file and name it anything you like as long as it has a .asc extension, say, "nightlight.asc". Then, invoke LTspice, navigate to the file and left click on it. Voila! The beautemous schematic will appear before your very eyes, ready to be run and probed :-) BTW, the X axis of the waveform viewer is set to correspond to a 24 hour day and you can adjust the voltage divider connected to the BJT's base to set the circuit's switching threshold to a function of time by regarding voltage as a function of irradiance. -- JF |
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#20
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
"John Fields" wrote in message ... On Wed, 12 Oct 2011 16:44:41 -0500, "Dave" wrote: Hey John. No, I don't have any data on the PV (I'm guessing that is "PhotoVoataic".) It's something I pulled out of my junkbox... --- PhotoVoltaic. :-) ^ --- BTW, I'm trying to run this sim in LTSpice, and can't figure out how to make it work. This is a netlist, right? --- No. It's an ASCII circuit description, and LTspice generates the needed netlist from it. --- How can I import it to my version of LTSpice and give it a test run. I'm really interested in seeing your changes. Thanks! --- OK. Save the list to a file and name it anything you like as long as it has a .asc extension, say, "nightlight.asc". Then, invoke LTspice, navigate to the file and left click on it. Voila! The beautemous schematic will appear before your very eyes, ready to be run and probed :-) BTW, the X axis of the waveform viewer is set to correspond to a 24 hour day and you can adjust the voltage divider connected to the BJT's base to set the circuit's switching threshold to a function of time by regarding voltage as a function of irradiance. -- JF THANK YOU! *Much appreciated.* Dave |
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#21
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On Wed, 12 Oct 2011 21:04:52 -0500, "Dave" wrote:
"John Fields" wrote in message .. . On Wed, 12 Oct 2011 16:44:41 -0500, "Dave" wrote: Hey John. No, I don't have any data on the PV (I'm guessing that is "PhotoVoataic".) It's something I pulled out of my junkbox... --- PhotoVoltaic. :-) ^ --- BTW, I'm trying to run this sim in LTSpice, and can't figure out how to make it work. This is a netlist, right? --- No. It's an ASCII circuit description, and LTspice generates the needed netlist from it. --- How can I import it to my version of LTSpice and give it a test run. I'm really interested in seeing your changes. Thanks! --- OK. Save the list to a file and name it anything you like as long as it has a .asc extension, say, "nightlight.asc". Then, invoke LTspice, navigate to the file and left click on it. Voila! The beautemous schematic will appear before your very eyes, ready to be run and probed :-) BTW, the X axis of the waveform viewer is set to correspond to a 24 hour day and you can adjust the voltage divider connected to the BJT's base to set the circuit's switching threshold to a function of time by regarding voltage as a function of irradiance. -- JF THANK YOU! *Much appreciated.* Dave --- My pleasure. :-) -- JF |
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#22
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
"John Fields" wrote in message ... On Wed, 12 Oct 2011 21:04:52 -0500, "Dave" wrote: "John Fields" wrote in message . .. On Wed, 12 Oct 2011 16:44:41 -0500, "Dave" wrote: Hey John. No, I don't have any data on the PV (I'm guessing that is "PhotoVoataic".) It's something I pulled out of my junkbox... --- PhotoVoltaic. :-) ^ --- BTW, I'm trying to run this sim in LTSpice, and can't figure out how to make it work. This is a netlist, right? --- No. It's an ASCII circuit description, and LTspice generates the needed netlist from it. --- How can I import it to my version of LTSpice and give it a test run. I'm really interested in seeing your changes. Thanks! --- OK. Save the list to a file and name it anything you like as long as it has a .asc extension, say, "nightlight.asc". Then, invoke LTspice, navigate to the file and left click on it. Voila! The beautemous schematic will appear before your very eyes, ready to be run and probed :-) BTW, the X axis of the waveform viewer is set to correspond to a 24 hour day and you can adjust the voltage divider connected to the BJT's base to set the circuit's switching threshold to a function of time by regarding voltage as a function of irradiance. -- JF THANK YOU! *Much appreciated.* Dave --- My pleasure. :-) -- JF Hey John, have a question RE the Spice schematic generated by the netlist which resulted from opening the ASCII circuit description you posted. The schematic shows V3, or the PV, as being four volts, not four hundred millivolts, which would accurately describe the real circuit I am working with. If I said that the PV generated 4 volts, I was full of crap. It is ..4V. Seems like this would change everything. But that's why I had a 4.2K in series with a 680 Ohm resistor for the voltage divider that drives the base of Q1. When I saw you had a 4.7K and a 10K for those resistors, I knew something was not right. Please give this another glance, and let me know what you think... Thanks, Dave |
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#23
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On Thu, 13 Oct 2011 16:37:32 -0500, "Dave" wrote:
"John Fields" wrote in message .. . On Wed, 12 Oct 2011 21:04:52 -0500, "Dave" wrote: "John Fields" wrote in message ... On Wed, 12 Oct 2011 16:44:41 -0500, "Dave" wrote: Hey John. No, I don't have any data on the PV (I'm guessing that is "PhotoVoataic".) It's something I pulled out of my junkbox... --- PhotoVoltaic. :-) ^ --- BTW, I'm trying to run this sim in LTSpice, and can't figure out how to make it work. This is a netlist, right? --- No. It's an ASCII circuit description, and LTspice generates the needed netlist from it. --- How can I import it to my version of LTSpice and give it a test run. I'm really interested in seeing your changes. Thanks! --- OK. Save the list to a file and name it anything you like as long as it has a .asc extension, say, "nightlight.asc". Then, invoke LTspice, navigate to the file and left click on it. Voila! The beautemous schematic will appear before your very eyes, ready to be run and probed :-) BTW, the X axis of the waveform viewer is set to correspond to a 24 hour day and you can adjust the voltage divider connected to the BJT's base to set the circuit's switching threshold to a function of time by regarding voltage as a function of irradiance. -- JF THANK YOU! *Much appreciated.* Dave --- My pleasure. :-) -- JF Hey John, have a question RE the Spice schematic generated by the netlist which resulted from opening the ASCII circuit description you posted. The schematic shows V3, or the PV, as being four volts, not four hundred millivolts, which would accurately describe the real circuit I am working with. If I said that the PV generated 4 volts, I was full of crap. It is .4V. Seems like this would change everything. But that's why I had a 4.2K in series with a 680 Ohm resistor for the voltage divider that drives the base of Q1. When I saw you had a 4.7K and a 10K for those resistors, I knew something was not right. Please give this another glance, and let me know what you think... --- You won't have enough gain with a single transistor and only 400mV deltaV on the base to get crispy switch points, but change R3 to 1K and R4 to 240 ohms and you'll at least get the LED to turn on and off as day turns to night turns to day. Have you tried Doctor Phil's circuit yet? -- JF |
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#24
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
"John Fields" wrote in message ... On Thu, 13 Oct 2011 16:37:32 -0500, "Dave" wrote: "John Fields" wrote in message . .. On Wed, 12 Oct 2011 21:04:52 -0500, "Dave" wrote: "John Fields" wrote in message m... On Wed, 12 Oct 2011 16:44:41 -0500, "Dave" wrote: Hey John. No, I don't have any data on the PV (I'm guessing that is "PhotoVoataic".) It's something I pulled out of my junkbox... --- PhotoVoltaic. :-) ^ --- BTW, I'm trying to run this sim in LTSpice, and can't figure out how to make it work. This is a netlist, right? --- No. It's an ASCII circuit description, and LTspice generates the needed netlist from it. --- How can I import it to my version of LTSpice and give it a test run. I'm really interested in seeing your changes. Thanks! --- OK. Save the list to a file and name it anything you like as long as it has a .asc extension, say, "nightlight.asc". Then, invoke LTspice, navigate to the file and left click on it. Voila! The beautemous schematic will appear before your very eyes, ready to be run and probed :-) BTW, the X axis of the waveform viewer is set to correspond to a 24 hour day and you can adjust the voltage divider connected to the BJT's base to set the circuit's switching threshold to a function of time by regarding voltage as a function of irradiance. -- JF THANK YOU! *Much appreciated.* Dave --- My pleasure. :-) -- JF Hey John, have a question RE the Spice schematic generated by the netlist which resulted from opening the ASCII circuit description you posted. The schematic shows V3, or the PV, as being four volts, not four hundred millivolts, which would accurately describe the real circuit I am working with. If I said that the PV generated 4 volts, I was full of crap. It is .4V. Seems like this would change everything. But that's why I had a 4.2K in series with a 680 Ohm resistor for the voltage divider that drives the base of Q1. When I saw you had a 4.7K and a 10K for those resistors, I knew something was not right. Please give this another glance, and let me know what you think... --- You won't have enough gain with a single transistor and only 400mV deltaV on the base to get crispy switch points, but change R3 to 1K and R4 to 240 ohms and you'll at least get the LED to turn on and off as day turns to night turns to day. Have you tried Doctor Phil's circuit yet? -- JF Haven't received the parts I ordered from Digikey yet. Maybe tomorrow or Saturday... And the 400 mV is coming from the tiny photocell, to counter part of the voltage divider's voltage at the base and turn Q1 off when the sun is shining. Dave |
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#25
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On Thu, 13 Oct 2011 22:51:29 -0500, "Dave" wrote:
"John Fields" wrote in message .. . On Thu, 13 Oct 2011 16:37:32 -0500, "Dave" wrote: "John Fields" wrote in message ... On Wed, 12 Oct 2011 21:04:52 -0500, "Dave" wrote: "John Fields" wrote in message om... On Wed, 12 Oct 2011 16:44:41 -0500, "Dave" wrote: Hey John. No, I don't have any data on the PV (I'm guessing that is "PhotoVoataic".) It's something I pulled out of my junkbox... --- PhotoVoltaic. :-) ^ --- BTW, I'm trying to run this sim in LTSpice, and can't figure out how to make it work. This is a netlist, right? --- No. It's an ASCII circuit description, and LTspice generates the needed netlist from it. --- How can I import it to my version of LTSpice and give it a test run. I'm really interested in seeing your changes. Thanks! --- OK. Save the list to a file and name it anything you like as long as it has a .asc extension, say, "nightlight.asc". Then, invoke LTspice, navigate to the file and left click on it. Voila! The beautemous schematic will appear before your very eyes, ready to be run and probed :-) BTW, the X axis of the waveform viewer is set to correspond to a 24 hour day and you can adjust the voltage divider connected to the BJT's base to set the circuit's switching threshold to a function of time by regarding voltage as a function of irradiance. -- JF THANK YOU! *Much appreciated.* Dave --- My pleasure. :-) -- JF Hey John, have a question RE the Spice schematic generated by the netlist which resulted from opening the ASCII circuit description you posted. The schematic shows V3, or the PV, as being four volts, not four hundred millivolts, which would accurately describe the real circuit I am working with. If I said that the PV generated 4 volts, I was full of crap. It is .4V. Seems like this would change everything. But that's why I had a 4.2K in series with a 680 Ohm resistor for the voltage divider that drives the base of Q1. When I saw you had a 4.7K and a 10K for those resistors, I knew something was not right. Please give this another glance, and let me know what you think... --- You won't have enough gain with a single transistor and only 400mV deltaV on the base to get crispy switch points, but change R3 to 1K and R4 to 240 ohms and you'll at least get the LED to turn on and off as day turns to night turns to day. Have you tried Doctor Phil's circuit yet? -- JF Haven't received the parts I ordered from Digikey yet. Maybe tomorrow or Saturday... And the 400 mV is coming from the tiny photocell, to counter part of the voltage divider's voltage at the base and turn Q1 off when the sun is shining. --- Yes, I know. Here are a few that work pretty well without it, using the big PV as the daylight/dark sensor: Version 4 SHEET 1 880 680 WIRE -512 -208 -528 -208 WIRE -432 -208 -448 -208 WIRE -400 -208 -432 -208 WIRE -320 -208 -336 -208 WIRE -224 -208 -240 -208 WIRE -96 -208 -112 -208 WIRE -16 -208 -32 -208 WIRE 192 -208 -16 -208 WIRE 368 -208 352 -208 WIRE 448 -208 432 -208 WIRE 512 -208 448 -208 WIRE 608 -208 576 -208 WIRE 736 -208 688 -208 WIRE -224 -160 -224 -208 WIRE 192 -160 192 -208 WIRE 736 -160 736 -208 WIRE -528 -112 -528 -208 WIRE -416 -112 -528 -112 WIRE -320 -112 -336 -112 WIRE -288 -112 -320 -112 WIRE -112 -112 -112 -208 WIRE 0 -112 -112 -112 WIRE 96 -112 80 -112 WIRE 128 -112 96 -112 WIRE 352 -80 352 -208 WIRE 464 -80 352 -80 WIRE 560 -80 544 -80 WIRE 688 -80 560 -80 WIRE -528 -32 -528 -112 WIRE -432 -32 -432 -208 WIRE -112 -32 -112 -112 WIRE -16 -32 -16 -208 WIRE 352 -32 352 -80 WIRE 448 -32 448 -208 WIRE -320 0 -320 -112 WIRE 96 0 96 -112 WIRE 192 0 192 -64 WIRE 560 0 560 -80 WIRE -528 96 -528 48 WIRE -432 96 -432 48 WIRE -112 96 -112 48 WIRE -16 96 -16 48 WIRE 352 96 352 48 WIRE 448 96 448 48 WIRE 192 112 192 80 WIRE -528 224 -528 176 WIRE -432 224 -432 176 WIRE -432 224 -528 224 WIRE -320 224 -320 80 WIRE -320 224 -432 224 WIRE -224 224 -224 -64 WIRE -224 224 -320 224 WIRE -112 224 -112 176 WIRE -16 224 -16 176 WIRE -16 224 -112 224 WIRE 96 224 96 80 WIRE 96 224 -16 224 WIRE 192 224 192 176 WIRE 192 224 96 224 WIRE 352 224 352 176 WIRE 448 224 448 176 WIRE 448 224 352 224 WIRE 560 224 560 80 WIRE 560 224 448 224 WIRE 736 224 736 -64 WIRE 736 224 560 224 WIRE -528 288 -528 224 WIRE -112 288 -112 224 WIRE 352 288 352 224 FLAG -112 288 0 FLAG 352 288 0 FLAG -528 288 0 SYMBOL LED 176 112 R0 SYMATTR InstName D2 SYMATTR Value NSCW100 SYMBOL res 176 -16 R0 SYMATTR InstName R5 SYMATTR Value 42 SYMBOL voltage -16 80 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value 4.8 SYMBOL voltage -112 80 R0 WINDOW 3 24 96 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value PULSE(0 8 0 12 12 0 24 1) SYMATTR InstName V1 SYMBOL res -32 -48 R0 SYMATTR InstName R2 SYMATTR Value .1 SYMBOL res -128 -48 R0 SYMATTR InstName R1 SYMATTR Value 58 SYMBOL pnp 128 -64 M180 SYMATTR InstName Q2 SYMATTR Value 2N3906 SYMBOL res 80 -16 R0 SYMATTR InstName R3 SYMATTR Value 10k SYMBOL res 96 -128 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value 1k SYMBOL nmos 688 -160 R0 SYMATTR InstName M1 SYMATTR Value 2N7002 SYMBOL schottky 368 -192 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D4 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL voltage 448 80 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V3 SYMATTR Value 4.8 SYMBOL voltage 352 80 R0 WINDOW 3 24 96 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value PULSE(0 8 0 12 12 0 24 1) SYMATTR InstName V4 SYMBOL res 432 -48 R0 SYMATTR InstName R8 SYMATTR Value .1 SYMBOL res 336 -48 R0 SYMATTR InstName R9 SYMATTR Value 58 SYMBOL res 560 -96 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R11 SYMATTR Value 1k SYMBOL res 704 -224 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R12 SYMATTR Value 39 SYMBOL res 544 -16 R0 SYMATTR InstName R10 SYMATTR Value 1k SYMBOL LED 512 -192 R270 WINDOW 0 72 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D5 SYMATTR Value NSCW100 SYMBOL schottky -96 -192 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D1 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL schottky -512 -192 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D3 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL voltage -432 80 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V5 SYMATTR Value 4.8 SYMBOL voltage -528 80 R0 WINDOW 3 24 96 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value PULSE(0 8 0 12 12 0 24 1) SYMATTR InstName V6 SYMBOL res -448 -48 R0 SYMATTR InstName R7 SYMATTR Value .1 SYMBOL res -544 -48 R0 SYMATTR InstName R13 SYMATTR Value 58 SYMBOL res -320 -128 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R14 SYMATTR Value 1k SYMBOL res -336 -16 R0 SYMATTR InstName R16 SYMATTR Value 200 SYMBOL LED -400 -192 R270 WINDOW 0 72 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D6 SYMATTR Value NSCW100 SYMBOL npn -288 -160 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904 SYMBOL res -224 -224 R90 WINDOW 0 -43 61 VBottom 2 WINDOW 3 -34 63 VTop 2 SYMATTR InstName R15 SYMATTR Value 42 TEXT -520 256 Left 2 !.tran 24 startup -- JF |
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#26
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
"John Fields" wrote in message ... On Thu, 13 Oct 2011 22:51:29 -0500, "Dave" wrote: "John Fields" wrote in message . .. On Thu, 13 Oct 2011 16:37:32 -0500, "Dave" wrote: "John Fields" wrote in message m... On Wed, 12 Oct 2011 21:04:52 -0500, "Dave" wrote: "John Fields" wrote in message news:ds2c97telu5u5m7dv63de8n5fsg44j39ka@4ax. com... On Wed, 12 Oct 2011 16:44:41 -0500, "Dave" wrote: Hey John. No, I don't have any data on the PV (I'm guessing that is "PhotoVoataic".) It's something I pulled out of my junkbox... --- PhotoVoltaic. :-) ^ --- BTW, I'm trying to run this sim in LTSpice, and can't figure out how to make it work. This is a netlist, right? --- No. It's an ASCII circuit description, and LTspice generates the needed netlist from it. --- How can I import it to my version of LTSpice and give it a test run. I'm really interested in seeing your changes. Thanks! --- OK. Save the list to a file and name it anything you like as long as it has a .asc extension, say, "nightlight.asc". Then, invoke LTspice, navigate to the file and left click on it. Voila! The beautemous schematic will appear before your very eyes, ready to be run and probed :-) BTW, the X axis of the waveform viewer is set to correspond to a 24 hour day and you can adjust the voltage divider connected to the BJT's base to set the circuit's switching threshold to a function of time by regarding voltage as a function of irradiance. -- JF THANK YOU! *Much appreciated.* Dave --- My pleasure. :-) -- JF Hey John, have a question RE the Spice schematic generated by the netlist which resulted from opening the ASCII circuit description you posted. The schematic shows V3, or the PV, as being four volts, not four hundred millivolts, which would accurately describe the real circuit I am working with. If I said that the PV generated 4 volts, I was full of crap. It is .4V. Seems like this would change everything. But that's why I had a 4.2K in series with a 680 Ohm resistor for the voltage divider that drives the base of Q1. When I saw you had a 4.7K and a 10K for those resistors, I knew something was not right. Please give this another glance, and let me know what you think... --- You won't have enough gain with a single transistor and only 400mV deltaV on the base to get crispy switch points, but change R3 to 1K and R4 to 240 ohms and you'll at least get the LED to turn on and off as day turns to night turns to day. Have you tried Doctor Phil's circuit yet? -- JF Haven't received the parts I ordered from Digikey yet. Maybe tomorrow or Saturday... And the 400 mV is coming from the tiny photocell, to counter part of the voltage divider's voltage at the base and turn Q1 off when the sun is shining. --- Yes, I know. Here are a few that work pretty well without it, using the big PV as the daylight/dark sensor: Version 4 SHEET 1 880 680 WIRE -512 -208 -528 -208 WIRE -432 -208 -448 -208 WIRE -400 -208 -432 -208 WIRE -320 -208 -336 -208 WIRE -224 -208 -240 -208 WIRE -96 -208 -112 -208 WIRE -16 -208 -32 -208 WIRE 192 -208 -16 -208 WIRE 368 -208 352 -208 WIRE 448 -208 432 -208 WIRE 512 -208 448 -208 WIRE 608 -208 576 -208 WIRE 736 -208 688 -208 WIRE -224 -160 -224 -208 WIRE 192 -160 192 -208 WIRE 736 -160 736 -208 WIRE -528 -112 -528 -208 WIRE -416 -112 -528 -112 WIRE -320 -112 -336 -112 WIRE -288 -112 -320 -112 WIRE -112 -112 -112 -208 WIRE 0 -112 -112 -112 WIRE 96 -112 80 -112 WIRE 128 -112 96 -112 WIRE 352 -80 352 -208 WIRE 464 -80 352 -80 WIRE 560 -80 544 -80 WIRE 688 -80 560 -80 WIRE -528 -32 -528 -112 WIRE -432 -32 -432 -208 WIRE -112 -32 -112 -112 WIRE -16 -32 -16 -208 WIRE 352 -32 352 -80 WIRE 448 -32 448 -208 WIRE -320 0 -320 -112 WIRE 96 0 96 -112 WIRE 192 0 192 -64 WIRE 560 0 560 -80 WIRE -528 96 -528 48 WIRE -432 96 -432 48 WIRE -112 96 -112 48 WIRE -16 96 -16 48 WIRE 352 96 352 48 WIRE 448 96 448 48 WIRE 192 112 192 80 WIRE -528 224 -528 176 WIRE -432 224 -432 176 WIRE -432 224 -528 224 WIRE -320 224 -320 80 WIRE -320 224 -432 224 WIRE -224 224 -224 -64 WIRE -224 224 -320 224 WIRE -112 224 -112 176 WIRE -16 224 -16 176 WIRE -16 224 -112 224 WIRE 96 224 96 80 WIRE 96 224 -16 224 WIRE 192 224 192 176 WIRE 192 224 96 224 WIRE 352 224 352 176 WIRE 448 224 448 176 WIRE 448 224 352 224 WIRE 560 224 560 80 WIRE 560 224 448 224 WIRE 736 224 736 -64 WIRE 736 224 560 224 WIRE -528 288 -528 224 WIRE -112 288 -112 224 WIRE 352 288 352 224 FLAG -112 288 0 FLAG 352 288 0 FLAG -528 288 0 SYMBOL LED 176 112 R0 SYMATTR InstName D2 SYMATTR Value NSCW100 SYMBOL res 176 -16 R0 SYMATTR InstName R5 SYMATTR Value 42 SYMBOL voltage -16 80 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value 4.8 SYMBOL voltage -112 80 R0 WINDOW 3 24 96 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value PULSE(0 8 0 12 12 0 24 1) SYMATTR InstName V1 SYMBOL res -32 -48 R0 SYMATTR InstName R2 SYMATTR Value .1 SYMBOL res -128 -48 R0 SYMATTR InstName R1 SYMATTR Value 58 SYMBOL pnp 128 -64 M180 SYMATTR InstName Q2 SYMATTR Value 2N3906 SYMBOL res 80 -16 R0 SYMATTR InstName R3 SYMATTR Value 10k SYMBOL res 96 -128 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value 1k SYMBOL nmos 688 -160 R0 SYMATTR InstName M1 SYMATTR Value 2N7002 SYMBOL schottky 368 -192 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D4 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL voltage 448 80 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V3 SYMATTR Value 4.8 SYMBOL voltage 352 80 R0 WINDOW 3 24 96 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value PULSE(0 8 0 12 12 0 24 1) SYMATTR InstName V4 SYMBOL res 432 -48 R0 SYMATTR InstName R8 SYMATTR Value .1 SYMBOL res 336 -48 R0 SYMATTR InstName R9 SYMATTR Value 58 SYMBOL res 560 -96 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R11 SYMATTR Value 1k SYMBOL res 704 -224 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R12 SYMATTR Value 39 SYMBOL res 544 -16 R0 SYMATTR InstName R10 SYMATTR Value 1k SYMBOL LED 512 -192 R270 WINDOW 0 72 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D5 SYMATTR Value NSCW100 SYMBOL schottky -96 -192 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D1 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL schottky -512 -192 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D3 SYMATTR Value 1N5817 SYMATTR Description Diode SYMATTR Type diode SYMBOL voltage -432 80 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V5 SYMATTR Value 4.8 SYMBOL voltage -528 80 R0 WINDOW 3 24 96 Invisible 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value PULSE(0 8 0 12 12 0 24 1) SYMATTR InstName V6 SYMBOL res -448 -48 R0 SYMATTR InstName R7 SYMATTR Value .1 SYMBOL res -544 -48 R0 SYMATTR InstName R13 SYMATTR Value 58 SYMBOL res -320 -128 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R14 SYMATTR Value 1k SYMBOL res -336 -16 R0 SYMATTR InstName R16 SYMATTR Value 200 SYMBOL LED -400 -192 R270 WINDOW 0 72 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D6 SYMATTR Value NSCW100 SYMBOL npn -288 -160 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904 SYMBOL res -224 -224 R90 WINDOW 0 -43 61 VBottom 2 WINDOW 3 -34 63 VTop 2 SYMATTR InstName R15 SYMATTR Value 42 TEXT -520 256 Left 2 !.tran 24 startup -- JF Man! Thank you! Choices yet! My God, I don't know what to say. Thanks. I'm still waiting on the 2N2007 from Digikey, but I may not need it now. Still, I have options. Thank you very much. And take it easy... Dave |
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#27
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On Sat, 15 Oct 2011 06:35:01 -0500, "Dave" wrote:
Man! Thank you! Choices yet! My God, I don't know what to say. Thanks. I'm still waiting on the 2N2007 from Digikey, but I may not need it now. Still, I have options. Thank you very much. And take it easy... --- Oops... (egg on face) The only one that works is the PNP; the others turn the LED on when it gets bright and off when it gets dark. Sorry 'bout that... -- JF |
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#28
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
John Fields wrote:
On Sat, 15 Oct 2011 06:35:01 -0500, "Dave" wrote: Man! Thank you! Choices yet! My God, I don't know what to say. Thanks. I'm still waiting on the 2N2007 from Digikey, but I may not need it now. Still, I have options. Thank you very much. And take it easy... --- Oops... (egg on face) The only one that works is the PNP; the others turn the LED on when it gets bright and off when it gets dark. Sorry 'bout that... Change the circuit slightly.. |
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#29
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
On Sun, 16 Oct 2011 13:02:12 -0800, Robert Baer
wrote: John Fields wrote: On Sat, 15 Oct 2011 06:35:01 -0500, "Dave" wrote: Man! Thank you! Choices yet! My God, I don't know what to say. Thanks. I'm still waiting on the 2N2007 from Digikey, but I may not need it now. Still, I have options. Thank you very much. And take it easy... --- Oops... (egg on face) The only one that works is the PNP; the others turn the LED on when it gets bright and off when it gets dark. Sorry 'bout that... Change the circuit slightly.. --- Post a schematic? -- JF |
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#30
Posted to alt.binaries.schematics.electronic
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Another question for those in the know...
Robert Baer wrote:
John Fields wrote: On Sat, 15 Oct 2011 06:35:01 -0500, "Dave" wrote: Man! Thank you! Choices yet! My God, I don't know what to say. Thanks. I'm still waiting on the 2N2007 from Digikey, but I may not need it now. Still, I have options. Thank you very much. And take it easy... --- Oops... (egg on face) The only one that works is the PNP; the others turn the LED on when it gets bright and off when it gets dark. Sorry 'bout that... Change the circuit slightly.. Which component is the "slightly"? :-) Ed |
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#31
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Damned, I am.
On Wed, 12 Oct 2011 12:55:56 -0700, Fred Abse
wrote: On Tue, 11 Oct 2011 16:46:39 -0500, Dave wrote: My local Radio Shack DOES stock that MOSFET. They have two of them Two is STOCK? For a particular Rat Shack it is. If you are discussing anyone else it is not. You cannot imagine my joy at finding a Newark within bicycle distance as a teen. Call them up, show up at the will call desk with the cash and leave happy with the parts you wanted. 40+ years ago. ?-) |
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#32
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Damned, I am.
josephkk wrote:
You cannot imagine my joy at finding a Newark within bicycle distance as a ^^^^^^^^^^^^^^^^^^^^^^^^^ teen. Call them up, show up at the will call desk with the cash and leave happy with the parts you wanted. 40+ years ago. _I_ can! Cheers! Rich |
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#33
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Damned, I am.
"josephkk" wrote in message
news 
snipYou cannot imagine my joy at finding a Newark within bicycle distance as a teen. Call them up, show up at the will call desk with the cash and leave happy with the parts you wanted. 40+ years ago. For me it was Lafayette Electronics. About 5 miles from my house but definitely bicycle distance (as a teen with a five transistor a day habit) |
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