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| Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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Dropping 1V from a Regulated 6V Wall Wart
I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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#2
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Dropping 1V from a Regulated 6V Wall Wart
On Mon, 29 Dec 2003 09:28:53 -0800, the renowned Watson A.Name - "Watt
Sun, Dark Remover" wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. Or just hang a dummy load on the output.. 1K0 or a bit higher (2K0) ought to do it. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
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#3
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Dropping 1V from a Regulated 6V Wall Wart
"Watson A.Name - Watt Sun, Dark Remover" wrote in message m... I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ Why not a 5volt zener and a resistor?....Just a thought... |
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#4
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Dropping 1V from a Regulated 6V Wall Wart
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#5
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Dropping 1V from a Regulated 6V Wall Wart
On Mon, 29 Dec 2003 20:12:23 GMT, the renowned Active8
,invalid wrote: I'm thinking 4.3V Zener and a series pass transistor. Wrong way. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
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#6
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Dropping 1V from a Regulated 6V Wall Wart
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#8
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Dropping 1V from a Regulated 6V Wall Wart
"Spehro Pefhany" bravely wrote to "All" (29 Dec 03 20:16:37)
--- on the heady topic of " Dropping 1V from a Regulated 6V Wall Wart" SP Xref: aeinews sci.electronics.misc:8735 sci.electronics.design:31375 SP sci.electronics.repair:16164 alt.binaries.schematics.electronic:7314 Would "you people", please, stop crossposting into sci.electronics.repair? Thanks In Advance! .... # --- electrocuted tribble |
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#9
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Dropping 1V from a Regulated 6V Wall Wart
In article uMZHb.254877$Ec1.8820445@bgtnsc05-
news.ops.worldnet.att.net, lid mentioned... "Watson A.Name - Watt Sun, Dark Remover" wrote in message m... I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. Why not a 5volt zener and a resistor?....Just a thought... Well, the output of the wall wart is already regulated to 6V at 200 mA. But 1V at 200 mA is going to require a 5 ohm resistor. And the zener will have to dissipate a lot of wasted power. And the wall wart may not like being run at its max and overheat. Using the 1 amp rectifier in series with the output dropped about .6 to .8V, depending on current, which isn't all that bad a regulation. But the circuit I drew above gives a voltage closer to 5V over a wider range of load currents. I suppose I could've used a LDO 5V regulator, but then the output's already regulated. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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#10
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Dropping 1V from a Regulated 6V Wall Wart
On Tue, 30 Dec 2003 01:32:13 -0800, Watson A.Name - "Watt Sun, Dark
Remover" wrote: I suppose I could've used a LDO 5V regulator, but then the output's already regulated. --- Yes, but the 5V output isn't at low currents, as you've already stated. The LDO will make that problem go away. -- John Fields |
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#11
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Dropping 1V from a Regulated 6V Wall Wart
On Mon, 29 Dec 2003 09:28:53 -0800, Watson A.Name - "Watt Sun, Dark
Remover" wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. Try this... + From wall wart --+ | +---+------+ | | \ | / | 20 \ / 2SC2334 or TIP31 ohm | |/ NPN power TO-220 o------| Heatsink optional | |\ | E\ | | | | | | | | | | | o----- + | | output | / to load | \ | / 2.2K __|___/ | / /\ | / \--------o / \ | -------- | | TL430 / | \ 2.7K | / | | | | | | - --o----------o------ - You may need a compensation cap between cathode and control pin. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice  480)460-2350 | || E-mail Address at Website Fax 480)460-2142 | Brass Rat || http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
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#12
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Dropping 1V from a Regulated 6V Wall Wart
On Mon, 29 Dec 2003 09:28:53 -0800, Watson A.Name - "Watt Sun, Dark
Remover" wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, .... 6VDC------+-----------------+ | | [R1] | | | +-----|+\ C | | ------B | +--| / E | | | | +----+---------+ | |+ | [R2] [C1] [RL] | | | GND-------+-------+---------+ R1/R2 = 5 C1 = Whatever you need to keep the thing from oscillating; 100µF is probably a good guess. -- John Fields |
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#13
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Dropping 1V from a Regulated 6V Wall Wart
On Mon, 29 Dec 2003 12:18:19 -0600, John Fields
wrote: R1/R2 = 5 --- R2/R1 = 5 -- John Fields |
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#14
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Dropping 1V from a Regulated 6V Wall Wart
I read in sci.electronics.design that John Fields jfields@austininstrum
ents.com wrote (in ) about 'Dropping 1V from a Regulated 6V Wall Wart', on Mon, 29 Dec 2003: On Mon, 29 Dec 2003 12:18:19 -0600, John Fields wrote: R1/R2 = 5 --- R2/R1 = 5 Not always. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! |
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#15
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Dropping 1V from a Regulated 6V Wall Wart
On Mon, 29 Dec 2003 19:07:59 +0000, John Woodgate
wrote: I read in sci.electronics.design that John Fields jfields@austininstrum ents.com wrote (in ) about 'Dropping 1V from a Regulated 6V Wall Wart', on Mon, 29 Dec 2003: On Mon, 29 Dec 2003 12:18:19 -0600, John Fields wrote: R1/R2 = 5 --- R2/R1 = 5 Not always. (;-) --- I'm sure there's a joke in there somewhere... :-) I meant that for 6V in and 5V into Rl, R2 = 5R1. -- John Fields |
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#16
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Dropping 1V from a Regulated 6V Wall Wart
I read in sci.electronics.design that John Fields jfields@austininstrum
ents.com wrote (in ) about 'Dropping 1V from a Regulated 6V Wall Wart', on Mon, 29 Dec 2003: On Mon, 29 Dec 2003 19:07:59 +0000, John Woodgate wrote: I read in sci.electronics.design that John Fields jfields@austininstrum ents.com wrote (in ) about 'Dropping 1V from a Regulated 6V Wall Wart', on Mon, 29 Dec 2003: On Mon, 29 Dec 2003 12:18:19 -0600, John Fields wrote: R1/R2 = 5 --- R2/R1 = 5 Not always. (;-) --- I'm sure there's a joke in there somewhere... :-) I meant that for 6V in and 5V into Rl, R2 = 5R1. OK, let's go on in the same vein. R2 is not always 5R1; it might be 5R6 or even 47K. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! |
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#17
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Dropping 1V from a Regulated 6V Wall Wart
In article ,
mentioned... On Mon, 29 Dec 2003 09:28:53 -0800, Watson A.Name - "Watt Sun, Dark Remover" wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, ... 6VDC------+-----------------+ | | [R1] | | | +-----|+\ C | | ------B | +--| / E | | | | +----+---------+ | |+ | [R2] [C1] [RL] | | | GND-------+-------+---------+ R1/R2 = 5 C1 = Whatever you need to keep the thing from oscillating; 100µF is probably a good guess. Thanks, but I think someone snipped the part where I said that I was trying to get this to fit across the pins of the RF modulator, and that the wall wart was already regulated. I guess I could do it if it was surface mount parts, but I'm not experienced with those. What kind of opamp works down to only 6V? A LM358? In order to put out 5V at the emitter, it would have to swing the base to 5.7 or more volts at 200 mA, so the opamp would have to swing close to the positive rail. Maybe a better idea would be to use a PNP for the emitter follower. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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#18
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Dropping 1V from a Regulated 6V Wall Wart
On Tue, 30 Dec 2003 02:46:55 -0800, Watson A.Name - "Watt Sun, Dark
Remover" said... In article , mentioned... On Mon, 29 Dec 2003 09:28:53 -0800, Watson A.Name - "Watt Sun, Dark Remover" wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, ... 6VDC------+-----------------+ | | [R1] | | | +-----|+\ C | | ------B | +--| / E | | | | +----+---------+ | |+ | [R2] [C1] [RL] | | | GND-------+-------+---------+ R1/R2 = 5 C1 = Whatever you need to keep the thing from oscillating; 100µF is probably a good guess. Thanks, but I think someone snipped the part where I said that I was trying to get this to fit across the pins of the RF modulator, can't find that spec anywhere. and that the wall wart was already regulated. I guess I could do it if it was surface mount parts, but I'm not experienced with those. What kind of opamp works down to only 6V? A LM358? In order to put out 5V at the emitter, it would have to swing the base to 5.7 or more volts at 200 mA, so the opamp would have to swing close to the positive rail. Maybe a better idea would be to use a PNP for the emitter follower. -- Best Regards, Mike |
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#19
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Dropping 1V from a Regulated 6V Wall Wart
What about using a 5V low-dropout voltage regulator?
Bob Watson A.Name - "Watt Sun, Dark Remover" wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. |
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#20
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Dropping 1V from a Regulated 6V Wall Wart
Watson A.Name - Watt Sun, Dark Remover wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. You almost had it- put the Vbe multiplier inside the feedback loop and buffer like so: Please view in a fixed-width font such as Courier. 6V ---+------+---------+ | | | | / | | 22 | | / | | \ c | | |/ | +-------| TIP31 | | |\ | | e----+-- 5V | | | === | +----+ | c | | | \| / | | |----- \ | | /| / === | e \ 1000U | | | | | | | | | | | | GND--+------+---------+----+-- GND |
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#21
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Dropping 1V from a Regulated 6V Wall Wart
Fred Bloggs wrote: Watson A.Name - Watt Sun, Dark Remover wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. You almost had it- put the Vbe multiplier inside the feedback loop and buffer like so: Please view in a fixed-width font such as Courier. 6V ---+------+---------+ | | | | / | | 22 | | / | | \ c | | |/ | +-------| TIP31 | | |\ | | e----+-- 5V | | | === | +----+ | c | | | \| / | | |----- \ | | /| / === | e \ 1000U | | | | | | | | | | | | GND--+------+---------+----+-- GND Then you can work a common 5.1V zener into the equation like so: Use a 2N3906 for the pnp for Vbe,max=6V rating. Please view in a fixed-width font such as Courier. 6V ---+--------+----------+-------------+ | | | | | / / | | 22 51 | | / / | | \ \ c | | | |/ | +----------|-----------| TIP31 | | | |\ | | | e----+-- 5V | c | | | \| | pnp | | npn |--+-----|-------- c e---+ | /| | | \ / | | e | | ---- | === | | | 180 | | | | | +----/\/\---+ | | | | | | | | | | | | | | | / _/ / === | | 1K /^ 5.1v 1.2K 1000U | | / - / | | | \ | \ | | | | | | | GND--+--------+----+-----+-----------+------+-- GND |
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#22
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Dropping 1V from a Regulated 6V Wall Wart
"Fred Bloggs" wrote in message ... : : Fred Bloggs wrote: : : Watson A.Name - Watt Sun, Dark Remover wrote: : : I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried : a 3 amp rectifier, but it varied by more than .2V over a range of : loads. So I tried this: (view with courier font) : : + From : wall : wart --+ | : +---+------+ : | | : | | : 400 \ / 2SC2334 or TIP31 : ohm / |/ NPN power TO-220 : WW \-----| Heatsink optional : pot / |\ : | E\ | | : | | : +----+-----+ : | | : +------ + output : to load : - -------------- - : From wall wart : : This has some advantages and disadvantages. It's simple and cheap, : and keeps the output at 5V within a tenth of a volt over a current : range. But it has a minimum current below which it loses regulation : and the output starts to go up to 6V, because the transistor is not : conducting and the current is being supplied thru the ww pot. This : circuit is sometimes used in the bias circuit for the output : transistors in high powered amplifiers. Also Win Hill showed us here : how to use a similar circuit to maintain the voltage steady for a : current regulator circuit used on four AA cell rechargeable batteries. : : I'm thinking about putting a 5.1V zener on the output so that if the : voltage climbs above that, it just shunts the excess current. Oh, : yeah, I set the pot to various values to see what the output voltage : was with various loads. The two resistances were 120 ohms for the : upper and 280 ohms for the lower. I suppose the 400 ohms total could : be raised to a higher value, but the transistor needs enough base : current to do its job. There's only 1V available minus the ..6V E-B : voltage, so even at 400 ohms, that's not a lot of current. : : : : You almost had it- put the Vbe multiplier inside the feedback loop and : buffer like so: : : Please view in a fixed-width font such as Courier. : : : 6V ---+------+---------+ : | | | : | / | : | 22 | : | / | : | \ c : | | |/ : | +-------| TIP31 : | | |\ : | | e----+-- 5V : | | | : === | +----+ : | c | | : | \| / | : | |----- \ | : | /| / === : | e \ 1000U : | | | | : | | | | : | | | | : GND--+------+---------+----+-- GND : : : Then you can work a common 5.1V zener into the equation like so: : Use a 2N3906 for the pnp for Vbe,max=6V rating. : : Please view in a fixed-width font such as Courier. : : : : : : 6V ---+--------+----------+-------------+ : | | | | : | / / | : | 22 51 | : | / / | : | \ \ c : | | | |/ : | +----------|-----------| TIP31 : | | | |\ : | | | e----+-- 5V : | c | | : | \| | pnp | : | npn |--+-----|-------- c e---+ : | /| | | \ / | : | e | | ---- | : === | | | 180 | | : | | | +----/\/\---+ | : | | | | | | : | | | | | | : | | / _/ / === : | | 1K /^ 5.1v 1.2K 1000U : | | / - / | : | | \ | \ | : | | | | | | : GND--+--------+----+-----+-----------+------+-- GND It's getting bigger. Soon he'll need a 2nd breadboard to build and test this thing. ;-) Bill @ GarberStreet Enterprizez };-) Web Site - http://garberstreet.netfirms.com Email - Remove - SPAM and X to contact me --- This email ain't infected, dude! Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.544 / Virus Database: 338 - Release Date: 11/26/03 |
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#23
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Dropping 1V from a Regulated 6V Wall Wart
Fred Bloggs wrote: [snip] This one will make the output tempco essentially that of the zener which is not bad for the 5.1V's. Ripple rejection is lacking due to the low overhead -at 14dB, but your 6V is regulated anyway. Please view in a fixed-width font such as Courier. 6V ---+--------+----------+-------------+ | | | | | / / | | 22 51 | | / / | | \ \ c | | | |/ | +----------|-----------| TIP31 | | | |\ | | | e----+-- 5V | c | | | \| | pnp | | npn |--+-----|-------- c e---+ | /| | | \ / | | e | | ---- | === | | | 1N4148 | | | | | +----||----+ | | | | | | | | | | | | | | | / _/ / === | | 1K /^ 5.1v 1.2K 1000U | | / - / | | | \ | \ | | | | | | | GND--+--------+----+-----+-----------+------+-- GND |
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#24
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Dropping 1V from a Regulated 6V Wall Wart
In article ,
mentioned... Watson A.Name - Watt Sun, Dark Remover wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. You almost had it- put the Vbe multiplier inside the feedback loop and buffer like so: Please view in a fixed-width font such as Courier. 6V ---+------+---------+ | | | | / | | 22 | | / | | \ c | | |/ | +-------| TIP31 | | |\ | | e----+-- 5V | | | === | +----+ | c | | | \| / | | |----- \ | | /| / === | e \ 1000U | | | | | | | | | | | | GND--+------+---------+----+-- GND I'll toss one together, but what value should I use for the Pot? 10k? Lower? This looks a lot like the current limiter circuit, 'cept for the pot. I'm wondering if it's such a good idea to have such a large cap on the output. When the wall wart is powered off, all that current tries to go backwards thru the pass transistor. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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#25
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Dropping 1V from a Regulated 6V Wall Wart
Watson A.Name - Watt Sun, Dark Remover wrote:
I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall [edited for brevity] wart --+---+-----+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+----+---- + output to load - ----------------- - Hmm, a complementary-darlington emitter-follower transistor would be less sensitive to changes in load current: : +6.0V, from wall wart : --+--------+------+ : | | | : | 220 | Q1 2sa1011 : | | |/E pnp TIP32 : | +----| etc : | | |\ : 1.0k |/ | : pot ---| Q2 | : | |\E npn | : | | | : 7.5k +------+----- + output : | to load : - --+--------------------- - Here the Q2 voltage drop is much more predictable, because it has a relatively steady current set by Q1's base-emitter resistor, which has about 0.55 to 0.75V across it despite output load changes. The Q2 current is about 3 - 5mA and we expect a Vbe drop of about 700mV. The lower end of the pot sits at about 5.3 volts. The most serious problem with this circuit is its complete reliance on a possibly-uncertain input voltage; the output will track any changes in input. analyzed Watson A. Name's circuit: You almost had it- put the Vbe multiplier inside the feedback loop and buffer like so: 6V ---+------+-------+ [edited for brevity] | | | | 22 c | | |/ Q1 | +-----| TIP31 | | |\ == | e---+----+---- 5V | c Q2 | | | \| / | | |------- \ | | /| / === | e | 1000U | | | | GND --+------+-----------+----+---- GND Watson A.Name - Watt Sun, Dark Remover asked: I'll toss one together, but what value should I use for the Pot? 10k? Lower? This looks a lot like the current limiter circuit, 'cept for the pot. No, it's an ordinary regulator, using Q2's Vbe (roughly 0.7V) as a voltage reference. The pot as shown would be a poor choice because valid adjustments would only use a small part of the pot's range. No doubt nospam knew that and was just simplifying his drawing by using one part instead of three. This should work; the top of the pot has about 0.82V when the regulator is calibrated for 5V out: | | ---+---- 5V | | | === | ,-2k2--+ | c Q2 | | | \| 100R | | |---- pot | | /| | === | e 330 1000U | | | | GND --+------+---------+------+---- GND This circuit has several problems. The tempco of Vbe is bad, but the uncertain current through Q2 an even worse problem. This is because the voltage difference between the +6V input and Q1's base is small (and may vary widely), and Q1's base current is unknown. If Q2's current changes by a factor of 10, its Vbe will change by about 60mV, or nearly 10% of its value. As a result Q2 makes a poor voltage reference in this circuit, even if manually adjusted. I'm wondering if it's such a good idea to have such a large cap on the output. When the wall wart is powered off, all that current tries to go backwards thru the pass transistor. A big cap is fine, maybe even necessary in that location, because a small output cap could make the feedback loop unstable. We discuss this issue in AoE and call it brute-force compensation. The current won't go backwards for several reasons. The wall wort probably doesn't draw output terminal current when the AC is off. If it wanted to, Q1's Veb breakdown would certainly be above 5V so no current would flow anyway. Jim Thompson wrote... Try this... + From wall [edited for brevity] wart --+---+-----+ | | 20 Q1 | | / 2SC2334 or TIP31 | |/ NPN power TO-220 o------| Heatsink optional | |\ | E\ | | | o----- + output | | to load __|___/ 2.2k / /\ | / \-------o / \ | -------- 2.7k | TL430 | | | - ------o---------o------ - You may need a compensation cap between cathode and control pin. This is a much better approach, using TL430's 2.75V reference with a built-in error amplifier. The more popular TL431 can be used with its 2.50V ref if the feedback-sensing resistors are the same value. But I'm not happy with the output emitter follower in the circuits above, because the low Vin - Vout difference leads to such widely- varying currents through the control element. Perhaps my circuit can be combined with Jim's circuit: : +6.0V, from wall wart : --+------+------+ : | | | : | 220 | Q1 2sa1011 : | | |/E pnp TIP32 : 750 +----| etc : | | |\ : | |/ | : +----| Q2 | : | |\E npn | : | | | : | +---+--+---- + output | | to load __|___/ 2.7k / /\ | / \--------o / \ | -------- 2.7k | TL431 | | | - ----o----------o------- - Thanks, - Win whill_at_picovolt-dot-com |
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#26
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Dropping 1V from a Regulated 6V Wall Wart
Winfield Hill wrote...
Perhaps my circuit can be combined with Jim's circuit: : +6.0V, from wall wart : --+------+------+ : | | | : | 220 | Q1 2sa1011 : | | |/E pnp TIP32 : 750 +----| etc : | | |\ : | |/ | : +----| Q2 | : | |\E npn | : | | | : | +---+--+---- + output | | to load __|___/ 2.7k / /\ | / \--------o / \ | -------- 2.7k | TL431 | | | - ----o----------o------- - I'm still not happy with the poor dropout-voltage capability of this circuit. It should be able to operate with Vin much closer to Vout. Aha! Simply adding a diode and resistor lets us reduce the dropout voltage down to near the saturation voltage of Q1. : +5.3 to 9V : --+-----+------, SIMPLE 5.0V REGULATOR : | | | : | 220 | Q1 2sa1011 : | | |/E pnp TIP32 : 470 o----| etc : | | |\ : | |/ | : o---| Q2 '----o---- +5.0V : | |\E npn | output : | | | to load : | | 1n4148 | : | '--o--||---o | | | __|___/ 1k 2.7k / /\ | | / \----- | -------o / \ | | -------- | 2.7k | TL431 | | | | | - ----o--------o--------o---- - Of course, an even more simple circuit is possible, using one of the many low-cost low-dropout three-terminal regulator ICs. : +5.3 to 9V etc : -------, EVEN MORE SIMPLE 5.0V REGULATOR : __|__ : | | : | |---+--- +5.0V : |_____| _|_ output : | --- to load : | | : - -------o------o--- - But this circuit isn't as much fun. :) Thanks, - Win whill_at_picovolt-dot-com |
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#27
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Dropping 1V from a Regulated 6V Wall Wart
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#28
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Dropping 1V from a Regulated 6V Wall Wart
Winfield Hill wrote: Winfield Hill wrote... Perhaps my circuit can be combined with Jim's circuit: : +6.0V, from wall wart : --+------+------+ : | | | : | 220 | Q1 2sa1011 : | | |/E pnp TIP32 : 750 +----| etc : | | |\ : | |/ | : +----| Q2 | : | |\E npn | : | | | : | +---+--+---- + output | | to load __|___/ 2.7k / /\ | / \--------o / \ | -------- 2.7k | TL431 | | | - ----o----------o------- - I'm still not happy with the poor dropout-voltage capability of this circuit. It should be able to operate with Vin much closer to Vout. Aha! Simply adding a diode and resistor lets us reduce the dropout voltage down to near the saturation voltage of Q1. : +5.3 to 9V : --+-----+------, SIMPLE 5.0V REGULATOR : | | | : | 220 | Q1 2sa1011 : | | |/E pnp TIP32 : 470 o----| etc : | | |\ : | |/ | : o---| Q2 '----o---- +5.0V : | |\E npn | output : | | | to load : | | 1n4148 | : | '--o--||---o | | | __|___/ 1k 2.7k / /\ | | / \----- | -------o / \ | | -------- | 2.7k | TL431 | | | | | - ----o--------o--------o---- - Of course, an even more simple circuit is possible, using one of the many low-cost low-dropout three-terminal regulator ICs. : +5.3 to 9V etc : -------, EVEN MORE SIMPLE 5.0V REGULATOR : __|__ : | | : | |---+--- +5.0V : |_____| _|_ output : | --- to load : | | : - -------o------o--- - But this circuit isn't as much fun. :) Thanks, - Win whill_at_picovolt-dot-com If you want a 1V drop (for some reason???) then something like this: Please view in a fixed-width font such as Courier. LM185-ADJ \ +---------| |---------+ | \ | | | +------+-------------------------+ | | | | | / | | | 470 | | | / | | | TIP42 \ | | Vin----+-------- e c ---+-------+-----------------------Vout | \ / | | | | --- | | c | 10K | 1N4148 | | 10K |/ +----/\/\---+---||----+ +--/\/\-----+---| | | |\ | c e | \| | | |---+ | /| | / e / 470 | 1.3K / | / \ | \ | | | --- --- --- |
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#29
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Dropping 1V from a Regulated 6V Wall Wart
In article ,
mentioned... AwwwRight! You gave me an excuse to use up those TIL430s that I've got laying around. Awesome! Thank you! [snip] Thanks, - Win whill_at_picovolt-dot-com -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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#30
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Dropping 1V from a Regulated 6V Wall Wart
On Mon, 29 Dec 2003 09:28:53 -0800, Watson A.Name - "Watt Sun, Dark
Remover" wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) [snip] See also "4V-Regulator.pdf" on the S.E.D/Schematics Page of my website, for a similar application. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice 480)460-2350 | || E-mail Address at Website Fax 480)460-2142 | Brass Rat || http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
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#31
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Dropping 1V from a Regulated 6V Wall Wart
Watson A.Name - Watt Sun, Dark Remover wrote:
I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. I've tried to do this on numerous occasions. If you need any amount of current at all, the big lump of stuff makes it too unweildy, even if you do bite the bullet and put in a complex circuit that works. Now, for regulated warts, I crack the case and shunt a resistor inside the wall wart. You can add a switch if you have multiple applications. If you need both voltages at once, it's still easier to use two warts than to have this lump of regulator stuff hanging about. I'm a little confused by your requirements. If you even considered a diode, you can't be too concerned about the actual voltage...but you're concerned about the .2V variability. Sounds like there's something in there that's important but not disclosed??? mike -- Return address is VALID. Bunch of stuff For Sale and Wanted at the link below. Toshiba & Compaq LiIon Batteries, Test Equipment Honda CB-125S $800 in PDX TEK Sampling Sweep Plugin and RM564 Tek 2465 $800, ham radio, 30pS pulser Tektronix Concept Books, spot welding head... http://www.geocities.com/SiliconValley/Monitor/4710/ |
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#32
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Dropping 1V from a Regulated 6V Wall Wart
In article , mentioned...
Watson A.Name - Watt Sun, Dark Remover wrote: I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. I've tried to do this on numerous occasions. If you need any amount of current at all, the big lump of stuff makes it too unweildy, even if you do bite the bullet and put in a complex circuit that works. Now, for regulated warts, I crack the case and shunt a resistor inside the wall wart. You can add a switch if you have multiple applications. If you need both voltages at once, it's still easier to use two warts than to have this lump of regulator stuff hanging about. I'm a little confused by your requirements. If you even considered a diode, you can't be too concerned about the actual voltage...but you're concerned about the .2V variability. Sounds like there's something in there that's important but not disclosed??? mike Well, I started out in this or another thread with a RF modulator that requires 4.75 to 5.25VDC, probably because it would be off freq if the supply V got out of tolerance. I talked about the weird connector, someone said it's a Belling Lee connector, AKA Euro or PAL connector. Now I now what it is, and I bot an adapter at Rat Shack for four bucks. But I wanted something simple that I could solder onto the pins of the RF modulator, I finally resolved the problem by using a 6V unregulated wall wart, which is more like 7 or 8V, and a 5.1V zener, and 39 ohm resistor as a shunt regulator. It works just fine. But I still wanted a way to drop a single volt, with reasonable regulation, better than a 1N4003 diode which varies by up to a quarter volt. With a 1N4003 the voltage could be as high as 5.3 or 5.4V. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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Dropping 1V from a Regulated 6V Wall Wart
I read in alt.binaries.schematics.electronic that Watson A. Name - Watt
Sun, Dark Remover wrote (in MPG.1a5cbb112ab587 ) about 'Dropping 1V from a Regulated 6V Wall Wart', on Wed, 31 Dec 2003: I talked about the weird connector, someone said it's a Belling Lee connector, That's a coaxial connector, a bit like a phono plug but with a smaller centre pin. Is that what you have? AKA Euro or PAL connector. I'd forget those descriptions if I were you. Certainly the Belling connector has very little indeed to do with PAL. It is the subject of an IEC standard - IEC 60169-2. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! |
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#34
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Dropping 1V from a Regulated 6V Wall Wart
On Wed, 31 Dec 2003 19:37:12 +0000,
said... I read in alt.binaries.schematics.electronic that Watson A. Name - Watt Sun, Dark Remover wrote (in MPG.1a5cbb112ab587 ) about 'Dropping 1V from a Regulated 6V Wall Wart', on Wed, 31 Dec 2003: I talked about the weird connector, someone said it's a Belling Lee connector, That's a coaxial connector, a bit like a phono plug but with a smaller centre pin. Is that what you have? AKA Euro or PAL connector. I'd forget those descriptions if I were you. Certainly the Belling connector has very little indeed to do with PAL. It is the subject of an IEC standard - IEC 60169-2. It looks (the outer part) exactly like one of those RS push on F connectors - the male one (male center conductor, female housing) but the center conductor is hollow and split as if the mating connector would compress it and cause it to seize the mating connector's center conductor which in that case would make the CIQ (connector in question) female and female no thread. I couldn't quite get a real idea of the size from the photo. Let's check Pasternack. The PAL connector in this book is a push on, but the CIQ can't be this PAL connector. The one I'm looking at is male-female into female-male with the male housing (which would correspond to the CIQ) is .370" OD. I see 75 ohm MCX connectors where the jack corresponding to the CIQ accepts a plug with a .147" OD housing - seisure and all. I'd replace the friggin' thing with something I can lay hands on easily. F connectors are common enough. Push ons I only use for testing. -- Best Regards, Mike |
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#35
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Dropping 1V from a Regulated 6V Wall Wart
I read in sci.electronics.design that Active8 mTHISREMOVEcolasono@earth
link.net wrote (in t ) about 'Dropping 1V from a Regulated 6V Wall Wart', on Thu, 1 Jan 2004: It looks (the outer part) exactly like one of those RS push on F connectors - the male one (male center conductor, female housing) but the center conductor is hollow and split as if the mating connector would compress it and cause it to seize the mating connector's center conductor which in that case would make the CIQ (connector in question) female and female no thread. I couldn't quite get a real idea of the size from the photo. Let's check Pasternack. You've described a Belling coax connector, I think. I don't know what Pasternack is; a connector distributor? The PAL connector in this book is a push on, but the CIQ can't be this PAL connector. The one I'm looking at is male-female into female-male with the male housing (which would correspond to the CIQ) is .370" OD. I just don't recognize the term 'PAL connector'. I see 75 ohm MCX connectors where the jack corresponding to the CIQ accepts a plug with a .147" OD housing - seisure and all. I'd replace the friggin' thing with something I can lay hands on easily. F connectors are common enough. Push ons I only use for testing. You should be able to get Belling-type connectors from Farnell/Newark. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! |
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Dropping 1V from a Regulated 6V Wall Wart
In article ,
mentioned... I read in alt.binaries.schematics.electronic that Watson A. Name - Watt Sun, Dark Remover wrote (in MPG.1a5cbb112ab587 ) about 'Dropping 1V from a Regulated 6V Wall Wart', on Wed, 31 Dec 2003: I talked about the weird connector, someone said it's a Belling Lee connector, That's a coaxial connector, a bit like a phono plug but with a smaller centre pin. Is that what you have? AKA Euro or PAL connector. I'd forget those descriptions if I were you. Certainly the Belling connector has very little indeed to do with PAL. It is the subject of an IEC standard - IEC 60169-2. Yeah, but here in the U.S. you go to Rat Shack and buy a Euro or PAL adapter, shove it in the socket, and forget about it for the rest of the life of the equipment. Everything else is done with F connectors, so it's not really an issue. In fact, I may heat up my big 100W soldering iron and make the adapter a permanent part of the equipment. ;-) -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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Dropping 1V from a Regulated 6V Wall Wart
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Dropping 1V from a Regulated 6V Wall Wart
Watson A.Name - "Watt Sun, Dark Remover" wrote in message om...
I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried a 3 amp rectifier, but it varied by more than .2V over a range of loads. So I tried this: (view with courier font) + From wall wart --+ | +---+------+ | | | | 400 \ / 2SC2334 or TIP31 ohm / |/ NPN power TO-220 WW \-----| Heatsink optional pot / |\ | E\ | | | | +----+-----+ | | +------ + output to load - -------------- - From wall wart This has some advantages and disadvantages. It's simple and cheap, and keeps the output at 5V within a tenth of a volt over a current range. But it has a minimum current below which it loses regulation and the output starts to go up to 6V, because the transistor is not conducting and the current is being supplied thru the ww pot. This circuit is sometimes used in the bias circuit for the output transistors in high powered amplifiers. Also Win Hill showed us here how to use a similar circuit to maintain the voltage steady for a current regulator circuit used on four AA cell rechargeable batteries. I'm thinking about putting a 5.1V zener on the output so that if the voltage climbs above that, it just shunts the excess current. Oh, yeah, I set the pot to various values to see what the output voltage was with various loads. The two resistances were 120 ohms for the upper and 280 ohms for the lower. I suppose the 400 ohms total could be raised to a higher value, but the transistor needs enough base current to do its job. There's only 1V available minus the .6V E-B voltage, so even at 400 ohms, that's not a lot of current. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ I did this a while back. Replaced the 7806 in the wall wart with a 7805. Wade |
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Dropping 1V from a Regulated 6V Wall Wart
Isn't that too practical and simple?
Bob (Wade Hassler) wrote: I did this a while back. Replaced the 7806 in the wall wart with a 7805. Wade |
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or what?
Hybrid Mode
