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#1
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
Let me first start by saying I am new to electronics and my
understanding of the principles discussed might be off a little. I will attempt to phrase my question properly, and rest assured I have been looking into this matter on my own for quite a bit before posting here. I have very little financial resources, and am saving every penny I get so I need to keep my budget low... anyways; I am attempting to turn an old rotary tool I have lying around into a basic water powered generator. The motor inside of the rotary tool is a series wound motor (I believe this is correct, but I could always be wrong). I am attempting to change the wiring around to turn this into a compound wound generator, but I am not sure if this will work, here's why: 1) I am not sure if a compound wound generator needs to have 4 coils representing the two fields, or if it can be made with 2 coils, such as those in the rotary tool. 2) I am not sure if "proportioning" of the fields requires modifying how many loops of wire are contained in the coils, or if resistors could be used for proportioning. I have chosen to use a rotary tool motor because I had one on hand and it has a nice shaft for me to mount a rotor blade. It is also small and light weight enough to send via mail. The project goal is to present to my parents (who live in the bush with no electricity) a proof of concept design so they can learn the basics and apply it with materials found at the local landfill. I am *quite* aware that this is not an efficient design. If this is not possible with only two coils, would an approach with series or shunt wound be recommended? If so, which would be better and why? I would appreciate very much any information given, and thank you in advance for your time. sincerely, distatica. References: Series Wound Motor http://tpub.com/content/neets/14177/css/14177_51.htm Compound Wound Gen. http://tpub.com/content/neets/14177/css/14177_30.htm P.S. PLEASE, PLEASE, PLEASE let me know if I've done something wrong with my post, flaming me is not going to teach me a thing. I have taken great care to ensure I've included the information I believe is needed to solve the problem, with my understanding of the problem, don't hesitate to ask for more information I will get it asap. |
#2
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
On Thu, 11 Jan 2007 21:22:13 GMT, distatica
wrote: Let me first start by saying I am new to electronics and my understanding of the principles discussed might be off a little. I will attempt to phrase my question properly, and rest assured I have been looking into this matter on my own for quite a bit before posting here. I have very little financial resources, and am saving every penny I get so I need to keep my budget low... anyways; I am attempting to turn an old rotary tool I have lying around into a basic water powered generator. The motor inside of the rotary tool is a series wound motor (I believe this is correct, but I could always be wrong). I am attempting to change the wiring around to turn this into a compound wound generator, but I am not sure if this will work, here's why: 1) I am not sure if a compound wound generator needs to have 4 coils representing the two fields, or if it can be made with 2 coils, such as those in the rotary tool. 2) I am not sure if "proportioning" of the fields requires modifying how many loops of wire are contained in the coils, or if resistors could be used for proportioning. I have chosen to use a rotary tool motor because I had one on hand and it has a nice shaft for me to mount a rotor blade. It is also small and light weight enough to send via mail. The project goal is to present to my parents (who live in the bush with no electricity) a proof of concept design so they can learn the basics and apply it with materials found at the local landfill. I am *quite* aware that this is not an efficient design. If this is not possible with only two coils, would an approach with series or shunt wound be recommended? If so, which would be better and why? I would appreciate very much any information given, and thank you in advance for your time. sincerely, distatica. References: Series Wound Motor http://tpub.com/content/neets/14177/css/14177_51.htm Compound Wound Gen. http://tpub.com/content/neets/14177/css/14177_30.htm P.S. PLEASE, PLEASE, PLEASE let me know if I've done something wrong with my post, flaming me is not going to teach me a thing. I have taken great care to ensure I've included the information I believe is needed to solve the problem, with my understanding of the problem, don't hesitate to ask for more information I will get it asap. While you certainly could convert a series wound motor into a generator (with DC output) the voltage outputted from this generator would not be what the original motor was designed to work with. In short you'd end up with a generator putting out a strange voltage that won't be useful powering much of anything really. A *much* better way woudl be to get an alternator off an automobile at a junk yard. Then you can get AC (which with a transformer can be converted to 120 or 240 volts depending out your county's standard) with a few simple modifications. Use one with a built in regulator. To get AC out of the alternator, simply wire into the stator windings where they connect to the diodes. Leave everything else alone, and use a small lead cell battery (old car, tractor, or motorcycle battery will work). The frequency output will not be 50 or 60 Hz (unless you find a way to regulate the alternator's speed, not easy to do.) but for standard incandesent lights and many other items this won't cause any serious problems. And, even better it is practical and useful where your idea is simply an interesting experiment. |
#3
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
On Thu, 11 Jan 2007 21:22:13 GMT, distatica
wrote: Let me first start by saying I am new to electronics and my understanding of the principles discussed might be off a little. I will attempt to phrase my question properly, and rest assured I have been looking into this matter on my own for quite a bit before posting here. I have very little financial resources, and am saving every penny I get so I need to keep my budget low... anyways; I am attempting to turn an old rotary tool I have lying around into a basic water powered generator. The motor inside of the rotary tool is a series wound motor (I believe this is correct, but I could always be wrong). I am attempting to change the wiring around to turn this into a compound wound generator, but I am not sure if this will work, here's why: 1) I am not sure if a compound wound generator needs to have 4 coils representing the two fields, or if it can be made with 2 coils, such as those in the rotary tool. Need two fields that means four coils around the 2 pole pieces you have. 2) I am not sure if "proportioning" of the fields requires modifying how many loops of wire are contained in the coils, or if resistors could be used for proportioning. A resistor would only waste power. They depend on having the fields balanced. I have chosen to use a rotary tool motor because I had one on hand and it has a nice shaft for me to mount a rotor blade. It is also small and light weight enough to send via mail. The project goal is to present to my parents (who live in the bush with no electricity) a proof of concept design so they can learn the basics and apply it with materials found at the local landfill. I am *quite* aware that this is not an efficient design. If this is not possible with only two coils, would an approach with series or shunt wound be recommended? If so, which would be better and why? I would appreciate very much any information given, and thank you in advance for your time. sincerely, distatica. Like another responder already said an alternator is a better bet if they can be found in land fills. What you could do with your motor is vary the one field you do have with a regulator to maintain the output voltage constant with motor speed and loading. But then you probably won't find the parts for a solid state regulator in the land fill (?). So that calls for something more clever (or ancient) like a coil that senses voltage and lowers the field strength by opening contacts when the output exceeds a predetermined level. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#4
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
default wrote:
snip Like another responder already said an alternator is a better bet if they can be found in land fills. What you could do with your motor is vary the one field you do have with a regulator to maintain the output voltage constant with motor speed and loading. But then you probably won't find the parts for a solid state regulator in the land fill (?). So that calls for something more clever (or ancient) like a coil that senses voltage and lowers the field strength by opening contacts when the output exceeds a predetermined level. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Thank you both very much for your responses. I was worried that I would be needing the 4 coils but no one would answer me on that issue, so thank you for clearing that up. And a resistor does seem like a dumb idea in hindsight. I was trying to avoid the use of an alternator (although I can clearly see this is a much better idea, especially a GM alternator with a built in regulator). The problem is my access in the city to one, and my budget. While I may be able to scrape enough money together to purchase a used alternator from a scrap yard, I doubt I would have the necessary cash left over to send it in the mail. However if this is going to output a useless voltage there's not much sense in doing it either. My parents (and myself to a lesser extent) are afraid of taking power and putting that into a device without knowing what will happen, which is smart. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? I believe I have come to the conclusion I need to purchase an alternator and send that, although I'm worried it's going to be one big box in the end. I would like the system to charge a small lead acid battery and use the battery as a regulator of sorts. Of course the alternator I pick up will include a built in regulator. I would like if in the end they were capable of using the creek to power/recharge their cell phone. My biggest confusion at this point comes from dynamo flashlights, the one's you never use batteries in. I have taken these apart and they look like a very simple DC motor with some gears for higher RPM. If this is the case how do they get all that power out of them to power a radio or 3 high intensity LED's? Is it a transformer of some sort? I'm not sure what is going on there. I looked at another flashlight that had a magnet moving through the center of a coil when you shook it, it claimed to have a capacitor that could be charged thousands of times, but when I applied a voltage to the largest capacitors I had around (from microwaves) I was only able to light an LED for a couple seconds. Exactly how much usable power can you get from a small DC motor like that? This would be a great alternative to my design... And since I have seen hand-spun Motorola battery chargers I assume it's enough to power a cellphone. I will however be using a creek and/or wind to spin the DC motor, not by hand. Once again, any information is very greatly appreciated. |
#5
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
"distatica" wrote in message
news:jRBph.624538$R63.323581@pd7urf1no... default wrote: snip Like another responder already said an alternator is a better bet if they can be found in land fills. What you could do with your motor is vary the one field you do have with a regulator to maintain the output voltage constant with motor speed and loading. But then you probably won't find the parts for a solid state regulator in the land fill (?). So that calls for something more clever (or ancient) like a coil that senses voltage and lowers the field strength by opening contacts when the output exceeds a predetermined level. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Thank you both very much for your responses. I was worried that I would be needing the 4 coils but no one would answer me on that issue, so thank you for clearing that up. And a resistor does seem like a dumb idea in hindsight. I was trying to avoid the use of an alternator (although I can clearly see this is a much better idea, especially a GM alternator with a built in regulator). The problem is my access in the city to one, and my budget. While I may be able to scrape enough money together to purchase a used alternator from a scrap yard, I doubt I would have the necessary cash left over to send it in the mail. However if this is going to output a useless voltage there's not much sense in doing it either. My parents (and myself to a lesser extent) are afraid of taking power and putting that into a device without knowing what will happen, which is smart. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? I believe I have come to the conclusion I need to purchase an alternator and send that, although I'm worried it's going to be one big box in the end. I would like the system to charge a small lead acid battery and use the battery as a regulator of sorts. Of course the alternator I pick up will include a built in regulator. I would like if in the end they were capable of using the creek to power/recharge their cell phone. My biggest confusion at this point comes from dynamo flashlights, the one's you never use batteries in. I have taken these apart and they look like a very simple DC motor with some gears for higher RPM. If this is the case how do they get all that power out of them to power a radio or 3 high intensity LED's? Is it a transformer of some sort? I'm not sure what is going on there. I looked at another flashlight that had a magnet moving through the center of a coil when you shook it, it claimed to have a capacitor that could be charged thousands of times, but when I applied a voltage to the largest capacitors I had around (from microwaves) I was only able to light an LED for a couple seconds. Exactly how much usable power can you get from a small DC motor like that? This would be a great alternative to my design... And since I have seen hand-spun Motorola battery chargers I assume it's enough to power a cellphone. I will however be using a creek and/or wind to spin the DC motor, not by hand. Once again, any information is very greatly appreciated. It's hard to say how much you can gain but trying to convert a series motor to a compound generator would require adding a shunt winding (likely not enough space for it) and also reducing the series field considerably (either by removing turns or by using a low resistance shunt across the field windings. Tain't worth the effort. As for the hand crank generators- they are really low power devices- a LED doesn't take much. -- Don Kelly remove the X to answer ---------------------------- |
#6
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
Don Kelly wrote:
"distatica" wrote in message news:jRBph.624538$R63.323581@pd7urf1no... default wrote: snip Like another responder already said an alternator is a better bet if they can be found in land fills. What you could do with your motor is vary the one field you do have with a regulator to maintain the output voltage constant with motor speed and loading. But then you probably won't find the parts for a solid state regulator in the land fill (?). So that calls for something more clever (or ancient) like a coil that senses voltage and lowers the field strength by opening contacts when the output exceeds a predetermined level. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Thank you both very much for your responses. I was worried that I would be needing the 4 coils but no one would answer me on that issue, so thank you for clearing that up. And a resistor does seem like a dumb idea in hindsight. I was trying to avoid the use of an alternator (although I can clearly see this is a much better idea, especially a GM alternator with a built in regulator). The problem is my access in the city to one, and my budget. While I may be able to scrape enough money together to purchase a used alternator from a scrap yard, I doubt I would have the necessary cash left over to send it in the mail. However if this is going to output a useless voltage there's not much sense in doing it either. My parents (and myself to a lesser extent) are afraid of taking power and putting that into a device without knowing what will happen, which is smart. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? I believe I have come to the conclusion I need to purchase an alternator and send that, although I'm worried it's going to be one big box in the end. I would like the system to charge a small lead acid battery and use the battery as a regulator of sorts. Of course the alternator I pick up will include a built in regulator. I would like if in the end they were capable of using the creek to power/recharge their cell phone. My biggest confusion at this point comes from dynamo flashlights, the one's you never use batteries in. I have taken these apart and they look like a very simple DC motor with some gears for higher RPM. If this is the case how do they get all that power out of them to power a radio or 3 high intensity LED's? Is it a transformer of some sort? I'm not sure what is going on there. I looked at another flashlight that had a magnet moving through the center of a coil when you shook it, it claimed to have a capacitor that could be charged thousands of times, but when I applied a voltage to the largest capacitors I had around (from microwaves) I was only able to light an LED for a couple seconds. Exactly how much usable power can you get from a small DC motor like that? This would be a great alternative to my design... And since I have seen hand-spun Motorola battery chargers I assume it's enough to power a cellphone. I will however be using a creek and/or wind to spin the DC motor, not by hand. Once again, any information is very greatly appreciated. It's hard to say how much you can gain but trying to convert a series motor to a compound generator would require adding a shunt winding (likely not enough space for it) and also reducing the series field considerably (either by removing turns or by using a low resistance shunt across the field windings. Tain't worth the effort. As for the hand crank generators- they are really low power devices- a LED doesn't take much. My understanding is that the hand crank generator is the same as a DC motor, and that is what is used for the generator. If I am incorrect please respond, if not don't bother responding I'll take no news as good news and we'll let this thread die. Thank you very much to those that responded, you've been very helpful. |
#7
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
On Fri, 12 Jan 2007 01:52:15 GMT, distatica
wrote: Thank you both very much for your responses. I was worried that I would be needing the 4 coils but no one would answer me on that issue, No, two coils would work. so thank you for clearing that up. And a resistor does seem like a dumb idea in hindsight. I was trying to avoid the use of an alternator (although I can clearly see this is a much better idea, especially a GM alternator with a built in regulator). The problem is my access in the city to one, and my budget. While I may be able to scrape enough money together to purchase a used alternator from a scrap yard, I doubt I would have the necessary cash left over to send it in the mail. However if this is going to output a useless voltage there's not much sense in doing it either. My parents (and myself to a lesser extent) are afraid of taking power and putting that into a device without knowing what will happen, which is smart. For a practical device, an alternator charging a battery is the *only* way to go. I'm not sure where you are (Canada?) but at least here a used alternator could be gotten for almost nothing if you know anyone with a junk yard. Do make sure you get one that has a built in regulator (some do not!) so research your device *before* investing any money. A Google will help greatly in this respect. A 'one wire' alternator would be an idea but they do have minimum RPM requirements which may exceed your drive (water wheel?) capabilities when water levels are low. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? I believe I have come to the conclusion I need to purchase an alternator and send that, although I'm worried it's going to be one big box in the end. I would like the system to charge a small lead acid battery and use the battery as a regulator of sorts. Of course the alternator I pick up will include a built in regulator. I would like if in the end they were capable of using the creek to power/recharge their cell phone. Alternator charging batteries. Batteries feeding an inverter. Power... Stable, clean and given enough water: significant amounts! Cost? Well, not free, but small 150 watt inverters are not that expensive. My biggest confusion at this point comes from dynamo flashlights, the one's you never use batteries in. I have taken these apart and they look like a very simple DC motor with some gears for higher RPM. If this is the case how do they get all that power out of them to power a radio or 3 high intensity LED's? Good assumption, yes they are simply small pernament magent stator DC motors, geared up to provide the necessary voltages. They then charge a NI-CAD or other battery so the power is available after crainking. Is it a transformer of some sort? No. I'm not sure what is going on there. I looked at another flashlight that had a magnet moving through the center of a coil when you shook it, it claimed to have a capacitor that could be charged thousands of times, but when I applied a voltage to the largest capacitors I had around (from microwaves) I was only able to light an LED for a couple seconds. g Those moving magnet flashlights are funny! The amount of power generated by that technique is nominal, at best. The tube the magent slides in increases the gap in the magnetic field to coil and that also reduces the power available. As to a capacitor, you need a high value, low voltage capacitor. The capacitor in a microwave is high voltage low value, just the opposite of what you really need. Exactly how much usable power can you get from a small DC motor like that? This would be a great alternative to my design... And since I have seen hand-spun Motorola battery chargers I assume it's enough to power a cellphone. Any, repeat, any small pernament magent DC motor will work as a generator. The bigger the motor, the more power. I use 90 volt DC motors in equipment frequently, they are half to one HP and capable of interesting feats of power. Why am I mentioning this? Easy: most electric treadmills (exercise machines) have a 90 volt DC motor in them--finding one of these in a dump or recycling center would give you a reasonable (higher voltage, however) generator. Any pernament magnet generator is going to be unregulated! That means you will need a regulator (even a simple series pass regulator would work) to safely use them to charge a battery or batteries. But it can be done. I will however be using a creek and/or wind to spin the DC motor, not by hand. The human body can put out through the arms maybe a hundred watts of power. Legs you can count on about 500 watts (much bigger muscles!) but not for sustained periods of time (unless you are Lance Armstrong, or Floyd... g) Creeks dry up, so always be sure you'll have water there when you need it. They also freeze (Canada? If so how far north? bg) The wind stops blowing, often just when you need electricity. But wind shortages are often short term so storage batteries can sometimes cover them, creeks drying up can be dry for months! Once again, any information is very greatly appreciated. There have got to be hundreds of similar projects documented on the web... Google is your friend, but it may take some digging to get to a practical example. FWIW, I have a huge alternator sitting here that I had planned to use in just such a project. It's rated at hundreds of amps (at low RPMs, too.) but it still is a great project. Some day I may build it. Who knows? |
#8
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
On Fri, 12 Jan 2007 04:16:37 GMT, distatica
wrote: Don Kelly wrote: "distatica" wrote in message news:jRBph.624538$R63.323581@pd7urf1no... default wrote: snip Like another responder already said an alternator is a better bet if they can be found in land fills. What you could do with your motor is vary the one field you do have with a regulator to maintain the output voltage constant with motor speed and loading. But then you probably won't find the parts for a solid state regulator in the land fill (?). So that calls for something more clever (or ancient) like a coil that senses voltage and lowers the field strength by opening contacts when the output exceeds a predetermined level. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Thank you both very much for your responses. I was worried that I would be needing the 4 coils but no one would answer me on that issue, so thank you for clearing that up. And a resistor does seem like a dumb idea in hindsight. I was trying to avoid the use of an alternator (although I can clearly see this is a much better idea, especially a GM alternator with a built in regulator). The problem is my access in the city to one, and my budget. While I may be able to scrape enough money together to purchase a used alternator from a scrap yard, I doubt I would have the necessary cash left over to send it in the mail. However if this is going to output a useless voltage there's not much sense in doing it either. My parents (and myself to a lesser extent) are afraid of taking power and putting that into a device without knowing what will happen, which is smart. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? I believe I have come to the conclusion I need to purchase an alternator and send that, although I'm worried it's going to be one big box in the end. I would like the system to charge a small lead acid battery and use the battery as a regulator of sorts. Of course the alternator I pick up will include a built in regulator. I would like if in the end they were capable of using the creek to power/recharge their cell phone. My biggest confusion at this point comes from dynamo flashlights, the one's you never use batteries in. I have taken these apart and they look like a very simple DC motor with some gears for higher RPM. If this is the case how do they get all that power out of them to power a radio or 3 high intensity LED's? Is it a transformer of some sort? I'm not sure what is going on there. I looked at another flashlight that had a magnet moving through the center of a coil when you shook it, it claimed to have a capacitor that could be charged thousands of times, but when I applied a voltage to the largest capacitors I had around (from microwaves) I was only able to light an LED for a couple seconds. Exactly how much usable power can you get from a small DC motor like that? This would be a great alternative to my design... And since I have seen hand-spun Motorola battery chargers I assume it's enough to power a cellphone. I will however be using a creek and/or wind to spin the DC motor, not by hand. Once again, any information is very greatly appreciated. It's hard to say how much you can gain but trying to convert a series motor to a compound generator would require adding a shunt winding (likely not enough space for it) and also reducing the series field considerably (either by removing turns or by using a low resistance shunt across the field windings. Tain't worth the effort. As for the hand crank generators- they are really low power devices- a LED doesn't take much. My understanding is that the hand crank generator is the same as a DC motor, and that is what is used for the generator. If I am incorrect please respond, if not don't bother responding I'll take no news as good news and we'll let this thread die. Thank you very much to those that responded, you've been very helpful. Hand crank generators are good enough for cell phone charging - although it will take more effort cranking to charge a battery as opposed to lighting an LED. Someone just gave me one of those LED crank type lights and I promptly took it apart. Inside was a large gear turning a small one - that spun a "motor" like device with a set of rectifier diodes on the output - so I assume they are spinning a few rare earth magnets past coils for power. An alternator. There were also 4 rechargeable cells in it and a switch. It says it will light for an hour with one minute of charging - it probably does - stays on for hours at a time. So, this one I have isn't DC it is an alternator. When I was a kid - long ago there were these flashlights that you squeezed and they produced light for a few seconds. You pushed on a sector gear with a spring return (the teeth of the gear were visible) that, in turn, spun some gears to increase the speed of rotation and spun a little DC motor. The gear mechanism had a device that would disengage the gears on the return stroke so inertia would keep the motor turning while you got ready to squeeze again - no storage battery lots of exercise. Small incandescent lamp. Well made and inexpensive, but not too practical. They had DC toy motors in them and produced DC to light the light. If you are interested in charging lead acid batteries - you won't need a regulator unless you tap into some significant power source with a real generator or alternator. You would still need a diode or relay to prevent the generator from discharging the battery when it isn't turning. Streams have to have some fast flowing water to be good candidates for power generation. Fast flow means large change in height over the course of the stream. I've been tinkering with this impulse motor that would probably charge a battery for lighting. The idea is to mount a magnet or two or more on a wheel and spin them by a coil. The magnets induce a voltage in the coil which turns on a transistor and another magnet which, in turn, kicks away the magnet that induced the voltage and once rotating it continues to rotate. It would be a practical generator for something like charging a battery for LED lights and cell phones. The wheel my magnets are mounted to is 20 centimeters in diameter and weighs several pounds - two ball bearings on a 13 mm shaft. As a motor it spins at a mere 120 - 200 RPM. The two magnets are 25 mm X 6 mm disks and very strong (rare earth). As the magnets pass the coil they light an LED as well as turn the transistor on - the voltage has to be greater than 4 volts to do that. My sense coil (the one turning on the transistor) has ~2,500 turns of 32 AWG magnet wire on it - very little copper - but very fine wire. The core is a bundle of steel wires 12 mm in diameter and 75 mm long. The DC resistance of the coil is about 230 ohms. There's a 6 mm gap between the magnets and the core of the coil as they pass it. More turns of wire or higher speed and it would generate more voltage. But most of the cell phones I see here require about 5 volts to charge so it is pretty close as-is. A stream moving at 41 meters a minute spinning paddle wheels with no gearing would be enough to provide useable energy to charge a cell phone. If you can get some rare earth magnets for a reasonable cost they could be incorporated in motors to provide a rotating field and you be making alternators from motors. I paid $20 for ten of the magnets I use. Probably be easier to just chuck out the motor armature or save just the shaft and turn a wooden cylinder to hold the magnets. A wood turning lathe is easy to make from scrap and can be muscle powered. My motor uses only two magnets (now) but I could just as easily mount all ten to the wheel and have it spin much faster (or generate more power). That's my next experiment . . . then I think I'll get a smaller lighter wheel and see how little current I can get the motor to run at. (right now it takes a pulse of 5 amps at 20 volts to turn 200 RPM). The drive coil (around the same core as the sense coil) is about 500 turns of 22 gauge wire - and only 4 ohms of resistance) Some guy is selling a bicycle tail light that uses a coil mounted to the bicycle frame and magnets mounted to the spokes - it lights red LEDs - more magnets, coils, and LEDs and it would be a practical headlight - and more expensive. White LEDs can be bought from Hong Kong for $12/100 post paid. A pretty good deal compared to local shops here. Search for "home power" the phrase - lot of good information on small scale power generation. ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#9
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
"distatica" wrote in message
news:FYDph.617316$5R2.309887@pd7urf3no... Don Kelly wrote: "distatica" wrote in message news:jRBph.624538$R63.323581@pd7urf1no... default wrote: snip Like another responder already said an alternator is a better bet if they can be found in land fills. What you could do with your motor is vary the one field you do have with a regulator to maintain the output voltage constant with motor speed and loading. But then you probably won't find the parts for a solid state regulator in the land fill (?). So that calls for something more clever (or ancient) like a coil that senses voltage and lowers the field strength by opening contacts when the output exceeds a predetermined level. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Thank you both very much for your responses. I was worried that I would be needing the 4 coils but no one would answer me on that issue, so thank you for clearing that up. And a resistor does seem like a dumb idea in hindsight. I was trying to avoid the use of an alternator (although I can clearly see this is a much better idea, especially a GM alternator with a built in regulator). The problem is my access in the city to one, and my budget. While I may be able to scrape enough money together to purchase a used alternator from a scrap yard, I doubt I would have the necessary cash left over to send it in the mail. However if this is going to output a useless voltage there's not much sense in doing it either. My parents (and myself to a lesser extent) are afraid of taking power and putting that into a device without knowing what will happen, which is smart. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? I believe I have come to the conclusion I need to purchase an alternator and send that, although I'm worried it's going to be one big box in the end. I would like the system to charge a small lead acid battery and use the battery as a regulator of sorts. Of course the alternator I pick up will include a built in regulator. I would like if in the end they were capable of using the creek to power/recharge their cell phone. My biggest confusion at this point comes from dynamo flashlights, the one's you never use batteries in. I have taken these apart and they look like a very simple DC motor with some gears for higher RPM. If this is the case how do they get all that power out of them to power a radio or 3 high intensity LED's? Is it a transformer of some sort? I'm not sure what is going on there. I looked at another flashlight that had a magnet moving through the center of a coil when you shook it, it claimed to have a capacitor that could be charged thousands of times, but when I applied a voltage to the largest capacitors I had around (from microwaves) I was only able to light an LED for a couple seconds. Exactly how much usable power can you get from a small DC motor like that? This would be a great alternative to my design... And since I have seen hand-spun Motorola battery chargers I assume it's enough to power a cellphone. I will however be using a creek and/or wind to spin the DC motor, not by hand. Once again, any information is very greatly appreciated. It's hard to say how much you can gain but trying to convert a series motor to a compound generator would require adding a shunt winding (likely not enough space for it) and also reducing the series field considerably (either by removing turns or by using a low resistance shunt across the field windings. Tain't worth the effort. As for the hand crank generators- they are really low power devices- a LED doesn't take much. My understanding is that the hand crank generator is the same as a DC motor, and that is what is used for the generator. If I am incorrect please respond, if not don't bother responding I'll take no news as good news and we'll let this thread die. Thank you very much to those that responded, you've been very helpful. ------------------ The hand crank machine is likely AC as that is simpler than a DC machine - no commutator. With permanent magnets -rotate the magnets so there is no need for a moving electrical contact. However a DC machine would work but there is no need for the added complication and diodes are cheap. Note I said machine rather than motor or generator as the basic difference between the two is the direction of power "flow". -- Don Kelly remove the X to answer ---------------------------- |
#10
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
PeterD wrote:
On Fri, 12 Jan 2007 01:52:15 GMT, distatica wrote: Thank you both very much for your responses. I was worried that I would be needing the 4 coils but no one would answer me on that issue, No, two coils would work. I have not been able to find out how, but that is OK, I've pretty much dropped the idea of converting my rotary tool motor to a generator for all practical uses. so thank you for clearing that up. And a resistor does seem like a dumb idea in hindsight. I was trying to avoid the use of an alternator (although I can clearly see this is a much better idea, especially a GM alternator with a built in regulator). The problem is my access in the city to one, and my budget. While I may be able to scrape enough money together to purchase a used alternator from a scrap yard, I doubt I would have the necessary cash left over to send it in the mail. However if this is going to output a useless voltage there's not much sense in doing it either. My parents (and myself to a lesser extent) are afraid of taking power and putting that into a device without knowing what will happen, which is smart. For a practical device, an alternator charging a battery is the *only* way to go. I'm not sure where you are (Canada?) but at least here a used alternator could be gotten for almost nothing if you know anyone with a junk yard. Do make sure you get one that has a built in regulator (some do not!) so research your device *before* investing any money. A Google will help greatly in this respect. A 'one wire' alternator would be an idea but they do have minimum RPM requirements which may exceed your drive (water wheel?) capabilities when water levels are low. Yeah, I am in Canada, and it can get mighty cold enough to freeze the creek, my idea to solve this problem was attempting to make a hybrid water/wind turbine but after further researching I believe the designs are just too different to compensate this. It will probably be a small scale, wind turbine, utilizing a DC motor. The smaller the better, however they have a good field with lot's of wind that would be perfectly suited to that purpose so functionality can win out. I have not dropped the water power generator, and may build a small DC motor based experiment, as my girlfriend seems really attached to this idea. This is my attempt to show via ascii what I wanted to do: +- - Output Wire __||__ \/ || || \/ - water flow || M1 || \/ \`````/ | | \`````/ - Water catchers \ / | | \ / \ / \ |____| / \/----- Water Entrance | \__||__/--|------ Splash Protector | || | | || | | \\\\|==|//// | - Rotor Blade |______________| \/ \/ \/ This entire thing is made with 2 plastic bottles (1x1L OR 600mL and 1x2L ). The output wire would actually go back like an anchor to the shore of a creek. M1 is the DC motor, and the Rotor Blade is anything that spins fast when hit with enough force. The output wire is sealed in a hole drilled in the bottle cap using silicone. Water moves along the outside and into the water catchers, which are just a 2l bottle neck cut off and flipped upside down. Inside there is the splash protector, which is the bottom of the bottle that has been cut off, hole drilled in it for the shaft to come out, and grease put in the hole to help further shield water. Then the piece is put up inside the bottle, with it's edges further up than the water entrance holes. The water moves down towards the bottom of the bottle and pushes it's way out through the rotor blade, which in turn turns the shaft. I can see a couple potential problems with this design however, one is the constant pull on the rotor blade, and how securely it is attached to the shaft will determine whether it disappears downstream or not. Another is that the force on the wire might be too great. And yet another is it will have a natural tendency to spin with the moving rotor, I *think* I might be able to overcome that with a pouch filled with rocks to anchor to the bottom of the stream. What do you hope to achieve - charge batteries or provide DC power for lighting? Is regulation necessary and why? I believe I have come to the conclusion I need to purchase an alternator and send that, although I'm worried it's going to be one big box in the end. I would like the system to charge a small lead acid battery and use the battery as a regulator of sorts. Of course the alternator I pick up will include a built in regulator. I would like if in the end they were capable of using the creek to power/recharge their cell phone. Alternator charging batteries. Batteries feeding an inverter. Power... Stable, clean and given enough water: significant amounts! Cost? Well, not free, but small 150 watt inverters are not that expensive. My biggest confusion at this point comes from dynamo flashlights, the one's you never use batteries in. I have taken these apart and they look like a very simple DC motor with some gears for higher RPM. If this is the case how do they get all that power out of them to power a radio or 3 high intensity LED's? Good assumption, yes they are simply small pernament magent stator DC motors, geared up to provide the necessary voltages. They then charge a NI-CAD or other battery so the power is available after crainking. Is it a transformer of some sort? No. That's good to know the voltages are achieved using only gearing, good news for me. I'm not sure what is going on there. I looked at another flashlight that had a magnet moving through the center of a coil when you shook it, it claimed to have a capacitor that could be charged thousands of times, but when I applied a voltage to the largest capacitors I had around (from microwaves) I was only able to light an LED for a couple seconds. g Those moving magnet flashlights are funny! The amount of power generated by that technique is nominal, at best. The tube the magent slides in increases the gap in the magnetic field to coil and that also reduces the power available. As to a capacitor, you need a high value, low voltage capacitor. The capacitor in a microwave is high voltage low value, just the opposite of what you really need. Ahhh.. that makes sense now. Exactly how much usable power can you get from a small DC motor like that? This would be a great alternative to my design... And since I have seen hand-spun Motorola battery chargers I assume it's enough to power a cellphone. Any, repeat, any small pernament magent DC motor will work as a generator. The bigger the motor, the more power. I use 90 volt DC motors in equipment frequently, they are half to one HP and capable of interesting feats of power. Why am I mentioning this? Easy: most electric treadmills (exercise machines) have a 90 volt DC motor in them--finding one of these in a dump or recycling center would give you a reasonable (higher voltage, however) generator. Any pernament magnet generator is going to be unregulated! That means you will need a regulator (even a simple series pass regulator would work) to safely use them to charge a battery or batteries. But it can be done. Wow! I really appreciate that hint, I'm sure there are treadmills around there, and that's good news for me, in the city a lot of people throw them out (granted some probably due to a dead motor). I just informed my parents and they are going to keep an eye out for treadmills. I will also ensure I use a regulator, thank you. I will however be using a creek and/or wind to spin the DC motor, not by hand. The human body can put out through the arms maybe a hundred watts of power. Legs you can count on about 500 watts (much bigger muscles!) but not for sustained periods of time (unless you are Lance Armstrong, or Floyd... g) Creeks dry up, so always be sure you'll have water there when you need it. They also freeze (Canada? If so how far north? bg) The wind stops blowing, often just when you need electricity. But wind shortages are often short term so storage batteries can sometimes cover them, creeks drying up can be dry for months! Wind won't be a problem unless it's of extreme importance for the battery charging to be uninterrupted. My parents right now use the alternator in their car to charge batteries while going to town, which is rare, and never really have enough battery power to do anything but make sure they can start their truck again. So anything will be a treat. Once again, any information is very greatly appreciated. There have got to be hundreds of similar projects documented on the web... Google is your friend, but it may take some digging to get to a practical example. FWIW, I have a huge alternator sitting here that I had planned to use in just such a project. It's rated at hundreds of amps (at low RPMs, too.) but it still is a great project. Some day I may build it. Who knows? I have been spending a great deal of time looking at google, wikipedia, and many other sites, trying to piece everything together. I have usually researched every one of my questions, but am unclear on what I have read, and need to make sure that I have the principles correct. As always, I do greatly appreciate the help you folks have given me. While looking up information on a regulator circuit that would fit my needs, I had the idea of powering something off the wood stove they have, that they keep fired year round. Currently they have a self powered fan that runs off the heat from the stove (which I understand runs off a difference of temperature,http://www.caframo.com/ecofantech.htm ) I figured if that fan could run off of that heat, surely I could run something else like one or more high intensity white LED's (?), I looked into a wood stove powered generator and found this site: http://www.hi-z.com/websit10.htm which boasts in their project a pretty impressive power output. I unfortunately don't have access to these HZ-20 modules, but if all they are is essentially thermocouples I'm going to try to build a couple and see what I can get from it. Granted I most likely won't be able to obtain the power they did from my materials, but a couple LED's *should* feasible... If anyone disagrees or has some other ideas, let me know. sincerely, distatica. |
#11
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
PeterD wrote:
Alternator charging batteries. Batteries feeding an inverter. Power... Stable, clean and given enough water: significant amounts! Cost? Well, not free, but small 150 watt inverters are not that expensive. Also not likely to put out 150W -I have a 150/300 peak and it cant cope with 70W constant draw. J |
#12
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
On Wed, 17 Jan 2007 22:31:17 +0000, Coyoteboy
wrote: PeterD wrote: Alternator charging batteries. Batteries feeding an inverter. Power... Stable, clean and given enough water: significant amounts! Cost? Well, not free, but small 150 watt inverters are not that expensive. Also not likely to put out 150W -I have a 150/300 peak and it cant cope with 70W constant draw. I'd suspect that inverter. My 150 watt unit will do 150 watts all day. Gets *warm* doing it (has a built in fan) so it is possible yours is either not well designed (overrated!) or maybe not working correctly? |
#13
Posted to alt.electronics
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Rewiring Series Motor to Compound Wound Generator
On Tue, 23 Jan 2007 14:18:41 +0000, Coyoteboy
wrote: PeterD wrote: On Wed, 17 Jan 2007 22:31:17 +0000, Coyoteboy wrote: PeterD wrote: Alternator charging batteries. Batteries feeding an inverter. Power... Stable, clean and given enough water: significant amounts! Cost? Well, not free, but small 150 watt inverters are not that expensive. Also not likely to put out 150W -I have a 150/300 peak and it cant cope with 70W constant draw. I'd suspect that inverter. My 150 watt unit will do 150 watts all day. Gets *warm* doing it (has a built in fan) so it is possible yours is either not well designed (overrated!) or maybe not working correctly? I think its over-rated - it runs flourescent lamps and soldering irons ok but a 70W pair of hair straighteners (dont ask, camping with the girlfriend) and it crapped out and blew a fuse in the car too! Worked fine on everything before and since too, and straighteners check out ok. Humm, I'd tend to want to check the current draw on the straighteners too. Bet they draw more than 70 watts (especially when first turned on). It is possible the *average* draw is 70 watts, but that there are peak draws many times that. Easy to check if you wanted... g |
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