resonant generator - colpitts osc.

[alpha-dog]

I've started building this today. I hope it will resonate.

981

[fisher]

Where is your gen? Is it the middle thingy? I see what looks like a coil on the left (what are you using for a coil? Ever think of a coil off an old car?) I see capacitors on the right. Is the gen in the middle? My thought was to build a resonant circuit with the gen acting as the capacitor.

Can you alter the frequency out of your PWM to find the resonant frequency? (the frequency at which you get the most generation of HH0?)

[alpha-dog]

Where is your gen? Is it the middle thingy? I see what looks like a coil on the left (what are you using for a coil? Ever think of a coil off an old car?) I see capacitors on the right. Is the gen in the middle? My thought was to build a resonant circuit with the gen acting as the capacitor.

Can you alter the frequency out of your PWM to find the resonant frequency? (the frequency at which you get the most generation of HH0?)

What happens when you put voltage and current on the generator plates are they break down the water dialectric. They need to charge. So to help that I add capacitors in parallel to each series cell. Capacitance adds in parallel like resistance adds in series. For a coil I've taken a piece of rebar and 12ga solid core wire and put 45 turns on it. I'm going to be measuring inductance and capacitance of my homemade devices on a meter at work probably tonight. For a capacitor I've just put two switch plates back to back with .040 shower pan liner ( air dialectric ) just like the generator only air instead of water. Also, my pwm's are still in the mail.
Russ

[fisher]

I may be telling you nothing you don't already know but...

Capacitors have a resistance to a particular frequency. The resistance decreases as frequency increases.

Inductors have a resistance to a particular frequency. The resistance increases as frequency increases.

So capacitors highly resist low frequencies, pass high frequencies.
So inductors highly resist high frequencies, pass low frequencies.

If you have a capacitor and an inductor in a circuit together, the cap will block low frequencies, the inductor will block high frequencies, but there will be some frequency in the middle where the effects of the capacitor (capacitive reactance) cancels out the effects of the inductor (inductive reactance) and that particular frequency sees almost no resistance. That is the resonant frequency of that particular circuit.

For your home-made inductor and capacitor, it will be almost impossible to measure the values of your devices, the measured inductance of your inductor, and capacitance of your capacitor. But if you knew them you could calculate the resonant frequency of the two.

Fr = 1/ (2 pi L C)
Fr is resonant frequency
2 times pi (3.14159) times the size of your inductor times the size of your capacitor
then divide 1 by that number for the frequency at which the two will resonate.

Suffice it to say that a bigger inductor and capacitor will resonate at a lower frequency, a smaller value of L and C will resonate at a higher frequency.

Anyway, you want your PWM to be pulsing at the Fr. This will create the least resistance, most current, most HHO.

[alpha-dog]

I may be telling you nothing you don't already know but...

Capacitors have a resistance to a particular frequency. The resistance decreases as frequency increases.

Inductors have a resistance to a particular frequency. The resistance increases as frequency increases.

So capacitors highly resist low frequencies, pass high frequencies.
So inductors highly resist high frequencies, pass low frequencies.

If you have a capacitor and an inductor in a circuit together, the cap will block low frequencies, the inductor will block high frequencies, but there will be some frequency in the middle where the effects of the capacitor (capacitive reactance) cancels out the effects of the inductor (inductive reactance) and that particular frequency sees almost no resistance. That is the resonant frequency of that particular circuit.

For your home-made inductor and capacitor, it will be almost impossible to measure the values of your devices, the measured inductance of your inductor, and capacitance of your capacitor. But if you knew them you could calculate the resonant frequency of the two.

Fr = 1/ (2 pi L C)
Fr is resonant frequency
2 times pi (3.14159) times the size of your inductor times the size of your capacitor
then divide 1 by that number for the frequency at which the two will resonate.

Suffice it to say that a bigger inductor and capacitor will resonate at a lower frequency, a smaller value of L and C will resonate at a higher frequency.

Anyway, you want your PWM to be pulsing at the Fr. This will create the least resistance, most current, most HHO.

I'm hoping to compute frequency at resonance. It may be impossable with the low freq.s the pwm will use. And even if I can the first ring pulse should be at best 63% of the input pulse. Isn't that why we experiment. I'm building these devices because of price, availiblity and high current demand. It would be nice to have a vector impedance meter but the meter we have does use freq.
Russ

[alpha-dog]

using .40 showerpan liner to seperate two switch plates my capacitor measures 102pf, my inductor measures 14.9uh. This gives me a resonant freq of 50Mhz. Its not looking good for a resonant dry cell.
Russ

[fisher]

Can you build two inductors and series them, also build two caps and parallel them to get bigger values, and a lower frequency of resonance?

A narrower gap in your cap will increase the capacitance.
More turns on your inductor will increase it's inductance.

[alpha-dog]

Can you build two inductors and series them, also build two caps and parallel them to get bigger values, and a lower frequency of resonance?

A narrower gap in your cap will increase the capacitance.
More turns on your inductor will increase it's inductance.

I suppose I could build something that looks like the generator but only be a bank of capacitors and connect them in parallel. for a colpitts that would be two parallel cofigurations of capacitors. I have 45 turns on the inductor now, I could just re-wire it for 90 or 100 turns. That'll still put me in the Mhz range so I would have to use a harmonic frequency. I think I will give it a try though. I might just try a harmonic of 50Mhz first. Another thing I can do is find a material That will let me put the two switch plates as close as possible to increase the capacitance, it'll need to handle 15amps though.
Russ

[H2OPWR]

Alpha-Dog,
I am looking forward to seeing how this works for you. I have been playing with almost the same thing for a while now. I know that it should help production but I am having huge problems keeping the reverse spike from the coil from frying the PWM's. I even made a step down transformer that ran in the water with two electrodes. I stepped 13.7 volts down 6 to one and used the secondary coil's to power the electrodes. It made hydrogen like crazy. I was at way lower current draw than my PWM's are capable of. The first one lasted only about 10 seconds. I blamed that on the PWM just being bad. Not only did the second one only last half that long the cooling fan also burned out. I am doing something way wrong and do not have the electrical knowledge to figure it out. I assume it is the reverse spike as the primary coil unloads that the PWM can not handle. It does have diodes in place to protect from that but they are both dead anyway. New ones should be here any time but until I can get answers I am not burning them out also.

[alpha-dog]

Alpha-Dog,
I am looking forward to seeing how this works for you. I have been playing with almost the same thing for a while now. I know that it should help production but I am having huge problems keeping the reverse spike from the coil from frying the PWM's. I even made a step down transformer that ran in the water with two electrodes. I stepped 13.7 volts down 6 to one and used the secondary coil's to power the electrodes. It made hydrogen like crazy. I was at way lower current draw than my PWM's are capable of. The first one lasted only about 10 seconds. I blamed that on the PWM just being bad. Not only did the second one only last half that long the cooling fan also burned out. I am doing something way wrong and do not have the electrical knowledge to figure it out. I assume it is the reverse spike as the primary coil unloads that the PWM can not handle. It does have diodes in place to protect from that but they are both dead anyway. New ones should be here any time but until I can get answers I am not burning them out also.

I'm glad you mentioned the the oscillation going back into the pwm. I believe a good diode can solve that. Just connect it in series on the pwm's output. You say you have diodes, Hmm, that should still be the one way valve to protect the pwm's.
Russ

[H2OPWR]

I'm glad you mentioned the the oscillation going back into the pwm. I believe a good diode can solve that. Just connect it in series on the pwm's output. You say you have diodes, Hmm, that should still be the one way valve to protect the pwm's.
Russ

I am not positive that it was the ocillation that destroyed them. I have not investigated the electronics further. I also think the frequency of my PWM's may have been too high. They were running at 400hz. The fet's may have overheated due to the high inrush each time the PWM cycled. The faster you run the fet's the more they heat. I probably should change the resistor that controls timing and slow one down to around 15 to 20 hz and try again. I just haven't had time and do not want to burn another one out. I will change out the fet's to bigger ones on one of the bad PWM's, see it it still works, slow it down and try again.

[fisher]

H20, It could be inrush current, you may have to use a power FET or a DIAC and let the PWM turn on the device and then let the device feed current to the generator. Or it could be the negative spike. But a diode will block a positive spike, but not a negative spike, maybe using the FET or DIAC would solve either problem.

Hmmmm, gotta think this one over a bit. Reply above is just my first guess. Eager to hear results either way.