Muller Dynamo

[konehead]

hi Minde

the ferro-RESONANCE might be that high speed, but HARMONICS and SUB HARMONICS are much slower speed.

[minde4000]

@konehead

Thanks. I just have never been able to witness anything more or less than 3rd subharmonic down or 3 harmonics up so I figured it might have not been the case..

Minde

[konehead]

hi all

here is halleffect/mosfet and driver coil-shorting circuit that I am using right now. no output-to-load cirucit is shown jsut how to fill up the DC cap from switch-shorting the coils at sinewave peak-periods...the 9v battery and/or the "supply coil" powers the mosfet gates and driver....this circuit will swtich AC since it has bidirectionally connected mosfets.

[DimaWari]

Thanks Kone this circuit is what I need...

[mariuscivic]

hi Mariuscivic

I am not sure what you mean - are you shorting the coil "with a reed" before the bridge rectifirer?

This would mean that you are "swtich-shorting" the generator coil??? and not continuous short???

If so, I bet also the timing of your reed swiych when things speed up  happens at peaks of sinewave too - if not, try that, and I will bet you will get best results...

IF you want to do this solid state, use high-amperage rated mosfets that have very low resistance to them...maybe put 4 or 5 in paralell to lower resistance even if you want to spend a few more bucks.
I have best results "swtich-shorting" with bidirectionally hooked up mosfets (gates and source of two mosfets connect, and swtichign happens betweeen the two drains)
Bidirectional mosfets are for AC switching - which I will guess is what you have going, since you are switching "before" the bridge rectifier...(if this is what you are doing?)
try some IRFP460 NPN mosfets (20A and 500V rated) - put a couple of these together bidirectional and it should be good to short coils....things like solid state relays, some transistors, SCRs wont work AT ALL shorting coils since their resistance is so high - reeds work great for shorting coils but they arent very reliable and things arent so perfect with them as you know.
Use a 4421 driver with the P460 mosfets is good if you want to try that..let me know if you want a complete circuit to short coils at peaks with hall effects and mosfets....

Hi Konehead

Yes, i'm shorting the gen coil before the bridge rectifier but as you seen my setup is quite small and its very hard to find the sweat spot. If you have some circuit that will short the coil i'll be glad to use it( but keep it simple please; i'm no good with components)
Today, whille playing with the rotor , i connected the gen coils(before the bridge rectifier) for the best output underload.I ended up with the duble voltaje and some more rpm. Then i realized that with those connections , the rotor speeds up when i short the  output. Does anyone had this effect before? Anyway i still can't get the speeding with a load;only in deadshort.