Shorting coil gives back more power

[i_ron]

Guys, when I chop the hall signal with the 555 circuit to get more shortings per sine peak the output decreases. I mean, from what I see one big bang per peak gives more output than many shorts per peak, this I see from what I collect in the output cap. Of course I've tried sweeping the frequency and duty cycle of the 555, even to match the ringing frequency of the coil, still no luck.
Anyone else getting the same?

Mario

Mario,

What I noticed, with a small load resistor across the collection cap, was  50 volts DC single pulse, 35 volts for three pulses and then back up to 52 volts when five pulsed.

However I have no resonance ringing so need to try a small cap across the coil

Ron

[gyulasun]

Hi Groundloop,

Here is another one, besides what i_ron already showed you:
http://www.overunity.com/index.php?topic=10398.msg276699#msg276699

Gyula

Konehead,

>>Also this summer Gyula gave me excellent bidirectional mosfet circuit, where mosfets >>connect at the source and gate so they switch AC this works very great.

Can you post this circuit here?

GL.

[popolibero]

Ron, thanks. You do have resonant ringing though, if you zoom in on the spike you'll see the natural ringing of the coil dictated by its inductance and self-capacitance.

regards,
Mario

[bolt]

Hi Doug, and All,

The simplest "peak finder" that I could find was this one...

http://www.8051projects.info/blogs.asp?view=plink&id=198

Just use an extra coil as you were doing and with one transistor... voila... zero crossing. With the coil adjustable one just moves the coil until it sits squarely on top of the sine peak.

Here is what the circuit looks like, the diode D2 separates the voltage regulator from the transistor sense part of the circuit...

Q1 puts out a positive logic signal so a 555 won't work, I used a CD4047 for the one shot. The one shot then triggers the CD4093. R5 is a pot to set the pulse width.

But minimal parts!

Second pic is my RV setup

Third pic is what the signal looks like, but not shorting the coil in this shot

Ron

Quite a nice circuit i like the way it charges off the second coil. Only thing i am not keen is the very fact a second coil is required. With direct zero point sensing this coil is redundant as can sense just the same coil that will be shorted and also my 555 setup will work with solid state devices. You may have seen yet another version in EVgray where Kone has a circuit that uses another hall trigger to get pulses off the magnets without using a coil then you can do all the timings from that instead.

BTW in case other builders are reading make sure you use independent power supplies batteries etc for these trigger circuits and coil shorting fets. The voltage levels are all over the place in respect to each other so don't try and common everything together they need to stay floating.

[bolt]

Hi Bolt can you please post a diagram of this?
Thanks

I am really bad with drawings i don't have any fancy 3D drawing packages. You draw it as you think i describe it and i tell you if its correct or not and if you need to change anything.