Kapanadze Cousin - DALLY FREE ENERGY

[itsu]

This is how I'm interpreting those schematics:

The "PWM Pulse Output Section" does seem to show the output side of the unit, the part on the right outlined with a red box. The transistors are the ones marked " Q6" to "Q9" on the left edge of the board. This schematic also shows the timing components Ct and Rt on the left side of the schematic.

The "Electric Fish" shows how a 494 can be used to drive an H-bridge of IRF3205 mosfets (with a driver stage in between) which then powers a stepup transformer to give a HV output for stunning fish.

The third diagram with the yellow square representing the 494 is very similar to the "electric fish" circuit but with different frequency and voltage, for use as a DC to AC inverter.

The final diagram looks like it's using the 494 as the oscillator in a DC-DC converter with a bipolar DC output.

If you've already built 494 oscillators for your projects I don't know why you'd want to try this unit. It doesn't appear to offer anything new, over the 494-based circuits you've been using. Of course, it's very inexpensive and just for that reason it might be something you could use, modify, experiment with.

Its for Nick, he is asking since some time for commercially available PWM boards to drive his Ruslan replication.
This one (with a tl494) comes very close to the one used by Ruslan and is as you say very inexpensive.

Itsu

[itsu]

You consider it usable then Itsu. 

Yes,  looks like it   

[itsu]

  Itsu:  My frequency reading at the 0.47uf cap is about 25Khz, not 32Khz as it was previously, nor 40Khz as you had mentioned.
So, maybe I should leave it as is, for now? Or perhaps add one more layer of 12 turns, then another if needed?

Nick, it reads 25Khz as that is what the mazilla is driving it with at the moment, but that is not the resonance frequency of the 2x 12 turn bifilar inductor coil with the 0.47uF cap.

Try to get it in resonance as mentioned before.

Regards Itsu

[Hoppy]

  Itsu:  My frequency reading at the 0.47uf cap is about 25Khz, not 32Khz as it was previously, nor 40Khz as you had mentioned.
So, maybe I should leave it as is, for now? Or perhaps add one more layer of 12 turns, then another if needed?

Nick,

With respect, you are going about the whole think arse about face. You need to start with the signal generator and work logically from grenade coil as previously suggested. When you have established the low frequency needed, the inductor can then be wound to suit your high voltage 0.47uF WIMA cap to hopefully resonate at that frequency.

[TinselKoala]

You'll need to use a higher-current output stage with that 494 board though; those little transistors on the board aren't going to be able to handle much power. The H-bridge of IRF3205s shown in one of those schematics might be a good choice of output stage.