Kapanadze Cousin - DALLY FREE ENERGY

[Jeg]

When the frequency is varying, a fixed-delay does not maintain a constant phase offset.
A fixed-delay board, like yours, is useful only if the frequency is constant.

P.S.
Manually adjustable delay still qualifies as a fixed-delay.

Verpies, it takes as input a constant frequency which is what comes out of tl494. I think for the job is enough.

[verpies]

Verpies, it takes as input a constant frequency which is what comes out of TL494.

If the frequency is constant then I have no objections to the fixed-delay technique.

[Jeg]

Verpies, do you find it too much if i use an optical isolator between 74hc132 and driver? Perhaps a tlp250 instead of driver?

[verpies]

Verpies, do you find it too much if i use an optical isolator between 74hc132 and driver? Perhaps a tlp250 instead of driver?

If the digital optocoupler is fast enough then go for it.

[Jeg]

Well, for the push pull i think it is a good choice for substituting ir2110 with two tlp250.
Some comparison:

TLP250: http://web.itu.edu.tr/yildiri1/mylibrary/data/tlp250.pdf
Io=1,5A
Propagation delay time=0,15uS typical (0,5us max)
output rise/fall time=6us

IR2110: http://www.irf.com/product-info/datasheets/data/ir2110.pdf
Io=2A
Turn-on propagation delay=0.12us typical (0,15us max)
output rise/fall time= around 25ns

There is a big difference between rising and falling times of the output pulse, but up to 25KHz that we need it for is fine. And of course what ever it happens at mosfet's side, our driving circuitry is protected up to 2500V
rms (min.)

The only issue is the need for creation of an isolated dc pwr supply (B2) for driving mosfet's gates. Personally i prefer an isolated dc voltage for tl494 driving.
The link below provides details on how to implement this.

http://tahmidmc.blogspot.gr/2013/05/using-tlp250-for-isolated-mosfet-gate.html