100khz tl494 hbridge driving capacitor votlage multiplier full wave

[panhandleman]

Hi,
I am new to this forum.
I am not an engineer but am wanting to build a smps utilizing a full wave capacitor multiplier instead of a traditional inductor or transformer. If anyone has ever tried this please let me know and any help or hints is welcome. I need the most help in the selection of smps chip, mofets, and related control circuitry. 24vdc, 20amp input.

 

[OperaHouse]

What do you have against transformers? Capacitor multipliers just don't work out except for small currents. Capacitors that can handle even a couple amps are really expensive. That said, I think you should try and build one. It will be an education.

 

[triphase]

The efficency will depend on the number of stages, as the number of stages increase the time constant to charge the mulitiplier and losses will increase exponentially. In a multiplier with a large number of stages you can encounter a condition known as a "starving multiplier" where the losses in charging the multiplier exceed the input power unless you start using huge capacitors. As stated unless you are trying to achieve high voltages at very low levels of current, there is very little advantage to this type of design unless the number of stages is very low (ie you want a doubler to have a high voltage so you dont have as much current through your magnetics).