my test is :
1.try to charge capacitor(spec=400V+),many values and see how many amps does consume.
2.use my 230VAC to DC half bridge rectify(1 diode =1n1198).

problem is :
-diode is very hot(burn my finger!!!) when charge big capacitor like 560uF 450V ,polar capacitor.because inrush current then i thought back to VIC .if VIC didn't have coil(resonant charging choke) primary will short,tranformer will burn.

http://en.wikipedia.org/wiki/Inrush_current -->find to protect it but wiki don't have inductor to solve that problem but inductor can solve that.inductor is better than resistor.

http://en.wikipedia.org/wiki/Pre-charge -->in-rush currents into capacitors

i found this,Hope this helps for understanding VIC.

thanks
geenee

geenee, when the capacitor is discharged and you connect the circuit, the initial amperage is only limited by the resistance in the circuit, which in your case is very close to zero.  Hence, something has to give and in your case it is the diode.

Transformers by their very nature are not current limiting devices.  They will attempt to transfer from the primary to the secondary as many amps as they possibly can.  This was a huge problem with respect to my plasma spark circuit, until I introduced a current limiting triac on the primary side.  The only other trick is to use small enough capacitors so the initial in-rush current is so brief the transformer doesn't have a chance to heat up.

use triac or variac to slowly step up voltage?
limit capacitance that's too hard for wfc.

thanks Dog-One
geenee