Pulse charging capacitors

[turniton]

would fast dc pulses (inductive collapse from a coil) charge a capacitor faster or slower then a capacitor charged normally. the reasoning being; it appears to have less resistance when charged in pulses.

the electrostatic charge in pulses would give the dielectric material in a capacitor more time to react and thus create less resistance to in-cumming surges, basically no charge pile ups -less capacitive reactance/reluctances

your opinions please!
Thanks!

[TinselKoala]

If you look at my YT channel you can find a video of me pulse-charging a cap bank with sparks and corona discharges from a small Van De Graaff machine. And you can see what happens when I discharge the stored energy.

When pulse-charging a cap from a squarewave pulse or an inductive collapse, the cap sees spikes of very high voltage that you don't see on meters or "less-expensive" oscilloscopes. There's a LOT of energy in these spikes (E=(CVV)/2) and the caps love it--if they have the right dielectric. You can easily explode cheap electrolytics, even if you think you are within their voltage range, by pulse charging with spiky voltages.
But the various titanate compounds like in RF doorknobs can take it.

I think actually the pulse charging gives the dielectric less time to react, not more.

[jadaro2600]

Might pulse charging a capacitor lead to dielectric breakdown?  ..in theory it would be like spiking the materials; seeing as how a pulse might cause the same effects as say ...rather than driving a load across a bridge, dropping a load onto the bridge would have a more negative effect even though it's the same weight.

Perhaps using a capacitor intended for AC, but in a DC pulse situation - you could avoid the likelihood of the capacitor failing.

Capacitors seem like a effective way to send a regulated amount of charge through something. ...maybe using one cap to charge another and a timer circuit.   That makes little sense though ...you'de have to slowly charge a cap anyway.

[turniton]

Hi, TinselKoala

Where is your yt channel located? Link please, did not know what that was… thanks.

This is basically where I’m heading… sharp high voltage square wave pulses from inductive collapse. Lots of energy, and the cap converts it to current for use, the caps DO like it a lot, hence my question. I have a bunch of hv caps (ceramics for now) at low value that are paralleled to reduce the esr on discharge. Still playing with different dielectrics.

Thanks!

[jadaro2600]

I think this is his channel: http://www.youtube.com/profile?user=TinselKoala&view=videos

Very interesting stuff there too!