Re: H bridge RSG

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Ray,

Primary caps in Tesla coils will always see AC during the firing cycle.  It
is possible to charge it up with DC initially but once the gap fires there
will always be AC going across the cap.

There are DC only caps around but none of them are suitable for Tesla coil
use.  H-bridges need DC driving them so maybe the filter or buss caps
behind the bridge were the concern.  However, they would see DC all the
time in any case aside from the current ripple they are meant to control
anyway.

Cheers,

	Terry
 

At 10:33 PM 5/18/2001 -0700, you wrote:
>I'm moving full speed on my MOT powered DC coil and was searching the pupman
>archives (that's what they're for, right? ;-) ) for information. I found
>postings about an H bridge RSG. There were some comments about how that
>approach charged the cap with alternate polarities and that this might be
>hard on the cap. I didn't see any resolution on that.
>
>Question (rhetorical?):
>Since the tank cap forms a resonate circuit with the primary and resonate
>circuits oscillate back and forth charging the cap first one way then the
>other, doesn't that mean all caps used in the primary tank circuits must be
>happy with AC charging? Also this seems to indicate that the alternating
>charge cycles of an H bridge RSG are not a problem, true?
>
>Ray
>