DC filter capacitor (was Re: tesla-d Digest V99 #16)

tesla-at-pupman-dot-com on 09.01.99 03:01:30

To:   tesla-at-pupman-dot-com
cc:    (bcc: Marco Denicolai/MARTIS)
Subject:  Re: tesla-d Digest V99 #16

Original Poster: Greg Leyh <lod-at-pacbell-dot-net>

tesla-d-request-at-pupman-dot-com wrote:

>If you really feel that a big 15uF filter capacitor is necessary, then a
>filter choke (about 2.5 henry for 15uF) is required between the 3-phase
>rectifiers and the filter capacitor.

Instead to limit the current on the secondary side, I was thinking to do
the same but
on the primary side, with 3 series inductors 10 - 20 mH, 400 V (one on each
Cheaper solution.

>In addition, a charging diode stack
>(with an RMS current rating 3X higher than the main stacks) must now be
>placed in series with the charging reactor, in order to trap the charge
>on the primary cap.

I tought to use that just as you suggest.

>Avoid the big DC filter cap if at all possible.
>If you really need 1% stability, active regulation
>is far simpler, and more accurate.

Without the filter cap the voltage will change from V to 0.866 V (ripple),
that is a stability of
+/- 6.7%. I would like at least 1% of stability, that's why the capacitor.

What do you mean with active regulation? SCRs ? But you cannot remove
ripple with SCRs without
using a capacitor, can you?