Re: HV DC supply design

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

Original poster: "Richard Williams by way of Terry Fritz <twftesla-at-qwest-dot-net>" <richardwwilliams-at-earthlink-dot-net>

Dwight,

Thanks for your replies!

quote:
"I would not feel safe until I had verified the voltages across all the
capacitors as substantially equal, however."

Will do.

quote:
"There are some excellent HV/RF isolation references and examples in the
archives if this supply is to power a TC."

Yes, it is for a TC and I've been following the isolation issue closely.
Steve Young has done a lot of work in this area as well as in triggered
gaps. Some of the ideas for isolation I'll definately try as RF wouldn't be
good for the electrolytics. One idea was using low ESR caps, about 1/10
value, in parallel with the main filter caps but I haven't yet found them at
a reasonable price.Low ESR caps at 56uf -at- 400v can be very costly and so is
any string to acheive 0.56uF -at- 40Kv with low ESR.

Experiments with isolation and triggered gaps will be carried out at a lower
power and in a safely prepared area using only an NST or two. If failure
occurs I'd like to keep it to a minimum. I've seen many electrolytic
failures in other fields of electronics and some can be quite, ummm,
impressive. :)

I believe it's the electrolytics that may be the weakest link. Large HV oil
caps MAY help here for filtering and resistance to the effects of RF.

Rick W.
Salt Lake City


----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, January 30, 2002 8:25 AM
Subject: Re: HV DC supply design


> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Dwight.Crider-at-regulusgroup-dot-com>
>
>
> Rick,
> Your checks were valid. I would not feel safe until I had verified the
> voltages across all the capacitors as substantially equal, however. Your
> ratings were conservative-good.  If you know the expected load and can
> adjust your saltwater load to match, you might want to check the
> temperature rise of the diodes, and transformer(s). If you were also
> conservative in that area you should have no problems with conventional
> loads. Tesla coils are another matter and HV/RF isolation is a complete
and
> separate issue. There are some excellent HV/RF isolation references and
> examples in the archives if this supply is to power a TC.
>
> Dwight Crider
>
>
>
>