Re: Variac - Case to what?

To: tesla-at-pupman-dot-com
Subject: Re: Variac - Case to what?
From: Mike Hammer <mhammer-at-midwest-dot-net>
Date: Mon, 25 Nov 1996 13:10:47 -0600

At 10:25 PM 11/24/96 -0700, you wrote:
>>From tesla-at-america-dot-comSun Nov 24 22:06:32 1996
>Date: Sun, 24 Nov 96 08:18 EST
>From: Bob Schumann <tesla-at-america-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Variac - Case to what?
>
>Howdy all,
>
>I would like to get some feedback as to waht the case of
>variac should be attached to. These are the choices :
>
>1) RF ground (I seriously doubt this one)
>2) House current 'neutral'
>3) House current ground (The water pipes and such)

I would think that grounding to neutral would be appropriate.
Be sure to keep your 60 cycle and RF grounds separate.

>thanks all,
>Bob
>
>P.S. I just recently wound some new chokes using the
>Hosfelt powered iron core toroids. I first wrapped the
>toroid in elec tape, then wound a wire layer, then another
>thick layer of tape, then another wire layer, and finally
>another layer of tape. They measure 1.15mh. I have yet
>to try them. I hope they don't smoke.
>

I wound some chokes with these toroids also. I put on 3 layers of tape
and 110 turns of # 26 magnet wire. Inductance was a little over 2 mh.

With two layers of wire you should have had more inductance unless you used
large wire. A heavy wire guage isn't needed here as the current flow is low even
at rather high power levels. A high Q inductor is NOT what is needed here.
The more inductance you can get the better.

I havn't had any problem "smoking" my chokes at up to 1.8 KVA.

Mike Hammer

mhammer-at-midwest-dot-net