Re: Homebrew Variacs? (fwd)

---------- Forwarded message ----------
Date: Thu, 16 Jul 1998 19:40:14 EDT
From: Esondrmn-at-aol-dot-com
To: tesla-at-pupman-dot-com
Subject: Re: Homebrew Variacs? (fwd)

In a message dated 98-07-16 01:39:48 EDT, you write:

 As to current carrying capacity of #10 AWG (they call this ampacity in
 the Electrical Code), a useful number to work with is 700 circular
 mils/Amp, #10 is 10400 circular mils, so 14 Amps.  If the wire has high
 temp insulation (and you don't wind it on a low temp PVC form), you
 could probably go to 500 cmil/amp, for 20 Amps, or even more. It is
 mostly determined by how hot you want the wire to get.
Standard household romex is #12 solid wire and is rated at 20 amps.  I thought
#10 was rated for about 28 amps - but do not have any wire tables handy.  And,
as you say, you can allow it to get hot if designed correctly - we certainly
tend to push ratings and limits in our coil projects.

I think your idea will work fine.  I believe you want a range of 5 to 25 mh
for a ballast inductor.

Ed Sonderman