Re: Coil Winder, solid-state high power control for pigs (fwd)

---------- Forwarded message ----------
Date: Tue, 12 Oct 1999 23:43:24 EDT
From: Bobbaust-at-aol-dot-com
To: tesla-at-pupman-dot-com
Subject: Re: Coil Winder, solid-state high power control for pigs

To: Gary Lau & all
> Re: unwinding from the end of the spool
> Plus, it avoids the problem of the
>  reel's inertia causing it to unwind after you stop the coilform.  

You can avoid the "spool-off" if you use the roll-off method just by 
stretching a couple of fat rubber bands across the top of the spool.

Also - hint for those winding primaries from 12 to 16 awg solid copper 
(romex).  If you take the bare wire length (20 feet or so) and clamp one end 
in a vise, put the opposite end in your cordless drill, stretch out the wire 
in a straight line and run the drill for a minute or so.  This puts a twist 
in the wire, straightening it and at the same time making it a little more 
"springy".  You won't believe how straight it gets.  You can then hook one 
end around the handle of a paint can, and twist the can to create 
near-perfect coils.

I've been doing the "twist" thing with wire for so long I don't remember 
where I heard about it.

Solid-state power control - Anybody tried using a circuit similar to an 
induction stove?  They heat pots (magnetic only, obviously) by inducing 
current in the pot from a 20-30 turn flat coil in the surface of the cooktop. 
 The coil is driven via triacs or SCRs from the 240 vac line. I know they use 
high frequency but I don't know how high or how they get it using SCRs on a 
60 hz power source.  

The voltage and current range is the same as you gung-ho boys use on pigs, 
though, and I wondered if anybody tried this.  I happen to have the remains 
of an inductive cooktop in my basement, waiting for me to fix it for the last 
2 years.  Not likely to happen in my lifetime.

Hey, would one of those coils make a good TC primary?