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Re: Transformer basics (winding)

>>>>
>Variable speed
>A turn counter
>Reversible power feed
<<<<

You can get variable speed with your variac, a turn counter at the electronic
surplus company (you'll also need some sort of cam on the shaft and a switch
mounted so that the cam clicks it once per rev.
The power feed is the cross wise feed to ensure that the wires lay flat.
Since they were 31 gauge, they wouldn't natrually lay flat like a coil
secondary's wire would.  I had to make sure that for one revolution, the
cross feed advanced the thickness of the wire.  I calculated the amount
the feed would have to advance based on a 28 thread/inch lead screw.  Then
I made some wooden pulleys that were the correct diameter.  This was not 
exact, so I used masking tape on the small pulley until I got the feed
correct.  I made the reversing mechanism with some salvaged gears.

If you saw the thing you wouldn't believe it.  I have a friend that is something
of a machinist, and he was too shy to even borrow it.  I'm sure he was too
embarassed to have such a kludgy thing in his shop.  

>>
What? Stop?  why did you reverse it? Are you talking about the direction of
rotation or the left-to-right winding direction?
<<
You have to stop the winding after each layer to apply the glue and mylar 
insulating strip.  Then you reverse the cross feed and wind on the wire.

If I reversed the direction that the wire takes around the core, I would
have made a non-magnetic heating coil :-)

Chip

As an aside to another message, when putting H2O under vacuum, it boils, it
doesn't outgas air.  That's all I'm going to say -- don't want an non-tesla
thread ;-)