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Re: Capacitor Help

Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hi Malcolm
Very good! It's always fun to watch how others perform their first secondary winding. You did a much better job than my first coil of which I hand spun.
These days, I set up a winding jig that is driven by a dc motor and use a belt which couples the drive pulley to the driven pulley. I set run the motor from a variable dc power supply and set the speed as needed for whatever process I'm doing (winding, applying varnish, letting varnish dry). I personally like to know exact turns, so I attach a 24VDC PNP inductive proximity sensor near one end and attach a small metal flag to the end of the form. As the form turns, the flag rotates in front of the sensor. The sensor output drives a counter (simple and sweet). Some build fancy winding machines, but I never had the need to. Winding machines are ok for a range of coil geometry's, but I prefer to simply set up a motor drive and hand guide the wire myself.
Are you planning on coating the secondary? If so, keep the secondary where it is. Keeping the coil turning while applying varnish will help to prevent ugly runs in the varnish. The reason I use the variable power supply to drive the motor is that I can set it to a very slow speed for applying coats and to a comfortable speed that will keep it turning all day until it's dry or ready for more coats. 

Take care,
Bart

Tesla list wrote:


Original poster: "MalcolmTesla" <tesla@xxxxxxxxxxxxx>

I wound my secondary tonight.  As I got started I realized I had no idea how
to do it LOL.  OK I realized I needed ends on the PVC for mounting so I cut
a piece of 1x2 trim board to fit and secured it with two little set scews if
you will.  I then put a bolt through the center for mounting.  See here

http://www.v8-ranger.com/temp/tesla/23.jpg

Now I needed some way to spin the PVC.  So I cut two pieces of metal stock,
drilled a hole in each end and mounted it to a 2x4 piece of wood.  So now
the PVC was suspended and could spin freely.  See here

http://www.v8-ranger.com/temp/tesla/24.jpg
http://www.v8-ranger.com/temp/tesla/25.jpg

At this point I was thinking about how to spin the unit.  Of course my drill
came to mind.  Only then I realized the 7/16" bolt I used in the center
wasn't going to fit my 3/8" drill.  DOH!.  So I welded a smaller bolt to a
7/16" nut.  See here

http://www.v8-ranger.com/temp/tesla/22.jpg (this bolt/nut is installed in
the pic above)

I knew I'd need both hands to feed the wire and didn't have anyone around to
work the drill so I zip tied the trigger down real slow.  This way it would
be consistant and the trigger wouldn't accidently be pulled hard.  It was
actually slow enough that just by applying pressure to the pvc with my hands
I could stop it.  As an added safety I put a power strip right there by my
foot so I could step on the off switch if I needed too.  Oh and I put the
spool of 27 AWG onto some round bar connected to a 4x4" block of wood so it
could spin freely and feed nicely.
I drilled three tiny holes on each side and fed the transformer wire
through.  I then powered up the drill and started the windings.  It actually
took less than an hour but felt like forever.  You can see two pics of my
setup here

http://www.v8-ranger.com/temp/tesla/26.jpg
http://www.v8-ranger.com/temp/tesla/27.jpg

I'm sure the pros are laughing :) that's OK though.  I've never done this
before and wasn't sure how else to do it.  I'm curious, how do the rest of
you wind your secondarys?  Oh and that's 20" of windings on 4" diameter PVC
with 27 AWG.

Thanks guys
Malcolm - KC