Transformers, Coils, Chokes

[Nick]

I like this one, my kind of mechanics...Simple...

A project of mine from a few years ago - I never made a video of my Tesla Coil winder - photo below - Its from when I had free access to a nice CAD-driven laser cutter. NEMA 23 Astrosyn 23L-C3xx series steppers with IMS IB462 drivers. Controlled by an Atmel ATmega328 programmed in avr-gcc all screwed onto an Ikea shelf with the ends cut off ('cos I have a load of them spare...)...

Haven't used it for a couple of years - should have written it up - its sort of in bits atm... I designed it for a specific project that needed several neatly wound 4 x 30 inch coils for a public exhibition...

Very simple concept - given the diameter of the wire plus enamel plus the thread of the bobbin drive plus the rpm of the main spindle, its very easy to write the code to move the bobbin correctly down the coil. You have to use toothed belts and pulleys, commonly called "timing belts" to keep everything in synch. Rapid have a pretty good selection ( http://www.rapidonline.com/electrical-po...lts-71294/ ) - drill out centre on the lathe and tap to M12 to fit the studding used as the main shaft.

The second photo shows the tensioner - experimented for a while before coming up with this - made out of a small bulldog clip with a hole drilled in the back of it and a grommet made out of a TO220 insulating washer inserted - the hole was designed to take an M3 bolt, so it works happily for AWG 20 and upwards. The clip was sprayed inside with 3M Spray Mount and lined with felt to help the wire run smoothly - smooth leather works well too... If I needed more tension, I put a second (bigger) bulldog clip round the first - I found that by savagely attacking the bulldog clip with heat and pliers, I could create a range of them with differing tensions to clip round the base installed one, which, of course, I couldn't remove without breaking the wire...

This works very well for autowinding large coils (1000+ turns on 4 inch formers) - stuff that is far too big for the Morris winder...

PS. Yes, I have got a bit of damp on that wall. Must fix the gutter on the shack. Grumble, grumble...