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Registered Member #3637
Joined: Fri Jan 21 2011, 11:07PM
Location: Buffalo, NY
Posts: 1068
Uh, have alot of time and patience to do it i guess. You could probably build a flyback winder using a motor and some hot glue. I've always sort of wanted to build one but still haven't really ever gotten around to it.
Registered Member #3605
Joined: Wed Jan 12 2011, 04:46AM
Location:
Posts: 12
I wound two the other day by hand and put them on a normal flyback core. I used an old dried out marker for the bob and rustoleum clear enamel (over each finished layer) then a layer of electric tape. Super glue comes in handy also. I wound each later about 1 1/2 inch wide with about 16th of an inch clearance each side. Used hot glue and HV wire to seal the deal at the end. Due to my cores being normal FB cores and having little room, I was forced to stop early but they put out over 3kvs with retarded current (plasma cutter anyone?). Took about 4 hours each but was worth it!
Registered Member #3610
Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506
I've wound a few, both on cores from old flyback transformers and gapped EE cores from flyback topology switching power supplies. You will probably want to vacuum impregnate the windings with epoxy or submerge the finished transformer in oil. The nice thing about a flyback transformer is you get a lot higher voltage than the turns ratio would imply.
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
I bought these, B67345, N27 cores rated for 1.5kW at 25kHz and 2.3kW at 100kHz in flyback mode and 2.5kW at 25kHz and 5kW at 100kHz in push-pull ( or H-bridge) mode. (per pair)
I can't get the link to the application notes/data sheet to load here properly, but search 'Siemens Ferrites And Accessories Catalogue' and you should find it.
I'm having to make my own coil formers (bobbins) as I'm having problems locating a supplier who has them in stock. My cores are unused, but 'third hand'. (The person I got them from got them from someone at a teslathon)
I'm planning to make a mandrel to fit in a battery drill to wind the secondary.
Registered Member #618
Joined: Sat Mar 31 2007, 04:15AM
Location: Us-Great Lakes
Posts: 628
Indeed for a flyback core from a crt I calculated ~400-600 turns using 24awg wire and ~1000 turns for 28awg, at least thats what I calculated for the core that I have and want to rewind.
Also just for an idea, why not treat each like a TC secondary and apply multiple coats of polyurethane, then apply the next layer and repeating.
Registered Member #3282
Joined: Wed Oct 06 2010, 05:01PM
Location:
Posts: 224
why can't we wind the secondary like this shown in the pic? having islands of wire each winding island has 25-50 windings. put a tube around the secondary pour hot parrafin in voila 800 windings.
Registered Member #3605
Joined: Wed Jan 12 2011, 04:46AM
Location:
Posts: 12
Microwatt wrote ...
why can't we wind the secondary like this shown in the pic? having islands of wire each winding island has 25-50 windings. put a tube around the secondary pour hot parrafin in voila 800 windings.
You can, it just gets progressively harder to wind each layer due to the "pits" you create from your flexible insulation. Even if you wind straight across, over time the layer forms a dome and winding becomes a real pain.
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winding my own
