The Spyder

[New Frontier]

Hello All

Has anyone ever built "The Spyder" transformer ?? How hard is it to be built ?? And, can anyone tell the maximum number of secondary coils can be wound ?

[R.G.]

Has anyone ever built "The Spyder" transformer ??

I have.

How hard is it to be built ??

It took me about an hour total. It's not too hard.

And, can anyone tell the maximum number of secondary coils can be wound ?

As a practical matter, only about eight. You have a fixed amount of space for wire to go on the bobbin, and so if you want four windings in the space that used to do one, you have to use wire 1/4 as big. Thinner wire is available but you reach a point of diminishing returns because the wire resistance goes up a lot as the wire gets small.

I recommend that people with no experience with transformers to buy several HiQ 12Vac/0.06A transformers. Mouser sells these for $2.76 each, and $2.29 each if you buy ten. $22.90 for ten of them. That's as compared to $14.00 for a flat pack transformer that you then have to rewind. The several transformers approach is bigger, but easier and just a little more expensive.

[New Frontier]

Tks R. G.
I thought it would be easier to buy 8 little trafos, but the Spyder sounded very interesting !! It saves a lot of room and

Well, my brother is studying Electrical Transformers and at this time he is winding some transformers, so, I think he can do it..
How did you isolated the coils ? Did you put some kind of tape ??

[niftydog]

Electrician tape or PVC tape works fine.

[R.G.]

OK. Be really, really careful to NOT disturb the primary sides of those bobbins.

I used #38 wire as I remember, and did not isolate the secondary windings from each other at all. The voltages are low, and wire insulation is enough. I put a layer of tape over the whole outside of the secondary part for insulation.