Use of transformer with 3 coils each having 3 turns

[petert]

Hello,

I disassembled a CCFL light bulb/energy saving lamp. It has what looks like a toroidal transformer, with 3 coils each having 3 turns only.

I assumed the point would be voltage conversion, but since each of the coils have the same number of turns (even if some are slighty more dense than others), I would assume they don't have much of an effect.

What use would such a component have?

[T3sl4co1l]

Trace two of the windings back to the base-emitter circuit of the two transistors.  I think you will find it's a rather critical part of operation.

Tim

[Zero999]

The transformer actually drives the transistors.

There are some specialised CFL driver ICs, but most lamps use the same basic circuit. See the links below.
http://educypedia.karadimov.info/library/AN00048.pdf#page=11&zoom=auto,-90,632
http://diycarmaint.blogspot.com/2017/11/ccfl-or-cfl-lamp-repair-energy-saver.html

[james_s]

The circuit is called a Royer oscillator. They have some disadvantages but it's hard to beat the simplicity. I actually hacked one together out of parts I literally found on the floor once and it worked on the first try, transferring enough power to light a 12V incandescent bulb.