On Fri, Nov 16, 2018 at 9:05 PM Manu Abraham <abraham.manu@gmail.com> wrote=
:
>
> Bob,
>
> Some additional thoughts on the same lines ..
>
> You can wrap a few turns of copper wire on top of the transformer that
> already exists. (2 or 3 turns, enough to drive the transistor.) The
> coupling is not a big issue, but try to make the winding as tight as
> possible to get maximum possible coupling. Since there is hardly very
> little current drawn, it's not an issue at all. This winding you can
> be consider as an auxiliary winding.
>
> If you have a LCR meter you can check and compare the inductance of
> the primary to the auxiliary, so that the primary and the auxiliary to
> be a 1:1 ratio. It's not absolutely necessary that you need a 1:1
> ratio, but you will get a reference for your calculations for the
> feedback. The winding you can use as a reference to control the
> primary side PWM, to avoid looking for high voltage components.

Scratch the PWM in there, replace it with Oscillations. There's no PWM
in a Joule thief. One hemisphere not keeping up fast with the other.
;-)

Cheers,
Manu
--=20
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