RussellMc wrote:

> Brent Brown wrote:
>=20
> > RussellMc wrote:
> >
> > > Brent Brown wrote:
> >
> > No doubt the rest will make sense once I get the first part right.
> >
>=20
>=20
> "I know you know this" applies only to the parts I get right :-)

That makes it easier ;-)

> Rushing again/still.
> I think I did a misconclude :-) there somewhere.
> I know what I meant but I think I got it wrong.
> I'll have a look later and see if I can revise it to something more
> sensible.

Thanks Russell, always appreciate your posts and the effort you put into th=
em.

> A major point I was meaning to make was that he wanted the sense resistor
> in the flyback loop if he wanted to control the current in constantish
> current mode.
> If he uses a low side sense resistor and a high side flyback diode he los=
es
> current monitoring during flyback.
> There are other ways of doing this - but my diode position comment was
> wrong.

Sorry, I was ignoring the current feedback issue till the diode was fully s=
orted. But=20
can see it's totally important in what he's trying to acheive.
=20
> The problem with zener overheat is that he is getting Iload_turnoff x
> Vzener dissipation which is quite large.

Agreed.




--=20
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