Russell,
One thing not mentioned in the circuit explanation is the contribution
of the zener diode noise to the switching frequency.I included a
version in a design (unfortunately not to see the light of day) and a
big advantage was that the zener noise "randomised" the switching
frequency - reducing noise (at least as far as conducted and radiated
noise measurements werre concerned).
I have another project coming up & it's a contender for that also.

The inductor-derived hysterisis effect is certainly real - it was also
used in my relay driver circuit at about the same time as your "GSR"
release that became the basis for the "Black regulator".

RP

On 08/11/06, Russell McMahon <apptech@paradise.net.nz> wrote:
> God's/my "GSR"* simple switching regulator circuit also features here.
>
>    http://sound.westhost.com//appnotes/an006.htm
>
> And in a constant current version here
>
>        http://sound.westhost.com//appnotes/an003.htm
>
> My friend Ken Mardle built a LED driving version of the GSR which was
> essentially the same as this circuit.
>
> I've never before seen this topology described independently so it's
> interesting to see it here. An obvious enough design in retrospect
> apart from the
> interesting means of providing hysteresis for switching (which Olin
> denied exists when I originally described the circuit, and may perhaps
> still do so).
> In trying to design this one might never get past the fact that "it
> can't work because it has no hysteresis" when, in fact, it does and it
> has.
>
> Over 10,000 of these have been built so far as a 13v to 200V input /
> 12V output power supply for an exercise machine.
>
> Original design was imparted on 24 Feb 2001 at about 10:43am :-)
>
>
>        Russell McMahon
>
>
> * GSR = God's Switching Regulator, as it was wholly his idea :-)
>
> Not the ultimate SR in many applications but met my written spec to
> the letter.
>
>
>
>
>
>
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