>
> sheesh - can I have your contract for heat sinks? I would not want to do this. I
> always understood you used a shunt regulator zener diode style with a current
> limiting source, at minimum a resistor which can supply the full current that is
> needed in the load plus a tiny bit for the regulator. Then if part of the load
> is switched off the shunt regulator draws more current. I have never heard of
> people having current limiting within the shunt regulator before.
>
> If I was doing the sort of thing you describe above I would be looking at having
> some form of OVP to drop the input to the supply and shut it down.
>
> the only other situation I could see where one might do it is if a minimum
> current draw is required to keep the voltage from going too high, like what
> might happen with a wall wart supply, where the transformer is being pushed to
> its limits and has no low current regulation. But I would not class such a
> device as a real shunt regulator because I would not be designing it to have
> high stability - again it would be a OVP current sink, but not to the full
> current capability of the supply, just enough to maintain the peak voltage
> within limits.

Hi Alan, no, with high current supplies the main
regulation concern is the transformer, and to keep
efficiency high it is often better to use a linear
shunt reg than a linear series reg. Especially for
very high currents with a definite high-low range,
that is not too far apart. Like a load that always
draws between 15 and 20 amps, but needs a regulated
voltage. :o)
-Roman

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