[R-390] 150 V regulator

[Tim Shoppa]

Andy wrote:
> Based on National Semiconductors website and their
> statement that the LM317HV operates isolated and can
> handle several hundred volts as long as the
> input/output difference is not more than 40v, could
> this device not be used as a very nice 150v regulator
> replacing the OA2?

Any transient increase in load above the dropout current (even, say,
a module with some capacitance in it being plugged in) would cause
the regulator to go into foldback, resulting in more than 40V
across the terminals, resulting in all the magic smoke coming out.

With the regulator on the audio deck but all the loads scattered
about the other decks, this is pushing it.

If (BIG IF) you wanted to solid-state the 0A2, the right choice
truly is a solid-state shunt regulator.

There's no shortage of 0A2's, especially mil-spec 0A2's. It's a
very nice regulator tube.

Tim.