> Anyone seen this problem before?

Not written as such but a couple of web PSU schematics specifically
included and mentioned a resistor as a minimum load. ISTR that in
both cases the regulators (7812) were used as a reference for pass
transistor bases, the implication being that if no collector current was
being drawn there'd be no or little base current

Can't say I've noticed it myself, eg running a sleeping PIC off a 7805,
but I generally don't use a very large (< 100uF) o/p cap and have,
when I remember, a discharge diode from o/p to i/p. Perhaps that's
enough to quench oscillating

Joe
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