[sdiy] 7915 regulators

[Ingo Debus]

media.nai at rcn.com wrote:
>>Analog Devices put out an article on this. They say to
>>rig a transistor as an emitter follower to drive the
>>power supply pins of opamps.
>>
>>Verbal schematic: collector to +V, emitter to opamp PS
>>pin, base has 10K to +V and 0.1uF to gnd. NPN for
>>positive pin, PNP for negative. This is a solution to
>>a PSRR problem in low noise circuits, but it applies
>>here, too.
> 
> 
> So how does that work??

If the cap is from base to emitter instead from base to ground, this 
is a simple gyrator. It emulates a big inductor (I know this from 1975 
Elektor, BTW).

Ingo