[sdiy] Really Small Linear Power Supplies ?

[Colin Hinz]

On Tue, 28 Oct 2008, George Hearn wrote:

> One very sensible option for a small efficient power supply is to use a
> 'wall wart' giving say 12V unregulated, probably the cheapest kind.  Then
> use a monolithic DC/DC converter module to yield +/-15V out from 12V in.  If
> the ripple is too much simply follow the DC-DC converter module outputs with
> linear regulators.  Because the voltage drop across the linear regulators
> can be made to be small, the linear regulators won't dissipate much power
> and hence won't need big heat-sinks if any heat-sink at all.  George

I've had really good results with the V-infinity VAWQ6 series of DC-DC
converters -- they have a really huge input range (9 to 36V) and offer
isolated +/- 15V outputs. And as power supplies go, they're tiny, about
the size of a pregnant EPROM (case dimensions 0.8" x 1.25" x 0.4") and
they don't break the bank, either.

I've used one to power a rackful of PAiA 9700 gear, and the DC source was
a bicycle powered generator -- talk about unregulated!! The wide voltage
input range was a real "win" in this application.

- Colin