[sdiy] PSU ripple/hum testing

[harrybissell]

Welcome back :^P

If you are going to build an amplifier, why not feed it into your scope
instead...
then you can watch the ripple.

A lot of scopes do not go much lower than 10mV anyway...

H^) harry

Lincoln Fong wrote:

> Good to be back after a long period of silence.
>
> Does anyone have a good way of testing for PSU ripple? I have some PSUs
> (11 of them!) that can deliver 10 amps at +/- 15V and 30 amps at 5V. The
> ripple under load is meant to be less than about 200 uV but my (not very
> good) scope only goes down to 10mV per division. I was thinking I could
> maybe build a small amplifier with DC input filter and 'listen' to the
> ripple, maybe with a few calibrated LEDs as I would like to be able to
> 'poke around' inside my huge old mixing board and PSU rack. The initial
> spike when attaching the probe could kill my amp/speaker/ears though.
> Any ideas or should I get a better scope?
>
> Thanks,
>
> Lincoln
>
> _________________________
> Lincoln Fong
> http://www.fongelectronic.com