Testing Power Supplies! Re: Norsk Data Nord-10/S restoration

[Tony Duell]

> The AC setting on a voltmeter will let you know if you have too much ripp=
> le=20
> on a DC supply.

That depends very much on the voltmeter!. Most of the ones I have here 
simply use a rectifier on the AC ranges so that the meter responds to 
either the peak or the mean of the absolute value of the input signal, 
with a suitable scalling correciton so the actual reading is the RMS 
value assuming a sine wave input.

They will quite happily indicate (and mis-read the value of, of course) a 
DC input when set to AC,.

-tony