Philips PM2505 electronic meter

[Mike Watterson]

A couple of sensitive leds could serve the same purpose today perhaps.

Any LED is a minimum of 1.2V, so two leds and an op-amp. AC would light both. AC with a DC offset could light one brighter? Very low frequency AC would flicker the LEDs.

If I was re-using my old meter I'd maybe use really fast op-amps to have a few MHz and it would really measure peak, so DC scale would be peak and another scale would be AC RMS assuming a clean sinewave.

For addition amusement add 300V approx via flash circuit from a single use camera via maybe several M Ohm to measure uA leakage or PIV or VCEBo etc.