UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Quick-and-dirty testgear: mains voltage monitor.

julie_m · 27th Aug 2018, 5:15 am

I don't think the dimmer switch would actually be letting any more energy through than if it were passing the full sine wave; the energy in the harmonics has to come from somewhere; whether it's from the "filtrate" that passed through the dimmer or the "precipitate" that would have been blocked.

Accuracy on a phase-chopped waveform would depend what detection method (peak, mean or RMS -- I know, but a gal's got to dream, right?) the meter module was using.

Still, these modules are cheap enough for it to be worth finding out the hard way .....

27th Aug 2018, 5:15 am	#34
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Quick-and-dirty testgear: mains voltage monitor. I don't think the dimmer switch would actually be letting any more energy through than if it were passing the full sine wave; the energy in the harmonics has to come from somewhere; whether it's from the "filtrate" that passed through the dimmer or the "precipitate" that would have been blocked. Accuracy on a phase-chopped waveform would depend what detection method (peak, mean or RMS -- I know, but a gal's got to dream, right?) the meter module was using. Still, these modules are cheap enough for it to be worth finding out the hard way .....