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Old 4th Feb 2021, 1:50 pm   #16
Uncle Bulgaria
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Join Date: May 2016
Location: Cornwall, UK.
Posts: 2,315
Default Re: Oscilloscope grounding confusion

Good idea, trobbins. Output was still nada, however. After going round the houses with 1.5hrs on hold to UPS whose operatives appear to have a hazy grasp of English, they finally put me onto the Bodmin depot where a competent person who agreed that my parcel from CPC didn't need an 'apartment number' personally fished it out of the 'return to sender' pile.

It contained an enormous amount of fresh air (why is there an inverse relationship between object and parcel volume?) but crucially some LM324AN ICs. On replacing with one of these, I get 40V on the electrode outputs so I'm going to see whether it arcs now.

The machine turns on as soon as it's plugged in, as there's no on/off switch, so it is always running the thyristors at the pulse frequency selected with the current potentiometer. This feels like it would have some effect on life-expectancy, but as the thing's obviously designed as a workhorse and is still working it can't have too much effect.
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