On Sunday 15 December 2024 12:13:34 am Andy via groups.io wrote:
But I believe there are more extreme cases where the mains 60 Hz waveform might have distortion around 25% or so.? And those are the kinds of waveforms you actually might want to look at on a 'scope.? 25% THD looks pretty bad.
There's a guy on YT that does a lot of videos on generators, and when he gets one fixed up and making power, he will load test it, which will also typically include hooking a meter and a scope (tablet style) to the output of the generator and seeing what the waveform looks like and how much distortion there is. I don't think I remember any of them being nearly as high as 25%, maybe half that at the most. The ones that were the best were the "inverter" types, which used some electronics to generate the output waveform. They were also the only ones that didn't have to run at a fixed speed, and were therefore more economical for light loads, but they were also the most expensive to fix, if there was any issue with the inverter circuitry.
Got a pile of UPSs to scrap out in the garage. Have any of you guys messed with those? Looked at waveforms, etc.? Schematics for them seems to be pretty scarce, I think I may have run across *one* in all the looking I've done for them. Most are 300VA, for whatever that's worth.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
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Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
