The transformer in this, and many other UPS’s stores enough power to allow the inverter to come on line. I don’t know if that’s still the case with newer ones.
This units manual shows 90% efficiency and has survived many lightning strikes. 2000-1 protection, up to 6000 volts, 200 amps, I think. I gave the manual back yesterday.
The computer company I work for has provided power conditioning/UPS systems for our computers for 15+ years. I’ve thrown out or sent back enough units to keep us all happy. In the old days computers needed more, and better quality power to run properly. This makes the older units more suited to my needs. The power losses of the older units is a concern, but in my experience they are MUCH more robust. I don’t like a 10% loss, but my needs are different from others. I’m just exploring options anyway. The newer UPS’s do clean up the power but are more for ensuring a controlled shut down of the server. Recovering from one day’s data loss for some of my clients is more costly than the price of a server. Our normal units these days are 1 kva and I’ve got a bunch of those as spares. I found my old o-scope a few months ago and when I get the time I’ll have to do some testing.
That being said there are probably many of these units out there, power conditioners or UPS’s, and many more thrown away. Electronic surplus houses, flea markets, military surplus. Ebay has an old 325-watt Oneac for $125.00 That’s ridiculous for such a tiny output. Current liability and litigation happy people make many company’s loathe to sell or give away anything no longer useful to them. What if they sold a used ups that got shorted in a dangerous way due to rough handling during shipment? A billion $ company has deep pockets.
Thanks, Geno