Talk:2642: Meta-Alternating Current

And today, we are reminded that Randall used to be a physicist (or at least has a physics degree). Not worth mentioning in the article, but while inverters can't reverse each other, transformers can. (Has Randall done the transformer/Transformer pun yet as an excuse to mock the movies?) Nitpicking (talk) 11:10, 7 July 2022 (UTC)

I haven't picked up the physics reference yet. I see electrical engineering here. Randall strikes me as somebody who would study physics given the opportunit, though. It's notable that this webcomic started while Randall was in college, if I recall right. 172.70.230.75 11:58, 7 July 2022 (UTC)

Long distance links, especially those between separate unsynchronized grids, use high voltage DC. There is a 2,000-mile link in China running at 1 MV. Arachrah (talk) 11:32, 7 July 2022 (UTC)

That's because at great distances, relatively high frequency AC loses a lot of ("active" = actually useful) power as ... reactive power, I think (didn't learn the terminology in English, unit seems right though). A typical grid has a lot of generators and load. A long distance connection results in a phase shift according to the transmission time (speed of light in medium x distance) in about the order of magnitude of the AC period (usually somewhere between 1/10 to 1/60 seconds) wastes a portion equal to the sine of the phase shift angle (up to 90° = all of it) as reactive power. DC isn't quite as easy to use but on long distances there is no power loss to reactive power. 627235 (talk) 12:25, 7 July 2022 (UTC)

Let's face it, the thing should be called an alternator. Of course that name's taken as a redundant word for (electrical) generator. 627235 (talk) 12:26, 7 July 2022 (UTC)

It always bothered me that UPS battery backups take the wall AC and convert it to DC to charge the battery, but then have to turn it back to AC to send it to the computer, so the power supply can convert it to DC to run the thing. I picture some connector that goes directly from the UPS to the power supply so that if power is lost it can just pull 12V directly from the battery. Andyd273 (talk) 12:47, 7 July 2022 (UTC)

NOT logic gates are also often known as inverters. An even number of those would indeed produce the same output as the (true/false) input. 108.162.242.58 16:03, 7 July 2022 (UTC)