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Last weekend at #VCFe I once again encountered the meme that using original power supplies for your home computers of the 80s is bad because the line voltage was raised by 10% from 220 V to 240 V since then. #electronics #retrocomputing #vintagecomputing

So instead of 5 V, as the story goes, they now deliver 10% more and would be outside the specs. But no, that's not how voltage regulators in power supplies work. They regulate voltage. That's their one job.

There's of course a real reason not to continue using the CBM linear power supplies for their 8 bit computers: they didn't have protection circuits that would prevent a failing voltage regulator from potentially frying your computer.

In typical linear power supplies you have a (big and heavy) transformer and rectifier that generates a low voltage DC from line AC, followed by a linear voltage regulator that generates the desired target voltage from that.