I have thought about a CVT and in fact I have two PSUs from Honeywell Keytape machines that contain them and supply 15 volts, so the right voltage, although I can't recall the current capacity but it would probably be enough. All I would need to do would be to remove the smoothing capacitors, which are probably the components most vulnerable to excessive ripple currents anyway. Although Honeywell used CVTs a lot I have not been keen on them myself as saturable reactors tend to leak EMR all over the place and Honeywell themselves sometimes put them in steel cases when they were close to electronics that might be affected by this. Also these keytape transformers are the weirdest hybrids imaginable as they are designed for a mains supply that probably doesn't exist anywhere on earth. The keytape machines were designed to work on the mains supply in the US so when companies wanted to use them in the UK the 60Hz transformers were replaced with 50Hz ones, the frequency no doubt being particularly critical in a CVT, but the voltage was left at the US level instead of being changed to the UK one, maybe because other components such as switches and motors in the tape drives weren't rated for use at the higher voltage and they didn't want to replace those components as well. To resolve this discrepancy a kilowatt autotransformer was added to bring the UK voltage down to the US level to run the entire machine on 120volts at 50Hz, which is nobody's mains standard I suspect unless someone knows different. Anyway, as I have these components to hand I can build them all into my computer. What's a bit more weight anyway so long as you're not sending it anywhere by air?
