said by leibold:Most electronic devices these days with switch mode power supplies are perfectly happy to accept AC in a wide range (e.g. 100V to 250V) and don't really care about the line frequency either.
And that 100-250V rating is the
nominal line voltage. There is an added tolerance on top of that. Realistically, most devices rated 100-250V should operate fine from about 90-270V or wider range.
For comparison the AVR feature in APC SmartUPS products, if my information is correct, only operates down to a minimum of 85V. So there's only a margin of about 5V where the AVR is actually useful as far as modern electronics are concerned.
Some double-conversion type UPS that I have tested (oh the fun one can have with a variac) will go down to 60V without using the batteries and maintain 120V at the output!