On 04/14/11 9:49 AM, Brunner, Brian T. wrote: > UPS and Power Supplies are not all the same. > If the UPS has a stepped voltage output (not smooth sine wave like the > local public grid has) in large enough steps to mess up the power > supply, you wind up with no UPS in effect. > > CLEARLY if there are enough steps to the stepped output of the UPS > (which depends on the UPS brand/model), the PC power supply happily will > see it as a sine wave input. How many is "enough" depends on the power > supply and the load. switched PC/Server PSU's *so* don't give a bleep about sinusoidal power, its not funny. first thing they do is full wave rectify the power to DC, then they run that DC through a high frequency (several 100Khz usually) oscillator and into a toroidal transformer. they would be perfectly happy running off a full squarewave