|reply to stephiso9 |
Re: Treadmill start = modem crash (interference)
All SmartUPS do pure sinewave, not squarewave, and even a line-interactive UPS can protect against overvolt or undervolt situations by switching to battery if the voltage is too far out of whack. In fact, that's more likely to correct voltage than "AVR", since "AVR" has such an enormous range that it doesn't really do much voltage regulation at all.
If you want an online UPS (the kind where the voltage is going to be dead stable because everything always goes through the inverter), they unfortunately cost almost double; the SmartUPS OnLine 1500VA tower model goes for $950ish, while the SmartUPS 1500VA tower model goes for $520ish.
EDIT: The lower-end APC models aren't squarewave either, they're stepped sinewave approximations:
»Re: "pure sine" in UPS
That's still nothing like a real sine wave, but it's also a big improvement over a square wave.
EDIT2: SPS doesn't stand for "Switching Power Supply" when used in relation to a UPS. It stands for "Standby UPS" or "Standby Power System". Line-interactive UPS are not SPS. The different product lines from APC:
Back-UPS: Standby (SPS), stepped sinewave
Back-UPS Pro: Line-interactive, stepped sinewave
Smart-UPS: Line-interactive, pure sinewave
Smart-UPS OnLine: Double-conversion online, pure sinewave
Developer: Tomato/MLPPP, Linux/MLPPP, etc »fixppp.org