"Ed Huntress" wrote in message
...
On Wed, 20 Jan 2016 08:48:09 -0600, Robert Nichols
wrote:

On 01/19/2016 04:44 PM, Jim Wilkins wrote:
I took a chance on the HF 2200W inverter generator #61169, $399.99
with a coupon. Hopefully it will be unnoticeably quiet from the
street
under my usual wintertime load of less than 200W and able to run
the
A/C or microwave if we have a summer hurricane outage.

Good luck trying to start an A/C with that little inverter
generator.
I also see no mention that the output is true sine wave, so some
computer power supplies might not be happy with the output waveform.

I'm curious about that. I've never investigated those power
supplies,
but I thought that the output from battery batckup, like my APC, was
square wave or something jagged, anyway. I've never put a 'scope on
mine but have thought about doing it.

Anyway, for anyone experienced with these power supplies, what's the
story?

--
Ed Huntress

The "modified sine" consists of flat-topped positive and negative
pulses of about 160 to 170V with some zero-output time between to
reduce the RMS to ~120V, hopefully. An average-reading meter gives the
wrong voltage. I've seen the pulse width vary with the load.
http://www.nooutage.com/inverter1.htm#waveforms

The peak value of a 120V sine wave is 170V, 120* SQRT(2).

A power brick that rectifies the input and accepts any worldwide
voltage -should- work fine with them but reports are that some don't.

APC sells both modified and true sine UPSs. I have the Smart-UPS 1400
which is true sine. It was free because the disgusted dealer couldn't
figure out how to open it to get the swollen batteries out. Actually
the front cover just pops off, exposing the screws.

-jsw