[HomeBrew] Smoothing a square wave

[Jim Miller]

I have an inverter that I blame for blowing up a 9 inch color TV that I use at my station and wanted it also to run on 12v as battery backup as my station does.  I scoped the output and it is a two-step (two positive and two negative) square wave output.  I had also  intended to connect my computer to it but haven't tried that because the TV blew up.  Does anyone know what the output of these UPS systems look like?

At 60 Hz, it would take a huge inductor to "round" the corners of the wave but I have a very large pole pig sitting here and wondered if one side could be used simply as an inductor or wire the two sides in series, maybe put a load on the unused side or something.  High side or low side?  How much of a load?  Use a cap instead of a load?  OK, dumb idea.

For a small TV only maybe a small LONG "extension" cord wound in a small coil would help smooth the square wave?

1. It says the max current is 1 amp.
2. 20 gauge (too much voltage drop?  I don't have the numbers to calculate it.
3. 100-200 feet?  Not long enough to create enough inductance?  

Opinions please, I am not a design engineer, just trying to get a small TV to safely run on an inverter or was it coincidence that it quit within minutes of plugging it into the inverter?

Thanks es 73 de Jim KG0KP