[sci.electronics] inverter and TV

leep@wang.com (Lee P.) (05/01/91)

I have a modern color TV that I'm operating off a cheap inverter.
It works fine, but the vertical oscillator appears non linear!
Upper 1/3 of screen is compressed, with rest of image elongated.  Entire
screen is illuminated.  There are no vertical or horizontal sync problems.
The inverter is outputing square waves.. of course.  Is there likely a
synchronization with line current occurring?  Would filtering help?
Any suggestions?  (Besides buying a good inverter.)


leep@leesys.wang.com 
"Better to die on ones' feet than to live on ones' knees." - Zapata

--
leep@leesys.wang.com 
"Better to die on ones' feet than to live on ones' knees." - Zapata

rogerm@hpfcso.FC.HP.COM (Roger Mitchell) (05/04/91)

One problem could be the fact that your inverter puts out a squarewave with
a 110 volt peak value where a 110 volt sign wave has a peak value of 155 volts
which is what you get out of a bridge rectifier with a filter cap attached.
The 110 volt square wave will only give you 110 volts DC after filtering, which
will cause the screen to shrink if the regulators in the powersupply of your 
television doesn't have enough headroom.
	
				Roger Mitchell
				N0MCR