Desi UPS with TV

Is there any harm in running TV on desi UPS? as it does not give sine wave output?

and what about the branded UPS ... do they give pure sin wave output?

Thanks

it may harm your tv.

do the usual desi UPS;s at our home produce a modified square wave or just throw out the normal square wave?

Desi UPS ... n a battery running in the house.

All I do when the lights out is watch tv :S ... infact, now ive got it to switch on the UPS. Just put a surge supressor in between ... or it goes poof!