In message , at
04:28:26 on Tue, 17 Mar 2015, whisky-dave
remarked:
Yes, but those changes are much slower than the backlight current
which is changing as the scenes change with the TV content.

My computer is far faster than my TV screen.

The rate at which the screen content changes isn't.

400 FPS on my TV is faster then 60HZ.

That isn't the rate at which the screen content changes.

and what do yuo think the backlight is doing then.

Working harder when the scene being shown was shot at night, less hard
when there's lots of white in it.

another vairiable, burning a DVD which I know takes an extra 5W of
power
which obviously all comes from the household's total consumption,

Yes, but again, much more slowly than TV scene changes.

Irrelivant.

That is how you work out what you are seeing current
wise is due to.

so what is this current ?

Driving the backlight.

--
Roland Perry