In message , at 21:12:26 on Sun, 8 Mar
2015, john james remarked:


"Roland Perry" wrote in message
...
In message , at 19:34:17 on Sun, 8
Mar 2015, john james remarked:

The backlight is probably the biggest power consumption factor in a TV.

I don't buy that.

There's some numbers here :

http://www.tomshardware.com/reviews/...ht,2930-5.html

Executive summary:

For LED the delta for 25% *brightness setting* change is 3W,

Which is bugger all in the total power consumption.

Irrelevant. It's a way of determining the power usages at full
brightness setting.

so at zero brightness

That is never seen with a TV when watching TV.

Ditto.

the total (ie the consumption of the non-backlight components alone)
would be ~16W, while at 100% brightness the backlight is consuming
29-16 = 13 watts. I doubt there's any one non-backlight component
taking 13 watts (of the 16 watts) on its own.

Meanwhile, the delta between black and white visible *content* is
smaller, at about 1W, which is the fluctuation we'd need to be
looking for.

Which is again bugger all in the total consumption.

And plenty of places won't have just one TV being watched too.

Then you'll have two channels to pick out of the total household
consumption - no different to a radio receiver picking out one signal
from hundreds of others.

CCFL similarly.

I've got a large non-LED TV as a computer monitor and I can feel
the heat coming off the screen from six inches away.

Yes, but that isn't the backlight.

What is it then (it goes away when I put the screen into standby).

The rest that isn't the backlight.

And I don't get anything like that with a LED TV.

That's because the total power consumption involved is smaller (but half
of it is still the backlight). This monitor here is a quite old 23-inch
CCFL. It keeps the whole room warm!

FWIW I've got an old 19-inch Dell "Ultrasharp" monitor in the other room
that's a little furnace.
--
Roland Perry