is it true a mainly black screen as opposed to a mainly white screen on a pc can save electricity ?

Question

is there a yahoo equivalent to www.blackle.com?

Answer 1

Depends - CRT, yes... LCD, no.

Answer 2

Technically, yes, but the amount is pretty insignificant compared to the overall usage. An average PC may use several hundred watts at any given time, but you may only be reducing that by a few hundred milliwatts.

With an LCD screen all you are doing is turning off most of the LCD pixels, the actual light source is a set of flourescent cold cathode tubes behind the LCD pixel grid. These tubes are always lit and use up most of the actual power consumed. The LCDs themselves use very little current to switch states, so any power savings with an LCD is pretty minimal.

With a CRT, it works a bit differently - there are three 'electron guns' that fire a constant stream of electrons that sweep across the screen, which is covered in a layer of phosphor dots that emit light when hit with the electron beam. The beam is controlled by applying voltage to various grids inside the tube to control the beam. The actual amount of current flow through the electron beam is not much - virtually all the power is used to heat the tube's cathodes, and create the electromagnetic fields that sweep the beam across the face of the tube.

Answer 3

Jeff H is right that is why I threw away my old CRTs. Now on LCD on my desktops.

Answer 4

the amount you will save displaying different colours is non existant.


if you want to save electric then switch it off

Answer 5

It's true because it requires less pixels to be lit.

Answer 6

yes