On Wednesday 08 Oct 2008 13:24, Rony wrote:
The sites are about LCD-CRT comparisons. What I want to know is the difference in power consumption between a CRT running a white image and the same running a black image. IMHO, there is no noticeable difference as the EHT power is generated all the time and the control and signal processing circuits are running all the time. The small differences in the cathode voltage and subsequent control of the beam current does not make any power saving. The only advantage may be to the eye as it reduces glare.
Most of the power is consumed by the deflection circuits and the filament. Not the cathode which emits electrons. The brightness is determined by the acceleration grid (afair). With an LCD the backlight consumes substantial power and keeping a black image on screen makes no difference to the power consumption.