Quote:
Originally Posted by DoctorWho
I am just curious as to what would happen if the EHT were AC instead of DC?
|
If the EHT was genuine AC sine wave, the screen would be blank for the -ve half cycles and varying wildly in brightness and scan size on the +ve half cycles. Might also be some odd space charge effects causing even more havoc. I doubt you'd damage the CRT.
With flyback EHT there isn't really a -ve half cycle to be blocked, the rectifier is only there to stop the smoothing cap discharging back into the LOPT.
Note on scan size. In electrostatic deflection the defelction sensitivity is inversely proportional to EHT voltage. In magentic deflection it's inversely proportional to the square root of EHT. This is a good reason to use magentic deflection at high EHT voltages since the scan sensitivity doesn't drop as fast when EHT is raised.