View Full Version : HV Discharge


GeorgeHC
07-27-2016, 03:38 PM
I've read that before removing a CRT the high voltage anode should be discharged to the set chassis (not to ground). Is this supposed to be done with the set still plugged in?

If not, how does this discharge it?

Electronic M
07-27-2016, 03:52 PM
It makes no difference whether the set is plugged in (though if it is turn it off first).

The outer dag (negative plate of the CRT's integral HV filter capacitor) is connected to the chassis, the inner dag (positive plate) is connected to the HV. Discharging the HV is merely connecting the plates together to discharge the integral HV filter cap formed by the bell of the CRT.

It is best to discharge HV through a high resistance such as a HV voltage probe. If you merely short it to discharge the HV charge on the cap tends to partially "bounce back" after a few seconds to minutes.