4 ms·
A level of high voltage in CRTs is directly related to the size of tube and whether it's B/W (monochrome) or color (higher for color as you need to attract 3 el
by dan_hawkins 5y ago
A level of high voltage in CRTs is directly related to the size of tube and whether it's B/W (monochrome) or color (higher for color as you need to attract 3 electron beams instead of one.) In small monochrome CRTs (like 9"-10") cathode voltages would be in single digit kilovolts range, while for large color CRTs (19"+) would be in tens on kilovolts (like 25kV.) Bottom line is that in 9" CRT lower voltages are a bit safer and dissipate quicker after power off.
- Sunspark 5y agoI plan to replace some RIFA caps on a 9" monochrome that hasn't been powered on for years but was still working last time it was powered on. Do you know how long it takes for an old CRT like that to bleed out all the power if it doesn't have a circuit to automatically do that?
- dan_hawkins 5y agoMinutes to tens of minutes (depends of voltage and air humidity.) Couple of hours would be on quite safe side. There's a simple procedure to quickly discharge HV of just turned off TV/monitor but I'd recommend that only for someone experienced working with high voltages.