Question about discharging things before working on TV

[Findm-Keepm]

Originally Posted by madlabs

If you want to be real careful, put a 1 Mohm resistor in series to ground. Prevents big sparks/currents and is easier on caps when discharging them.

With some large (100uF) capacitors, the R-C discharge time with a 1 Megohm resistor could be over a minute.

Pomona Electronics made a 40KV discharge set (lucite handle, cooper bronze shank with swappable probe, hook, and balled ends) for the Navy - they used a 5K series resistor. That kept the RC time for discharge under 6 seconds for just about everything. Not sure of the composition/wattage of the resistor, but we had to megger it as a daily test. Me, I'd use a 2 Watt Carbon Comp in series, say 5100 or 5600 ohms, standard values.

450V discharging through a 5K resistor to ground keeps it under 100mA at all times on the discharge curve - no sparky-sparky at all.

Or, if you want to visually see the discharge effects, build one of these:

http://jestineyong.com/build-your-ow...scharge-probe/

Has LEDs that indicate if there is still voltage present.