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Comment by nathan_f77 | Hacker News Reader

I'm working on a project where I may need to open and repair an old device that probably contains some high-voltage capacitors. Would it be relatively safe to do this if I was wearing rubber gloves + shoes, and used a multimeter to check for voltages, and a large resistor to discharge any capacitors? What kind of bleed resistor is typically used, e.g. for old TVs?

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This might be a nice feature of a multimeter: discharge mode.

Putting the leads over a capacitor, the multimeter will show the voltage and discharges the capacitor with a constant safe current. Beeps can be used to indicate when the capacitor is safe to handle or not.

It kind of already has a discharge mode, just short the leads of the capacitor with one of the probes.

That is not how you properly discharge a capacitor, though. Especially big ones.

> a multimeter to check for voltages, and a large resistor to discharge any capacitors

That's all that I use. Don't hold the resistor in your hand though, depending on the size of the capacitor they can get quite hot. I usually use some pliers to hold the resistor.

If it's 250V or less then that's probably overkill. Rubber gloves alone will protect against a few hundred volts. Bleed resistors depend on the capacitor size but are usually in the high kilaohms.

Just short the positive side to ground to discharge them.

Note: do NOT do this with thin wires and large capacitors / arrays of capacitors, or you may get a hot copper shower.

Preferably connect it to ground through a resistor.

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