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Whenever working on capacitors with bleed resistors, I still check for voltage or short across the capacitor, etc. You can not always visually tell if the resistor is functioning.
Whenever working on capacitors with bleed resistors, I still check for voltage or short across the capacitor, etc. You can not always visually tell if the resistor is functioning.
That's a good way to destroy your DMM. Dump the energy into a 40W light bulb. The inertia of the filament is more than enough for the residual energy. The worst that can happen is that the filament will blow.
Shorting caps may shorten their life.just shorting them with a screwdriver
And won't necessarily remove the charge. After shorting, a cap can still "recover" a little bit over time and have to be discharged again. At the moment, the offical terminology escapes me.Shorting caps may shorten their life.
How is measuring the voltage going to destroy my DMM?
And won't necessarily remove the charge. After shorting, a cap can still "recover" a little bit over time and have to be discharged again. At the moment, the offical terminology escapes me.
And won't necessarily remove the charge. After shorting, a cap can still "recover" a little bit over time and have to be discharged again. At the moment, the offical terminology escapes me.
Not quite what I had in mind.A very low leakage capacitor acts like a bucket as well and can pickup a charge. A high voltage capacitor can build up a significant charge when exposed to say something like negative ion generator type air cleaner much like leaving a bucket outside on a rainy day.
After a while, the capacitor has the ability to dump the contents.
Shorting caps may shorten their life.
By measuring a voltage source far beyond the rating of the meter that can provide a significant current.
The high voltage capacitor inside a microwave is rated 2100v AC, so depending on where the peak was, it can hold about 3,000v DC (2100 * sqrt 2).
If the bleeder resistor is dead and your DMM sees 3kV, it goes poof.
The safety factor isn't the same proportion across all voltage. A 5v rated IC may survive 20v fine. That doesn't mean that 1,000v device will withstand 4,000v.
And won't necessarily remove the charge. After shorting, a cap can still "recover" a little bit over time and have to be discharged again. At the moment, the offical terminology escapes me.
This can happen with large transformers too, from what I have been told. Any truth to it?Dielectric absorption was the official term I was looking for.
If the interwinding capacitance is significant. Small capacitance will reduce the time duration of the shock you get and voltages above 600v will puncture the skin and so increase the current into your body.This can happen with large transformers too, from what I have been told. Any truth to it?
I'm not sure but a transformer certainly has some capacitance and some polarization takes place so I would not be surprised.This can happen with large transformers too, from what I have been told. Any truth to it?
Working on a microwave that the display lights up and accepts inputs but when you press start the microwave does not heat, I have done the resistance checks on the magnatron and it checks good. would appreciate any help. thanks