How to check a capacitor?

[Dan Hintz]

A sidenote... auto-ranging digital meters will add to your measuring difficulties. Find an analog meter, if you can.

[Ken Garlock]

My source for all good things electrical is Chris Padilla.
My question to you is: Chris said: "However, it takes a certain period of time for the capacitor to charge up once a voltage is applied across it." Is that time constant? Inquiring minds want to know.

[Dick Holt]

I usually try the easy/cheapest way out first. In this case, I will order a new capacitor and try that. If that does not work, THEN I will check out the centrifugal switch. I do not want to take the motor apart unless absolutely necessary. Thanks for all your help. I will let you know how I make out.

Dick

[Robert Malone]

This has been very helpful for me cause I'm having the same problem with my HF DC.

Dick, take the time this week to check the volts coming in to both legs of your shop and keep a record.

[Dan Hintz]

MChris said: "However, it takes a certain period of time for the capacitor to charge up once a voltage is applied across it." Is that time constant? Inquiring minds want to know.

It's dependent upon the size (Farads) of the capacitor (among other things)... there's a well-defined formula to determine it exactly, but for our intents and purposes, it's pretty darn short (<1s).

[Marty Paulus]

I usually try the easy/cheapest way out first. In this case, I will order a new capacitor and try that. If that does not work, THEN I will check out the centrifugal switch. I do not want to take the motor apart unless absolutely necessary. Thanks for all your help. I will let you know how I make out.

Dick

I may be wrong but the simplest and cheapest way to check would be to simply blow out the motor with compressed air. The switch would be caked up with dust if it is sticking and simply blowing the air into the motor should get rid of some if not all of the gunk. Next I would check to see if there are oil cups for the bearings. Then I would go to the electrical components. But that is just me.

[Ken Garlock]

It's dependent upon the size (Farads) of the capacitor (among other things)... there's a well-defined formula to determine it exactly, but for our intents and purposes, it's pretty darn short (<1s).

HI Dan, I was just trying to give our friend Chris some harassment.

Thanks to Mr. Euler, and the manipulating of his number, one time constant is defined to be 63+ percent of the final value, in this case the capacitor fully charged value. Multiple time constants operate at the same 63+ percent remaining charge, and repeated ad infinitum.

But Dan, you already knew that...