Capacitor Tester, is this too Cheap?

[Tom Wesenberg]

About 10 years ago I bought a SUPCO capacitor tester and paid about $30 or $40 for it. Yesterday I saw this tester on ebay, but the price is so low I was wondering if anyone has tried it and found it to be accurate?

http://www.ebay.com/itm/381190482187...%3AMEBIDX%3AIT

[marc hildebrant]

Tom,

These type of testers are very common and popular. However, I have always used an impedance bridge (General Radio) as a bridge gives both the value and "dissipation" factor.

As I remember the story, the inventor (MIT Student) submitted the idea as a school project and received a "C" for the idea.

The testers work by measuring the RC time constant of the capacitor and a precision internal resistor. Using math, the unknown cap is calculated.

Marc

[Kevin in NJ]

What do you need it for?

My experience with the low end testers is some do a job, most seem to fail or act strange. At $13 you are not out much.

[katy]

I just use my Fluke 87

[marc hildebrant]

Originally Posted by katy

I just use my Fluke 87

I believe that the Fluke meter uses the same technology, i.e measure the RC decay time with a known R.

Marc

[BILL WILLIAMSON]

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Originally Posted by marc hildebrant

I believe that the Fluke meter uses the same technology, i.e measure the RC decay time with a known R.

Marc

I forgot, I have a Fluke in Gregg's (RIP) tool box, gotta' check the Model # He has special tools that I don't even know what they're USED FOR????
Bill W.

[ronn]

free tester at Harbor freight this month if you have the coupon

can buy something under a buck to use....................

[Tom Wesenberg]

Originally Posted by ronn

free tester at Harbor freight this month if you have the coupon

can buy something under a buck to use....................

Those 2 bar magnets are a good thing to buy for a buck. If you don't have a use for them, then give them to kids. Hopefully it will help to start their interest in science and mechanics.

[Bruce of MN]

I mis-ordered a similar tester on Ebay when I needed an inductance meter for timing a magneto. You can have it for postage if you want. PM me.

[Tom Wesenberg]

For those of you that bought this tester, you have probably found the instructions to be rather poor. I bought one and tried it out yesterday, so here's my instructions for using the meter.

Install a new 9 volt battery. Notice the + and - markings are very small, so be careful to install it correctly.


Insert the black clip lead into the center jack.
Insert the red clip lead into the left jack. I also tried the right jack, and it doesn't seem to matter, so I don't know why they have both.
Turn the switch to straight up, which is the 2uF setting. The meter should show .000 at this time.
Connect the red lead to the ground on the Model A capacitor.
Connect the black lead to the brass terminal on the capacitor and the meter should read about .233, at least that's what my new capacitor shows.
If you want the reading to show after you unclip the capacitor hit the hold button before disconnecting the capacitor.
Turn the switch to off as soon as you are done, to save battery life.


Capacitors should be shorted first before testing just to be sure they aren't holding a charge that could damage the meter.

[Doug in NJ]

Wouldn't you have to test an ignition condenser at its full working voltage to be sure it is OK? I think a generic capacitor meter uses just a couple of volts, but an ignition condenser sees peak voltages of at least 100 volts...

Doug

[Tom Wesenberg]

Originally Posted by Doug in NJ

Wouldn't you have to test an ignition condenser at its full working voltage to be sure it is OK? I think a generic capacitor meter uses just a couple of volts, but an ignition condenser sees peak voltages of at least 100 volts...

Doug

Yes, plus the heat factor. I would check it with the meter first, and if it passes the capacitance test, then I'd install it and make sure it runs OK in the heat.

[BUBBAS IGNITION]

Originally Posted by Doug in NJ

Wouldn't you have to test an ignition condenser at its full working voltage to be sure it is OK? I think a generic capacitor meter uses just a couple of volts, but an ignition condenser sees peak voltages of at least 100 volts...

Doug

Very good point Doug , i agree . The primary side of the ignition especially running could be anywhere from 100 to 500 volts. Condensors are also tested with a automotive tester using not only capacity in mfds but series resistance and leakage....takes all three to make a good ignition cap..