Tsunami's and capacitors?

[sizemore]

So I'm wiring in the decoder for the Super-Berk; how do I know the capacitor is working correctly? Anything I could read with an Volt/Ohm meter?

The S.

[wm3798]

The first challenge with the capacitor is to make room for it.  The second is to match the plus and minus wires to the terminals.  If you can manage those two things, then God will smile upon you, and it will work.

Lee

[sizemore]

Thats not the answer to the question. Putting the capacitor in a place where it fit I bent leads up, then in my infinite wisdom bent them again and I want to make sure I didnt damage the capacitor so I want to check it. Given that the Berk is in a million and one peices makes this quite difficult to test. If there was a way to test the capacitor using an voltmeter that'd be awesome.

The S.

[wm3798]

Take an extension cord and cut off the female end.  Pull apart the wires, and strip about 1.5" of the insulation from each wire.  Now carefully and securely wrap those wires around the handles of two forks.  Silver works best, but stainless will be fine if that's all that's handy.  Now, stick the forks into each end of a frozen hot dog.  Plug in the cord to your household 110, and monitor the hot dog as it cooks.  Don't touch the hot dog or the forks during this process.  It goes pretty quickly.  Unplug the cord, then use a hot dog bun to hold the dog while you remove the forks.  Apply the condiments of your choice.

I'm not sure how this relates to testing a capacitor, but it will sure make dinner more interesting.

Lee

[sizemore]

Take an extension cord and cut off the female end.  Pull apart the wires, and strip about 1.5" of the insulation from each wire.  Now carefully and securely wrap those wires around the handles of two forks.  Silver works best, but stainless will be fine if that's all that's handy.  Now, stick the forks into each end of a frozen hot dog.  Plug in the cord to your household 110, and monitor the hot dog as it cooks.  Don't touch the hot dog or the forks during this process.  It goes pretty quickly.  Unplug the cord, then use a hot dog bun to hold the dog while you remove the forks.  Apply the condiments of your choice.

I'm not sure how this relates to testing a capacitor, but it will sure make dinner more interesting.

Lee

You a funny guy Docta' Jones.

Short Round

[seusscaboose]

Moriarty strikes again

[sizemore]

I love T-34's with wood frames to make them look like Tiger I's!

I did find this in my homework:

Testing- Testing capacitors can be tricky at best. The quick and easy way for the average home electrician is to hook up your multimeter to the discharged leads of the capacitor. You will have to find the polarity of the capacitor, and then hook up the corresponding meter leads.

Unfortunately with most meters, unless it's very new or expensive, you will only be checking if the capacitor is shorted or not. Also, in most cases, you will need to take at least one lead off the circuit card. Once your leads are hooked up as stated above, your readings should be: Any capacitor that measures a few ohms or less is bad. Most should test infinite even on the highest resistance range.

For electrolytes in the uF range or larger, you should be able to see the cap charge when you use a high ohms scale with the proper polarity, the resistance will increase until it goes to infinity. If the capacitor is shorted, then it will never charge. If it is open, the resistance will be infinite immediately and won't change. If the polarity of the meter leads are reversed, it will not charge properly either, which is why you must determine the polarity of your meter and mark it, they are not all the same.

http://www.ohmcheck.com/capacitor.htm

To the Multi-Meter BATMAN!
The S.

[DKS]

The problem here is that you must de-solder it from the circuit to test it, because capacitors that are part of a circuit cannot be reliably tested. This could add to the stress the capacitor has already received from bending. Recommend doing a visual/mechanical test. Examine the leads under magnification for breaks. If you see none, then if a break exists, it's most likely just inside the capacitor jacket. To check this, very gentle twist the cap side-to-side. If it feels relatively solid, then it's unlikely the leads are broken; if however it feels wobbly, it probably needs replacement.

[sizemore]

The problem here is that you must de-solder it from the circuit to test it, because capacitors that are part of a circuit cannot be reliably tested. This could add to the stress the capacitor has already received from bending. Recommend doing a visual/mechanical test. Examine the leads under magnification for breaks. If you see none, then if a break exists, it's most likely just inside the capacitor jacket. To check this, very gentle twist the cap side-to-side. If it feels relatively solid, then it's unlikely the leads are broken; if however it feels wobbly, it probably needs replacement.

The jacket and cap are good. Thanks Dave -maybe I'm alright. Stopping by Radio Shack and grabbing a couple extreees as well. Between an ohm check, visual check, and cooked hotdogs this should close up the decoder in the tender install.

Thanks guys,
The S.

[Ed Kapuscinski]

How much was the capacitor? Do you have spares? Why not just use a fresh one and save yourself the aggravation?

[sizemore]

How much was the capacitor? Do you have spares? Why not just use a fresh one and save yourself the aggravation?

It was like $2. I'm going to wire in a new one anyway, now that I have spares from "the Shack" that way I eliminate potential issues that were not caught in the visual checks. I have to add the programming booster but thats a project when this is fully completed.

The S.

[Chris333]

Wouldn't the way to test if it working be to run the locomotive and pick it up. If the wheels keep turning then the cap is working.

[wazzou]

That's cool Chris.

[sizemore]

Wouldn't the way to test if it working be to run the locomotive and pick it up. If the wheels keep turning then the cap is working.

/>

Nah the capacitor is only a "keep-alive" for the decoder and it's sound features. With a 220mF capacitor has just enough juice to prevent the decoder sound from going kaputzky. You'd have to wire in a separate capacitor for motor for the "electric flywheel". Plus with DCC I don't know how the "electric flywheel" would effect the BEMF functions which really make a motor run well.

The S.