Smokstak.com is a great discussion forum for Antique Tractor Enthusiasts!

Rating: 0 - 0 votes

Company Logo

Company Name

Company Contact

Website Analysis

Domain Whois

WHOIS information for Smokstak.com

Powered by who.is

Page Type

This page is about a company.

Title

Antique Engines Antique Tractors Traction Steam Engines and Old Iron

Description

Hi, I would like to offer my help to those folks that may not understand capacitors also called condensors. What it is; Two metal plates placed near each other and seperated by insulating material such as paper. Engine capacitors are usually two long strips of aluminum foil about an inch wide sandwitched between layers of waxed paper, rolled up and placed in a metal case. One plate is connected to the case and the other to a lead out wire. What does it do? When connected to a voltage source such as a battery it will momentarily act as a closed circuit while current flows to charge the plates, neg electrons on one plate and pos on the other. When the voltage across the plates builds up to the battery voltage current flow will stop and it will act as an open circuit. They will remain in this charged condition even when disconnected from the battery. A capacitor stores elect power just like a battery. If a circuit path is connected to the plates it will discharge thru that path. If the voltage polarity is reversed it will recharge to the oposite polarity. How can you tell if its good? If you have a ohmmeter connect the test leads together and zero the meter. If the meter wont zero replace the battery. Select the highest R times range you have R times 10,000 works good. Connect the test leads to the capacitor while watching the meter. The movement on scale means it took the charge. And the prompt movement back to full left means there are no leaks. A leak means there is a small amount of current flowing thru a high resistance bridge across the plates. Did we drive into a patch of fog here? Ohmmeter a problem? Ohmmeter is nothing more than a meter and a battery and the appropriate resistance connected in series. You send current from the battery thru the meter, some resistance and your project. The resistance controls how much and the meter measures it. It should be noted here that even your body circuit will interfere with this test. Dont touch the conductors. Repeat the test while reversing the test leads each time. Test several known good capacitors to establish a reference. Your ohms range dont go that high? Needle movement to small? In the lower ranges this happens to fast for the needle to follow. Add resistance to your test lead until the needle gets on scale. You have a volt meter only? Connect one of your test leads in series with a battery and enough resistance to get on scale reading. After you set your reference readings rember to use the same componants in the future. Capacitors have a important characteristic. When charging, the current builds up on the plate fast but the voltage builds up a little slower. voltage lags the current. This is a important feature when used---guess where!! We'll save that for another day. Not a scientist or engineer, just a BellSouth retiree. I apologize for the long post and I hope this info is helpful to someone.

Thanks Ralph. A couple of times, I've been doing stuff like trying to fix our microwave where I had to discharge a capacitor. Now I sort of know a little bit about what I was doing.

Your post is correct and of interest. Magneto condensers (capacitors) have several failure modes that a simple ohmmeter test will not identify.