Thread: charging system
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Old 09-21-2009, 07:46 PM
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Originally Posted by vernz View Post
simplyconnected - I have a question about the procedure you discussed. My generator is putting out about 1 volt. I pulled it and found that a brush spring was broken and the arm that pushed down on the brush was loose inside the generator. I saw no damage to anything so I replaced the spring and put it together after cleaning up the commutator. I decided to try polarizing the generator by removing the field wire at theregulator and touching it to the battery connection at the regulator. It instantly became too hot to hold.....a lot of current flowing. In your answer below you talk about the same connection being made for up to two minutes. Does this indicate I have a shorted filed winding?

It sure looks like it, Vern. To make sure, you are talking about the FIELD wire getting too hot, not the armature wire, right?

A shorted field winding will play hell with a regulator. Use a resistance check for your Field windings. Under full load, the FIELD should pull about an amp or two. The field and armature are both internally grounded at the end of the coil. That's why you should have a separate ground wire going to your regulator (just to be sure).

Here's another check that most people are unaware of: The field is an inductive coil. With all wires disconnected from your generator, (bench-testing) connect a continuity light (with two AA batteries) to ground. If you 'scrape' the other continuity light lead to the Field terminal, you should see a pretty blue spark. If it's shorted, no spark, but the continuity light will shine bright.

Just a thought; make sure you didn't ground your field wires inside the case, when you put it together. It's easy to pinch a wire, there isn't a lot of room.

The ARMATURE current will be around 35-45-amps. Replace that wire with at least a #10-AWG.

Sounds like your field wire may have got cooked. No biggie, it goes from your regulator to your generator and nowhere else, and it hangs in free air. That wire is skinny because only one or two amps go through it. Remember, the voltage regulator turns your field on and off. Then the field magnetism controls the armature output.

You should be able to tie the armature and field wires together, run that wire to Battery, and watch the generator put out like gangbusters. Remember, it's un-regulated. Be careful you don't put out too much voltage by reving too high. I like to use an old headlight for the load. You can see it go from dim to bright with rpm changes.

Field wires are connected in series. You can buy field windings. Use a crimp connector (not solder) when connecting inside.

Hope this helps, Vern. If I'm foggy on a point, please re-ask. - Dave
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