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vern hodgson 10-16-2021 08:01 PM

Generator charging revisited
 

Ok, using a digital voltmeter, set on 20v dc. Wiring disconnected output side of cut out reads 8+ volts. Connecting wiring to cut out to check voltage the volt meter goes bannanas. What is going on

Patrick L. 10-16-2021 08:28 PM

Re: Generator charging revisited
 

The generator can put out 20v and yours goes nutz probably because of the 'dirty' signal. An old analog meter will probably work.

Herb Concord Ca 10-16-2021 08:37 PM

Re: Generator charging revisited
 

Unless you a high quality DVM, like Patrick says use an analog Voltmeter.

vern hodgson 10-16-2021 09:29 PM

Re: Generator charging revisited
 

Quote:

Originally Posted by Herb Concord Ca (Post 2067324)
Unless you a high quality DVM, like Patrick says use an analog Voltmeter.

Ok. Thanks guys.

nkaminar 10-17-2021 07:21 AM

Re: Generator charging revisited
 

Another option is to add a capacitor across the DVM leads. A condensor normally used for the ignition can be used. If you use another capacitor make sure it is installed correctly. An electronic capacitor will have a negative and positive side. You can just leave it installed if you want because it will eliminate most electrical noise coming out of your generator. You may be able to hide it inside the cutout or you can just install it anywhere, like inside the instrument panel. Just connect the capacitor between the lead coming from the generator to ground.

rotorwrench 10-17-2021 08:47 AM

Re: Generator charging revisited
 

I have to assume this is a 3-brush model A type generator. This type of generator gets it's voltage sense from the battery since there is no voltage regulator. It may be easier to check voltage at the battery terminals when using a digital unit. The system connections all have to be tight to get a good reading. Any loose connections and it will be intermittent in operational indications.

Badpuppy 10-17-2021 10:19 AM

Re: Generator charging revisited
 

Do not run a generator with output connections open. With no load it tries to produce infinite voltage. (And burns out.)

vern hodgson 10-17-2021 10:47 AM

Re: Generator charging revisited
 

Quote:

Originally Posted by Badpuppy (Post 2067464)
Do not run a generator with output connections open. With no load it tries to produce infinite voltage. (And burns out.)

Oops, hope didn’t damage it, ran less than a thirty seconds or so.

katy 10-17-2021 11:28 AM

Re: Generator charging revisited
 

The DMM will also pick up RFI from the ignition system causing it to go nuts.

Badpuppy 10-18-2021 09:05 AM

Re: Generator charging revisited
 

Quote:

Originally Posted by vern hodgson (Post 2067479)
Oops, hope didn’t damage it, ran less than a thirty seconds or so.

Should take longer than 30 sec for damage. But the field coil wasn't happy about it nonetheless.

If you're trying to check generator voltage out, probe as close to the battery as you can get. It's a great noise filter.


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