Generator output -- again

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Fixman
Posts: 135
Joined: Sun Apr 08, 2007 6:38 pm
Location: Charlottesville, VA

Generator output -- again

#1

Post by Fixman » Sun Apr 03, 2005 7:47 pm

Author: fixman

I have a standard 6 volt three brush generator with relay. Since I don't have an Amp meter, can someone tell me what the voltage range should be, with everything off, at idle and say 1500 or 2000 RPM?



fourthgear
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Location: north florida

Re: Generator output -- again

#2

Post by fourthgear » Mon Apr 04, 2005 10:54 am

Fixman
Look at the thread about trouble shooting GM Gen. about two threads below this one , I think Kell wrote it and I believe it has one tip about the Voltage readings at the batt. should help, good reading and should be mandatory if you are using a gen. for charging your Batt.

kell
Posts: 369
Joined: Sat Jun 19, 2004 2:58 am

Re: Generator output -- again

#3

Post by kell » Mon Apr 04, 2005 7:09 pm

It looks like that chevy generator document I posted the link to only has info about two-brush generators.
If you can suss is out from that great, otherwise somebody with knowledge of three-brush generators ought to chime in.

Fixman
Posts: 135
Joined: Sun Apr 08, 2007 6:38 pm
Location: Charlottesville, VA

Re: Generator output -- again

#4

Post by Fixman » Tue Apr 05, 2005 4:08 pm

Really not able to find what I want in the document, but it sure is good info. I believe I am slightly overcharging my battery, but before I start turning things, I would really like to know what voltage it should be putting out at idle, and at a couple thousand rpm. If I had an amp meter, I could just put it in the circuit and adjust for a 4 amp charge rate.

King
Posts: 373
Joined: Fri Apr 02, 2004 5:05 pm

Re: Generator output -- again

#5

Post by King » Thu Apr 07, 2005 7:34 am

This thread brings up a question of mine. Does anyone know of a source for an amp meter that reads in the low numbers? The only ones I have read + - 30 amps range.

kell
Posts: 369
Joined: Sat Jun 19, 2004 2:58 am

Re: Generator output -- again

#6

Post by kell » Thu Apr 07, 2005 10:57 pm

Many common digital multimeters ("DMM") have a setting that measures current up to ten amps. At this link you can scroll down about to the middle and see a typical meter that costs about ten bucks:
http://www.allelectronics.com/cgi-bin/c ... pment.html" onclick="window.open(this.href);return false;

You can probably find a meter like that if you go to your local Radio Shack.
The meters with the ten amp setting usually have a jack dedicated to that setting. The high current ammmeter circruit often doesn't have a fuse, so they have to make it separate from the other circuits on the meter. You just pull the red lead out of its regular hole and stick it in the ten amp hole.
Besides All Electronics there are other surplus houses on the internet like Electronics Goldmine, or you can go to one of the major electronics suppliers like Mouser or Digikey. Mouser doesn't have a minimum order.

1950bobber

Re: Generator output -- again

#7

Post by 1950bobber » Fri Apr 08, 2005 4:08 pm

I have several installable Amperes meters that read in the low numbers....if you want to buy one, I could take pics for you of the choice I currently have available. I use to colect these at one time.
Jim in Seattle "1950 Bober"

Fixman
Posts: 135
Joined: Sun Apr 08, 2007 6:38 pm
Location: Charlottesville, VA

Re: Generator output -- again

#8

Post by Fixman » Sat Apr 09, 2005 4:54 am

Thanks Kell. The ten buck meter looks like the way to go to me. I also did an google search a while back, but the meters were for AC amps and higher amp readings. Rather than try and get the voltage readings, I'll just order one of these and be done with it.

jack moghrabi
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Joined: Mon Jul 14, 2008 2:59 pm

Re: Generator output -- again

#9

Post by jack moghrabi » Sat Apr 09, 2005 8:06 pm

Hey Fixman,

I have a twenty dollar multipletask digital combination voltmeter/ammeter that I bought at the auto parts store. On my '63 I usually measure in the area of 13.4 volts with the motor a bit above idle but not racing. Not to complicate things though, I have started my bike with the battery as low as 9volts when I was heavier in the "de-bugging" process a couple of months ago. Also, I've managed to shove in a bigger battery in the horseshoe oil tank that originally had just enough room for that stock tiny battery.

Fixman
Posts: 135
Joined: Sun Apr 08, 2007 6:38 pm
Location: Charlottesville, VA

Re: Generator output -- again

#10

Post by Fixman » Sun Apr 10, 2005 10:42 am

Thanks! The little 10 Buck DMM that Kell directed me to should be arriving in the next couple of days. then I'll take off the negative battery terminal and put the amp meter in the circuit in series (as per the manual), and I should be good to go to set up a 4 amp charge rate for my six volt system.

I received the little 10 buck DMM that Kell pointed out to me, and it is really a little jewel. Checked its accuracy against my digital volt meter, and it is dead on. Thanks again Kell.
I first checked the current draw with the bike not running, and with everything on (including the headlight on high beam), and it was about 8.8 amps. I guess the 15 amp fuse I put in-line is sized about right.
With the bike running, and everything on, the generator output at idle is about 4.3 amps (the meter jumps around considerably). At about 2K RPM, output is down to about 1 amp, and it goes negative shortly thereafter as RPM is increased. I am not sure how this compares to proper operation, but since everything is working OK, I think I will leave it alone for now.
One other thing. The third brush is adjusted fully to the left against the stop, so I couldn't lower the output even if I wanted to. Me thinks the generator might need to be rebuilt.

kell
Posts: 369
Joined: Sat Jun 19, 2004 2:58 am

Re: Generator output -- again

#11

Post by kell » Sun Apr 10, 2005 10:21 pm

That three-brush generator just sounds like a real headache.
Think about converting to two-brush and a voltage regulator. Then you can take your bike for a long ride on the highway at night, with the headlight on, no worries!

Fixman
Posts: 135
Joined: Sun Apr 08, 2007 6:38 pm
Location: Charlottesville, VA

Re: Generator output -- again

#12

Post by Fixman » Mon Apr 11, 2005 9:45 am

Unfortunately, I am a purest and am trying to bring my 57 back to the way it came out of the factory. I am stuck with the traditional relay configuration although the old points relay has been replaced with an electronic version.

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