[AJD] Delco generator 1102761??

[Tom in N Texas]

Michael,

Nice discussion. Thanks. My little JD MT was converted, to 12 Volts and an 
alternator, when I got it in 1995. So I don't have a generator, right now. 
I expect to get a 620 someday, which will be 12 Volt with a generator.

I used to watch my Dad adjust voltage regulators, on the car, thoroughly 
warmed up. He used an accurate Voltmeter and a thermometer. He had tables 
of Voltage versus temperature. He always measured the final setting with 
the lid on the Voltage regulator. I messed with them a little bit many 
years ago.

The cutout relay and current regulator settings are relatively easy. But 
the Voltage regulator adjustment is very touchy. And if you get them wrong, 
you either over-charge or under-charge the battery, shortening its life.

Nowadays, alternators are easier all the way around. The diodes do the 
cutout relay function. The alternator design limits current, so no need for 
a current regulator. The Voltage regulator is electronic and not adjustable 
nor repairable, so you replace it.

As you say "Who knows about the specs of today's after market units?" If we 
had the capability, we should probably check the adjustments on a new 
after-market regulator (depending on where we got it).

I think it's a good idea to never try to charge a flat battery with a 
generator: Charge the battery first with a 110-Volt battery charger. This 
reduces the chance of a bad or mis-adjusted current regulator letting the 
generator burn itself up.

Thanks again for the information. I enjoyed reading it.

Tom in North Texas
--------------------------------------------------
At 04:07 PM 11/14/05 , you wrote:
>The Farmall tractors also used Delco electrics on many models up through 
>1978 at least. Some of the Farmall models had three brush generators plus 
>a regulator. The three brush with regulator was the second step in the 
>evolution of charging systems.
>
>On the forum YT MAG, at the Farmall/IH section, a man named BobM posts and 
>is the most knowledgeable individual about charging systems that I have 
>encountered- plus a first class gentleman to boot. Search their archives 
>for his posts or post your new question there.
>
>Basically, the speed of a generator determines the voltage output, more 
>speed, more voltage. The third brush limited the maximum amperage output 
>of the generator. Excess amperage output is what burns up the generator. 
>Limiting the field exciter voltage will limit the voltage output.
>
>Many tractors with relay-only had a low charge switch position which 
>introduced a resistor in the field circuit to reduce the charge rate when 
>desired.
>
>The 2-coil regulators had one coil for the relay, the other was either a 
>voltage regulator or a two-winding on one core with that unit crudely 
>controlling both voltage and amperage.
>
>The 3-coil regulators are more precise in their control.
>
>In the old auto parts catalogs, regulators were matched to the generator. 
>For example, a 30 amp generator matched to a 40 amp regulator might result 
>in premature burnout of the generator. Who knows about the specs of 
>today's after market units?
>
>----- Original Message -----
>From: "Tom in N Texas" <tdulin at pulse.net>
>To: "Antique John Deere mailing list"
><antique-johndeere at lists.antique-tractor.com>
>Sent: Monday, November 14, 2005 8:39 AM
>Subject: Re: [AJD] Delco generator 1102761??
>
>
> >
> > Bus Driver,
> >
> > Do you happen to remember which generators were three-brush and used
> > regulators? Or what they were used on?
> >
> > Mainly just curious.
> >
> > Thanks, Tom in North Texas

Tom in N Texas, KC5INU,  tdulin at pulse.net, "Nothing Runs like a JD MT Deere",
1949 John Deere MT, JD No. 50 Box Blade,  1954 JD No. 5 Sickle-Bar Mower,
1975 JD 214 Lawn Tractor, 1918-22 JD Dain Horse-Drawn Sickle-Bar Mower