Alternator question

pomester

Well-known Member
So that I may use a tachometer, I am considering this alternator which our host sells: https://www.yesterdaystractors.com/ADR0382_Alternator-with-Tach-Drive_30699.htm . It is described as 'internally regulated', but to make it 'single wire self exciting' they sell this: https://www.yesterdaystractors.com/ADR9209_Alternator-Conversion-Plug_30984.htm .

I don't understand the nature of the installation without the conversion plug. Can someone explain?
thanks
David
A tach must be able to adjust for the drive speed and output pulse frequency of the alternator. The one wire conversion probably has a different regulator. Jim
 
A tach must be able to adjust for the drive speed and output pulse frequency of the alternator. The one wire conversion probably has a different regulator. Jim
It's a mechanical tach drive. I'm uncertain of the nature of the charging system installation if not using the 'conversion plug'.
 
Looks to me like the "conversion plug" feeds alt terminal #1 (excite) by a resistor connected to sense terminal #2. There will be a 24/7 drain on the battery by this method of one wire conversion. My opinion: not a good method.

1738089518360.jpeg
 
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What are you installing this on?? Here is a generic diagram for a Delco 10si alternator. The side spade terminal 1 has to be fed by the ignition through a diode as shown. If the machine is diesel with a manual fuel shut off the diode can be eliminated. A substitute for the diode can be a dash lamp (ie 194 bulb) wired in the series in the circuit. The wire for the circuit off the back terminal needs to be 10 gauge throughout back to its connection to the battery. Generic Delco 10si diagram
 
What are you installing this on?? Here is a generic diagram for a Delco 10si alternator. The side spade terminal 1 has to be fed by the ignition through a diode as shown. If the machine is diesel with a manual fuel shut off the diode can be eliminated. A substitute for the diode can be a dash lamp (ie 194 bulb) wired in the series in the circuit. The wire for the circuit off the back terminal needs to be 10 gauge throughout back to its connection to the battery. Generic Delco 10si diagram
Gas Ferguson TO30 - that diagram helps, thanks. Our host here does not go into detail about the model of the alternator other than '63 amps'. I've got most of the rest of the tractor sorted out, but the electrical is a cobbled mess as is the existing alternator mounting.

I think I will give a call to the local generator shop and see what he has to say. I don't know if there's a Delco with facility to mount a tach drive or not, he likely will.

Another question occurs to me. I see references to 'using the smallest pulley possible' when making the generator to alternator swap. To have the tachometer work, I'd have to use a stock sized pulley. Will that run the alternator fast enough to work well? This tractor spends most of it's life pulling a herbicide sprayer which uses a 12v pump to apply chemical. I don't really want to have to run the engine at hight RPM's to make it work.

Another possibility is a 12v generator...
 
Gas Ferguson TO30 - that diagram helps, thanks. Our host here does not go into detail about the model of the alternator other than '63 amps'. I've got most of the rest of the tractor sorted out, but the electrical is a cobbled mess as is the existing alternator mounting.

I think I will give a call to the local generator shop and see what he has to say. I don't know if there's a Delco with facility to mount a tach drive or not, he likely will.

Another question occurs to me. I see references to 'using the smallest pulley possible' when making the generator to alternator swap. To have the tachometer work, I'd have to use a stock sized pulley. Will that run the alternator fast enough to work well? This tractor spends most of it's life pulling a herbicide sprayer which uses a 12v pump to apply chemical. I don't really want to have to run the engine at hight RPM's to make it work.

Another possibility is a 12v generator...
If you want to use the stock generator pulley on the alternator you are best to use a 3-wire alternator.
 
The alternator shown in your link looks to be a Delco 10si model equipped with a mechanical tach drive.
Just got off the phone with my generator/starter guy. The good news is that a Delco 10si is readily available, with the correct 1/2" pulley, one wire, low speed turn on, tach drive. Two days away. Bad news is that it's $325. He also has an adjustable/slotted bracket to make aligning pulleys easy. $40.

He says lots of guys working on old Case and Allis use them.

Nice to talk to someone who doesn't stare blankly when posed the question....
 
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