Re: One Wire 6 volt positive ground alternator
Posted by DavidPackard On 2015/8/26 22:23:11
Hello again;
As a parting shot I've included a photo of the PowerGen 'old school generator' alternator installed in my '48.
I completely agree with BigKev on the superior attributes of a three wire installation, versus the quick and dirty one wire installation of a Delco 10SI type alternator. You can dramatically change the 'cut-in' speed of a Delco 10SI by trickling an excitation current to terminal 1. I would recommend something near 1 ampere of current. That would be 6 ohms of circuit resistance if your car is 6 volt, or 12 ohms for a 12 volt system. I have many years of experience with an alternator with one ampere of excitation. That amount of current lowered the cut-in from 1100 rpm to 400 rpm on my '30 Model A ( converted to 12 volt negative ground ). When that car was 6 volt positive ground with an alternator I did not perceive a late cut-in. By the way I have a few pages from a Toronado shop manual, and that shows a 10 ohm resistor in parallel with the 'idiot' light, with both connected to terminal 1 of the alternator.
Terminal 2 is intended to be the battery voltage feedback to the alternator . . . very useful if the battery is electrically a long way from the alternator. Note the emphasis on 'electrically a long way' that could be a short distance with undersized conductors (wires), or a large physical distance, as in the battery mounted in the trunk. I think that feature was built into alternators to help reduce the amount of copper GM was putting in cars. My shop manuals show this terminal connected to a battery junction block. The Saturday night show crowd run a short jumper wire from the alternator output back to terminal 2. The irony is that many 'one wire' internal regulators have this feature built-in.
I have a pretty comprehensive Delco alternator parts book. I have not found rotors or stators specifically for 6 volt applications. I do find a distinction between 12 volt versus 24 volt components. I've assumed 6 volt alternators are assembled using 12 volt components. There are 6 volt specific voltage regulators ( no surprise there ), and positive or negative ground specific rectifiers ( again no surprises ). Some of the regulators are clearly described as 'one-wire', and some regulators have webbed terminals ( terminals 1 and 2 connected together). I'm not sure what that's all about yet.
You can go too far wrong installing a 'one wire' alternator with only one wire connected . . . that is the intent of that product. My motivation with the Model A was to configure the wiring to accept a standard replacement alternator available as a 'rebuilt' from any parts house just in case of a break-down a long way from home. The GM standard was a three-wire configuration, so that's how I wired my Model A. Along the way to that goal I got a cut-in speed more suited to the Model A's idle speed. If the PowerGen on the '48 lets me down on the road, then a considerable more creativity will need to be exercised.
dp
Attach file:
(109.10 KB)
As a parting shot I've included a photo of the PowerGen 'old school generator' alternator installed in my '48.
I completely agree with BigKev on the superior attributes of a three wire installation, versus the quick and dirty one wire installation of a Delco 10SI type alternator. You can dramatically change the 'cut-in' speed of a Delco 10SI by trickling an excitation current to terminal 1. I would recommend something near 1 ampere of current. That would be 6 ohms of circuit resistance if your car is 6 volt, or 12 ohms for a 12 volt system. I have many years of experience with an alternator with one ampere of excitation. That amount of current lowered the cut-in from 1100 rpm to 400 rpm on my '30 Model A ( converted to 12 volt negative ground ). When that car was 6 volt positive ground with an alternator I did not perceive a late cut-in. By the way I have a few pages from a Toronado shop manual, and that shows a 10 ohm resistor in parallel with the 'idiot' light, with both connected to terminal 1 of the alternator.
Terminal 2 is intended to be the battery voltage feedback to the alternator . . . very useful if the battery is electrically a long way from the alternator. Note the emphasis on 'electrically a long way' that could be a short distance with undersized conductors (wires), or a large physical distance, as in the battery mounted in the trunk. I think that feature was built into alternators to help reduce the amount of copper GM was putting in cars. My shop manuals show this terminal connected to a battery junction block. The Saturday night show crowd run a short jumper wire from the alternator output back to terminal 2. The irony is that many 'one wire' internal regulators have this feature built-in.
I have a pretty comprehensive Delco alternator parts book. I have not found rotors or stators specifically for 6 volt applications. I do find a distinction between 12 volt versus 24 volt components. I've assumed 6 volt alternators are assembled using 12 volt components. There are 6 volt specific voltage regulators ( no surprise there ), and positive or negative ground specific rectifiers ( again no surprises ). Some of the regulators are clearly described as 'one-wire', and some regulators have webbed terminals ( terminals 1 and 2 connected together). I'm not sure what that's all about yet.
You can go too far wrong installing a 'one wire' alternator with only one wire connected . . . that is the intent of that product. My motivation with the Model A was to configure the wiring to accept a standard replacement alternator available as a 'rebuilt' from any parts house just in case of a break-down a long way from home. The GM standard was a three-wire configuration, so that's how I wired my Model A. Along the way to that goal I got a cut-in speed more suited to the Model A's idle speed. If the PowerGen on the '48 lets me down on the road, then a considerable more creativity will need to be exercised.
dp
Attach file:
(109.10 KB)
This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=165875