Re: 1 wire alternator confusion

Posted by DavidPackard On 2022/12/8 22:20:17

Humanpotatohybrid:

14.8 volts seems on the high side for a warm condition, especially after a 10 minute drive.

A 7 year old battery that has been at a low state of charge for the last 4 years is well beyond my experience. I would think that battery may exhibit static voltage non-repeatability.

Oldsmobile manual was referring to a 12 volt system.

I would do the excitation current calculations using the battery static voltage degraded with one start. A fraction of a second later the excitation on terminal 1 will bring the alternator ‘on-line’, but before that the voltage will likely be 12.0 – 12.5. Quite academic . . . I think the 1 ampere target has quite a bit of bandwidth.

Think about a 16 ohm resistor in parallel with the 20 cp bulb.

All of this discussion about an excitation resistor talks to the ability of the alternator to ‘cut-in’ at low speed. You didn’t add any additional information on that subject. I’ll assume that’s still the issue.

I looked at your link to Digikey. I looked on that site also but restricted my search to Ohmite units.

You may try battery voltage to terminal 2. I have seen some discussions on over voltage if terminal 2 is not connected. That was not a Delco document so I took it with a grain of NaCl.

I agree the terminal 2 feature was introduced to enable packaging or a general reduction in circular mils.

I’ve experienced missing CRLFs when composing in Word and then ‘cutting and pasting’ into the forum. This posting was composed in Word with one additional CRLF included in Word . . . NO additional clean-up in the forum's textbox.

dp