For example, a gm alternator for an LS engine may need 8 volts excitation to get 14 volts out,

It depends on the alternator wiring, manufacturer, output, purpose etc.

If someone is in this situation, you can buy the power supply, and start at the lowest voltage on the trimpot, and slowly start turning it up while it's running, while monitoring the output voltage, and then stop when you're at the right output,

Keeping in mind that the charging voltage will increase once you're driving, and to avoid possibly damaging electronics or blowing a fuse, to set it low, as I said possibly attaching via glue, something to the trimpot,

Getting the voltage up to 14.4 at idle,

Then dialing it back to maybe 12v, then going for a drive, and seeing what the output voltage is,

And adjusting it at a highway speed,

And set that speed each time with your cruise control, do not exceed it (do not pass anyone)

Going slower is better than not getting there at all... That's the whole point

Also I believe this will work with almost any alternator, assuming you can bypass the regulator, and keep the diodes intact for DC output, then vary the excitation voltage,

The power supply I used can output as high as 40v, which should be ample, and 15 watts before it needs a heat sink, 3v@1.5A is less than 5 watts so ample

 

*I don't know what the *actual* excitation voltage is for a gm LS alternator*

...

 

You *also* could use an Arduino device, program it to monitor output voltage, keep it within 14.4v, and create a program to add excitation voltage, 1.2 (100mph??) to 3v (idle)

I mean anything is possible with Arduino

Cheaper than a new alternator, and you can afford to have a spare pre programmed or two

Your van will like like doc's time machine inside

All you need then is a flux capacitor

 

Theories, 2:

Set the excitation voltage to idle (3v) if you're in traffic, so the battery charges when idling, however the moment you step on the gas, it would overcharge the electrical system,

Set it at highway voltage (1.78/55mph) and try to stay at highway speeds,

Or, set it to highway speed, (to avoid over charging) and when you get to your destination, set it to idle charging, and let the battery charge for a while while you let your van idle...

This way it will at least stay relatively charged,

Because lead acid batteries, unless they are deep cycle, can be harmed by deep discharge, so best to keep them as topped up as possible,

If you have solar panels of sufficient wattage, they can recharge the battery too

 

Exhaust manifold will get well over 1,000 (F) after driving around a bit.

 

So I believe if the charging control circuit goes out, so does the transmission control circuit,

My van seems to now be stuck in third gear,

I can manually shift it into first while stopped then second , then third

4th is gone.

The adjustment potentiometer on the power supply is tiny and all I can do is use my fingernail to try and turn it,

As I thought highway voltage is too low for in town driving. If I increase the voltage better for in town driving, it quickly hit 15 plus volts once I get going,

Also it shouldbe said if you are driving highway on cruise control and you go up a hill, if the transmission drops a gear to go up a hill, you will suddenly likely have 15+ volts which isn't bad temporarily but sustained it will cook the battery

I am going to try to super glue a piece of metal to the trim pot (or drill a hole in a ****) so I can make quick changes while driving in town/highway.

This is all subject to a 1.2-3v excitation voltage.

I believe there is an alternator out there that can monitor for 14v output and regulate the field coils within 1-3v. Then all I need to do is wire it in to the wires already going to the power supply.

Of note, the vehicles instrument cluster voltage gauge is unbalanced, if voltage drops to 12.2, it falls all the way to the left, 8v mark and the check instruments light and chime comes on, if it goes higher than 15.1 volts, the the gauge swings all the way to the right (and stays there in both cases. The gauge doesn't "recover" even when the power supply is reading 14v. Once it goes one way or the other it stays there.) and I get the check instruments light and chime.

So you cannot rely on the dashboard gauge at all

I would set the power supply to input voltage only as that's the one you want to monitor, and keep it in a place easy to see at a glance while driving so you can make a change if you have to (the dash board will yell at you if the voltage gets too high or too low.)

This is inconvenient, but the van stays on the road, and that's what matters

 

To test a regulator, it may be possible to add + and - 12vdc from a power supply into the inputs (see pi out of the alternator it comes out of.)

And vary the input voltage 10-16v, with a volt meter on the field/excitation coil output, if that voltage is 1-3 volts (maybe more? The alternator regulator should self regulate.)

If the voltage is .5-1v, of course that will not work, same as if the voltage to the field coil is 20-50v which is wayyyy too much.

But if it is within 1-3v it should work

Hopefully.

 

I fabricated a **** for the potentiometer so I can adjust the voltage on the fly,

I have noticed that there is a "saturation" point in electromagnetic flux in the alternator, where the voltage is too low when driving, then I add voltage to the excitation circuit, and suddenly the voltage grows exponentially and becomes far too high.

Whereas if it's idling, the adjustment is far more stable

Also, since the transmission is in limp mode 3rd gear only, and I have to shift it manually, the RPM varies wider than if the computer was controlling it, means the alternator output also varies much wider, which creates under/over voltage as I drive.

I am make the best out of a bad situation

 

I say, "saturation", because I keep the RPM steady while driving, yet when I change the voltage ****, (3/32" drill bit in a brass ****) the voltage does not respond linearly

And it seems to slowly increase, but not proportional to turning the ****,

Such as it takes 3 turns while driving to increase the voltage,

But it only takes 1/4 turn to increase the voltage while it's idling (and it's stable)

Just FYI

Maybe for the Arduino ?

 

It could also be due to the inversion of linear voltage production,

Such as,

At a lower RPM, (idle) it needs a higher excitation voltage,

And, what this does is introduce a higher electromotive potential (higher excitation voltage/current to induce the proper output voltage)

At idle

So the output voltage is more stable,

But at driving speeds, because the rotor is spinning faster,

It needs less excitation voltage - meaning a weaker electromagnetic field,

And this needs more turns of the voltage output,

And,

Is less stable, due to the weaker electromagnetic field in the excitation winding

Okay that makes sense

Is also inverted, so maybe hard to understand at first