Alternator regulator

[Andrei]

Hi,

My name is Andrei and I'm looking for someone who can guide me to modify my alternator regulator for ages. I'm not an electronic guru but I'm confident I can do it. I've been reading many threads and different opinions about how to do it but nothing helped. Recently I have found Gary's web page that looks promising but no circuit diagram (by the way wish you all the best). On his page I have found this forum so I thought to give it a try.
I want to build an adjustable external regulator for my alternator that allows me to set the voltage output, I need to get it up to 15.5V when I need and then take it back to 13.8V, does anyone knows how to do it?

[retiredat55]

Hi Andrei,

In my opinion you can use Gary's diagram for the car alternator and make a switch for choosing
different zener diode or just switch 3 extra diodes in place of the 1N4148 diode in the schematic
diagram, just to get a higher output. (see also Gary's text in the description)

chemelec.com/Projects/Alternator/Alternator-Reg.htm


Take care,

Dante

[Andrei]

Hi,
I was wondering if someone has modified it to use a potentiometer instead for more precise adjustment

[volkswagenvan]

Hi Andrei.
Your looking for a variable reference voltage to use on Gary's regulator.
It can be done but it would be Best to do what Dante has suggested.
A pot can drift in value with temperature and be quite a pain.

What are you trying to do that you need to swing 1.7 volts?

[retiredat55]

If your circuit must be "adjustable" you can play with a TL431 like in the next diagram which takes the place of the zener (and 1N4148) in Gary's diagram.

ozcott.com/NomadTronics/product/tl431a-adjustable-zener/

[Andrei]

I was thinking about replacing the zener with a pot but I'm not sure how to do it and if the rest of the components will be happy with the mod. So if I use the TL431A with a pot instead the zener and 1N4148 I should get a adjustable regulator, but who is going to set the max output voltage in this case?

[volkswagenvan]

Whoever adjusts the pot i would guess.