Alternator Regulation

[crazyhorse]

Since most alternators are "automotive" types (full charge for a few minutes then trickle), is there any circuit diagrams out there to make your own external regulator?

[Cheechako]

The basic Ample power unit is good. Control panels allowing dialed amperage and a meter used to be sold but they were discontinued, (one version had the option of a high output regulator built in with a switch for manual or regulated operation.). (Cruising Equipt Company?) Basically, you can regulate it with a large rheostat or poteniometer if you want, but be aware, you can fry batteries or your alternator pretty easy. I found a huge difference in output between the Ample Power reg and the Balmar (ARS version II) in the same boat with the same alternator. The ample power allowed the 100 amp alternator to put out 75-80 amps for maybe 20 minutes or so, the Balmar backed off a lot earlier and only asked for 70 amps or so. Something cool might be a rheostat with a temperature sensitive relay that connects to your Alternator, kicking it out at a given temperature. It's just hard to beat a good 3 step unit that does it all for you....

[boden36]

There is a way of making your own. Find the internal wire between the alternator and the regulator , cut it and solder some lengths of insulated wire onto the cut ends. lead these outside the alternator to a convenient place.
Get three reasonably robust diodes (from an old alternator maybe) wire them in series between the two wires that you led out of the alternator.
Each diode has a voltage drop of 0.6 of a volt, so the three in series equal 1.8 volts.
This voltage drop tricks the regulator into thinking the battery is 1.8volts lower than it really is, and it puts the charge in at a high rate.
You want to regulate the charge, so wire three switches, one across each diode.
With all the switches turned on, the system workes as normal, but as you open each switch you introduce an added voltage drop and the charge increases.
You will need heatsinks for the diodes.
I made one of these systems with a Bosch alternator some years ago and it worked well.
Make sure your batteries can accept the extra charge. I disconnected it when we got gel batteries.
Regards, Richard.

[colemj]

Richard,
I think your basic idea can be implemented simpler. Couldn't you just put the diode switch bank in line with the field sense lead to the alternator and leave the internal regulator alone? If you do it that way, you can use cheap, light zener diodes instead.

Mark

[boden36]

Thanks Mark, that's what I did, but I guess my explanation was not too clear. Regards, Richard