boosting the car's 12VDC to 24 or 48 VDC

[livehho]

I've gotten Leese-Neville units from industrial equipment that were rated at 28 volts 200 amps. I have seen some very large construction equipment with 48 volt 100 amp alternators, but I dont recall the manufacturer. (but they are about a foot in diameter and nearly a foot long too)

If you take a stock alternator apart and just supply a constant voltage to the rotor field coils and you will get a proportional output that varies with the RPM's. Many stock GM alternators rated for 12 volts at 100 amps can hit well over 100 volts at 50 amps doing that! (10K+ RPM's though)

With the GM and most internally regulated alternators you can cheat the regulators voltage reference signal and fake it into boosting the actual output. Just put a voltage divider on the reference line. But if you get much over double the normal running voltage the regulators internal components burn up!
But you can still get around that by using an external power source for the regulators control power.
Most alternator regulators have a master current feed line coming from either after the main bridge rectifiers or from an independent rectifier set. Just put what was the normal voltage to that point and the regulator can then control the alternators output at any voltage within reason.

By using the cheater method you could realistically get 48 - 72 volts or higher from most stock 24 volt alternators and still hold the full amp rating too!

Many of the larger commercial and industrial alternators actually have both the positive and negative isolated. That does make them capable of being stacked to a limited degree. Or set up as a dual system with one running standard negative ground and the other running positive ground.

As far as getting a new one check with your local commercial truck and heavy construction or farming equipment dealers.

If you dont mind doing a rebuild your self you can get them at the scrap yards for cheap! Thats were all of mine come from. A rebuild kit is way cheaper than a new or re-manufactured alternator.
Plus while doing a rebuild you can tweak and modify it if you want to!

u know ur stuff huh..

 

[tcmtech]

u know ur stuff huh..

I've played around with, experimented with and done the mad scientist aproach to alternative energy since I was in my early teens (20+ years now)

I've read about countless alternator modifications on the internet over the years and have actualy tried many of them too. The ones I have tried and that did actualy work are what I tell others about. Still there are limits to the actual practicality of these modifications! They do work but are often best suited to specific application uses.

for experimentaion purposes taking a cheap and well used device and modifying it for a specific application is often way cheaper than buying a new unit and hoping you dont accidently kill it the first time you try using it in that modified condition.
Once the sacrificial devices prove its a vaiable design consept then spending money on a new device to do the job become more justifiable.

Buying used alternators from the truck or auto salvage or scrap yards for $10- $20 each and killing several of them in the name of research does not hurt the pocket book so much as buying a brand new $500 unit and watching it die and not having any waranty coverage because you opened it up and modified it!

I do a fair amount of my work specificaly around larger construction equipment and have had many chances to work on, repair, and replace larger than normal alternators. But I dont know all there is to know by any means.

Had I not been in the right place at the right time I may very well could have never found out any of this information relating to the larger application alternators!
I got lucky and fixed one once for a friend and it sort of just snowballed from there.

I just know what I have done and found reasonable to do and work with.