electrical engeeners and like minded

For my electric vehicle I plan on extensive reworking this winter I need to regulate the voltage at 80 volts on an altermator. I do have an army surplus regulator rated at 300 amps 28volts DC Any help will be really appreciated. [email protected]

You can use a transformer to step up the voltage, probably the easiest way to go. Your amperage is going to go up with the lower voltage. With trains the change speed by regulating the amperage, not the voltage.

No great problem, just put in a resistive voltage divider on the voltage sample line, so the regulator sees 28/80 th the output voltage. Then the limits are the voltage rating of the field pass transistor and the voltage ratings of the rectifier diodes. Long ago, car alternators used to be able to run 120 volts DC with an adapter between the regulator and the alternator, but these days they fry the diodes because while diodes are better controlled the makers choose lower voltage rated diodes to save money.

Gerald J., Electrical ENGINEER.

You cannot transform DC voltage, only AC voltage can be stepped up or down, it will have to be controlled through resistance.

Hi Bill,

I'm going off the top of my head and that can be really dangerous.
It's been too many years since someone picked my brain on the
subject, so what you get may be a little rusted.

The alternator/generator output is determined by the input.
Example: 12vdc at 100amp rating = 1200w@ 2000rpm is common
By applying a 80vdc input, then you'd expect a 15a output@2000rpm
80x15=1200w so your not exceeding the rated capability of the
alternator/generator.

To make the 80vdc input, you can series low ahr battery's.

From reading about current hy-brid vehicles using NIMH battery's,
there using a 80/20% rated state of charge to yield long battery life.
Me, I can't see why all battery recharging can't use the 80/20 scheme
on dry cell battery's to yield the same results.

If this is true, then one should be able too use a common made 90vdc regulator to regulate a 80vdc battery bank state of charge.

Depending on the 90vdc regulator spec's, that's going to put you in the 100vdc range on a full state of charge battery bank.

Using a common IC555 timer circuit, you can disconnect the generator input fields at 80% or 20% thus not over charging the battery's.

The IC555 timer circuit schematics should be easy to obtain over the internet. There very easy too roll/build your own.

A good source for home brew DC electronics is the ham bible, aka the ARRL Handbook, a great one source text reference.

T_Bone

Gerald J.
I wonder if your point was recognised.

That regulator may have came off the electric drive T23 tank. They also had a 300 amp generator. Knuckey Truck company in California
made this electric drive Mobile Field Dynamometer from the parts in this electric drive tank in 1945-1946. It used 2 500hp Ford engines from that tank too. There's one of those tank's at Ft Knox KY on display. We used this vehicle for drawbar and cooling tests. Hal