# Gem Car Controller



## madderscience (Jun 28, 2008)

based on about 10 minutes of research, my opinion is your chances of successfully mating the GEM controller with an old WWII aircraft generator is possible, but probably not recommended.

At least the modern gems do use DC with regen, which means they use shunt wound motors, and the aircraft generator you are looking at is also shunt wound. I do not know if the GEM controller that you have is designed for a shunt motor however. Hopefully it says on it what type of motor it is for. Failing that, if there is a separate "field" output it is probably for a shunt wound motor.

Regardless of whether it would be possible at all to make the WWII aircraft generator work, you would be better off looking at more modern golf cart motors with HP rating as close to what the gem motor is as possible. You will find them more reliable, and probably smaller and lighter for the same HP rating as well, not to mention with higher voltage ratings. Only down side with most golf cart motors is they are designed to be intergal with a differential housing, meaning they don't have a front bearing. You'd have to fabricate something to make them work in a different environment.

72V at 350A is a pretty low power controller. I hope you don't plan on building a car with a top speed of more than about 35mph. For the sake of comparison, even the old standby (the curtis 1231) is a 144v, 500A controller. The curtis will get you around OK in a compact to midsize car but you aren't going to be tearing up the road with it.

Good Luck.


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