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Old 09-24-2012, 10:05 PM   #75 (permalink)
rmay635703
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Quote:
Originally Posted by SeniorSell View Post
Hey Ryan, I read your earlier forums on a piece of bare wire shunted across by an aux contactor once above 25 or so. Is that correct?
Nope, the main contactors on the miles have nothing to do with field weakening.
Everything you need to do is done by tapping the field terminals on the motor itself. The motor has 4 terminals (2) are for field, add some addition cables to those to mess with the field.

Anyway...

My first version was two 6' sections of 8 guage wire with a hacksaw blade resistor, it worked poorly.

I used a jumper cable clamp and did the same thing and omitted the hacksaw blade and it worked great but put a lot of stress on components. Top speed went from roughly 29mph to 36-38mph.

I ended up with a starter relay and went down to 10 guage wire. Top speed is 32-36mph but there is less stress on the motor and controller. I also can flip a switch on the dash to turn it on and off instead of attaching a jumper cable under the dash.

SO what is is field weakening?

The motor has a field winding, you "short out" the field winding with wire that hopefully has roughly the same resistance as the field itself more and it is less effective, less it can become TOO effective and burn something up.

Cheers
Ryan
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