# Operation of a Curtis 1231C 144v controller??



## clone477 (Sep 21, 2008)

Hello everyone,
I had a question about this and simular controllers. I always assumed that Series DC motor would have two connections, power going in to first field coil, then to first brush, then to coil of armature, then out of brush, to last field coil, and finally to other terminal of battery. 

But after looking at the 9" ADC and Warp motors, they have 4 terminal connections. There are two for the field coils, and two for the armature coils. 

When looking at the wirring diagrams of the controllers and motor, battery positive goes to A1 of motor(feeds two armature brushes), S2 goes to connection on controller M-(why doesn't it go back to battery negitive??).
Then A2 off controller powers A2 and S1 on motor(other side of field coils and other two armature brushes).

I know the controller PWM the power to feed the motor, but why does the negitive run back to the controller and not the battery negitive directly?? 

Thanks for any help guys.


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## elevatorguy (Jul 26, 2007)

I am not a controller expert but the M- is the PWM output to the motor and controls the motor. B+ is positive and on with the main contactor. A2 is used for plug braking if used, and looks like it may be used for current sensing in the controller, at least by the block diagram I looked at.
If the M- is hooked to ground, the motor would see 100% power
Hope this helps.


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## HDS (Aug 11, 2008)

I think that with the motor you have, S1 & S2 are available for the purpose of running the motor in forward or reverse. With external relays, you change the direction that the current flows in the motor field; S2 to S1 in Forward or S1 to S2 in reverse. 

If you go to www.curtisinstruments.com you may find the schematic that you need. 

Good Luck


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