Simple 18v15 one direction only

Support Motor controllers/drivers and motors
1

Hello,

I have connected the Pololu Simple High-Power 18v15 Motor Controller to a 22v motor and a 12v battery using only Vin, Gnd, OutA, and OutB and the USB connection. On the Simple Motor Control Center, I can control the motor just fine in one direction - changing ramping, max speed, etc… but when I try to make the motor go in the opposite direction, I get an over temperature error. When I use the incremental buttons to set the speed in that direction, I get to .16 and the temperature starts to increase. At .22 the temperature has climbed to 42 degrees C, and at .25 the motor is shut down with the over temperature error message. In the ‘good’ direction, the motor will ramp smoothly from 0 to 100% staying at about 25 degrees C.

When I invert the motor direction on the control center, I have the same problem but with the directions reversed on the control panel. If my problem was with the positive direction, now positive direction is fine and negative direction is overheating. I have tried resetting to the default settings several times.

I’ve disconnected the motor and made sure that it is running well in both directions directly from the battery. I’ve reversed the leads into the OutA and OutB terminals. Now the motor runs in the opposite direction but the same problem happens when I try to reverse its direction on the control center.

Any idea what might be happenning?

2

Hello,

Can you tell us the specific model of your motor or at least what its stall current rating is?

-Paul

3

Hello.

What happens if you do the same tests without the motor connected? Does the board start getting when trying to drive in one direction? Was the board ever able to drive the motor in both directions?

- Ben

4

Hello,

I don’t know what the stall rate is. The motor is a second hand Matsushita GMN-6MP026A, part # FH7-1750. Yes, the 18v15 is doing exactly the same thing without the motor connected. It goes all the way to 100% in one direction but overheats in the opposite direction.

5

It sounds like one of the H-bridge MOSFETs has been damaged in a way that prevents it from turning off. Please contact me directly at ben at pololu dot com for an RMA number.

- Ben