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Author Topic: Have I burned out my motor controller? Beyond repair?  (Read 882 times)

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Offline DaaniiTopic starter

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Have I burned out my motor controller? Beyond repair?
« on: May 09, 2011, 10:33:14 PM »
I bought a Pololu Simple Motor Controller (www.pololu.com/catalog/product/1373)that I have been using with a windshield wiper motor. I smelled something getting hot, and thought it was my potentiometer shorting out. Turns out it was the motor controller.

Now whenever I plug my 12V power source into the motor controller, it starts heating up gradually. It never used to do that before. I tried using it to control the motor, but get nothing.

I can't think of what I might have done to ruin the motor controller. But it looks like I have. Nothing physical seems to be wrong with it, from a visual inspection. Is there anything to check or fix?

Offline Kylepowers

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Re: Have I burned out my motor controller? Beyond repair?
« Reply #1 on: May 10, 2011, 11:26:52 AM »
I think you might have damaged one of the chips on the board. Which then will slowly heat up over time. It might be able to be fixed if you can solder but im not sure. Im also talking shot at whats wrong with it.

Offline Soeren

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Re: Have I burned out my motor controller? Beyond repair?
« Reply #2 on: May 10, 2011, 10:26:31 PM »
Hi,

I can't think of what I might have done to ruin the motor controller. But it looks like I have. Nothing physical seems to be wrong with it, from a visual inspection. Is there anything to check or fix?
Did you perhaps remove the power while the motor was still spinning?
(That would be one way of doing it).

A fix really depends on whether you can find the fault.

The damage could be as little as a diode, a small signal transistor or eg. a cap that failed, or it could be more serious, but without knowing its innards, I don't even know if I could talk you through it - do you have a schematic of it?
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline kl22

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Re: Have I burned out my motor controller? Beyond repair?
« Reply #3 on: May 11, 2011, 10:22:14 PM »
Hey,
I did the same thing with my Pololu Simple Controller.

Tried to use it on a RC car motor and it fried when the stall current kicked in. One of the MOSFET's (at least I think its a mosfet) in the h-bridge (looks like a h-bridge to me :D) went up in flames.. literally in flames and almost set my li-po on fire. Talking to Pololu right now to see if I can get it replaced because they told me that it would work perfectly with my motor. Maybe you should try the same? Contact them via [email protected], they got back to me within 2 hours at 9PM EST. They ask a lot of questions so be prepared :D.

I'd suggest looking at the 4 ICs hidden under the Cap, one of those is what fried for me.

Offline DaaniiTopic starter

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Re: Have I burned out my motor controller? Beyond repair?
« Reply #4 on: May 14, 2011, 02:28:44 PM »
It is hard to tell what is not working on my motor controller now. It is also hard to tell what might have caused it to fail. But given its small size, I'm sure it is beyond my skills to fix it.

Soeren, you mentioned that removing power while the motor is still spinning might be a problem. I don't recall doing that. But why would that cause a problem?

Offline Soeren

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Re: Have I burned out my motor controller? Beyond repair?
« Reply #5 on: May 14, 2011, 05:51:05 PM »
Hi,

It is hard to tell what is not working on my motor controller now. It is also hard to tell what might have caused it to fail. But given its small size, I'm sure it is beyond my skills to fix it.
Then there's no loss if you fail - a nice opportunity to test your skills :)


Soeren, you mentioned that removing power while the motor is still spinning might be a problem. I don't recall doing that. But why would that cause a problem?
It depends on the protection installed in the driver unit of course, but say the motor is spinning fast(-ish) and you take the power, the motor will be a generator until it stops and can generate quite high voltages (depending on the exact motor).
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline kl22

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Re: Have I burned out my motor controller? Beyond repair?
« Reply #6 on: May 14, 2011, 08:31:10 PM »
Soeren is correct about it not having the protection to handle the motor situation. The only protection it offers is temperature nothing else (from what I gather from the datasheet for the controller).

 


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