Motor shield v2.0 fire

Adafruit Ethernet, Motor, Proto, Wave, Datalogger, GPS Shields - etc!

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
peteb238
 
Posts: 2
Joined: Mon Dec 29, 2014 7:08 pm

Motor shield v2.0 fire

Post by peteb238 »

I've connected a Pololu 12V DC motor (http://www.pololu.com/product/1106) to a brand new V2 Motor Shield, as well as a 12V battery to the external motor shield power, with the Vin jumper removed. I ran the DC Motor test from the Adafruit libraries successfully for several minutes on the M3 port. I did stall the motor for a few seconds to test the torque, and after another couple of minutes the motor port stopped working. I reconfigured the motor to another port (M1) and it started working again. The TB435A1 chip on the M3 port side caught fire after another couple of minutes. Can you please explain why this happened? I'm guessing the stall current (5A) fried the chip. Why was that chip even getting power when no motors were configured or powered on that side? Is this defective behavior? I have had multiple motor shields from you that have never done this. Can a current limiting resistor be put in line with the motor to prevent this? Are there more powerful motor shield options for arduino that would be recommended?

Thanks,

Pete

User avatar
Franklin97355
 
Posts: 23912
Joined: Mon Apr 21, 2008 2:33 pm

Re: Motor shield v2.0 fire

Post by Franklin97355 »

These can be controlled by a micro http://www.pololu.com/category/10/brush ... ontrollers As to why the chip burned, it may have been damaged by the overload and failed internally.

User avatar
peteb238
 
Posts: 2
Joined: Mon Dec 29, 2014 7:08 pm

Re: Motor shield v2.0 fire

Post by peteb238 »

Thank you, is there no overload protection built into these things? It would seem like something that be necessary since a lot of motors in the listed spec range could potentially overdraw current in certain situations. Is this item eligible for exchange/refund?

Thanks,
Peter

User avatar
adafruit_support_mike
 
Posts: 67454
Joined: Thu Feb 11, 2010 2:51 pm

Re: Motor shield v2.0 fire

Post by adafruit_support_mike »

The Motor Shield is a very simple H-bridge controller intended for light-duty work. It doesn't have overcurrent limiting, chopping, or any of the other features you'll find in more advanced motor controllers.

WRT replacement, the product page and documenation make a point of saying the TB6612 can deliver 1.2A per channel and a peak current of 3A. A 5A load is well beyond those limits, so I'm afraid this doesn't qualify for replacement.

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: Motor shield v2.0 fire

Post by adafruit_support_bill »

is there no overload protection built into these things?
There is thermal overload protection. But in extreme overload conditions, it is entirely possible to incur damage before the thermal sensors can detect a problem. The absolute maximum rating for the chip is 3.2A for a 10ms pulse. 5A for a 'few seconds' would be a rather severe overload. http://www.adafruit.com/datasheets/TB66 ... 121101.pdf
Are there more powerful motor shield options for arduino that would be recommended?
www.pololu.com has some with higher current rating. There is also www.robotpower.com/catalog/

Locked
Please be positive and constructive with your questions and comments.

Return to “Arduino Shields from Adafruit”