Thread: Blown talon srx modules
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Unread 06-02-2015, 14:50
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Re: Blown talon srx modules
Quote:
Originally Posted by daneelshof View Post
Manually rotating the motors does generate current and can fry motor controllers. We have fried many Victors and Jaguars this way. We have adopted the following "rule" because of this:

Do not push the robot. Do not manually turn mechanisms. Pick up the robot or use a cart to move it.

Also, we've started adding connectors between the motors and the controllers. Among many other benefits, one is being able to disconnect the motor if we need to manually rotate the motor.
Quote:
Originally Posted by GregGarner View Post
Our team has blown 3 talon srx modules. We have been watching very carefully to try to understand how they got fried. The common element seems to be that they stop working when we move the motor connected to the talon manually. My theory is that the motor is generating a voltage that is backfeeding the talon and frying it. We believe at least one of the talons was fried when there was no 12v power on the talon.

We did verify that there is no short to ground or other kind of short. Each time the talon fried it happened on a different motor.

The motors are generating voltage when moved, and if there it's no load presented by the talon then the voltage can be very high.

Had anyone else seen this problem?

We did send the first two units back to crosstheroads electronics but have not heard back from them on the analyses. They did replace the first two.

We will send the third talon back for analyses as well.

The purpose of this thread us to try to understand why we are blowing talons, and to see if anyone else is having a similar problem.
Can either of you offer an explanation as to why numerous teams have pushed numerous robots great distances with power on, or off, and have never suffered a blown motor controller? What about mechanisms (like the drive-train) that create the same back-current as they coast down?

If your theory cannot explain all present evidence, you may want to revise your theory.

In all my years in FRC I have never blown a Victor. Jaguars, sure, never Victors though.
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