Blown Victors - WHY?

[Jeff K.]

It was probably just as other people said, some metal shavings that brought out the magic smoke.

[greencactus3]

shorting. metal. reverse ploarity. or overload (which i guess will fall into shorts). or moisture inside.

[Al Skierkiewicz]

Originally Posted by wmurphy

We built a prototype robot that worked fine using a base plate of press board to mount the electronics; however, when we changed the press board to a metal plate - TWO VICTORS BLEW! What is the problem? Continuity tests check out O.K. Victors did not blow until joysticks were moved.

In addition to the above suggestions, might I add the following...
Remove the output wiring from the controller and check the Resistance of the wiring with a good VOM. It should be low but not zero. If it is zero than disconnect one of the motor leads and try again. If it is still zero, check for continuity from each of the output wires to robot frame. It is possible that when moving to the metal frame some wires were damaged or crimped under the mounting hardware. If you ran wiring through a metal channel on the metal base, someone may have drilled through the channel and into some wiring shorting the wires. My bet is shorted wiring or reverse wiring on the controllers. I would mark each controller for input voltage and motor output so there will not be confusion when mounting or wiring the controllers.

[Rickertsen2]

Are you sure the victors are really bad? in my experience about 85% of speed controller issues are really PWM cable issues. What are the symptoms of blown-ness?

After that i would check for metal shavings in the fins of the FETS. At different times some are HOT and others a Ground..... metal shavings from hot to ground = bad!!

This may sound stupid bit is worth mentioning. Don't blow compressed air into the victor fans.. It makes them go VERY fast and produce a voltage the the victors are not designed to withstand.


Fun little experiment:
Take one of those useless little muffin fans included in the kit and blow conpressed air through the blades. If you get the angle right, it will spin unbleievably fast and make an earsplitting noise. Don't do this to a fan you are using.