Blown Victors - WHY?

[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.