What caused the servo to burn out

power supply

I'm working on a servo project. I connected 12 servos to a single Adafruit servo shield and plugged in a 5V 10 amp (http://www.adafruit.com/product/658) switching power supply to the shield. Instantly, the motors became very hot and one of the motor became unresponsive.

What could be the reason for this? The only rational reason would be that a large amount of current went through the motors but physically how could this happen? I thought V = IR, since voltage at 5 V, then current should have been divided evenly across the motors so it would have been very small?

Best Answer

(EDIT: This answered OP's original title question, which was "What happens if you use a load that exceeds the maximum regulated current output from your power supply?")

As for the power supply overload question, it depends on the power supply. Some behaviours include:

  • latching the output off
  • reducing the output voltage while keeping the output current constant
  • hiccupping (switching the output off and on)
  • going into thermal shutdown with autorecovery
  • blowing a fuse
  • blowing up

It will all depend on the power supply itself and the nature of the overload.