Originally Posted by itzkramer
I left my stir plate plugged in, but not running. The 5v power source burnt out so I'm gonna give one of the radio shack variable DC power supplies a shot.
The fan is 3-wire 12v DC. Any idea why it would have burnt out?
For most common appliances, if you want to turn it off and leave it plugged in ( say for a coffee maker) you put a SPST switch on the hot leg from the wall to the motor. That would stop power from flowing to the device and eliminate the likelyhood of burnout. How have you wired your stir plate? Do you have a pot as a speed control? If you turn it "all the way down" to stop the rotation, even at minimum speed (max resistance) there is still power flowing, which could vcreate trhe effect you describe. You could either install a separate switch to turn the stir plate off or install a pot with a built-in SPST switch (the one that clicks at max resistance) to accomplish the same thing.