Thermistor

 

Defenition: A thermistor is a type of resistor whose resistance varies with temperature.

Spindle usage: Thermistors are placed on or near the spindle stator to monitor the heat of the motor windings. The machine control monitors the outputs of the thermistor and if the outputs reach an overheat level the spindle is shut down.

There are two types of thermistors used in spindles, one increases the resistance as the temperature increases and one decreases resistance as the temperature increases. For obvious reasons the proper thermistor needs to be installed if they are found to be faulty or if the field needs to be rewound.