My new spindle motor has a thermistor fitted rather than a thermal switch like the old one did. Natrually the machine only supports a high/low switched input as a way of informing it about an over heating motor.

So question is how can I use this thermistor connection on my motor to provide a useful input to my machine ? Is there a cheap off the shelf solution which I can connect my motor's internal thermistor to which will switch a relay at a set threshold?

Or what about buying a thermal switch and fixing it to the outside of the motor casing.