[SOLVED] What is the difference between varistor and thermistor?

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RHeTTRoNiCS

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Been googling it also but need your ideas based on experience. Is the varistor always on a high-ohm (normally open), connected in parallel....and will "short" for any voltage surge? Is the thermistor always on a low-ohm (normally close), and connected in series...and will "open" for any increase i temp? Thanks a lot.
 

A varistor is essentially an open circuit until its breakdown voltage is exceeded which point it begins its resistance drops steeply. A thermistor is more of a temperature sensitive resistor; it's not "normally closed", it's a resistor.
 
You COULD think of varister as a zener diode

and

a thermistor as a resistor which is very temperature dependent
 
That would depend on what the function of the varistor is, don't you think? If it's just for protection, go ahead and test your device.
 

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