Discussion in 'General Electronics Chat' started by viki2000, Jun 18, 2013.

  1. viki2000

    Thread Starter Member

    Jun 18, 2013
    Varistor, Voltage Dependent Resistor (VDR), Metal Oxide Varistor (MOV)…
    I need one and I have difficulties to find it, to know if what I need/want really exists in reality by various manufacturers…
    Basically I need one resistor which is 56K at 100V and is 112K at 200V.
    The main problem that I have is: based on resistor value at certain voltages to identify that varistor (if exists) in the data sheets of the manufacturers.
    In the data sheets or catalogs or web pages of varistor are all kind of parameters, but I cannot search varistor based on their basic definition: value of the resistor ta given voltages, a curve.

    How do you find/identify the varistor based on resistance/voltage variation curve at manufacturers?
    If you know one manufacturer, could you provide some examples?
  2. Andreas

    AAC Fanatic!

    Jan 26, 2009
    A MOV (Varistor) is used for circuit protection to shunt high transient currents away from more delicate components. Resistance doesn't really come into it from a specification point. Capacitance on the other hand does but in any case you can spec your MOV by considering what the Varistor Voltage, Clamping Voltage and Clamping Current should be.
    A search from any of the big suppliers yields results. I.E. Digikey, Farnell, RS Components to name a few.
    If you have a dud one then take a photo of it and post it up and someone should be able to give you more information on what you need.