Metal Oxide Varistor (MOV)
Varistor current-voltage characteristics for zinc oxide (ZnO) and silicon carbide (SiC) devices
http://upload.wikimedia.org/wikiped...ien.gif/220px-Typische_Varistorkennlinien.gif
Example datasheet...............
http://www.ibselectronics.com/ibs/cmpnts/rgaco/catalog/D/MetalOVD2_16-opt.pdf
Connect MOV and resistor in series
Select resistor so that dissipated power do not exceed Rated Wattage value given in MOV´s datasheet
varistor DC current is normally 1.0mA or lower. (check datasheet)
Connect voltage higher than MOV´s Clamping Voltage to R and MOV series circuit.
Measure voltage across MOV
Test circuit
View attachment 62725