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  1. #1
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    dielectric withstanding voltage

    I need to know what does “Dielectric Withstanding Voltage” means in a high voltage resistor, as in a resistor the voltage is applied to its leads which are metal not dielectric.

    In a capacitor, “Dielectric Withstanding Voltage” has a clear meaning because the voltage is applied across internal dielectric, but in a resistor what does it mean?

    •   Alt24th February 2009, 17:07

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    withstanding voltage

    Most resistors, except for a straight wire, are build on a dielectric body and can suffer from dielectric breakdown, if the voltage rating is considerably exceeded. So the meaning is obvious, I think. With DC load, only high ohmic resistors are at breakdown risk, while low ohmic reach thermal overload first.



    •   Alt24th February 2009, 17:37

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    dielectric withstand voltage

    You are right, but what confusing me is that “Dielectric Withstanding Voltage” for a 40KV resistor (100MΩ) is only 700V or at most 1000V (as in manufacturers datasheet). does it mean the dielectric will damage in rated voltage? If no, what does it means?



    •   Alt24th February 2009, 19:24

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    what is dielectric withstanding voltage

    Yes, that sounds confusing. In this case the specification is apparently designating a different property, i guess, the electrical strength of the encapsulation. But it should be explained in the datasheet.



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    dielectric withstanding

    Means that the maximum applied voltage is not to be calculated with Ohm law but must be a maximum that is written on the data sheet

    Working with a voltage across the resistor that is above the maximum allowed will bring to arcing and surface currents that will destroy the resistor and probably also the electronics around

    Also another question

    A 100 MOhm resistor is a special resistor used in very special circuits and seems to me that a voltage of only 1000 V is too small

    Isn't just a theoretical question ?

    Mandi



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    definition of resistor withstanding voltage

    to FANT:

    If you look at High Voltage resistor manufacturer, you will find high voltage resistor with resistance value more than 10GΩ (10,000 MΩ) and voltage ratings above 20,000 Volts. 100MΩ is completely practical in high voltage circuits.

    for example look at this website: http://www.token.com.tw/resistor-hv/resistor-ri82.htm



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