Even such a mundane component as a resistor has special requirements when it comes to high voltage applications. The usual little 1/4 watt carbon film resistor used in most other electronics is only rated to 250 or 500 volts, a far cry from the kilovolt levels needed. The voltage limitation is usually set by power dissipation issues: a 10K resistor with 1 kV across it dissipates 100 watts! And, of course, the physical length of the device of around a centimeter means that around 5-10 kV, arcing around the resistor body is a significant problem. There are a number of manufacturers of resistors intended specifically for high voltage applications, and of course, you can construct a resistor suitable for your application.
Commercial products
- High resistance, low power - These are typically used for measuring high voltages as part of a voltage divider (or as a meter series multiplier). Generally constructed by thin film techniques on a ceramic substrate of appropriate size for the voltage rating. Suppliers include Caddock, Gigohm, ....
- High precision - Used in precision voltage dividers for measurement applications.
- High power - Typified by the products of the Cesewid corporation (formerly Carborundum), these units are designed to take large peak or average powers and are often constructed so they are non-inductive. A typical application would be as a current limiting device in a capacitor discharge circuit, components in pulse forming/shaping networks, or as a energy dump load. Suppliers include Cesewid and Maxwell Labs..
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