High Voltage Resistors

Questions and Answers

OhmWeve resistors are rated at 20kV and work well in pulsed applications.  They can be wired in series to increase the voltage rating.  Our resistor cages are designed to handle high voltage and heat.  Resistors are rated at 400W ambient, 1000W with forced air.  Click here to see available resistor values.

Q – What is a high voltage resistor?

A – Resistors are devices that resist the flow of electricity.  High voltage resistors are typically defined as any resistor rated for 1000 volts or higher.  See our Resistor Primer page to learn more about basic resistors.

Q – What are high voltage resistors used for?

A – Resistors are used to:

Limit current in an electrical circuit.

Reduce voltage in portions of an electrical circuit.

Dissipate electrical energy by turning it into heat (as with load resistors).

Q – How are high voltage resistors rated?

A – High voltage resistors are rated by:

Resistance – This describes the device’s ability to resist the flow of electricity.  It is measured in ohms.

Watts – This specifies the maximum power the device can handle.  Wattage is calculated with this equation (Watts = Voltage x Current in amperes) or by (Watts = Current squared x Resistance in ohms).

Voltage – This specifies the maximum voltage the device can handle.

Joules – This specifies how many Watts the device can withstand for 1 second.  It is helpful information in pulsed power applications.  This rating is less common than the first three.

Q – How do resistors fail?

A – Resistors can fail from exceeding their specifications on Watts, Voltage or Joules.  The symptoms are:

Watts – failure due to excessive wattage results in charring and smoke.

Voltage – failure due to excessive voltage results in arcing.  Electricity travels across the surface of the resistor, rather than through it and sometimes makes a snapping sound.  This can deteriorate the surface of the resistor or break down the material it is made of.

Joules – failure due to excessive joules results in breakdown of the resistor material.

Q – What types of high voltage resistors are there?

A – There are different ways to construct high voltage resistors.  Construction types include:

Ceramic (cylindrical)

Ceramic (doorknob style)

Film

Electrolytic

Woven