This article focuses on electrical resistors that dissipate high power through the Joule effect. Operating at high temperatures (over 400°C), they are made of refractory materials. They are a key component in Joule-effect heating systems (electric furnaces, hot-forming devices, etc.). Electric motor starting and braking rheostats also use the same refractory materials.
For other resistors, please refer to the articles Resistors. Potentiometers
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, Semiconductor ceramics
[13]
and Varistors
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, in the Electronics section, and, for ceramic varistors, to the Specific components for protection against interference sections
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in this section.
After reviewing the operation of electrical resistors or "heating elements" in the case of electric furnaces, we present the various refractory materials used, focusing on their limits, service life and current applications. For a more complete overview of all furnace components (insulation, regulation, power supply, etc.), please refer to the article Electrothermics. Joule effect heating in this treatise
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.