Ceramic Resistor Construction

Terminals are attached and the insulation coating is applied to the outside.

Ceramic resistor construction.

Their resistive elements are commonly lengths of wire usually an alloy such as nichrome nickel chromium or manganin copper nickel manganese wrapped around a ceramic or glass fibre rod or tube and coated in an insulating flameproof cement film. This resistor consists of two terminals like a normal resistor. The construction of a carbon film resistor can be done by placing the carbon layer on a substrate of a ceramic. The construction of ceramic composition resistors concentrates nearly all of the component mass into the resistive element resulting in a rugged device with high energy capacity.

Wirewound resistors are very variable in construction and physical appearance. Tcr varies from 75 till 200 ppm c. However even this description is out of date. Composition resistors are produced using a mixture of a finely ground insulator and conductor.

Cement resistor only describes the appearance of common power resistors like that shown above. The majority of the power wirewound resistors have a ceramic core and a ceramic coating to protect the winding. The resistor is made by taking an alumina or ceramic substrate. It is a nickname for the heat resistant ceramic case in which a coil of resistance wire is potted.

This mixture is then compressed into a cylindrical shape. The end connection electrode bases are then placed onto this and then this is fired to ensure they are robustly held in place. The construction of a resistor is shown in the below diagram. Typical resistance values are in the range from 1ω til 10 kω.

They are most often wire wound resistors. The ceramic coating combines a high insulation and physical protection with good heat dissipation. Metal film resistors are produced by depositing a resistive element on a high grade ceramic rod.