Resistor Dictionary, Terms, and Definitions

Resistor Terms:

Resistor Encapsulation

Encapsulation: A plastic protective coating applied to a component. The plastic determines the color, finish and hardness of the finished part. Note that the type of encapsulation may effect the resistors power rating; refer below. Except for the application method Encapsulation and Potting are nearly the same thing. This style package may also be called conformal coated, which just means that the resistor package has been coated with a material that conforms to the shape of the package being coated.

Derating an Encapsulated Resistor

Derating: Guide Lines to derating a resistor. The process of reducing the rated wattage of a resistor based on the possible maximum operating temperature. The curves above show different derating guidelines depending on the encapsulation material; either Epoxy or Thermoplastic. The graph applies to a Surface Mount Chip resistor.

Encapsulated SIP Resistor

Encapsulated Resistors The graphic shows two encapsulated resistor networks, one covered in yellow plastic, the other encapsulated in red plastic. Component encapsulation is the same regardless of the component being a resistor network, a capacitor network or a hybrid combination containing both resistors and capacitors. See the definition of SIP Package.

Editor note; I'm not aware of the actual color of the coating meaning any thing. The color of the coating may just be a marketing tool, although having different colors could help with installing the part. As it should be easier to distinguish the color difference than the text printed on the component.