Resistors

What is a Resistor?

A resistor is a passive electrical component with two terminals that limit or regulate the flow of electric current in electrical circuits.

It is typically comprised of a ceramic rod with copper wires coiled around it and an outer part that is coated with an insulating paint.

What is the Purpose of a Resistor?

Resistors are primarily used to reduce the current flow and lower the voltage in a circuit's particular portion.

What is the Symbol for a Resistor?

The resistor symbol is a graphical representation of the device’s presence in an electrical diagram. It denotes the type used and its orientation without requiring a physical inspection.

In a resistor symbol, the main body is generally depicted as a squiggle or rectangle, with the terminals extending from its sides. Additionally, the symbol will usually have a resistance value (Ohms, Ω) and name to make determining its type easier.

Types of Resistor Symbol

Fixed Resistor Symbol

This symbol represents a fixed resistor, a variant with a specific resistance value that cannot be changed. Some examples of fixed resistors are wire-wound resistors, thin-film resistors, and thick-film resistors.

Variable Resistor Symbol

This symbol represents a variable resistor, a variant without a specific resistance value, thus allowing it to be changed with a dial, knob, or screw. As such, they are commonly used in radio receivers for controlling volume and tone.

Common types include the potentiometer and rheostat.

Photo Resistor Symbol

This symbol represents a photo resistor, a model that changes its resistance value based on the amount and intensity of light it is receiving.

Add Resistor Symbols Quickly and Easily With Capital X Panel Designer!

With so many different types of resistor symbols, it can be difficult to remember and draw them all. Fortunately, you can skip this time-consuming process with Capital X Panel Designer! This electrical CAD software contains an extensive library of pre-made resistor symbols that you simply drag and drop onto your electrical schematic diagrams. You can even copy and paste any symbols you need multiples of, greatly improving your production speed.

Learn more about how to create custom electrical symbols.