Electronic Component Symbols

CIRCUIT SYMBOLS

Electronic Component Symbols - CIRCUIT SYMBOLS

Resistors

resistor symbol

resistor

Resistors only allow limited amounts of current to flow through them. A resistor is indicated by a rectangle drawn parallel to the circuit. The wire line doesn’t go through the rectangle.

 

variable resistor symbol

variable resistor

rheostat variable resistor also limits current, but its upper limit is variable. Lamp dimmers are variable resistors. This is indicated by a resistor rectangle with an arrow drawn through it.

 

potentiometer symbol

potentiometer

Some variable resistors are controlled by potentiometers, which are used to adjust voltage. This is indicated by a resistor rectangle with a downward-pointing arrow on top of it.

 

preset symbol

preset

A preset variable resistor is cheap style of variable resistor that is adjusted with a screw and screwdriver. This is indicated by a resistor rectangle with a capital T drawn through it.