Electrical Wire
Conductor of electrical current
Connected Wires
Connected crossing
Not Connected Wires
Wires are not connected
Switch Symbols and Relay Symbols
SPST Toggle Switch
Disconnects current when open
SPDT Toggle Switch
Selects between two connections
Pushbutton Switch (N.O)
Momentary switch - normally open
Pushbutton Switch (N.C)
Momentary switch - normally closed
DIP Switch
DIP switch is used for onboard configuration
SPST Relay
Relay open / close connection by an electromagnet
SPDT Relay
Jumper
Close connection by jumper insertion on pins.
Solder Bridge
Solder to close connection
Ground Symbols
Earth Ground
Used for zero potential reference and electrical shock protection.
Chassis Ground
Connected to the chassis of the circuit
Digital / Common Ground Resistor Symbols
Resistor (IEEE)
Resistor reduces the current flow.
Resistor (IEC)
Potentiometer (IEEE)
Adjustable resistor - has 3 terminals.
Potentiometer (IEC)
Variable Resistor / Rheostat (IEEE)
Adjustable resistor - has 2 terminals.
Variable Resistor / Rheostat (IEC)
Trimmer Resistor
Preset resistor
Thermistor
Thermal resistor - change resistance when temperature changes
Photoresistor / Light dependent resistor (LDR)
Photo-resistor - change resistance with light intensity change
Capacitor Symbols
Capacitor
Capacitor is used to store electric charge. It acts as short circuit with AC and open circuit with DC.
Capacitor
Polarized Capacitor
Electrolytic capacitor
Polarized Capacitor
Electrolytic capacitor
Variable Capacitor
Adjustable capacitance
Inductor / Coil Symbols
Inductor
Coil / solenoid that generates magnetic field
Iron Core Inductor
Includes iron
Variable Inductor Power Supply Symbols
Voltage Source
Generates constant voltage
Current Source
Generates constant current.
AC Voltage Source
AC voltage source
Generator
Electrical