SYMBOLS ELECTRICAL TABLE

 

Table of Electrical Symbols

Symbol	Component name	Meaning
Wire Symbols
	Electrical Wire	A 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 voltage is generated by mechanical rotation of the generator
	Battery Cell	Generates constant voltage
	Battery	Generates constant voltage
	Controlled Voltage Source	Generates voltage as a function of voltage or current of other circuit element.
	Controlled Current Source	Generates current as a function of voltage or current of other circuit element.
Meter Symbols
	Voltmeter	Measures voltage. Has very high resistance. Connected in parallel.
	Ammeter	Measures electric current. Has near zero resistance. Connected serially.
	Ohmmeter	Measures resistance
	Wattmeter	Measures electric power
Lamp / Light Bulb Symbols
	Lamp / light bulb	Generates light when current flows through
	Lamp / light bulb
	Lamp / light bulb
Diode / LED Symbols
	Diode	Diode allows current flow in one direction only - left (anode) to right (cathode).
	Zener Diode	Allows current flow in one direction, but also can flow in the reverse direction when above breakdown voltage
	Schottky Diode	Schottky diode is a diode with low voltage drop
	Varactor / Varicap Diode	Variable capacitance diode
	Tunnel Diode
	Light Emitting Diode (LED)	LED emits light when current flows through
	Photodiode	Photodiode allows current flow when exposed to light
Transistor Symbols
	NPN Bipolar Transistor	Allows current flow when high potential at base (middle)
	PNP Bipolar Transistor	Allows current flow when low potential at base (middle)
	Darlington Transistor	Made from 2 bipolar transistors. Has total gain of the product of each gain.
	JFET-N Transistor	N-channel field effect transistor
	JFET-P Transistor	P-channel field effect transistor
	NMOS Transistor	N-channel MOSFET transistor
	PMOS Transistor	P-channel MOSFET transistor
Misc. Symbols
	Motor	Electric motor
	Transformer	Change AC voltage from high to low or low to high.
	Electric bell	Rings when activated
	Buzzer	Produce buzzing sound
	Fuse	The fuse disconnects when current above threshold. Used to protect circuit from high currents.
	Fuse
	Bus	Contains several wires. Usually for data / address.
	Bus
	Bus
	Optocoupler / Opto-isolator	Optocoupler isolates connection to other board
	Loudspeaker	Converts electrical signal to sound waves
	Microphone	Converts sound waves to electrical signal
	Operational Amplifier	Amplify input signal
	Schmitt Trigger	Operates with hysteresis to reduce noise.
	Analog-to-digital converter (ADC)	Converts analog signal to digital numbers
	Digital-to-Analog converter (DAC)	Converts digital numbers to analog signal
	Crystal Oscillator	Used to generate precise frequency clock signal
⎓	Direct current	Direct current is generated from constant voltage level
Antenna Symbols
	Antenna / aerial	Transmits & receives radio waves
	Antenna / aerial
	Dipole Antenna	Two wires simple antenna
Logic Gates Symbols
	NOT Gate (Inverter)	Outputs 1 when input is 0
	AND Gate	Outputs 1 when both inputs are 1.
	NAND Gate	Outputs 0 when both inputs are 1. (NOT + AND)
	OR Gate	Outputs 1 when any input is 1.
	NOR Gate	Outputs 0 when any input is 1. (NOT + OR)
	XOR Gate	Outputs 1 when inputs are different. (Exclusive OR)
	D Flip-Flop	Stores one bit of data
	Multiplexer / Mux 2 to 1	Connects the output to  selected input line.
	Multiplexer / Mux 4 to 1
	Demultiplexer / Demux 1 to 4	Connects selected output to the input line.

 

Name	Electrical Symbol	Alternate Symbol	Description
ground/earth			This symbol identifies an earth(ground) terminal used for a zero potential reference point and electrical shock protection.
equipotential			It is a symbol to identify parts with the same voltage (i.e., the same electrical potential or equipotential). Since equipotential surfaces all have the same voltage, you won't be shocked if you touch two such surfaces unless you are also touching another part with a different potential from the first two parts.
chassis ground			It is a link between different metallic parts of a machine to ensure an electrical connection between them. It must not be considered as a link to the earth.
battery			It is a device that consists of one or more electrochemical cells with external connections to empower electrical devices and generates constant voltages.
resistor			It is an electrical component that reduces the electric current, for example, to limit the current passing through an LED. A resistor is used with a capacitor in a timing circuit.
attenuator			It is an electronic device that reduces the power of a signal with appreciably distorting its waveform, which is the opposite of an amplifier.
capacitor			It is a device with two terminals, which stores electric energy. The effect of a capacitor is known as capacitance. It can also be used as a filter to block DC signals but pass AC signals.
accumulator			It is an energy storage device that accepts, stores, and releases energy, increasing or relieving pressure in the system.
antenna			An antenna also knows as an aerial, is a device designed to transmit or receive electromagnetic (e.g., TV or radio) waves.
loop antenna			A loop antenna is a radio antenna consisting of a loop (or loops) of wire, tubing, or other electrical conductors with its ends connected to a balanced transmission line.
crystal			A crystal oscillator uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with an exact frequency.
circuit breaker			A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit.
fuse			A fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit.
ideal source			An ideal voltage source is a two-terminal device that maintains a fixed voltage drop across its terminals. It is often used in the simplified analysis process of a real electric circuit.
generic component
transducer			A transducer is a device that converts energy from one form to another. Usually, a transducer converts a signal in one type of power to a signal in another.
inductor			A coil of wire creates a magnetic field when current passes through it. It may have an iron core inside the coil. It can be used as a transducer converting electrical energy to mechanical energy by pulling on something. It is a passive two-terminal electrical component used to store energy in a magnetic field.
half inductor
pickup head
pulse
saw tooth
step function
explosive squib			Explosive squib is often used on stage and film to trigger various special effects.
sensing link squib
squib igniter
surge protectors			Surge protectors protect your electronics from power surges in your electrical system.
instrument			For example, a voltmeter is an instrument used for measuring the electrical potential difference between two points in an electric circuit. The wattmeter is an instrument for measuring the electric power in watts of any given circuit.
material
delay element			The delay element provides a specified delay between the actuation of the propellant-actuated devices.
permanent magnet			A permanent magnet is a material or object that produces a magnetic field.
magnet core
ferrite core
igniter plug
bell			The electric bell is found in an ordinary house doorbell, and when activated, it makes a ringing sound.
buzzer			An electrical buzzer is similar to the bell that makes a constant buzz noise instead of a single tone or bell sound.
thermal element
thermocouple
thermopile
lamp			A transducer converts electrical energy to light, used for a lamp providing illumination, for example, a car headlamp or torch bulb.
fluorescent lamp
speaker			A speaker can take digital input and turn it into analog sound waves—one of the most important parts of a wide range of electrical products like TVs and telephones.
microphone
oscillator			It produces a repetitive electronic signal, often a sine wave or a square wave.
AC source			Alternating Current, continually change direction.
DC source			Direct Current, always flow in one direction.

Electrical wiring construction including outlets, switches, and lamps.