Table of Electrical Symbols:

Wires

Symbol	Component Names	Description
	Electrical Wire	A conductor is a device that conducts electrical current. Also known as a power line, electric line, or wire.
	Connected Wires	The connection of two conductors is represented by this symbol. The intersection is indicated by a dot.
	Not Connected Wires	Represents two unconnected wires/conductors.
	Input Bus Line	Represents a bus for input or incoming data.
	Output Bus Line	Represents a bus for output or outgoing data.
	Terminal	Represents start or end point.
	Bus Line	A bus wire is made up of several conductors that are linked together.

Switch Symbols

	Pushbutton Switch (N.O)	When the button is pressed, this switch is in the ON position; otherwise, it is in the OFF position.
	Pushbutton Switch (N.C)	This switch is initially turned on. When this is released, it returns to the OFF state.
	DIP Switch	DIP switch is used for onboard configuration
	SPST Toggle Switch	SPST stands for Single Pole Single Throw. This serves as an ON/OFF switch.
	SPDT Toggle Switch	SPDT stands for single pole double throw. By altering its position, this switch permits current to flow in either of two directions.
	DPST Switch	DPST stands for double pole single throw. This switch can power two circuits at the same time.
	DPDT Switch	DPDT is an abbreviation for double pole double throw. By adjusting the position, you may connect the four circuits.

Ground Symbols

	Earth Ground	Theoretically it is equivalent to 0V and is used as zero potential reference.
	Chassis Ground	It creates a barrier between the user and the circuit, preventing electric shock.
	Digital / Common Ground	It serves as a reference point against which the signal is measured. Because of voltage losses in a circuit, there may be many signal grounds.

Relay Symbols

	SPST Relay	SPST Stands for single-pole single-throw relay
	SPDT Relay	Single Pole Double Throw Relay (SPDT). The Relay consists of a coil, 1 common terminal, 1 normally closed terminal, and one normally open terminal.
	Jumper	Close connection by jumper insertion on pins.
	Solder Bridge	Solder to close connection

Resistor Symbols

	Resistor (IEEE)	It is a device that is designed to opposes the flow of current in a circuit. These two symbols are used to represent fixed resistor.
	Potentiometer (IEEE)	Adjustable resistor – has 3 terminals.
	Potentiometer (IEC)	Adjustable resistor – has 3 terminals.
	Variable Resistor / Rheostat (IEEE)	It is a variable resistor with two terminals. They are typically used to regulate the current in a circuit. Typically used in tuning circuits and power control applications such as heaters and ovens.
	Variable Resistor / Rheostat (IEC)	It is a variable resistor with two terminals. They are typically used to regulate the current in a circuit. Typically used in tuning circuits and power control applications such as heaters and ovens.
	Trimmer Resistor	Preset resistor
	Thermistor	Thermal resistor – change resistance when temperature changes
	Photoresistor / Light dependent resistor (LDR)	Photo Resistors are another name for them. LDR resistance varies with the intensity of the incident light. They are commonly seen in light detecting applications.
	Attenuator	It is a device that reduces the power of a signal. They are constructed from basic voltage dividers and so belong to the resistor family.
	Memristor	The resistance of a memristor varies with the direction of charge flow. Memristors can be utilised in signal processing, logic/computation, non-volatile memory, and other applications.

Capacitor Symbols

	Non-Polarized Capacitor	Capacitor is used to store electric charge. It acts as short circuit with AC and open circuit with DC.
	Polarized Capacitor	Polarized capacitors have a small size but a large capacitance. They are utilised in direct current circuits. They can be used to bypass or pass low frequency signals as filters.
	Electrolytic capacitor	Almost all electrolytic capacitors are polarised and so used in direct current (DC) circuits.
	Variable Capacitor	The variable capacitor’s capacitance can be modified by turning the knob. They are commonly used to modify the frequency, or to tune.
	Feed through Capacitor	For high frequency transmissions, they provide a low impedance path to ground.

Inductor / Coil Symbols

	Iron Core Inductor	These are used to replace ferrite core inductors. Ferrite core inductors have a high permeability and require an air gap to lessen it. This air gap is built into iron powdered core inductors.
	Ferrite Core Inductors	The core material in these inductors is constructed of ferrite. These are generally used to reduce electromagnetic wave interference.
	Center Tapped Inductor	These are used in coupling of signals
	Variable Inductor	The most popular type of variable inductors are movable ferrite magnetic core inductors. By moving the core in and out of the coil, the inductance may be changed.

Power Supply Symbols

	Voltage Source	It is a dependent voltage source. Usually depends on other sources (voltage or current).
	Current Source	Generates constant current.
	AC Voltage Source	This represents AC supply in the circuit.
	Generator	Electrical voltage is generated by mechanical rotation of the generator
	Battery Cell (DC)	This represents the DC power supply. It applies DC supply to the circuit.
	Battery	Combination of multiple single cell batteries or a single large cell battery. The voltage is usually higher.
	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

Transformer Symbols

	Transformer	The basic element that transmits energy from one circuit to the other by electromagnetic induction is the transformer. They are commonly used in electric power applications to increase or reduce the voltage of an alternating current.
	Iron Core Transformer	As a core, a piece of magnetic material is used. Iron and other ferro magnetic metals are commonly used. The magnetic field is contained by the core, which has a high permeability.
	Center Tapped Transformer	The secondary winding of a center-tapped transformer is divided into two portions, each with the same number of turns. This produces two distinct output voltages across two-line ends. Rectifier circuits use this.
	Step Up Transformer	The number of turns in secondary winding more than that of primary winding. The output voltage exceeds the input voltage. Inverters make extensive use of it.
	Step Down Transformer	The number of turns in secondary winding is less than the number of turns in primary winding. The input voltage is greater than the output voltage. It’s common in low-power applications.

Miscellaneous Symbols

	Motor	Electric motor converts electrical energy to mechanical energy
	Electric bell	It is a sound producing device that rings when voltage is applied
	Buzzer	This is a sound-generating device. When the voltage is applied, a buzzing sound is produced.
	Fuse	The fuse disconnects when current above threshold. Used to protect circuit from high currents.
	Fuse	The fuse disconnects when current above threshold. Used to protect circuit from high currents.
	Bus	Contains several wires. Usually for data / address.
	Bus	Contains several wires. Usually for data / address.
	Bus	Contains several wires. Usually for data / address.
	Optocoupler / Opto-isolator	Optocoupler isolates connection to other board
	Loudspeaker	This is also an audio device. The electrical signal is converted into sound signal here.
	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

Table of Electronic Symbols

Transistor Symbol

	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

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	It denotes a Schottky diode. It features a minimal forward voltage drop and switches quickly. Voltage clamping, rectifiers, reverse current, and discharge prevention are all applications for this material.
	Shockley Diode	This diode has four layers. Because of its quick switching function, it is useful in switching applications.
	Varactor / Varicap Diode	Varicap or variable capacitance diode is another name for a varactor diode. The capacitance of this diode varies with the applied voltage. This is utilised in frequency regulated oscillators, frequency multipliers, and other applications.
	Tunnel Diode	This is also known as Esaki diode. It can switch quickly and operate well in the microwave frequency band. This is employed in oscillator and microwave circuits.
	LED (Light Emitting Diode)	The light emitting diode is similar to the PN junction diode in that it emits energy in the form of light rather than heat. These are typically utilised in lighting and indicator applications.
	Photodiode	Photodiode allows current flow when exposed to light
	Thyristor	It is made up of four layers of alternating P and N materials. They function as bistable switches and are employed in circuits with high voltages and currents.
	Laser Diode	The laser diode is equivalent to the light emitting diode. In the PIN structure, the active region is produced in the intrinsic region. Laser diodes are used in laser printing, laser scanning, and other applications.
	Constant Current Diode	Also known as a current limiting or current regulating diode. It restricts the current to a set maximum value.

Antenna Symbols

	Antenna / aerial	This symbol of Aerial or Antenna. It turns electrical power into radio waves. It’s utilised in wireless communication to send and receive signals.
	Loop Antenna	The loop antenna gets its name from the loop-like curvature of its wire or other electrical conductor. They are used as low-frequency reception antennas.
	Dipole Antenna	It is most commonly used antenna. Mainly used in set-top TV, shortwave transmission and FM receivers.

Logic Gates Symbols

	Inverter (NOT Gate)	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	Connects the output to selected input line.
	Demultiplexer / Demux 1 to 4	Connects selected output to the input line.