Electronic Circuit Symbols: master set

Polarized Capacitor

Polarized capacitors are small in size but have high capacitance. They are used in DC circuits. They can be used as filters, for bypassing or passing low frequency signals.

Input Bus Line

Represents a bus for input or incoming data

Output Bus Line

Represents a bus for output or outgoing data.

Bus Line

Represents a number of conductors joined together to form a bus wire.

Pulse Generator

Represents pulse or square wave generator.

Sinusoidal Generator

Represents sine wave generator.

Triangular Wave

Represents triangular wave generator.

Spdt Switch

Single pole double throw is abbreviated as SPDT. This switch allows the current to flow in any one of the two directions by adjusting its position.

Tapped resistor

A wire-wound type fixed resistor with one or more terminals along its length. Generally used in voltage divider applications.

Electrolytic Capacitor

Almost all electrolytic capacitors are polarized and hence used in DC circuits

Non Polarized Capacitor

Capacitor stores the charge in the form of electrical energy. These two symbols are used for non-polarized capacitor. Non-polarized capacitors are big in size with small capacitance. They can be used in both AC and DC circuits.

Multi Cell Battery

Combination of multiple single cell batteries or a single large cell battery. The voltage is usually higher.

Dpdt Switch

Double pole double throw is the full form of DPDT. This can connect the four circuits by changing the position.

Dpst Switch

Double pole single throw is abbreviated as DPST. This switch can drive two circuits at a time.

Chassis Ground

It acts as a barrier between user and the circuit and prevents electric shock.

Varistor

It is a Voltage Dependent Resistor. It has non-linear current-voltage characteristics. Generally used in circuit protection from voltage surges and excessive transient voltages.

Controlled current Source

It is a dependent current source. Usually depends on other sources (voltage or current).

Controlled Voltage Source

It is a dependent voltage source. Usually depends on other sources (voltage or current).

Fixed Resistor

It is a device that opposes the flow of current in a circuit. These two symbols are used to represent fixed resistor.

Attenuator

It is a device used to lower the power of a signal. They are made from simple voltage dividers and hence can be classified in the family of the resistors.

Preset

It is a mini variable resistor. It is also called Trimmer Resistor or Trim Pot. The resistance is adjusted with rotary control present on top of it with the help of a screw driver. They are used to adjust the sensitivity of the circuit like temperature or light.

Signal Ground

It is a reference point from which the signal is measured. There may be several signal grounds in a circuit due to the voltage drops in a circuit.

Thermistor

It is a temperature sensitive resistor. They are used in temperature sensing, current limiting circuits, over-current protection circuits etc.

Rheostat

It is a two terminal variable resistor. They are generally used to control the current in the circuit. Generally used in tuning circuits and power control applications like heaters, ovens etc

Ground

It is equivalent to theoretical 0V and is used as zero potential reference. It is the potential of perfectly conducting earth.

Spst Switch

Single pole single throw is abbreviated as SPST. This acts as ON/OFF switch. Poles define the number of circuits it can be connected to and throws defines the number of positions that a pole connects.

Variable Capacitor

The capacitance of the variable capacitor can be adjusted by turning the knob. They are widely used to adjust the frequency , that is for tuning.

Memristor

The resistance of memristor is varied according to the direction of flow of charge. Memristors can be used in signal processing, logic/computation, non-volatile memory etc.

Constant Current Source

The symbol represents an independent current source which delivers constant current.

Magneto Resistor

They are also called as Magnetic Dependent Resistors (MDR). The resistance of magneto resistor varies according to the external magnetic field strength. They are used in electronic compass, ferrous material detection, position sensors etc.

LDR

They are also called as Photo Resistors. The resistance of LDR varies with the intensity of the light incident on it. They are generally used in light sensing applications.

Feed through Capacitor

They provide low impedance path to ground for high frequency signals

Single Cell Battery

This provides supply to the circuit.

AC Supply

This represents AC supply in the circuit.

DC Supply

This represents the DC power supply. It applies DC supply to the circuit.

Relay Switch

This represents the relay switch. This can control the AC Loads using the DC voltage applied to the coil.

Push Button (Normally Open)

This switch is in ON state when the button is pressed otherwise it is in OFF state.

Push Button (Normally Closed)

This switch is initially in ON state. This goes to OFF state when it is released.