1. Wires

   Represents a conductor that conducts electrical current. also called a power line or electrical line or wire

2. Connected Wires

   Represents the connection of two conductors. Dot shows the junction point

3. Unconnected Wires

   Represents two unconnected joints or wire

4. Input Bus Line

   Represent a bus for input or incoming data

5. Output Bus Line

   Represents a bus for Output or outgoing data

6. Terminal

   Represents start or end point

7. Bus line

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

Switches

1. Push Button (normally open)

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

2. Push Button (Normally closed)

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

3. SPST Switch

   Single pole single throw is abbreviated as SPST. This acts as an on/off switch. Poles define the number of circuits it can be connected to, and throws defines the number of positions that a pole connect.

4. SPDT Switch

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

5. DPST switch

   A double pole single throw is abbreviated as. his switch can drive two circuits at a time

6. DPDT switch

   double pole double throw is the full form of DPDT. This can be connect to the four circuits by change the positions.

7. Relay Switch

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

   AC = alternating current

   DC = Direct Current

Sources

1. AC supply

   This represents AC supply in the circuit

2. DC supply

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

3. Constant Current Source

   The symbol represents an independent current source which delivers constant current

4. Controlled Current Source

   It is a dependent current source. usually depends on other sources

5. Controlled Voltage Source

   It is a dependent voltage source. Usually depends on other sources

6. Single Cell battery

   This provides supply to the circuit

7. Multi Cell Battery

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

Wave Generators

1. Sinusoidal Generator

   Represents sine wave generator

2. Pulse Generator

   Represents pulse or swuare wave generator

3. triangular Wave

   Represents triangular wave

Ground

1. Ground

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

   • Neutralizes the possible electric currents such as lightings.

2. 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.

   • mostly used for telco

3. Chassis Ground

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

Resistor

1. Fixed Resistor

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

Variable Resistor

1. 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.

2. 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 screwdriver. They are used to adjust the sensitivity of the circuit like temperature or light.

3. Thermistor

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

4. 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 voltage.

5. Magneto Resistor

   They are also called a Magnetic Dependent Resistors. The resistance of magneto resistor varies according to he external magnetic field strength. They are used in electronic compass ferrous material detection, position sensors

6. LDR

   They are also calls 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.

7. Tapped resistor

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

8. Attenuator

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

Memristor

The resistance of memristor is varies according to the direction of flow of charge. Can be used in signal processing, logic/ computation

Capacitor

1. Non-polarized

   Stores the charge in the form of electrical energy. Theses two symbols are used for non-polarized capacitor are used fro

2. Polarized

Inductors

1. Center Tapped Inductors

   Used in Coupling of signals

2. Variable Inductors

   Movable ferrite magnetic core

3. Iron Core

4. Ferrite Core inductors