Resistor:
- Symbol: A zigzag line. It represents resistance in a circuit and is used to limit the flow of current. Resistors are used for voltage division, current limiting, and signal attenuation.
Capacitor:
- Symbol: Two parallel plates. It stores electrical energy in an electric field. Capacitors are used for filtering, energy storage, and in timing circuits.
Inductor:
- Symbol: A coil. It stores energy in a magnetic field. Inductors are used in filters to block high-frequency signals, in transformers for voltage transformation, and in resonant circuits.
Battery or Power Supply:
- Symbol: A long line representing the positive terminal and a short line representing the negative terminal. It provides a source of electrical energy to the circuit.
Ground or Earth Symbol:
- A triangle with three horizontal lines inside. It is used as a reference point in a circuit and is typically connected to the earth for safety purposes. It helps in establishing a common reference potential.
Switch:
- Open Switch: A break in the circuit represented by an open line. When the switch is open, no current can flow through the circuit.
- Closed Switch: A solid line indicating that the circuit is complete and current can flow.
Fuse:
- A symbol that looks like a thin wire with a line through it. When the current through the fuse exceeds a certain value (rated current), the fuse melts and breaks the circuit to protect the rest of the circuit from excessive current.
Relay:
- It consists of an electromagnet coil and a set of normally open (NO) and normally closed (NC) contacts. When the coil is energized, the magnetic field attracts the movable contact, changing the state of the contacts. Relays are used for switching large currents or for isolating control circuits from high-power circuits.
Transformer:
- It has two sets of coils, the primary coil and the secondary coil, wound around a common magnetic core. The symbol shows two sets of coils with dots to indicate the phase relationship. Transformers are used for voltage transformation, such as stepping up or stepping down AC voltages.
These are some of the essential electrical symbols used in power systems and circuit diagrams to represent different components and their functions.