Electrical Circuits Basics

Basics

• An electrical circuit is a path through which electric current flows from a power source, through one or more devices, and back to the power source.
• It consists of three main components:
  • Power source (e.g. battery, generator)
  • Conductors (e.g. wires)
  • Load (e.g. light bulb, motor)

Types of Circuits

• Series Circuit: A circuit where the current flows through each component in sequence.
  • Characteristics:
    • Current is the same throughout the circuit
    • Voltage is divided among components
    • If one component fails, the entire circuit is broken
• Parallel Circuit: A circuit where each component has its own separate path for the current to flow.
  • Characteristics:
    • Voltage is the same across each component
    • Current is divided among components
    • If one component fails, the other components remain operational
• Series-Parallel Circuit: A combination of series and parallel circuits.

Circuit Components

• Resistors: Components that reduce the voltage or current in a circuit.
  • Measured in Ohms (Ω)
  • Types:
    • Fixed resistors
    • Variable resistors
• Capacitors: Components that store energy in an electric field.
  • Measured in Farads (F)
  • Types:
    • Ceramic capacitors
    • Electrolytic capacitors
• Inductors: Components that store energy in a magnetic field.
  • Measured in Henries (H)
  • Types:
    • Air-core inductors
    • Iron-core inductors

Circuit Analysis

• Kirchhoff's Laws:
  • KVL (Kirchhoff's Voltage Law): The sum of voltage changes around a closed loop is zero.
  • KCL (Kirchhoff's Current Law): The sum of currents entering a node is equal to the sum of currents leaving a node.
• Ohm's Law: The relationship between voltage, current, and resistance in a circuit.
  • V = I × R
  • I = V ÷ R
  • R = V ÷ I

Safety Precautions

• Short Circuit: A circuit where the current flows directly from the power source to ground, bypassing the load.
• Overload: A circuit that carries more current than its rated capacity.
• Grounding: A safety measure to prevent electrical shock by connecting the circuit to the earth.