Switches

1. Definition

1.1 Switch

A switch is an electromechanical device used to open or close an electrical circuit, thereby controlling the flow of current.
It can be manually operated (toggle, push-button) or mechanically triggered (limit switch).

Switch examples

Switch Symbols

Switch symbols

1.2 Types of Switches

  • SPST: Single Pole, Single Throw (simple on/off).
  • SPDT: Single Pole, Double Throw.
  • DPST/DPDT: Double Pole variations.
  • Momentary: Normally open (NO) or normally closed (NC).

2. Features

  • Simple operation.
  • Mechanical lifespan (number of actuations).
  • Contact rating (voltage & current).
  • Mounting style (panel, PCB).

4. How to Use

Safety Note

Always ensure the switch is rated for the circuit voltage and current.

4.1 Identify terminals

  • SPST: Two terminals.
  • SPDT: Three terminals (common, NO, NC).

Switch pinout

4.2 Install in circuit

  • Connect in series with load to control power flow.

4.3 Applications

  • Power control.
  • Mode selection.
  • Reset buttons.

5. Video Explanation

video coming soon