Optocouplers are devices used to prevent high (or rapidly changing) voltages on one side of the circuit from damaging components or distorting transmissions on the other side. They transfer electrical signals by using light rather than passing energy and can only send in one direction. Optocouplers can be used for a number of different uses and applications, including:

  • Input and output switching, especially in electronically noisy environments
  • Switch-mode power supplies
  • Signal isolation
  • Power control
  • PC/Modem communications
  • Controlling transistors