You might already know what optical coupler is, an electrical isolation semiconductor device to transmit electrical signals using light waves in order to provide coupling.

However, do you know how many types of optical couplers are there?

There are dozens of types of optical couplers and the main types are general-purpose optocoupler(also divided into no base-lead and base-lead types), Darlington optocoupler, Schmidt optocoupler, high-speed type, optical integrated circuit type, optical fiber type, photosensitive thyristor type (also divided into one-way thyristor, bidirectional thyristor), and photosensitive field-effect tube type.

Now let´s looking into the advantages of optical couplers.

With optocouplers, the signal is transmitted in one direction, therefore the input end and the output end are completely electrically isolated, and the output signal has no influence on the input side. It has strong anti-interference ability, works stably with no contact, long service life and high transmission efficiency. Optocoupler is a new type of device developed in the 70s, which is now widely used in electrical insulation, level conversion, inter-stage coupling, drive circuit, switching circuit, chopper, multi-harmonic oscillator, signal isolation, inter-stage isolation, pulse amplification circuit, digital instrumentation, long-distance signal transmission, pulse amplification, solid state relay (SSR), instrumentation, communication equipment and microcomputer interface. In a monolithic switching regulator, the use of linear optocouplers can form an optocoupler feedback circuit to change the duty cycle by adjusting the current at the control end to achieve precise voltage regulation.