What is the definition of an optocoupler?

An optocoupler, also known as an opto-isolator, is defined as a component that consists of an LED (light-emitting diode) and a photosensitive device, such as a phototransistor, photodiode, or photoSCR. The primary function of an optocoupler is to transmit signals while maintaining electrical isolation between its input and output.

When an electrical signal is applied to the LED within the optocoupler, it emits light. This light then activates the photosensitive device, which in turn allows a current to flow in response to the received light. The key feature of an optocoupler is that it provides isolation between the high-voltage side and the low-voltage side, protecting sensitive parts of a circuit from high voltages or surges.

In summary, the definition of an optocoupler precisely describes its construction of an LED coupled with a photosensitive device, enabling safe and efficient signal transmission with electrical isolation.