Pure resistor and non-polarity output. "off" at the high resistance. Simple circuit configuration suitable for DC and AC use. An optocoupler, also known as photocoupler or opto-isolator, is a device which can transfer an electrical signal across two galvanically-isolated circuits by way of optical coupling. Unlike transformers or capacitors, which can only transfer AC signals across the isolation barrier, optocouplers can. Photocouplers (also known as optocouplers) generate light by using a light-emitting diode (LED) to generate a current which is conducted through a phototransistor. Internal Equivalence Circuit Here, we will describe how a general-purpose photocoupler with this basic structure is used. It typically consists of a light-emitting diode (LED) on the input side and a photodetector (usually a phototransistor, photodiode, or. Internally an optocoupler contains an infrared or IR emitter LED (normally built using gallium arsenide).
[PDF Version]