Valotransistorit

Valotransistorit, also known as optocouplers or opto-isolators, are electronic components that transfer electrical signals between two isolated circuits using light. They typically consist of a light-emitting diode (LED) and a photodetector, such as a phototransistor, integrated into a single package. When current flows through the LED, it emits light. This light strikes the phototransistor, causing it to conduct and allowing current to flow in the second circuit.

The primary function of a valotransistor is to provide electrical isolation between the input and output sides. This isolation is crucial in applications where high voltages or noisy environments are present, preventing damage to sensitive components or ensuring signal integrity. The input and output circuits share no direct electrical connection, with the light acting as the sole medium for signal transmission.

Valotransistorit are characterized by their isolation voltage, which indicates the maximum voltage difference they can withstand between the input and output. They also have a current transfer ratio (CTR), representing the ratio of output current to input current. These devices find widespread use in power supplies, industrial control systems, medical equipment, and telecommunications for signal isolation, noise reduction, and protection against voltage transients.