ROHM Photo Transistors
A phototransistor is a photoelectric conversion element that can amplify the photocurrent generated by illuminating light to the base part by the action of a transistor. In most cases, it has a two-legged shape without a base terminal. Used as a light sensor and automatic door as a light detector that converts a signal from light into an electric signal. The package is made of resin or glass that transmits light. Since the phototransistor has an npn structure, electrons from the emitter are also added to the current, and the current is amplified and flows. This amplification function means it is not necessary to install a new amplifier, simplifying the circuit. Select and use a through-hole mounting type, surface mounting type, etc. depending on the application. There is also an infrared phototransistor that detects infrared light.