1. A semiconductor device that converts light into an electrical current, used as a light detector in electronic circuits.
Usage: technical; electronics

Examples

• The phototransistor in the camera sensor responds to incoming light by generating an electrical signal.
• Engineers used a phototransistor to detect the presence of objects on the assembly line.
• A phototransistor is more sensitive than a simple photodiode because it includes amplification.
• The circuit included a phototransistor that triggered an alarm when the light beam was interrupted.
• Phototransistors are commonly found in optical communication systems and light-sensing applications.