Origin of phototransistor; from photo- (sense )
phototransistor - Computer Definition
A transistor that uses light rather than electricity to cause an electrical current to flow from one side to the other. It is used in a variety of sensors that detect the presence of light. Phototransistors combine a photodiode and transistor together to generate more output current than a photodiode by itself. See photoelectric, photodiode and transistor.