British Dictionary definitions for phototransistor
phototransistor
noun
a junction transistor, whose base signal is generated by illumination of the base. The emitter current, and hence collector current, increases with the intensity of the light
A transistor that regulates current or switches it on and off based on the intensity of the light it is exposed to rather than an external electric signal. Phototransistors are used in many electric-eye applications, including digital cameras, in which millions of tiny phototransistors map an image into an array of electrical signals. See also photoelectric effect.
