phototransistor

[ foh-toh-tran-zis-ter ]

noun

, Electronics.

1. a transistor that amplifies current induced by photoconductivity.

phototransistor

/ ˌfəʊtəʊtrænˈzɪstə /

noun

1. 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

phototransistor

/ fō′tō-trăn-zĭs′tər /

1. 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.
2. See also photoelectric effect

Word History and Origins

Origin of phototransistor¹

First recorded in 1945–50; photo- + transistor