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

Example Sentences

To support learning projects, the following devices are integrated onto the board: Four green LEDsOne RGB LEDOne infrared LEDTwo momentary pushbutton switches for digital inputsOne thumbwheel potentiometer to introduce analog measurements and controlsOne piezo element to create tones and measure vibrationsOne phototransistor to detect infrared and visible lightAn I2C digital temperature sensor to introduce between-device digital communication While the above short bullet list may not sound like much, they have truly packed this little board with functionality and utility.

From Forbes