DinizApp/Electronics Center

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  A phototransistor is a bipolar transistor encased in a transparent case so that light can reach the base–collector junction. The phototransistor is similar a photodiode, having higher sensitivity to light, because electrons that are generated by photons in the base–collector junction are injected into the base, and this photodiode current is amplified by the transistor's current gain. Phototransistors also have significantly longer response times. They are used inside optical couplers, with an infrared light emitting diode.

   
  A phototransistor is a bipolar transistor encased in a transparent case so that light can reach the base–collector junction. The phototransistor is similar a photodiode, having higher sensitivity to light, because electrons that are generated by photons in the base–collector junction are injected into the base, and this photodiode current is amplified by the transistor's current gain. Phototransistors also have significantly longer response times. They are used inside optical couplers, with an infrared light emitting diode.

   
  Um fototransistor é um transistor bipolar encapado em uma capa transparente que permite que luz possa atingir a base coletora da junção. O fototransistor funciona de maneira similar a um fotodiodo, apresentando uma sensitividade muito maior à luz, pois os elétrons gerados pelos fótons na junção da base-coletora são aplicados na base do transistor, e sua corrente é então amplificada pela operação do transistor. O fototransistor apresenta um tempo de resposta maior do que o fotodiodo. São utilizados dentro de acopladores ópticos, junto a um diodo emissor de luz infravermelha.

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