Solid-state relay

Abstract

Abstract PURPOSE:To ensure the assured ON and OFF for the output transistor and reduce the heat generation of the transistor, by feeding the output of the transistor provided at the back step of the photodetector back positively to the photodetector and thus securing the hysteresis for the output transistor. CONSTITUTION:When step voltage ei is applied between terminals t1 and t2, photodiode PD emits the light to make phototransistor PT conduct. Thus voltage eb of resistance R4 increases to make transistor T1 conduct, and as a result transistors T2 and T3 conduct to actuate relay RY. Voltage ephi at both ends of collector resistance R6 of transistor T2 is fed positively back to the base of diode PD to improve the rise and fall of transistor T3. At the same time the hysteresis is secured.

Inventors

• 👤 Masayoshi Hoshimoto

Bibliographic Details