NPN TRANSISTOR AS SWITCH
NPN TRANSISTOR AS SWITCH
Based on the voltage applied at the base terminal of a transistor switching operation is performed. When a sufficient voltage (VIN > 0.7 V) is applied between the base and emitter, collector to emitter voltage is approximately equal to 0. Therefore, the transistor acts as a short circuit. The collector current VCC / RC flows through the transistor.
Similarly, when no voltage or zero voltage is applied at the input, transistor operates in cutoff region and acts as an open circuit. In this type of switching connection, load (here an LED is used as a load) is connected to the switching output with a reference point. Thus, when the transistor is switched ON, current will flow from source to ground through the load.
