In a grounded-emitter transistor circuit, such as the light-switch circuit shown, as the base voltage rises, the emitter and collector currents rise exponentially. The collector voltage drops because of reduced resistance from collector to emitter. If the voltage difference between the collector and emitter were zero (or near zero), the collector current would be limited only by the load resistance (light bulb) and the supply voltage. This is called saturation because current is flowing from collector to emitter freely. When saturated, the switch is said to be on. COUNT 5
QSN1 Why does the collector voltage drop in grounded-emitter transistor circuits? ANS1 reduced resistance from collector to emitter QSN2 What would happen if the voltage difference from collector and emitter were zero? ANS2 the collector current would be limited only by the load resistance (light bulb) and the supply voltage QSN3 What is the term for a zero difference between collector and emitter? ANS3 saturation QSN4 Why is the term saturation named as such? ANS4 current is flowing from collector to emitter freely QSN5 What position is the switch in when saturated? ANS5 on