A technician is troubleshooting a solid-state switching circuit that utilizes a silicon PNP bipolar junction transistor. The emitter terminal is connected directly to a +12V DC power source, and the collector is wired in series with a ground-referenced load. In order to drive this transistor into saturation and fully power the load, what specific voltage condition must exist at the base terminal, and what is the direction of conventional current flow through the device?
- AThe base must be at a higher voltage potential than the emitter; conventional current flows from the collector to the emitter.
- BThe base must be at a higher voltage potential than the emitter; conventional current flows from the emitter to the collector.
- The base must be at a lower voltage potential than the emitter; conventional current flows from the emitter to the collector.Cevap
- DThe base must be at a lower voltage potential than the emitter; conventional current flows from the collector to the emitter.
Cevap
The base must be at a lower voltage potential than the emitter; conventional current flows from the emitter to the collector.
The correct response accurately synthesizes both fundamental rules for a PNP transistor. First, to achieve saturation (full conduction), the base must be at a lower potential than the emitter to forward-bias the emitter-base junction. Second, unlike NPN devices, conventional current in a PNP transistor enters through the emitter and exits through the collector, following the direction of the emitter arrow on its schematic symbol.
Adım Adım Çözüm
Anahtar Kavram
PNP Transistor Biasing and Current Flow