Presentation is loading. Please wait.

Presentation is loading. Please wait.

Module 2 Bipolar Junction Transistor. Learning Outcomes 1.The 3 terminals or regions of a BJT. 2.Construction and symbol of NPN and PNP types 3.Low power.

Similar presentations


Presentation on theme: "Module 2 Bipolar Junction Transistor. Learning Outcomes 1.The 3 terminals or regions of a BJT. 2.Construction and symbol of NPN and PNP types 3.Low power."— Presentation transcript:

1 Module 2 Bipolar Junction Transistor

2 Learning Outcomes 1.The 3 terminals or regions of a BJT. 2.Construction and symbol of NPN and PNP types 3.Low power and high power packages 4. CE. CB. CC configuration 5.The relation between the emitter, collector and base current 6.Regions of operation 7.Transistor as a switch 8. The applications of a transistor.

3 Regions of a Transistor

4 A Bipolar Junction Transistor is a three terminal device containing 3 regions: Emitter, Base and Collector.

5 THE TRANSISTOR There are two types of (bipolar junction) transistors, npn and pnp Bipolar transistor symbols

6 NPN vs PNP NPN and PNP function the same way Power supply polarities are reversed For NPN, positive supply is used NPN has higher frequency response as electrons are the charge carriers. NPN is more widely used

7 A transistor consists of two PN junctions. Thus a transistor is like two PN – junction diodes connected back to back.

8 2.2 Packages Examples of transistor packages

9 Transistor Packages (low power & high power)

10 2.4 Transistor Configurations common emitter (CE) common base (CB) common collector (CC).

11

12 Currents in CE Circuit

13 2.5 Emitter, collector and base currents

14 In the CE configuration:

15 Transistor Operation Regions Operation Region BiasApplication CUT OFF REGIONI B and I c are 0 (base-emitter junction is reverse biased) Open Switch (OFF) SATURATION REGION Base emitter junction is forward biased; I B flows Closed Switch (ON) ACTIVE REGIONB-E junction is forward biased but C-E junction is reverse biased; Amplifier

16 Transistor Applications: Transistor can act as a Switch

17

18 Transistor Applications Switch Amplifier Oscillator

19 Transistor as a Switch Light operated switch Darkness operated switch Digital Logic Gates Switching power supply

20 Transistor as a Variable Resistor Amplifier Oscillator Modulator Detector

21 Light Failure Warning System using Transistor as a Switch

22 Light Failure Warning System In this, the transistor is used as a switch LDR is a light dependant resistor. It is a light sensor. When it is dark, LDR resistance increases; base current flows; the transistor becomes ON and relay switches. So the bell rings.


Download ppt "Module 2 Bipolar Junction Transistor. Learning Outcomes 1.The 3 terminals or regions of a BJT. 2.Construction and symbol of NPN and PNP types 3.Low power."

Similar presentations


Ads by Google