Lecture Notes - Chapter 3
(These Lecture Notes are for courses using the book
Complete Electronics Self-Teaching Guide with Projects. Instructors of courses
using that text are permitted to use these Lecture Notes as-is or adapt
them for their use).
Introduction to The Transistor
- Understanding Transistors
- Discuss the similarity of a bipolar transistor to two
diodes placed back-to-back (figure 3.2).
- Discuss the structure of a bipolar transistor(figure 3.3).
- Introduce the terms; Emitter, Collector, and Base (figure
- Introduce the schematic symbol for NPN transistors (figure
- Introduce the schematic symbol for PNP transistors (figure
- Introduce the term base current (IB).
- Review the equation to calculate IB.
- Introduce the term; transistor action.
- Introduce the term; collector current.
- Discuss the direction in which base current and collector
current flow (figure 3.13).
- Introduce the term; current gain (β).
- Review the equation for current gain.
- Inside The Bipolar Transistor
- Discuss the depletion regions present in an unbiased
- Forward bias on the base-emitter junction shrinks the
- The base region is thin, allowing electrons from the emitter
to pass through to the collector and current to flow.
- Calculating Currents
- Introduce the equation β = IC/IB.
- Discuss the use of this equation to determine IB.
- Discuss the use of this equation to determine IC
- Discuss Project 3.1: The Transistor
- Review the circuit (figure 3.19).
- Mention that this experiment is a demonstration of the
relationship between beta and the base and collector currents.
- Turning a Transistor ON
- Discuss the similarity of a ON transistor to a closed switch
- Introduce the term; Saturated Transistor
- Discuss Project 3.2: The Saturated Transistor
- This project uses the same circuit used in Project 3.1.
- Discuss the relationship, shown in this project, between IB,
IC and VC as the transistor becomes
- Turning a Transistor OFF
- Discuss the similarity of a OFF transistor to a open switch
- The Junction Field Effect Transistor (JFET)
- Introduce the terms; source, drain and gate.
- Discuss the structure and schematic symbols of JFETs (figure
- Review a typical biasing circuit for a JFET (figure 3.29).
- Introduce the terms; normally ON, and normally OFF.
- Inside the JFET
- Discuss how the depletion regions cut off current flow in
the channel when negative voltage is applied to the gate of a
- Introduce the term; cutoff voltage.
This page includes material extracted, by
permission of the publisher, Wiley Publishing, from Complete
Electronics Self-Teaching Guide with Projects, ISBN: 9781118217320.
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