(These Lecture Notes are for courses using the book
the *
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).

- Turning the Transistor ON
- Discuss the use of a lamp in place of the collector resistor
R
_{C}(figure 4.3). - Introduce the terms; load and load current.
- Review the equation to calculate the required load current.
- Discuss the calculation to determine the base current that will result in the required load current.
- Show the calculation used to determine the value of the base resistor needed to obtain the desired base current.

- Discuss the use of a lamp in place of the collector resistor
R
- Why Transistors are used as Switches
- Discuss the advantages of transistor switches vs. mechanical switches.
- Discuss Project 4.1: The Transistor Switch
- Review the circuit diagram (figure 4.9).
- Mention that circuits similar to this are commonly used in stores to ring a buzzer when a customer walks through the door.
- The Two Transistors Switch
- Discuss the two transistor switch circuit (figure 4.16)
- Summarize how the voltages and currents in the circuit change when the switch is changed from position A to position B (figure 4.17).
- Discuss the calculations needed to find the values of R
_{1}, R_{2}and R_{3}to produce a specified load current. - The Three Transistor Switch
- Discuss the three transistor switch circuit (figure 4.19)
- Summarize how the voltages and currents in the circuit change when the switch is changed from position A to position B.
- Discuss the calculations needed to find the values of R
_{1}, R_{2}, R_{3}and R4 to produce a specified load current. - Alternative Base Switching
- Discuss the transistor circuit with the base terminal at the
junction of R
_{1}and R2 (figure 4.20). - Discuss the calculations needed to find the values of R
_{1}and R_{2}. - Discuss Project 4.2: The JFET
- Review the circuit diagram (figure 4.22).
- Discuss the expected result of this project; the I-V curve for the JFET.
- Switching the JFET
- Review the JFET circuit diagram (figure 4.29).
- Discuss the calculations needed to find the value of R
_{D}.

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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