Amplifier Teaching Aid (GTZ, DED; 86 pages) Preface Introduction Lesson 1 - Semiconductor Review Lesson 2 - Bipolar Transistor Bipolar Transistor II First Evaluation Lesson 4 - Transistor Fundamentals Lesson Plan The load line The operating point Recognizing saturation The transistor switch Worksheet No. 4 Lesson 5 - Transistor Biasing Lesson 6 - Transistor Biasing II Second Evaluation Lesson 7 - Small Signal Amplifier Lesson 8 - Small Signal Amplifier II Lesson 9 - Small Signal Amplifier III Lesson 10 - Large Signal Amplifier Third Evaluation

The load line contains every possible operating point for the circuit. A line is defined by two points. To draw the load line you have to get. the saturation point and the cutoff point:

Saturation point: Tells you the maximum possible collector current for the circuit.

Calculate: Visualize a short between the collector and emitter.

VCE --- > 0

Cutoff point : Tells you the maximum possible collector emitter voltage for the circuit. Calculate: Visualize the transistor internally open between collector and emitter.

VCE -- > VCC

VCE (cut) = VCC

Ex: Draw the load line for the given circuit.

Fig. 4-1: CE amplifier base biased

Fig. 4-2: Output curve

Saturation point:

Cutoff point:

VCE (cut) = VCC = 15V

Fig. 4-3: Output curve with loadline

HO: Suppose the collector resistance (in Fig. 4-1) is increased to 6KΩ. What happens to the dc load line?

Solution:

VCE (cut) = 15V