EL - 200

Electronic Devices

Lab #3 Transistor Circuits

Andrew Buettner

March 6, 2003

Objective

The objective of this lab is to construct two transistor biasing circuits, and observe the changes that occur between two different circuits caused by the change in the components.

Equipment Used

1) N3904 Transistors (2)

2) 330KW resistor

3) 820W resistor

4) 33KW resistor

5) 9.1KW resistor

6) 220W resistor

7) Multimeter Serial #: 22-221

8) Trainer Serial #: 1052

Procedure

1) Assemble the following circuit:




2) Record the values of V_B, V_C, and V_E.

3) Calculate IB, IC and b.

4) Replace the first transistor with a second.

5) Repeat steps 2 and 3.

6) Assemble the following circuit:




7) Repeat steps 2 and 3.

8) Replace the first transistor with a second.

9) Repeat steps 2 and 3.

10) Compare b and V_BE to the theoretical values given in the text.

Results

A) Table 1: Values for Schematic 1

	VB	VC	VE	IB	IC	b
Transistor 1	.59V	5.4V	0.0V	34.6mA	8.0mA	231
Transistor 2	.60V	5.8V	0.0V	34.5mA	7.6mA	220

B) Table 2: Values for Schematic 2

	VB	VC	VE	IB	IC	b
Transistor 1	1.41V	5.3V	1.00V	106mA	5.73mA	54.1
Transistor 2	1.68V	5.4V	1.01V	68mA	5.61mA	82.5

C) Table 3: Values of V_BE and b between experiments and given values.

Schematic #1 Schematic #2

	Transistor 1	Transistor 2	Transistor 1	Transistor 2	Given
VBE	.59V	.60V	.41V	.67V	.65V
b	231	220	54.1	82.5	100

Conclusions

From this experiment, one can see that in transistor biasing, the effects of component changes is greater on the second schematic than the first, when the transistors are swapped.

Attachments

A) Original Handout

B) Original Lab Data

C) Calculations