lab report

EET 2010 Lab Exercise #6 Electronics Principles

Common Emitter Amplifier

Equipment

1. Function Generator

2. Oscilloscope

3. DC Power Supply

4. Multimeter

Materials

1. 2N3904 NPN Transistor

2. 470 k Resistor

3. 100 k Resistor

4. 3.9 k Resistor

5. 1 k Resistor

6. 1 F Capacitor

7. 10 F Capacitor

Procedure

1. Using the multimeter, measure the resistances of each resistor.

R1 = R2 =

RE = RC =

2. On a breadboard, construct the dc circuit shown in Figure 6-1 (for now omit the

capacitors and ac source).

3. Measure IB, ICQ and VCEQ of the circuit.

4. Setup the function generator to produce a sinusoidal signal with a high value of 20 mV

and low value of -20 mV (do not use the peak-peak Amplitude option), set the frequency

at 10 kHz, and an offset value of 0. Add the ac portion to the circuit (capacitors and ac

signal).

5. Use Channel 1 of the oscilloscope to measure Vin minimum and maximum voltages. Use

Channel 2 to measure the minimum and maximum output voltages, Vout (Vc).

Figure 6 – 1

R1 470kΩ

R2 100kΩ

RC 3.9kΩ

RE 1kΩ

2N3904

VCC 12V

C2 10µF

C1

1µF Vs

20mVpk

10kHz 0°

EET 2010 Lab Exercise #6 Electronics Principles

6. Take a screenshot including measurements in the following order: (top) Channel 1

Min, Channel 1 Max, Channel 2 Min, Channel 2 Max.

Question 1: Compare the Vin and Vout signals. How are they different?

Question 2: What is the measured gain of this circuit?

Question 3: What is DC of this circuit using measured currents?

Question 4: What is the internal emitter resistance, r’e?

Submittal: All sections must be completed digitally. (Not hand-written/drawn)

1. Lab Cover Sheet (filled in appropriately)

2. Title Page (Appropriate information is described in the ‘Format of a Technical Report’

found on Blackboard)

3. OBJECTIVE – This section is in paragraph form comprised of complete sentences stating

the purposes for doing the experiment. (What theory was this experiment supposed to

verify?)

4. DATA section including:

a. Circuit

b. Calculations: Theoretical values for ICQ, VCEQ, r’e, Av and Vout (use DC = 130)

c. Screenshots (1)

d. Table 6-1: This table should include measured and calculated values of all the

parameters listed in step b. above.

e. Answers to the Questions 1 through 4 in Step 6.

5. DISCUSSION – This section is in paragraph form comprised of complete sentences

stating specific examples of comparisons of theoretical values to actual/measured

values. This need not include a direct comparison of every parameter.

6. CONCLUSION – This section is in paragraph form comprised of complete sentences

stating whether or not the experiment was successful, how did the student know it was

successful, and how successful it was (% error).

Hint: For a successful submittal, make sure your submittal components are presented in the

above order. This makes organized and logical sense for an explanation of data. Be sure

headings are stated (for example: DATA) and all components of the DATA section (for example:

TABLE 6-1, CALCULATIONS, Screenshot) are labeled.