OBJECTIVES
After performing this experiment, you will be able to:
1. Explain the four functional blocks on an oscilloscope and describe the major controls within each block.
2. Use an oscilloscope to measure ac and dc voltages.
EVALUATION AND REVIEW QUESTIONS
1. (a) Compute the percent difference between the DMM measurement and the oscilloscope measurement for each dc voltage measurement summarized in Table 1.
Table 1
|
Power Supply Setting
|
VOLTS/DIV
Setting
|
Number of Divisions of Deflection
|
Oscilloscope (measured voltage)
|
DMM
(measured
voltage)
|
|
1.0 V
|
0.2 V/DIV
|
5.0 DIV
|
1.0 V
|
1.0 V
|
|
2.5 V
|
2.5V/DIV
|
5.o DIV
|
2.5 V
|
2.5 V
|
|
4.5 V
|
1.0 V
|
4.5 DIV
|
4.5 V
|
4.5 V
|
|
8.3 V
|
2.0 V
|
4.1 DIV
|
8.2 V
|
8.3 V
|
(b) Which do you think is most accurate? Why?
2. Describe the four major groups of controls on the oscilloscope and the purpose of each group.
3. If you are having difficulty obtaining a stable display, which group of controls should you adjust?
4. (a) If an ac waveform has 3.4 divisions from peak to peak and the VOLTS/DIV control is set to 5.0 V/div, what is the peak-to-peak voltage?
(b) What is the rims voltage?
5. If you wanted to view an ac waveform that was 20.0 Vrms, what setting of the VOLT/DIV control would be best?
6. Most analog oscilloscopes have a single beam, which is shared with two signals. If you are using an analog oscilloscope, when should you select ALTernate and when should you choose CHOP?