EET160 Experiment number 2
1.0
The Tektronix CFG253 Function Generator
1.1
Figure 1 illustrates the front panel controls, connectors and indicators with
brief descriptions listed below:
1.
Power On light
2.
Amplitude control
3.
DC Offset
4.
SYMMETRY KNOB (Not used in this course)
5.
Range (Hz)
6.
FUNCTIONS – Choose either sine, square or sawtooth waveforms
7.
Frequency control
8.
Not used in this course
9.
Not used in this course
10.
Not used in this course
11.
Not used in this course
12.
VOLTS OUT. Push in for maximum amplitude of 2 volts p-p.
Out position gives maximum amplitude of 20 volts p-p.
13.
Not used in this course
14.
OUTPUT
15.
Power
Figure 1
2.0
The TDS3012 Oscilloscope
2.1
Figure two illustrates the menu buttons
1.
MEASURE. Performs automated measurements of waveforms
2.
CURSOR. Activates the cursor
3.
SAVE/RECALL. Saves and recalls setups and waveforms tp
memory or a floppy disk.
4.
DISPLAY. Changes the appearance of waveforms and the display
screen
5.
QUICKMENU. Activates QuickMenus such as the built- in Scope
QUICKMenu
6.
UTILITY. Activates the system utility function.
Figure 2
2.1
Figure 3 illustrates additional menu buttons
7.
VERTICAL MENU. Adjusts the scale, position and offset of
waveforms. Sets the input parameters
8.
TRIGGER MENU. Adjusts the trigger functions
9.
ACQUIRE MENU. Sets the acquisition modes and horizontal
resolution, and resets the delay time.
Figure 3
2.2
Figure 4 shows the Dedicated controls. These dedicated buttons and
controls generally control waveforms and cursors without the use of
menus.
1.
2.
3.
4.
5.
6.
7.
COARSE. Causes the general purpose knobs to make adjustments
more quickly.
SELECT. Toggles between the two cursors to select the active
cursor.
General purpose knob. Moves the cursor. Sets numerical
parameter values fo r some menu items. Push COARSE to make
adjustments quickly.
VERTICAL POSITION. Adjusts the trigger
HORIZONTAL POSITION. Adjusts the trigger point location
relative to the acquired waveforms. Push COARSE to make
adjustments quickly.
TRIGGER LEVEL. Adjusts the trigger level.
RUN/STOP. Stops and restarts acquisition.
Figure 4
“2.2” Continued
8.
SINGLE SEQ. Sets acquisition, display, and trigger parameters
for a single-shot (single sequence) acquisition.
9.
SET TO 50%. Sets the trigger level to the midpoint of the
waveform.
10.
AUTOSET. Automatically sets the vertical, horizontal and trigger
controls for a usable display.
11.
FORCE TRIG. Forces an immediate trigger event.
12.
WAVEFORM INTENSITY. Controls waveform intensity.
13.
B TRIG. Activates the B trigger. Changes the trigger menu to set
the B-trigger parameters.
14.
DELAY. Enables delayed acquisition relative to the trigger event.
Use horizontal POSITION to set the amount of delay.
15.
HORIZONTAL SCALE. Adjusts the horizontal scale factor.
16.
HORIZONTAL ZOOM. Splits the screen and magnifies the
current acquisition horizontally.
17.
WAVEFORM OFF. Removes the selected waveform from the
display.
18.
VERTICAL SCALE. Adjusts the vertical scale factor of the
selected wave.
“2.2” continued
19.
20.
3.0
CH1, CH2, MATH. Displays the waveform and chooses the
selected waveform. REF shows the reference waveform menu.
MENU OFF. Clears menu from the display. Note that item 20 is
not shown in figure 4. If you have trouble locating it on your
oscilloscope, ask your instruc tor for help.
Getting started.
3.1
Connect the Tektronix function generator to CH 1 of the Oscilloscope.
3.1.1 Now turn the function generator on. Set the function to sinusoidal
and the frequency to about 2500 Hz. Make sure that the DC offset
control is pushed to the “in” position, the VOLTS OUT control is
set for 0 – 20 volts p-p and the amplitude is set somewhere in the
mid-range area (40% to 60% of maximum value).
3.1.2 Connect the function generator to channel 1 of the scope and turn
the scope on. Select CH1 (Item 19, figure 4) and press the
AUTOSET (Item 10, figure 4) button. Select menu 7 (Figure 3)
and choose dc coupling from this menu. Play with the vertical
scale control (Item 18 in figure 4) until an ideal setting is observed.
2.0.1.1 Determine the peak voltage and the peak to peak voltage.
Vp = ____________________________ Volts
Vp-p = __________________________ Volts
Predict the rms. value.
Vrms = __________________________ Volts
Recall: Vrms = 0.707 *Vp
3.1.3
Play with the horizontal scale control until an ideal setting is
found. Determine the frequency.
f = _________________________ Hz
3.1.4
To determine the accuracy of the results found in 2.1.2 and 2.1.3
push the measure button (Item 1 in figure 2) Play with these
menus until you determine the peak to peak voltages, the rms
voltage and the frequency. Compare these results to the ones
you’ve obtained in 2.1.2 and 2.1.3. Remove all of the
measurements observed on the screen.
3.2
3.3
3.4
3.5
Repeat 2.1 for a sinusoidal function having a frequency of about 60 K Hz
Repeat 2.1 for a triangle function having a frequency of 120 K Hz
Repeat 2.1 for a square wave function having a frequency of 120 K Hz
Learning about the trigger level
3.5.1 Connect the scope as described in section 3.3.
3.5.2 Push the delay button (Item 14 in figure 4) so that the light is turned
off. Adjust the level control (Item 6 in figure 4). Draw conclusions.
4.0 The dc offset
4.1 Set up the circuit as described in section 2.1, but with the function generator’s
dc offset switch pulled to the ON position.
4.2 Set the oscilloscope for dc coupling. Rotate the function generator’s dc offset
control and observe what happens.
4.3 Set the oscilloscope for ac coupling. Rotate the function generator’s dc offset
control and observe what happens. Draw conclusions.
4.4 Determine the purpose of the “GND” function in the coupling menu.
4.5 Program the function generator for a square wave operation with a frequency
of about 20 k Hz. Adjust the amplitude control and the dc offset control until
you observe a pulse function having a 0 to 5- volt amplitude. (No negative
voltage). You have just programmed the function generator for TTL
operations.