DN082-02v02
JYE Tech - 4 - www.jyetech.com
(a) Under compensation
(b) Right compensation
(c) Over compensation
Fig 4
Fig 5
Fig 6
3)
Set vertical sensitivity to 2V (V.Sen 1 switch in position
“
1V
”
And V. Sen 2 switch in position
“
X2
”
).
4)
Set the coupling switch to the
“
DC
”
position. (See Fig 3)
5)
Press the [ V.POS ] button, and adjust 0V indicator to the position shown in Fig. 3.
6)
Press the [ SEC/DIV ] button, and set the Time-base to 0.5ms. Waveform shown in Fig. 3 should be
seen. (If you find the display is unstable, you can press [LEVEL] and turn the knob so that a stable
display is obtained.)
7)
Changing position of V. Sen 2 switch you should see that the waveform amplitude changes accordingly.
You can compare the amplitude readings.
8)
Changing the Time-base setting to 0.2ms, for instance, you should see the signal waveform widens
accordingly. Compare readings and experiment with other settings.
9)
Now, select
“
AC
”
with the coupling switch and you should see that the waveform is shifted down to a
position where the VPos indicator is at its midway point.
Example 2 Observe saw signal (Learn how to use trigger modes)
The schematic on the right is a simple sawtooth signal generator.
We are going to use the scope to observe its output. Build the circuit
according to the schematic. Connect power and oscilloscope as
indicated.
1)
Select coupling switch to DC. Set V. Sen. 1 switch to the
“
1V
”
position and V. Sen. 2 switch to the
“
X2
”
position.
(i.e. sensitivity is set to 2V/Div). Adjust the 0V to the
second last point on the vertical scale. (See Fig 4)
2)
Power the circuit. Select Time-base to 0.5ms (or other
depending on type of transistor used). You should see a
waveform similar to that shown in Fig 4.
3)
Select AUTO trigger mode and change the trigger level.
You should be able to observe that the waveform stabilizes
itself when it intersects with trigger level (the internal
trigger source should be selected here). Otherwise, the
waveform will jump and you won
’
t be able to get a clear
view of it.
4)
Change the trigger mode to NORM, and vary the trigger
level. Notice that the waveform only update when they
intersect with the trigger level (internal trigger source
should also be selected here). Otherwise, it will stall.
5)
Press the [HOLD] button to put the oscilloscope into the HOLD state.
“
HOLD
”
is displayed. Now you
can shift the waveform back and forth to view the un-displayed waveform. Pressing [HOLD] again will
release the HOLD state and put oscilloscope back into captured signal sample state.
Use 10X Probe
10X probe offers the advantage of higher input voltage range, higher
impedance, and less interference to the circuits being measured. In order to
effectively use 10X probe the compensation cap trimmer (see Fig 5) must be
calibrated. This can be done using the built-in 1KHz/5V test signal.
Set the probe attenuation to 1/10 by setting the attenuation switch in the
probe handle to the
“
10X
”
position. Insert the probe tip into the centre
conductor of M.F.T. connector. Set oscilloscope Time-base to 0.2ms/Div and
adjust trigger level so that a stable waveform display is obtained. Tune the cap
trimmer carefully (see Fig 5) so that right compensation figure is reached
(refer to Fig 6).
At using 10X probe remember to multiply vertical reading by 10 for true results. If, for example, the displayed
signal amplitude is 2.5V the real signal amplitude is actually 25V.
