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For the examination of the input and output of the circuit in the form of X-Y
coordinate graph, please operate according to the following steps:
Set the probe menu attenuation coefficient for 10X and that of the
switch in the probe for 10X.
Connect the probe of channel 1 to the input of the network and that of
Channel 2 to the output of the network.
Push down the Autoset button, with the oscilloscope turning on the
signals of the two channels and displaying them in the screen.
Turn the VOLTS/DIV knob, making the amplitudes of two signals
equal in the rough.
Press the Display button and recall the Display menu.
Press the H3 button and choose XY Mode as ON.
The oscilloscope will display the input and terminal characteristics of
the network in the Lissajous graph form.
Turn the VOLTS/DIV and VERTICAL POSITION knobs, optimizing
the waveform.
With the elliptical oscillogram method adopted, observe and calculate
the phase difference (see Figure 87).
Based on the expression sin (q) =A/B or C/D, there into, q is the phase
difference angle, and the definitions of A, B, C, and D are shown as the graph
above. As a result, the phase difference angle can be obtained, namely, q =±
arcsin (A/B) or ± arcsin (C/D). If the principal axis of the ellipse is in the I
and III quadrants, the determined phase difference angel should be in the I and
IV quadrants, that is, in the range of (0 ~
axis of the ellipse is in the II and IV quadrants, the determined phase difference
angle is in the II and III quadrants, that is, within the range of (
/2).
~3
90
Page
The signal must be
centered and kept in the
horizontal direction.
Figure 87. Lissajous Graph.
/2) or (3
/ 2 ~2
). If the principal
/ 2 ~
) or (
June 2017
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