3.5 X-Y Function application
The phase change of the measured signal is displayed as XY after the signal passes
through a certain electric network, and the following steps are carried out:
1. Press
[CH1]
to set the probe option as 10×.
2. Press
[CH2]
to set the probe option attenuation as 10×.
3. Set the switches on both probes as ×10.
4. Connect the probe of channel 1 to an input point of the network, and connect the
probe of channel 2 to an output point of the network.
5. Press
[AUTO]
.
6. Revolve
[Volt/div]
to make that the signal amplitudes displayed on the two channels
are roughly the same.
7. Press
[DISPLAY]
, and select “XY” in a format option.
A Lissajous pattern is displayed on the screen to represent input and output
characteristics of the circuit.
8. Revolve
[Volt/div]
and the vertical [POSITION] so as to optimize the display.
9. Observe and calculate the phase difference by an elliptical oscillography graphical
method. (Shown in the figure below)
The phase difference angle theta is equal to +/- arcsin (A/B) or theta is equal to +/-
arcsin (C/D) according to the formula sin theta=A/B or C/D, wherein theta represents
the phase difference angle between the channels, and A, B, C and D are defined in the
figure above.
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