Ceyear 4456 Series, Руководство пользователя

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Chapter XIX Application Examples
231
Fig. 19.2 Example of Pulse Measurement by Using Peak Detect Mode
19.3 Viewing Phase Difference between Two Signals
For viewing the phase difference between two signals with the same frequency and amplitude, there are two
common methods: XY measurement method and direct parameter measurement method.
19.3.1 XY Measurement Method
In XY mode, the oscilloscope will convert two input channels to voltage-voltage display from voltage-time
display. The X axis and Y axis will track the voltage of CH1 and CH2 respectively. The phase difference between
two signals with the same frequency can be easily displayed and measured with Lissajous method.
The operation steps are as follows:
1) Connect the ground wire on the probe to the circuit under test. The needle of the probe touches the measured
point of the circuit.
2) Press
【
AutoSet
】
key and the oscilloscope will automatically set to display optimal waveforms. On the basis
of this, you may further adjust the vertical and horizontal positions until the waveform display meets your
requirements.
3) Press the
【
Display
】
key to pop up the level 1 menu at the bottom of the screen and click the [XY Display]
menu.
4) Calculate the phase difference of the two signals according to the principle of Figure XY. The figure below
shows the XY display graphs of several common phase differences.
Fig. 19.3 Principle Diagram of Phase Difference Measurement
5) If the frequency or phase difference of the two measured signals is an integer multiple, the frequency and
phase relationship between the two signals can be derived from the graph.
Signal
Phase difference
0 degrees 45 degrees 90 degrees 180 degrees 270 degrees 360 degrees