Tips for using an oscilloscope

The purpose of calibration is to optimize the current measured value and not be affected by the external temperature environment, etc. The calibration method is to call the calibration file loaded by the oscilloscope for calibration. Basically, just press the calibration key.

Compensation is to prevent the signal integrity problem of the input oscilloscope signal due to impedance mismatch. The compensation method is to connect the probe to the square wave signal pin of the oscilloscope (this pin is available on all oscilloscopes and is mainly used for compensation calibration), and use a small screwdriver to adjust the tightness of the probe so that the square wave signal presents the correct shape. Excessive compensation will cause the waveform to surge up and down, and insufficient compensation will cause the waveform to be too slow.

2. Adjust the oscilloscope's range, time base, observation center point coordinates, etc. to achieve the best observation state of the waveform.

3. Measurement of power supply wave

The correct method for power supply oscilloscope measurement: (1) Remove the probe cap to reduce the parasitic inductance introduced by the probe, (2) Reduce the ground loop as much as possible, wrap the ground wire around the probe, or directly use a ground clamp (many oscilloscope manufacturers have them, e.g. R&W), (3) Add a 10uF and a 0.1uF capacitor to the measurement end, and limit the bandwidth of the oscilloscope to 20MHz to act as a low-pass filter to prevent high-frequency signal crosstalk that will cause inaccurate measurements, (4) According to the Nyquist sampling rate, the time base should be selected so that the measurement frequency is more than twice the switching frequency, and (5) The test point should be far away from the interference source.

4. Use a differential probe on the primary side of the transformer and a normal probe on the secondary side. Do not use different probes at the same time because the grounds of the normal probes are connected, but there is a voltage difference between the grounds of the primary and secondary sides. This will short-circuit the grounds of the oscilloscope and risk burning out the oscilloscope.