Precautions against damage to the oscilloscope due to misuse
Many junior engineers use multiple probes to measure the power supply, just as soon as the power supply products "fried", and even damage to the oscilloscope. They will ask me, the oscilloscope is not directly connected to the probe between the components to be tested? I do not seem to be connected to the wrong ah, why would this happen ah? That's because they don't know how to connect the channel and ground of the oscilloscope. Multiple probes on an oscilloscope share a common ground inside the oscilloscope. Therefore, when measuring the primary and secondary sides of the power supply at the same time, if one probe is connected to the ground of the primary side and the other probe is connected to the ground of the secondary side, it is equivalent to short-circuiting the ground of the primary side and the secondary side of the power supply because the ground of the internal channels of the oscilloscope is connected together, however, there is a voltage difference between the primary side and the secondary side of the ground, and then the high current of short-circuiting is easy to burn out the product and the probes, and even the oscilloscope might be damaged as well. When testing the primary and secondary voltages, you should use a differential probe on one side and an ordinary probe on the other. Even when testing the same side of the line, the ground of the probe should be a common reference point. The ground of the oscilloscope is in turn connected through the power supply ground. Many companies basically add an isolation transformer in front of the oscilloscope, this method is quite good. Some companies directly cut the power supply three-phase ground PIN pin, so there is no ground, touch the oscilloscope chassis, leakage current will increase. It is recommended not to use this way.
In fact, the problem is not only these, such as in the dynamic application, the application of computing between probes, test voltage value of attention to matters such as. We all know that oscilloscopes are very powerful, almost no electronic engineers do not use oscilloscopes, so their own use of oscilloscopes must think more, more tests, more understanding of the functions of oscilloscopes, the difference between the internal options key, to understand the impact of the different oscilloscope parameters on the measurement, so that it can better help us. Do not just to complete the task, randomly. Do it seriously and observe carefully, so that our progress will be great. Experience is accumulated step by step.
