SMD capacitors are widely used in DC blocking, coupling, bypass, filtering, tuning loops, energy conversion, control circuits, etc. Most of the reasons for the damage of electrical products may be due to the damage of the capacitor. We have several methods to detect the quality of the chip capacitor.
1. Diode file of digital multimeter to check the quality of electrolytic capacitor
This method is suitable for the case where the electrolytic capacitor is broken down. Put the digital multimeter in the diode position and connect the two test leads to the two ends of the electrolytic capacitor. At this time, pay attention to whether the digital multimeter makes a "drip" sound. If not, it proves that it is good. Was broken down.
Second, the capacitance resistance test method
This method is suitable for detecting small capacitors below 10pF, and it can only be qualitatively checked for leakage, internal short circuit or breakdown. When measuring, you can choose a multimeter R×10k block, and use two meter pens to connect the two pins of the capacitor at will, and the resistance should be infinite. If the measured resistance value (the pointer swings to the right) is zero, it means that the capacitor is damaged by leakage or internal breakdown.
3. Direct capacitance test method
Some powerful digital multimeters have a capacitance test position. When we switch to the capacitance test position, the red test lead is connected to the positive electrode and the black test lead is connected to the negative electrode. If there is infinity, the capacitor is open and drained; when it is measured as zero, it means that it has been broken down. A number in the normal range is normal.
Fourth, the resonance method
We observe the data through the LC resonant circuit. If there is an error in the data or the waveform is incorrect, it means that the capacitor is broken.
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