Method for detecting equipment power capacitor

1. When testing a small power supply capacitor under 50pf, because the fixed capacitor under 50pf can hold a small amount, use a multimeter to detect, only to detect the presence or absence of leakage, internal burnout or breakdown. When testing, you can select the multi-meter R × 15k block, use two rods to separate the two pins of the power supply capacitor, the resistance will be infinite. If the sense resistance value shows 0, then it is clear that the inside of the capacitor is burnt out or breakdown occurs.

2. Test whether the power supply capacitor from 50pf to 10000pf has a supplementary charge behavior, and then consider its good or bad. The multimeter uses R×5k block. Both bipolar transistors have a beta coefficient of more than 90, and the penetration current requires the application of a transistor to form a Darlington. The red and black bars of the multimeter are respectively connected to the emitter E and the collector junction C of the Darlington tube. Because of the amplification effect of the Darlington tube, the charging and discharging process of the capacitor to be tested is amplified, so that the amplitude of the multimeter pointer swing is increased, thereby facilitating observation. It should be noted that during the detection and operation, especially when measuring the small-capacity power supply capacitor, it is necessary to repeatedly adjust the two points of the measured capacitor pin contact A and B to clearly see the swing of the multi-meter pointer. C According to the fixed capacitance above 10000pf, the R×15k block of the multimeter can be used to detect the power supply capacitor. There is no charging phase and no short circuit or leakage, and the capacity of the capacitor can be calculated according to the amplitude of the pointer from the right swing.

3. Rotate the shaft slightly with your hand. If you feel very smooth, you won't feel it sometimes loose or even smooth. When the load is extended in all directions, such as around the axis, the shaft will not be loose. The hand will be rotated by the rotating shaft, and the other hand will touch the surface of the set with little force, and there will be no falling off. The power supply capacitor that contacts the defective product between the rotating shaft and the moving piece cannot be used any further.