Before using film capacitors, the quality of film capacitors can be judged from four aspects, one is to judge from appearance, the other is to judge by resistance method, the third is to use capacitance meter to measure, and the fourth is to judge by replacement method. Take a look.
How to judge the quality of film capacitors
1. Judging from the appearance
Check the appearance for cracks, discoloration, etc. If there are any of the above phenomena, it can be judged that the capacitor is damaged.
2. Judging by the resistance method
Judging whether it is good or bad according to the measured resistance value, the resistance between the two feet should be very high resistance, if the resistance value is too small, there may be leakage and breakdown.
3. Measure with capacitance meter
If there is a capacitance meter, use the capacitance meter to measure the film capacitance, and observe whether the measured capacitance is consistent with the marked capacitance.
4. Judgment by substitution method
If it cannot be judged by the above, it can be judged by the substitution method.
How to measure 115j400v film capacitor?
1. Measurement of electrolytic capacitors: use RX1 gear for thousands of microfarads, RX10 gear for 100 microfarads to several hundred microfarads, and RX100 or RX1K gear for below 100 microfarads.
2. Measurement of ordinary capacitance: 1000 picofarads to 0.1 microfarads use RX10K gear, 1 picofarads use RX1K gear, the needle swings a large range, and the capacity is large.
The capacitance of 1000 picofarads can be measured with a shaker, and the general insulation resistance should be between 10-100 megohms.