What are the methods of multimeter to distinguish good or bad capacitors
Know how to use a multimeter to identify good or bad capacitors, especially those capacitors that exceed the range of the multimeter. Today I will tell you how to use a multimeter to identify good or bad capacitors, especially those with relatively large capacity. theme.
direct observation to discern
Generally, if a capacitor is broken, it can be identified from the appearance. The most obvious feature is that it will crack and have obvious signs of damage. For example, the picture below is a real shot of a capacitor explosion. This method is easy to identify. There are also many capacitors in the circuit that are damaged due to explosions, so this method is still very useful.
Use a multimeter capacitor file to identify
For the capacitor with small capacity, you can directly use the capacitance file of the multimeter to distinguish it. It is relatively simple to measure the capacitance with the multimeter. The capacitance of the capacitor is generally marked on the outside of the capacitor, so you can compare the capacity measured by the multimeter with the marked size. If there is a big difference between the two, or the data cannot be measured at all, then it can be concluded that the measured capacitor has been broken. , On the contrary, the capacity is relatively close, then this capacitor is good.
Use diode files to identify
Although the previous method is very reliable, but when the capacity is large, the capacitance capacity has exceeded the range of the multimeter at this time, this method will not work, it does not matter, we still have a way, that is to use the diode file to measure, the measurement method and the measurement of capacitance The method is very similar, but slightly different. It is not necessary to distinguish the positive and negative poles of the capacitor when using the capacitor file to measure, but this is the difference. Put the black test lead on the positive pole of the capacitor (when using the internal power supply, the current Flow out from the black test lead), and the red test lead is placed on the negative pole of the capacitor. If you see that the number on the dial of the multimeter is increasing continuously, and the larger the capacity is, the phenomenon is more obvious, then it can be concluded that the capacitor is good.
Use electric barrier to distinguish
In addition to the above three methods, you can also use the resistance file to measure. Unexpectedly, this method is very similar to the diode file measurement. It is also to distinguish the positive and negative electrodes. Connect the black test lead to the positive electrode of the capacitor and the red test lead to the negative electrode of the capacitor. , choose the appropriate resistance range, in the test I choose the gear of 20K, this phenomenon is obvious when measuring, you can clearly see that the number is increasing on the display of the multimeter, if the capacity of the capacitor is larger, this phenomenon It will be more obvious and the growth rate will be slower.
