Film capacitor energization

Film capacitors have many excellent characteristics, no polarity, high insulation resistance, excellent frequency characteristics (wide frequency response), and low dielectric loss. Therefore, film capacitors are used in large quantities on analog circuits. Today I want to tell you about the energization of the film capacitor. The current operation of the film capacitor is very regular. When using the film capacitor, we will find that the current is abnormal. How do we deal with this problem at this time? It.

Film capacitors are manufactured and polarized similarly to the method of manufacturing aluminum electrolytic capacitors, however their storage time is not limited and can be operated for a long time without DC polarity. The instantaneous counter voltage generally does not damage the capacitor, and the aluminum electrolytic capacitor is different.

In practice, there is not always a DC bias voltage. Non-polar tantalum capacitors can also be manufactured, but they are more expensive and not necessarily used after storage. If two identical tantalum capacitors are connected in series back to back, a non-polar capacitor can be obtained. The total capacitance is half of each series capacitor, which is C/2.

A good performance film capacitor at the moment of power-on, the multimeter's hands should have a large swing; the larger the film capacitor capacity, the greater the swing of the hands, after the swing, the hands can gradually return to zero. If the capacitor does not swing when the power is turned on, the pointer of the multimeter does not swing, indicating that the capacitor is broken or open; if the pin always indicates the power supply voltage without swinging, it indicates that the capacitor has been short-circuited; if the hand swings normally, but does not return to zero , indicating that the capacitor has leakage current.

If you encounter an abnormal current, you can try it according to the method described in this article. I hope this article can help you solve the problem.