DC power line is the first to apply to the control equipment commercial frequency ripple less DC voltage, but also to prevent the control equipment generated by the high frequency ripple to the AC power line, so the capacitor from the AC power line or rectifier, on the 50Hz frequency, it is necessary to appear low impedance; and the capacitor from the control equipment, on the high frequency ripple, but also to appear low impedance If the impedance is 0, the ripple voltage and the high frequency noise voltage will be 0.
Therefore, the electrode area S will be increased, you can add the electric capacity. In the case of electrolytic capacitors, the electrode structure is made of a thin metal foil wound into a cylinder, and the inductance of the thin electrode is added in addition to the capacitance. In addition, the terminal wire used to lead the electrode outside also has an inductance component, and the specific resistance of the electrolyte forming the cathode of electrolytic capacitors is about 100Ω-cm, which is one of the factors limiting the filtering effect.
Film capacitors use plastic film as the insulating material, and metal foil is wound into a cylinder or laminated to increase the area. However, in the case of film capacitors, the inductance can be reduced a lot because the electrodes are leaded out by metalcon after being reversed.
Capacitor de magnetizador de 2kv-1000uf - Capacitor de pulso - Capacitor de magnetizador de alta tensão
The effectiveness of the parallel film capacitor is achieved by using a crystal step-down chopper (chopper) to switch the DC power line at 50 kHz with a high frequency voltage waveform. In the electrolytic capacitor terminal of 2200μF, there is about 2V of noise, but if the film capacitor of 2.2μF is connected in parallel, it will be 0.1V. If the capacitance of film capacitor is not satisfied, the peak voltage of noise will be reduced, and its oscillation frequency is low, so it will be easy to be seen.