In a sense, capacitors are a bit like batteries. Although the two work in very different ways, they all store electrical energy. But the capacitor is much simpler than the principle of the battery, and it can't produce electrons - it just stores electrons. Like a battery, a capacitor also has two electrodes. Inside the capacitor, the two electrodes are respectively connected to two metal plates separated by a dielectric. The dielectric can be air, paper, plastic or any other material that is non-conductive and prevents the two metal electrodes from contacting each other.
The capacitors in the electronic circuit are as shown:
When the capacitor and battery are connected together:
After charging is complete, the capacitor has the same voltage as the battery (if the battery voltage is 1.5 volts, the capacitor voltage is also 1.5 volts). Small capacitors have a low capacity, but large capacitors can hold a large amount of charge. For example, a soda can size capacitor can hold enough charge to run a flashlight bulb for a few minutes.
Suppose you connect the capacitor to the circuit as follows:
You have a battery, a light bulb and a capacitor. If the capacitor is very large, you will see that after the battery is connected, current flows from the battery to the capacitor to charge it, and the bulb will be illuminated. The bulb will then gradually dim and, finally, once the capacitor reaches its capacity, the bulb will extinguish immediately. At this point, you can remove the battery and replace it with a length of wire.Current will flow from one pole of the capacitor to the other. At this point,the light bulb will reproduce the light, and soon the light bulb will gradually dim and. Finally, the capacitor discharge ends(the number of electrons on both poles of the capacitor is equal), the bulb is extinguished.
The function of the capacitor can be described by a water tower connected to the water pipe. The water tower can be used to "storage"the water pressure - when the water supplied by the water supply system exceeds the amount of water required by the town, the excess water will be stored in the water tower. Then, when the demand for water is high, excess water will flow out of the water tower to maintain water pressure. The capacitor stores the electrons in the same way, and the electrons can be released later. This is how the capacitor works.
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