What is capacitor and its classification

The so-called capacitor is an electronic component that holds and releases electric charge. The basic working principle of the capacitor is charging and discharging, and of course there are rectification, oscillation and other functions. In addition, the structure of the capacitor is very simple, mainly composed of two positive and negative electrodes and an insulating medium sandwiched in the middle, so the type of capacitor is mainly determined by the electrodes and the insulating medium. The uses of capacitors are very many, mainly as follows:
1. DC isolation: The function is to prevent DC from passing through and allow AC to pass through.
2. Bypass (decoupling): Provide a low impedance path for certain parallel components in the AC circuit.
3. Coupling: As a connection between two circuits, it allows AC signals to pass through and be transmitted to the next level of circuit
4. Filtering: This is very important for DIY. The capacitors on the graphics card basically have this function.
5. Temperature compensation: Compensate for the impact caused by the lack of adaptability of other components to temperature and improve the stability of the circuit.
6. Timing: Capacitors and resistors are used in conjunction to determine the time constant of the circuit.
7. Tuning: System tuning of frequency-related circuits, such as mobile phones, radios, and televisions.
8. Rectification: Open or close a semi-closed conductor switching element at a predetermined time.
9. Energy storage: Store electrical energy for release when necessary. For example, camera flash, heating equipment, etc. (Today, the energy storage level of some capacitors is close to that of lithium batteries. The energy stored in a capacitor can power a mobile phone for a day.