Electronic production need to use a variety of capacitors, they were to play the circuit in a different role. And resistor similar, usually referred to as its capacitance, with the letter C said. As the name suggests, the capacitor is the "charge-storage containers." Despite the wide variety capacitors, but their basic structure and principles are the same. 2 is close by the middle of a metal material (solid, liquid or gas) separated, constitute a capacitor. Two metal plate known as the middle of the material called medium. Capacitors are divided into a fixed capacity and variable capacity. But common is a fixed capacity of capacitors, the most common is the capacitance electrolytic capacitors and tiles.

     Different capacitor storage capacity is not the same charge. Provisions of the capacitor plus 1 volts DC voltage by the charge of storage capacitors, as the capacity. Capacitance for the basic unit of Farah (F). But in fact, Farah is a very popular unit, because the capacity of capacitors are often much less than 1 Farah, common-law (μ F), satisfied that the law (nF), Paper Act (pF) (also known as pico Paper Law Act ), Their relationship is this: 1 Farah (F) = 1000000-law (μ F) 1-law (μ F) = 1000 satisfied that the law (nF) = 1000000 Paper Act (pF)

     In electronic circuits, capacitors and used through the exchange of separated DC, is also used to store and release charge to act as filters, smooth pulse output signal. Small-capacity capacitors, usually in the use of high-frequency circuits, such as radios, transmitters and in the oscillator. Large-capacity capacitors are often made by filtering and storage charge. But also a feature, generally more than 1 μ F capacitance electrolytic capacitors are, and 1 μ F below for more tiles capacitance capacitors, of course, there are also other, such as monolithic capacitors, polyester capacitors, small capacity, such as mica capacitor. Electrolytic capacitor has a Lvqiao inside full of electrolytes and leads to the two electrodes, as is (+), negative (-) very, capacitors and other differences in their polarity of the circuit can not be wrong then, while the other capacitor No polarity.

     Capacitor to the two electrodes were then in power now, the negative electrode, in a moment even if the power disconnect, between the two pins there will still be residual voltage (after school tutorials, can be observed multimeter), we said that capacitors Save the charge. To establish inter-voltage capacitor plate, the savings from power, a process known as capacitors charge. Filling good, capacitors at both ends of a certain voltage. Capacitors store the charge to the circuit release process, known as capacitors discharge.

     Take a real life example, we see the market pull out the plug in the power rectifier, above the light-emitting diodes will continue to be bright while, then gradually extinguished, it is because the inside of the electric energy storage capacitors in advance, and then released. Of course, this was originally used as capacitor filter. As for the capacitor filter, I wonder if you have no use Rectifier the experience of listening to Walkman, the general low quality of power supply due to cost savings for manufacturers to consider using a smaller capacity of the filtering capacitor, causing a buzz in the headphones. At this time in power at both ends and connected to a larger capacity electrolytic capacitor (1000 μ F, to the attention of cathode cathode), and generally improve its effectiveness. Production HiFi stereo enthusiasts should use at least 10,000 of these micro-capacitors to filter, filter capacitance is, the output voltage of the closer DC, and the capacitance of storage function, so that the sudden arrival of large-signal, the circuit Sufficient energy for the conversion of the powerful audio output. At this time, the capacitor is similar to the role of the reservoir, allowing the raging water to smooth out, and can guarantee that the lower reaches of the heavy water supply.

     Electronic circuits, capacitors charge only in the course of the current can flow, the charge after the end of the process, the DC capacitor is not passed, plays an in-circuit "at DC". Circuit, capacitors are often used as coupling, bypass, filtering, are using it "-the exchange, at DC" features. Why then AC through the capacitor can be » Let us first look at the characteristics of AC. AC alternating not only the direction of reciprocating, it is also the size of the change. Capacitor to the AC power, the capacitor to charge a row, discharge, the circuit will flow with the alternating current changes of the same charge current and discharge current.

     Capacitor Selection involves a lot of problems. The first is the question of pressure. An increase in the ends of the capacitor voltage more than its rated voltage capacitor breakdown will be damaged. General electrolytic capacitor-file pressure for 6.3 V, 10V, 16V, 25V, 50V, and so on.