capacitor is one of the most common elements of electronic circuits.Types of capacitors, some of the parameters, such as resistance of the capacitor, considered in this article.
can say that the two metal electrodes separated by a layer of air, and there is a capacitor.Each of the plates has its output and can be connected to an electrical circuit.Such a device has certain characteristics, and one of them is the resistance of the capacitor.
capacitor or, as it is called, the capacity to be a very interesting device.Suffice it to say that he does not pass DC.If we look at the DC from this viewpoint, the resistance of the capacitor is very large, nearly infinite DC.
At the same time, the first time when the container is connected to the DC current is its charge.Inside this complex processes occur.After the charge capacity, the current flow is virtually stopped.But there is one caveat, due to the quality of the dielectric.No matter how good an insulator may be, still it flows through it current miserable.It's called leakage current.
This leakage current is an indication of the quality of the dielectric used in the manufacture of capacitors.What better insulator, the leakage current is less.Here you can see one thing: there is the voltage to which the charged capacity, there is a leakage current, which flows through the charged member.So Ohm's law we can calculate the impedance of the capacitor.It will be great, leakage currents in modern containers are fractions of microamps.
little bit different picture appears when the capacitor is exposed to an alternating current.The current flowing freely through the container.This is explained by the fact that the process of constantly discharge-charge the capacitor.And any process of current flow associated with its loss due to the presence of resistance in this case, in addition to resistance wires present capacitance of the capacitor due to the process name of its charging and discharging.
electrical properties of the finished product depends on many factors.These include shape, the geometrical dimensions, the type of dielectric.There are various types of capacitors as a dielectric are used in a vacuum, air, plastic, mica, paper, glass, ceramics, aluminum-electrolyte tantalum electrolyte.
last two types called electrolytic capacitors, they typically have a high capacity.Other capacitors are called according to the type of dielectric - paper, ceramic, glass.They each have their own characteristics, their behavior under different parameters of electric current, their characteristics and applications.
example, ceramic capacitors are mostly used in the circuits for filtering high frequency noise, electrolyte - for eliminating noise at low frequencies.And together with the parallel connection of the ceramic and electrolytic capacitors, it turns out the most common filter used in almost all schemes.In all cases the container is a fixed value such as 0.15 microfarads.
must note the presence of the variable capacitance capacitors in which capacitance is changed depending on the position of the regulating knobs.This is achieved by changing the overlap of the capacitor plates.As a special case of variable capacitors, there are so-called trimmer capacitors.They can also change capacity - but to a limited extent and only at the stage of adjustment of the apparatus.
nomenclature used capacitor is huge - both on the type of dielectric, and by design.
