Capabilities of Capacitors
At one point or another, you may have confused a capacitor for a battery. They are similar in size, shape, and function; however, the applications in which they are used distinguish them from one another. A capacitor is an electronic device that is capable of storing energy in the form of an electric charge. The amount of energy it can store is 10,000 times smaller than that of a battery, but it still contributes to the overall success of circuit designs. Let’s take an in depth look at how capacitors are created, as well as how they function.
A capacitor is constructed of two plates that are separated by an insulating material called a dielectric (electrical insulator). The plates can be made out of aluminum, tantalum, or other metals. The dielectric is manufactured out of any kind of insulating material such as glass, ceramic, paper, or anything that obstructs the flow of the electrical current. The overall available storage of electric energy within a capacitor is called its capacitance. Capacitance is measured in farads and is directly proportional to the surface area of the two plates combined with permittivity of the dielectric. The smaller the distance between the plates, the greater the capacitance; the greater the distance, the lower the capacitance.
As we know already, capacitors have the capability of storing electrical energy and resupplying it to a electrical circuit board when needed. When capacitors interact with DC and AC power supplies the results may vary. When it functions with a DC supply, the charge remains in the capacitor after removal until it is discharged. If AC supply is given to the capacitor, the polarity of both plates changes according to the input of the AC. The capacitor charges itself in the first half of the cycle, then discharges the energy in the next half cycle. This process creates an impedance within AC power supplies. The impedance depends upon the value of the capacitor and the frequency of the AC supply. If you’re looking to convert AC voltage into DC voltage, a diode rectifier will be needed alongside a capacitor.
Signal filtering is another application of capacitors. Due to their specific response time, they are able to block low frequency signals while allowing higher frequencies to pass through. This is common in radio receivers for fine tuning undesired frequencies and in crossover circuits inside speakers. These types of capacitors separate low frequencies geared towards the subwoofer and higher frequencies aimed towards the tweeter speakers.
There are many capacitors on the market, each one with their own application and function. Different types of capacitors include simple, mica, paper, ceramic capacitor, foil, pin-up, flat ceramic, storoflux, and many more.