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SD Card Data Logging. RFID Module. Arduino Radar Sonar. Color Sorter Machine. A capacitor is so-called because it has the "capacity" to store energy. In this article, we'll learn exactly what a capacitor is, what it does and how it's used in electronics.
We'll also look at the history of the capacitor and how several people helped shape its progress. Capacitors can be manufactured to serve any purpose, from the smallest plastic capacitor in your calculator, to an ultra capacitor that can power a commuter bus.
Here are some of the various types of capacitors and how they are used. Inside a capacitor, the terminals connect to two metal plates separated by a non-conducting substance, or dielectric. You can easily make a capacitor from two pieces of aluminum foil and a piece of paper and some electrical clips. It won't be a particularly good capacitor in terms of its storage capacity, but it will work. In theory, the dielectric can be any non-conductive substance.
However, for practical applications, specific materials are used that best suit the capacitor's function. Mica, ceramic, cellulose, porcelain, Mylar, Teflon and even air are some of the non-conductive materials used. The dielectric dictates what kind of capacitor it is and for what it is best suited. Depending on the size and type of dielectric, some capacitors are better for high-frequency uses, while some are better for high-voltage applications.
Once it's charged, the capacitor has the same voltage as the battery 1. For a small capacitor, the capacity is small.
But large capacitors can hold quite a charge. You can find capacitors as big as soda cans that hold enough charge to light a flashlight for a minute or more. Even nature shows the capacitor at work in the form of lightning. One plate is the cloud , the other plate is the ground and the lightning is the charge releasing between these two "plates. Here you have a battery, a light bulb and a capacitor. If the capacitor is pretty big, what you will notice is that, when you connect the battery, the light bulb will light up as current flows from the battery to the capacitor to charge it up.
The bulb will get progressively dimmer and finally go out once the capacitor reaches its capacity. If you then remove the battery and replace it with a wire, current will flow from one plate of the capacitor to the other.
The bulb will light initially and then dim as the capacitor discharges, until it is completely out. In the next section, we'll learn more about capacitance and take a detailed look at the different ways that capacitors are used. One way to visualize the action of a capacitor is to imagine it as a water tower hooked to a pipe.
A water tower "stores" water pressure — when the water system pumps produce more water than a town needs, the excess is stored in the water tower. Then, at times of high demand, the excess water flows out of the tower to keep the pressure up. A capacitor stores electrons in the same way and can then release them later. A capacitor's storage potential, or capacitance , is measured in units called farads. A 1-farad capacitor can store one coulomb coo-lomb of charge at 1 volt. A coulomb is 6.
One amp represents a rate of electron flow of 1 coulomb of electrons per second, so a 1-farad capacitor can hold 1 amp-second of electrons at 1 volt. A 1-farad capacitor would typically be pretty big. It might be as big as a can of tuna or a 1-liter soda bottle, depending on the voltage it can handle. For this reason, capacitors are typically measured in microfarads millionths of a farad. If it takes something the size of a can of tuna to hold a farad, then 10, farads is going to take up a LOT more space than a single AA battery!
Positive charge will collect on one plate and negative charge on the other. There are many different capacitor types. Many alarm clocks are powered by the electrical outlet on the wall in a house. Sometimes, the power goes down. Most alarm clocks have a backup battery that will take over and power the alarm clock until the power comes back on so that the time is not reset.
For example if you have a circuit with a microcontroller running some kind of program. If the voltage for the microcontroller drops for only a split second, the microcontroller restarts.
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