Capacitors are electronic components that have important applications. In addition to introducing them, we will show you the types of capacitors and talk about the main differences between them. With that, we will help you to determine which is the correct capacitor to be used in each situation.
Capacitors – How do they work?
Capacitors are components that have the function of storing electrical energy. When you connect a capacitor to a power source, it absorbs it until it has the same voltage as the source. When you remove the source, the capacitor will remain charged and you can use this energy to supply a circuit. This process is very similar to that of a battery, but the capacitor charges and discharges much faster than the batteries, in addition to being able to repeat this cycle many more times before it spoils.
Another difference between capacitors and batteries is in the way they store energy. In batteries, energy is stored in a chemical way and heat is generally generated by charging and discharging. The main advantage of batteries over traditional capacitors is that they store much more energy in the same volume, that is, the batteries have a density much higher than a capacitor.
Capacitors – How to choose?
To choose a capacitor correctly you need to be aware of 3 important points, they are: The capacitance, the maximum voltage, and the type of capacitor. It is necessary to understand that each type of capacitor has a different way of listing these important points.
- Capacitance: It is the ability of an element to store electrical charge. Whenever two conductors are separated by an insulating material, which may even be air, there is a capacitance. That is why parasitic capacitances exist in virtually every circuit! The capacitance unit is the Faraday, but in general, in the capacitors, you will see the sub-multiples as shown in the image below.
- Maximum Voltage: The higher the voltage, the greater the number of insulators between the conductors, consequently the larger the capacitor size. Each capacitor supports a maximum voltage, for example, if a capacitor has a specified voltage of 16V it does not mean that it will be at 16V all the time! If you put 5V on it, it will stay with 5V, the difference is that if you put 16V, it means that it is already at the limit, and beyond that, there are risks of leaks or even explosions. Therefore, when there is a need to change the capacitor, it is essential to choose one with a voltage equal to or greater than the original capacitor.
- Capacitor type: The type has to do with the form of construction and the materials that are used. There are ceramic, polyester, tantalum, mica, glass, Teflon, aluminum capacitors and even capacitors that use oil in their composition. As for the format, they can be flat, cylindrical, square, SMD of various sizes, and even in other less conventional formats. This huge variation in size and appearance can be seen in the image below.
Capacitors – Features!
As stated, the higher the capacitance and voltage, the greater the volume that the capacitor has. Ceramic capacitors, for example, have layers of metal separated by a ceramic insulator. Other capacitors can use different insulators with the same construction. This type of capacitor does not usually have a large capacitance in relation to its volume and this is where the electrolytic capacitor comes in!
Electrolytic capacitors generally have polarity as shown in the image below, but there are some types that do not. Therefore, when connecting an electrolytic capacitor to a circuit, it is very important to pay attention to the polarity described in it, because if you invert an electrolytic capacitor that has a polarity, there is a huge risk of leakage or explosion.
These capacitors have an electrolyte in their composition and their insulator is a very, very thin layer created by a chemical process. In this following video from the World of Electrical, you can see what the inside of a cylindrical capacitor looks like, see how interesting the way in which the layers of insulating material and conductive material are rolled up, in order to increase the area of the conductive plates separated by the insulator.
In this indicated video, in addition to viewing the inside of the capacitor as mentioned, it is possible to see in practice what happens with the capacitors that are used outside the ideal conditions and many other tips on the types of capacitors. Then that’s it! If you learned anything here, share this article so that others can learn as well. Help us spread this important information about capacitors. If you have any questions, just leave them in the comments and we will answer them!