Ceramic capacitors, electrolytic, variable or adjustable, capacitors for a / c, ground, start … There are many types of capacitors and, of course, uses. In this post I will explain in a simple way what they are and what they are so that the next time you see one in a circuit you understand why it is there.
Among the elements that you can find in a circuit, the capacitor is one of the most common . You can try to open any electronic device that you have at home (a TV, a computer, a radio …) and you will see what I mean. Moreover, if the device you have dissected is relatively new, you will probably only recognize some capacitors, because the other components will be made in silicon, that is, you will see them in the form of integrated circuits (Y type capacitors).
If you like DIY electronics, surely you have already used capacitors more than once. You may have read a tutorial or seen a post in which they were used and put it (although without understanding very well why). As I was saying, in this post I will try to explain what a condenser is, what it is for, what are the types that exist and which one should be chosen according to your needs .
What is an electrical capacitor?
An electric capacitor (also known as a capacitor ) is a device capable of storing electric charge.
It is composed of two metal plates that do not touch each other (hence its symbol circuital) and between which there is a dielectric element (a substance that misses the electricity), which generates a voltage difference between the two plates.
As a quick note in relation to the circuit symbol, tell you that if you see that it is not symmetrical or has a “+” symbol, it is an electrolytic capacitor. This type of capacitors have polarity and you must connect them with the positive part (long pin) to the positive voltage. We will go into more detail, but I wanted to clarify it as soon as possible because it can be dangerous.
The voltage difference is proportional to the electrical load that the capacitor is able to store. That proportionality is measured by a value known as capacitance (C), whose unit is the Faradio (that’s the value you can see in your capacitor).
When an electrical signal reaches the condenser it begins to charge it. Once the capacitor has completely charged, it stops driving the current. If you stop applying charge to the condenser (or the one you apply is smaller than what you already have), the capacitor starts to discharge, releasing the electrical energy stored in the circuit and driving the current again (Y type capacitors).
You can test this by mounting a circuit similar to the one you have in the image and measuring with your multimeter how only current flows when the battery is connected and disconnected , that is, when charging and discharging the capacitor. If in the previous circuit you modify the value of the resistance, you will be changing the time it takes the capacitor to charge (the higher the resistance the longer it will take). This is because the load (Q) is the product of the current (I) for the time (t) and when increasing the value of the resistance you are reducing the current that passes through the circuit .
Note that if you remove the capacitor after charging the capacitor, it will maintain the charge. If it is a large capacitor, be sure to remove the load before handling it.
If the capacitor you are manipulating is electrolytic, you must connect it with the proper polarity. Remember that in most devices the longest pin is the positive pole. Also, in the case of electrolytic capacitors, you can see a black strip that represents the negative pole of the capacitor (you will tell me that I have told you before, I will tell you that it is important ).