Analog Electronics

This tutorial aims to provide a comprehensive understanding of the basic principles, workings, and types of the Capacitor. What is a Capacitor? The capacitor is an energy-storing device that stores electrical charges as energy between two conductor plates. Dielectric electric material is placed between two conductors so that charges cannot get from one conductor to another. Capacitors are charged by connecting two conductors to the battery and discharged when the voltage decreases below the capacitor's voltage. Figure: Different types of Capacitors Symbol of a Capacitor Figure: Symbol of a capacitor How do Capacitors work? A capacitor typically contains two conductor plates and a dielectric material. When we connect two plates to a battery, the conductor attached to the positive terminal of the battery is positively charged, while the conductor connected to the negative terminal is negatively charged. Figure: polarity of a capacitor The battery charges the capacitor until it reaches the same voltage as it. Dielectric material prevents charges from flowing from one plate to another, resulting in potential differences between the two plates. This potential difference represents the energy stored inside the capacitor. What is the capacitance of capacitors? Capacitance is the amount of electric charge that one capacitor can store for a one-volt voltage. If one capacitor is given Q amount of charge and V volt voltage then the equation for capacitance will be: Farad is the unit for capacitance. If a capacitor has 10F capacitance, it can hold 10C (coulombs) of charge at a voltage of one volt. The capacitance of a parallel plate capacitor A parallel plate capacitor is constructed using two conductor plates, and a dielectric medium is utilized to isolate them. The capacitance of a parallel capacitor can be calculated using the flowing equation: The following formula is derived from C=Q/V. Where is the relative permeability, A is the area of the capacitor plates and d is the distance between two conductor plates. The value of ϵ depends on the dielectric medium. Figure: Parallel plate capacitor How to calculate the energy of a capacitor? Capacitors hold energy in the form of electric charges. This energy depends on the capacitance of the capacitor. The greater capacitance a capacitor has, the more electric charge it can keep, thus the more energy it can hold. If a capacitor has a capacitance of C, it has been supplied Q quantity of charge therefore V volt potential difference appeared in the capacitor. The equation for the energy of the capacitor will be: U is denoted as the energy of the capacitor. we know the relation between capacitance and charge. If we replace Q with Q = C*V in the capacitor’s energy equation, we obtain: Replacing C with C=Q/V, Uses of Capacitors Capacitors are used in electrical circuits to protect against voltage spikes. Capacitors stabilize voltage in circuits. Capacitor filters out noise from the signal. The capacitor is used to smooth the DC output in the rectification process. Capacitor is used in Dynamic Random Access Memory(DRAM) for remembering bits. Recap Capacitor Definition: A capacitor stores electrical energy between two conductive plates, separated by a dielectric material. How Capacitors Work: When connected to a battery, one plate becomes positively charged and the other is negatively charged, leading to a potential difference between two conductor plates. Capacitance: Capacitance is a capacitor's ability to store charge per unit voltage, expressed as C=Q/V, with the unit Farad (F). Capacitance of Parallel Plate Capacitors: The capacitance of a parallel capacitor can be calculated using the equation C=ϵA/d. Calculating the Energy of a Capacitor: The equation for the energy of a capacitor is U=1/2*Q^2/C.