Last Updated on October 24, 2023 by Kevin Chen
We are incredibly reliant on mobile apps and devices on the digital electronic platform, whether for leisure or job. Rechargeable batteries are a convenient feature of laptops and mobile phones. Charge and discharge cycles are observed in these batteries. These become mobile when charged. Capacitors can be found in all rechargeable circuits.
Filling these capacitors with other dielectrics can produce different types of capacitors. An illustration would be a paper or mica capacitor. The capacitance can be increased using a parallel plate capacitor, another form of capacitor. The majority of energy-storing materials are utilized in this way. So, grab a cup of coffee, and let’s get started as we discuss parallel plate capacitors in this article.
The Parallel Plate Capacitor
Those capacitors that feature an arrangement of insulating material and electrodes are known as parallel plate capacitors. Electrodes are created from the two conducting plates with a dielectric between them. This separates the plates for you.
In a parallel plate capacitor, the two plates have similar sizes. The power supply is connected to them. A positive charge is applied to the plate when linked to the battery’s positive terminal. However, the plate linked to the battery’s negative terminal picks up a negative charge. Due to the attraction, charges are imprisoned inside the capacitor’s plates.
The Principle of Parallel Plate Capacitor
We are aware of the maximum charge that a plate can get. A charge leakage could occur if we add more charge since the potential increases. A negative charge will flow to the side of the plate that is closest to the positively charged plate if we install another plate adjacent to the positively charged plate.
Given that there are charges on both plates, the negative charge on plate 2 will lessen any potential difference with plate 1. As opposed to this, the positive charge on plate 2 will make plate 1’s potential difference greater. However, plate 2’s negative charge will exert more of an influence. So, plate 1 can receive a higher charge. The potential difference will be smaller due to the negative charges on plate 2. This is how a parallel plate capacitor works.
Dependence of Charge Stored in a Capacitor
The potential difference between the parallel plate capacitor’s two plates directly relates to the quantity of electric charge stored on any one plate. Considering this relationship as:
Q ∝ V
Therefore, Q = (constant)×V = CV
Where C is the capacitor’s capacitance, Q is the charge it can store, and V is the potential difference between the two plates.
The Capacitance of Parallel Plate Capacitor
A parallel plate capacitor’s capacitance determines its capacity. The equation above demonstrates that the higher the value of C, the more charge a capacitor can keep. Consequently, it is clear that the capacitance is dependent on:
- The Distance D – Between Two Plates.
- The Area A – Of The Medium Between The Plates.
The electric field can be expressed in writing using the Gauss law as follows:
We can write capacitance as follows since we are aware that it is defined by the formula V = Q/C:
We achieve the highest capacitance when the plates are arranged closely together and have a big surface area.
Dielectric Material Inserted between Two Plates
The dielectric’s non-conductive characteristic prevents electric current from passing through it. However, under the influence of the applied voltage source’s electric field, the atoms of the dielectric material become polarized. As a result, dipoles are created due to polarization. Moreover, a negative and positive charge is stored on the plates of a parallel plate capacitor.
As charges build up on the plates, a charging current begins to flow through the capacitor, keeping it charged until the source potential is reached and the potential difference between the plates is equal. When compared to a rechargeable DC battery, a parallel plate capacitor is a device that can store electrostatic energy in the form of charge in the dielectric medium between the plates.
A short circuit between the plates results from dielectric breakdown if the working voltage of the capacitor rises above the threshold voltage limit. This breakdown happens because an increased applied voltage that goes beyond the limit causes the dielectric medium to heat up excessively, which causes the capacitor to rupture. To protect the capacitor against these circumstances, the operating voltage of the capacitor should be selected in a manner that is within the maximum threshold voltage.
To raise the threshold voltage level and improve the capacitor’s capacity for storing charge, we utilize a variety of dielectric mediums, such as porcelain, mica, oxides of different metals, or other materials with high permittivity. The capacitance depends on the plate area that overlaps, the medium’s permittivity, and the space between the plates.
Where A is the overlapped plate area, d is the distance between the plates and is the medium’s permittivity. The overlapping area, the distance between the plates, or the introduction of a dielectric material with a different permittivity value can all be changed to alter the capacitance of a parallel plate capacitor.
When an Alternating Current source is connected to a parallel plate capacitor, it operates as a short circuit and acts as an open circuit when a DC source is connected across it. A parallel plate capacitor can filter harmonics from an AC source, thanks to the feature above. In electronic circuits for various uses, a parallel plate capacitor can also be used for tuning. Additionally, it is used in certain transducer applications.
A capacitor is a critical component of power system auxiliaries because it can operate as a source of capacitive reactive power. This increases the power factor of the system, which increases stability. Because a magnetic field has a better capacity for storing energy than an electric field, we rarely utilize a parallel plate capacitor to store energy. Charge leakage, a flaw in the dielectric that is employed in it, precludes us from using a capacitor as the ideal charge storage device since it limits how long a capacitor can maintain a charge.
The state of a parallel plate capacitor when a medium is in contact with air or another substance.
It is possible to determine a capacitor’s capacitance when the space between its parallel plates is partly filled with air and partly with another substance. Let’s imagine that there is a parallel plate capacitor, as illustrated in the image below, where the medium between the similar plates is primarily made of air and part of another substance:
Multiple Parallel Plate Capacitor
Multiple Parallel Plate Capacitors are formed by grouping parallel plate capacitors made of dielectric materials in between them to fit within one another. Calculations for the capacitance of several parallel plate capacitors are as follows:
Where A = Area Of Each Plate, 0 = Vacuum’s Relative Permittivity, 8.854 10-12 F/M, R Is The Dielectric’s Relative Permittivity, D = Distance Between Plates, And N = Total Number Of Plates.
Charge on Parallel Plate Capacitor
We’ll assume that a capacitor has capacitance C, electric charge Q, and is electrically neutral.
V stands for the difference in potential between the plates. The potential difference of plate 1 will be V1, and plate 1’s charge will be Q1 if the charge on the two plates of the parallel plate capacitor differs. Even because V2 will represent the potential difference between plate 2 and charge Q2 =−Q + δQ
Applications of Parallel Plate Capacitor
The following are some uses for parallel plate capacitors:
- Batteries (Rechargeable Energy Systems) are one application for these capacitors.
- These capacitors are used in dynamic digital memory systems.
- Such capacitors are used in pulsed LASER circuits and radars.
- Parallel plate capacitors are used in the coupling or suppression of signals.
FAQs of Parallel Plate Capacitor
What Is the Purpose of The Second Plate in A Parallel Plate Capacitor?
By functioning as the first plate’s conducting neighbor, the second plate serves to increase the capacitance.
What Factors Affect A Parallel Plate Capacitor’s Capacitance?
Depending on the size of the plates and the space between them, parallel plate capacitors’ capacitance factors are determined.
What Occurs If A Dielectric Is Placed Within A Capacitor?
Based on the applied potential difference, the capacitor can now store more charges thanks to the addition of a dielectric.
What Happens If A Battery and A Capacitor Are Separated?
Charges continue to be repaired when the battery is disconnected. In the event that the capacitance changes, the potential difference also changes.
Last but Not Least
An arrangement of two parallel metal plates separated by a certain distance makes up a parallel plate capacitor. A dielectric medium covers the area between the plates. The dielectric medium can be anything that isn’t conducting, including mica, vacuum, glass, air, wool, paper, and electrolytic gel, among many other non-conducting materials.
Regarding the storage of the charges, there is a specific restriction. There is a danger that the charge will leak if it surpasses. Two plates are needed to prevent this from happening. Thus, these parallel plate capacitors are highly useful when storing large amounts of charge is necessary.
At ICRFQ, we manufacture the best electrical components. To know more about parallel plate capacitors, contact us at ICRFQ.
If you want to find more Electronic Components Distributors, please check out the following articles:
- The Art of Sourcing: How We Identify and Partner with Top IC Manufacturers - November 24, 2023
- Essential Electronics Test Equipment You Should Know About - November 24, 2023
- How To Finish PCBA Design Process Quickly? - November 24, 2023