Capacitors in Parallel

Introduction

With the use of capacitors in parallel and in series, it’s possible to create capacitors with different properties and functions. As electric current flows through a capacitor, it creates an opposing charge on each of its plates. As you might guess, each electrode attracts opposite charges that are equal and opposite of one another.

What are they, how do they work, and why would you want to use them? This tutorial will cover all the basics you need to know about capacitors in parallel as well as offer some suggestions on how to use them in your next project.

Capacitors in Parallel

Parallel circuits are wired such that all wires between two points lead to each component, with all components joined by conducting wire. It means the capacitor's first and second plates are, respectively, connected to the next capacitor's first and second plates.

Connecting the capacitors in parallel helps to increase the capacitance power. This allows electricity from power sources or batteries to flow freely through each component before being dumped into a final point. We can think of capacitors in parallel as being stacked on top of each other, with all their plates sharing one common electrode.

For example, if we have two equal-valued 1 $\mathrm{\mu F}$ capacitors, then we can think of them as being functionally equivalent to a single 2 $\mathrm{\mu F}$ capacitor.

Working of Capacitors in Parallel

When two or more capacitors are connected in parallel, it means we want to increase the storage capacity of the circuit. Their individual capacitance value remains unchanged, while their equivalent capacitance value is calculated using a formula involving all of their values.

Let's imagine two capacitors C1 and C2 are connected in a parallel circuit and the charge Q is divided into Q1 and Q2 that respectively flow from C1 and C2

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So, the Total charge between a and b is

$\mathrm{Q \:= \:Q_1\:+ \:Q_2}$

$\mathrm{Q = C_1V \:+ \:C_2 V}$

$\mathrm{Q/V = C_1 \:+ \: C_2}$

$\mathrm{C = C_1 \:+ \:C_2}$

Where,

• Q = Total Charge in circuit
• V = voltage applied on the circuit
• C = Capacitance power of capacitor

When we add lots of capacitor in parallel than

$\mathrm{C_T = C_1\:+ \: C_2 \:+ \: C_3 \:+ \: C_4………. \:+ \: C_n}$

Example

Let’s say we have three capacitors; each one has a capacitance of 50 nF. They are then connected in parallel with the 200 supply. Calculate the Equivalent capacitance

Solution:

$\mathrm{C_1 \:= \:C_2 \:= \: C_3 \:= \: 50\: \times\: 10^{-9} F}$

Total capacitance in parallel

$\mathrm{C_T = C_1 \:+ \: C_2 \:+ \: C_3 \:+ \:C_4………. \:+ \:C_n}$

$\mathrm{C_T = (50+50+50) \: \times\:10^{-9}}$

$\mathrm{C_T = 150\:nF}$

Advantages of using Capacitors in Parallel

• A capacitor is a passive electronic component that can store energy and deliver it on demand. When we connected capacitors in parallel, it increases the storage capacity of the circuit.

• When connected to an alternating current, a capacitor resists changes in voltage and has several electrical properties that make it useful as part of an electronics circuit.

• These include its ability to block DC (direct current) while allowing AC (alternating current) signals to pass through. The first thing is simply that, when capacitors are connected in parallel with each other, their voltage decreases proportionally.

• Connecting capacitors in parallel help to reduce the number of resistors that are used in the system.

Disadvantages of using Capacitors in Parallel

• For example, a parallel combination of two 0.1 $\mathrm{\mu F}$ capacitors has an equivalent capacitance of 0.2 $\mathrm{\mu F}$ because both capacitors will share a voltage drop (Voltage division) of 1 V for every doubling of their total capacitance. If one capacitor is accidentally allowed to discharge through another, there could be more than 4 A transient current through one capacitor if it is charged and discharged quickly. This type of current flow may result in severe damage to either or both units and should be avoided at all costs by not paralleling such components without careful consideration.

• We know that capacitors in parallel is storing a huge amount of energy but they release this energy in a very short span of time. So, this can be caused heavy injuries or damage to the electrical wiring. Because of that reason, it is not used in the industry materials.

FAQs

Q1. Calculate the charge on capacitors in parallel.

Ans. The first thing we need to do is calculate the total charge stored by each capacitor, $\mathrm{Q \:T = \Sigma CiV \:i}$ , where C i is each capacitor’s capacitance and V i is each capacitor’s voltage.

Q2. What are the rules for parallel combinations of capacitors?

Ans. When two or more capacitors are connected in parallel then the equivalent capacitor is the sum of individual capacitor. Their equivalent is made up of parts from each component. The same holds true for resistors and inductors.

Q3. Why do you add capacitors in parallel?

Ans. Adding capacitors in parallel is a common strategy for stabilizing an amplifier’s gain. If you add two capacitors with different values, you can increase stability as well as lower input impedance (assuming both are equal value). As we will see, however, there are trade-offs when adding capacitance to a circuit.

Q4. What factors affect capacitance in parallel circuit?

Ans. To understand capacitance and capacitors, you need to know that an ideal capacitor has no resistance, voltage or current: These variables aren’t relevant for an ideal capacitor. If a capacitor isn’t ideal, however, it is always best practice to design a circuit with as low a resistance and voltage across its capacitor as possible. This means it will have less dissipation of power (lower loss) and will be capable of charging quicker.

Q5. Is charge constant across capacitors in parallel?

Ans. In a parallel circuit, current is split up and delivered to all components. It turns out, there’s more than one way of thinking about how electrical charge and voltage works across capacitors in parallel.

Q6. What happens if the charge on a parallel plate capacitor is doubled?

Ans. The capacitance does not change when the charge on a parallel plate capacitor is double. The capacitance varies only on configuration of your capacitors.

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Updated on: 13-Oct-2022

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