What is Voltage Division? Voltage Divider Example, Circuit
Hi, in this article we are going to know about the voltage division. Also, we will know the examples of voltage dividers and the circuit diagram of voltage dividers.
What is Voltage Division?
When a voltage is applied across an electrical or electronic circuit having multiple components connected in series, then the voltage drop across those components will be proportional to their resistance and the sum of all the voltage drop will be equal to the applied voltage. This is known as Voltage Division or Voltage Divider Rule. The voltage divider is also known as a potential divider. So, the voltage drop will be maximum across the resistor which has maximum resistance, and the voltage drop will be minimum across the resistor which has minimum resistance.
The voltage division rule is applicable for both AC and DC circuits. But for AC circuits, impedance(the algebraic sum of inductive reactance and capacitive reactance) also be considered when calculating the voltage drops. Also, remember that voltage drop not only happens in a pure series circuit but also happens in combinational circuits also. Calculation of voltage division is much easier for a pure series circuit than a combinational circuit.
You can see the effect of voltage division more if the circuit contains pure resistors and is connected to the DC supply. For AC circuits voltage drop depends upon the frequency of the supply. So, when calculating the voltage division for AC circuits, frequency, voltage, and current all should be considered.
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Voltage Divider Circuit Diagram
Here, you can see a simple circuit diagram of a voltage divider having two series resistors and a DC power supply. You can see two resistors are connected - one is 2 ohms and another one is 4 ohms. Of course, a 4-ohm resistor will drop Voltage more than a 2-ohm resistor. As it is a series circuit, so the current flow through each element will be the same. The total resistance will be the summation of to individual resistors.
Explanation of Voltage Divider Rule
Let's take the above circuit as an example to understand the voltage dividing rule. Here, you can see, the circuit is connected across a 12V power supply and has two resistors R1 = 2 ohms, R2 = 4 ohms.
The total resistance of the circuit is, (R1+R2) = (2+4) = 6 ohm
The current flow in the circuit is 12/6 = 2A
As per the voltage divider rule, the voltage drop will be,
Across Resistor(VR1) = 2 x 2 = 4V
Across Resistor(VR2) = 2 x 4 = 8V
Also, the algebraic sum of all voltage drops will be equal to the supply voltage.
Vs = VR1 + VR2
12 = 4+8
12=12
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Voltage Divider Formula
When you don't know the flow of current, then also you can calculate the voltage drop across each resistor using this formula.
VR1 = V[ R1 / (R1+ R2+ R3+……+ Rn)]
VR2 = V[ R2 / (R1+ R2+ R3+……+ Rn)]
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VRn = V[ Rn / (R1+ R2+ R3+……+ Rn)]
So, for the above circuit,
VR1 = V[R1/(R1+R2)]
= 12 x [2/(2+4)]
= 4V
VR2 = V[R2/(R1+R2)]
= 12 x [4/(2+4)]
= 8V
Voltage Divider Examples and Applications
Potentiometers, volume control, and series-connected lamps are common examples of voltage dividers.
1. Voltage divider is used for voltage step-down purposes.
2. Voltage divider is used for motor speed control such as an electrical fan regulator.
3. Voltage Dividers are used in LED Chaser Circuits.
4. Voltage divider circuit is used to produce reference voltage for analog circuits, comparators, etc.
5. Voltage divider is used in amplifier circuits, oscillator circuits, voltage regulator circuits, etc.
Voltage Division in DC Circuit VS AC Circuit
The main difference between voltage division in a DC (direct current) circuit and an AC (alternating current) circuit lies in the behavior of the components and the way voltage is distributed.
DC Circuit:
In a DC circuit, voltage division occurs based on the resistances (Ohm's Law) connected in series. According to Ohm's Law, the voltage across each resistor is directly proportional to its resistance value. Therefore, in a simple series circuit with multiple resistors, the voltage is divided based on the ratio of each resistor's resistance to the total resistance of the circuit.
AC Circuit:
In an AC circuit, voltage division is affected by the impedance of the components, which considers both resistance and reactance. Reactance depends on the frequency of the AC signal and the impedance property of the inductors and capacitors.
In AC circuits, the voltage across a resistor is still determined by its resistance, as in DC circuits.
But the inductors and capacitors have impedance along with their internal resistance that introduces reactance which affects the voltage division. The impedance of an inductor increases with frequency, causing it to have a greater voltage drop as the frequency rises. Conversely, the impedance of a capacitor decreases with frequency, resulting in a lower voltage drop as the frequency increases.
Therefore, in an AC circuit with inductors, capacitors, and resistors connected in series, the voltage division depends not only on the resistance but also on the reactance of the components at a given frequency.
In summary, while DC circuits use resistance to divide voltage, AC circuits use impedance, which incorporates both resistance and reactance. The reactance introduced by inductors and capacitors in AC circuits alters the voltage distribution based on the frequency of the AC signal.
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What is Voltage Division? Voltage Divider Example, Circuit
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September 07, 2021
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