Back EMF Equation of DC Motor Calculator

✖Number of Poles is defined as the number of poles in an electrical machine for the flux generation.ⓘ Number of Poles [n]			+10% -10%
✖Magnetic flux (Φ) is the number of magnetic field lines passing through the magnetic core of an electrical dc motor.ⓘ Magnetic Flux [Φ]			+10% -10%
✖The number of conductors is the variable we use for getting the correct number of conductors placed in the rotor of a dc motor.ⓘ Number of Conductors [Z]			+10% -10%
✖Motor Speed is the speed of the rotor(motor).ⓘ Motor Speed [N]			+10% -10%
✖The Number of Parallel Paths in a DC machine refers to the number of independent paths for current to flow in the armature winding.ⓘ Number of Parallel Paths [n_\|\|]			+10% -10%

✖The Back emf opposes the current which causes it in any dc machine.ⓘ Back EMF Equation of DC Motor [E_b]

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Back EMF Equation of DC Motor Solution

STEP 0: Pre-Calculation Summary

Formula Used

Back EMF = (Number of Poles*Magnetic Flux*Number of Conductors*Motor Speed)/(60*Number of Parallel Paths)
E_b = (n*Φ*Z*N)/(60*n_||)
This formula uses 6 Variables

Variables Used

Back EMF - (Measured in Volt) - The Back emf opposes the current which causes it in any dc machine.
Number of Poles - Number of Poles is defined as the number of poles in an electrical machine for the flux generation.
Magnetic Flux - (Measured in Weber) - Magnetic flux (Φ) is the number of magnetic field lines passing through the magnetic core of an electrical dc motor.
Number of Conductors - The number of conductors is the variable we use for getting the correct number of conductors placed in the rotor of a dc motor.
Motor Speed - (Measured in Radian per Second) - Motor Speed is the speed of the rotor(motor).
Number of Parallel Paths - The Number of Parallel Paths in a DC machine refers to the number of independent paths for current to flow in the armature winding.

STEP 1: Convert Input(s) to Base Unit

Number of Poles: 4 --> No Conversion Required
Magnetic Flux: 1.187 Weber --> 1.187 Weber No Conversion Required
Number of Conductors: 14 --> No Conversion Required
Motor Speed: 1290 Revolution per Minute --> 135.088484097482 Radian per Second (Check conversion here)
Number of Parallel Paths: 6 --> No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

E_b = (n*Φ*Z*N)/(60*n_||) --> (4*1.187*14*135.088484097482)/(60*6)

Evaluating ... ...

E_b = 24.9433380970217

STEP 3: Convert Result to Output's Unit

24.9433380970217 Volt --> No Conversion Required

FINAL ANSWER

24.9433380970217 ≈ 24.94334 Volt <-- Back EMF

(Calculation completed in 00.004 seconds)

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Created by Prahalad Singh

Jaipur Engineering College and Research Centre (JECRC), Jaipur

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Birsa Institute of Technology (BIT), Sindri

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< DC Motor Characteristics Calculators

Machine Construction Constant of DC Motor

LaTeX Go Constant of Machine Construction = (Supply Voltage-Armature Current*Armature Resistance)/(Magnetic Flux*Motor Speed)

Back EMF Equation of DC Motor

LaTeX Go Back EMF = (Number of Poles*Magnetic Flux*Number of Conductors*Motor Speed)/(60*Number of Parallel Paths)

Armature Current given Electrical Efficiency of DC Motor

LaTeX Go Armature Current = (Angular Speed*Armature Torque)/(Supply Voltage*Electrical Efficiency)

Supply Voltage given Electrical Efficiency of DC Motor

LaTeX Go Supply Voltage = (Angular Speed*Armature Torque)/(Armature Current*Electrical Efficiency)

Back EMF Equation of DC Motor Formula

LaTeX Go

Back EMF = (Number of Poles*Magnetic Flux*Number of Conductors*Motor Speed)/(60*Number of Parallel Paths)
E_b = (n*Φ*Z*N)/(60*n_||)

How does back EMF affect supply voltage?

As the back emf depends on the current their value also decreases. The magnitude of the back EMF is nearly equal to the supply voltage. If the sudden load is applied to the motor, the motor becomes slow down. As the speed of the motor decreases, the magnitude of their back emf also falls down.

How to Calculate Back EMF Equation of DC Motor?

Back EMF Equation of DC Motor calculator uses Back EMF = (Number of Poles*Magnetic Flux*Number of Conductors*Motor Speed)/(60*Number of Parallel Paths) to calculate the Back EMF, Back EMF Equation of DC motor shows that a motor has coils turning inside magnetic fields, and a coil turning inside a magnetic field induces an EMF. This EMF, known as the back EMF, acts against the applied voltage that's causing the motor to spin in the first place and reduces the current flowing through the coils of the motor. Back EMF is denoted by E_b symbol.

How to calculate Back EMF Equation of DC Motor using this online calculator? To use this online calculator for Back EMF Equation of DC Motor, enter Number of Poles (n), Magnetic Flux (Φ), Number of Conductors (Z), Motor Speed (N) & Number of Parallel Paths (n_||) and hit the calculate button. Here is how the Back EMF Equation of DC Motor calculation can be explained with given input values -> 24.94334 = (4*1.187*14*135.088484097482)/(60*6).

FAQ

What is Back EMF Equation of DC Motor?

Back EMF Equation of DC motor shows that a motor has coils turning inside magnetic fields, and a coil turning inside a magnetic field induces an EMF. This EMF, known as the back EMF, acts against the applied voltage that's causing the motor to spin in the first place and reduces the current flowing through the coils of the motor and is represented as E_b = (n*Φ*Z*N)/(60*n_||) or Back EMF = (Number of Poles*Magnetic Flux*Number of Conductors*Motor Speed)/(60*Number of Parallel Paths). Number of Poles is defined as the number of poles in an electrical machine for the flux generation, Magnetic flux (Φ) is the number of magnetic field lines passing through the magnetic core of an electrical dc motor, The number of conductors is the variable we use for getting the correct number of conductors placed in the rotor of a dc motor, Motor Speed is the speed of the rotor(motor) & The Number of Parallel Paths in a DC machine refers to the number of independent paths for current to flow in the armature winding.

How to calculate Back EMF Equation of DC Motor?

Back EMF Equation of DC motor shows that a motor has coils turning inside magnetic fields, and a coil turning inside a magnetic field induces an EMF. This EMF, known as the back EMF, acts against the applied voltage that's causing the motor to spin in the first place and reduces the current flowing through the coils of the motor is calculated using Back EMF = (Number of Poles*Magnetic Flux*Number of Conductors*Motor Speed)/(60*Number of Parallel Paths). To calculate Back EMF Equation of DC Motor, you need Number of Poles (n), Magnetic Flux (Φ), Number of Conductors (Z), Motor Speed (N) & Number of Parallel Paths (n_||). With our tool, you need to enter the respective value for Number of Poles, Magnetic Flux, Number of Conductors, Motor Speed & Number of Parallel Paths and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

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