Hello guys, in this post we are going to provide Speed Control of DC Motor PDF direct download link to help the Engineering and Diploma students. In this article, we have explained the Speed of a DC motor in detail. If you are preparing for the Engineering and Diploma exams then you should prepare for the exam from this post. The back emf E_{b} of a DC motor is nothing but the induced emf in armature conductors due to rotation of the armature in a magnetic field.

### Speed Control of DC Motor PDF – Explanation

E_{b} = ^{PØNZ}/_{60A}

(where, P = no. of poles, Ø = flux/pole, N = speed in rpm, Z = no. of armature conductors, A = parallel paths)

E_{b }can also be given as,

E_{b} = V- I_{a}R_{a}

thus, from the above equations

N = ^{Eb 60A}/_{P}_{ØZ}

but, for a DC motor A, P and Z are constants

Therefore, N ∝ K ^{Eb}/_{Ø} (where, K=constant)

This shows the speed of a dc motor is directly proportional to the back emf and inversely proportional to the flux per pole.

Thus, the magnitude of E_{b} can be given by EMF equation of a DC generator. We have already explained that the speed of a dc motor is inversely proportional to the flux per pole. Thus by decreasing the flux, speed can be increased and vice versa.

**Here you can download the Speed Control of DC Motor PDF by click on the link given below.**