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DC MOTOR

Let’s 1st begin with the only DC motor doable. it’s like as shown in the Fig.1. The mechanical device may be a static magnet and provides a continuing force field. The coil, that is that the rotating half may be an easy coil.

DC motor and electric motor
The coil is connected to a DC power supply through a try of electrical switch rings. once this flows through the coil AN magnetic force is iatrogenic on that per the Lorentz law, therefore the coil can begin to rotate. The force iatrogenic because of the magnetic force induction
You will notice that because the coil rotates, the electrical switch rings connect with the ability supply of opposite polarity. As a result, on the left aspect of the coil the electricity can continually flow ‘away ‘and on the correct aspect, electricity can continually flow ‘towards ‘. This ensures that the torsion action is additionally within the same direction throughout the motion, therefore the coil can continue rotating.



Shunt & Series Motors
D.C motorsThe field coils are connected to the rotor windings in a pair of totally different ways; parallel or series. This results into a pair of totally different varieties of DC motor constructions; a shunt and a series motors.
The series wound motor has sensible beginning force, however, its speed drops drastically with the load.
The shunt motor includes a low beginning force, however, it’s able to run virtually at a relentless speed, no matter the load engaged on the motor. this can be a lovely operation characteristic of a shunt wound motor, the character of the speed-torque variation
The conception of Back E.M.F
Unlike the opposite electrical machines, D.C motors exhibit a singular characteristic; the assembly of back voltage. A rotating loop in flux can manufacture AN voltage in step with the principle of magnetism induction.
The case of rotating coil loops is additionally an equivalent. an interior voltage is elicited that opposes the applied input voltage. the rear voltage reduces coil current by an outsized quantity. Back voltage is proportional to the speed of the rotor. At the beginning of the motor, back voltage is simply too low, therefore the coil current becomes too high, resulting in burnout of the rotor. therefore a correct beginning mechanism that controls the applied input voltage is critical in massive D.C motors.
One of the fascinating variations of the DC motor could be a universal motor, that is capable of running underneath each A.C and D.C power sources. we are going to bear it’s operating and operational options in an exceedingly separate article.



July 16, 2017svnarasimharao