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What is a shaded pole motor? , Shaded pole motor kya hai?

Hello friends In this article we will know what is shaded pole motor? What are the benefits of shaded pole motor? What is the operation of shaded pole motor? And learn about many facts related to it.

shaded pole motor | Shaded pole motor

shaded pole Motor (Shaded pole motor) is very popular for ratings less than 0.05 hp. (= 40 W) because of its extremely simple construction. It has main poles excited by a single-phase supply on the stator and a squirrel-cage rotor as shown in Fig. 27.1. A portion of each pole is surrounded by a small circular twist of copper strip called a shading coil.


Operation of shaded pole motor | Operation of Shaded pole motor

As the flux across the poles of the field is alternating, a voltage is induced in each shading coil which is short-circuited. transformer Acts as secondary winding. The polarity of the induced voltage is mmf. Which opposes the change in flux linkage of the coil.

Shaded pole motor

Thus when the flux in the pole is increasing, the shading-coil current produces a mmf. opposing the increase. Thus, the flux density of the shaded part of the pole is greater than the flux density of the shaded part. When the pole flux is decreasing, the shading-coil current flows to counteract the decrease.

so in the shaded part flux Density is less than the shaded part. Thus the effect of the shading coil is to produce a change in flux from the unshaded part to the shaded part. This change in flux can be considered a partially rotating field and is sufficient to produce a small starting torque.

Provided there is little or no load on the motor, the motor moves in the direction of shift in flux. Due to the small starting torque developed in the motor and the relatively large power loss in the shading coil, the shaded pole motor is made in a smaller size, the most common application for fans.

What is the principle of operation of shaded pole motor?

A shaded-pole motor is basically a small single-phase squirrel cage motor in which the starting winding is made up of a short-circuited copper ring (called a shaded coil) around one-half of each pole. . The effect of the shading coil causes a current to sweep across the face of the pole from the shaded side of the pole to the shaded part of the pole, producing a weak rotating magnetic field. As a result, the rotor is set in motion due to the induction principle.

Why are shaded-pole motors so popular for low-power (up to 40 W) applications?

Shaded-pole motors are very popular for low-power applications (up to 40 W) for the following reasons:
(i) Their manufacture is very simple. (ii) No centrifugal switch is required. (iii) They are quite cheap.

Why can’t the direction of rotation of a shaded-pole motor be changed?

The direction of rotation of the rotor of a shaded-pole motor is from the shaded pole of the motor to the shaded pole. The direction of rotation cannot be changed as it is determined by the position of the copper rings.

How can the rotation of a shaded pole motor be reversed?

The winding of a shaded-pole motor can only be reversed if the machine is so constructed that the shading coil can be moved to the other half of the pole. Otherwise the direction of rotation of such motors cannot be reversed.

What are the applications of shaded pole motors?

Shaded-pole motors generate a very weak rotating magnetic field. As a result, the starting torque of such motors is very small. They are suitable only for running small appliances like small fans, electric clocks, relays etc.


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