A shaded pole induction motor is a type of self-starting 1-phase induction motor. It consists of a stator and a squirrel cage type rotor. The stator of the shaded pole motor is made up of salient poles and each pole is slotted on a side and a copper ring is fitted on the smaller part of the slot as shown in the figure. The part with copper ring is known as shaded pole and the copper ring is known as shading coil which is usually a single turn coil.The main winding surrounds the entire pole and is given the 1-phase ... Read More

A 1-phase supply produces a pulsating magnetic field which does not rotate in the space. Therefore, a 1-phase supply cannot produce rotation in a stationary rotor. Although, like a 3-phase supply, the 2-phase supply can also produce a rotating magnetic field of constant magnitude. Therefore, all the single-phase induction motors, except shaded pole induction motor, are started as 2-phase motor. Once so started, the motor will continue to run on the 1-phase supply.How does a 2-Phase Supply Produce Rotating Magnetic Field of Constant Magnitude?Consider a 2-phase, 2 pole motor, where the phases A and B are fed by a balanced ... Read More

A repulsion-start induction-run motor consists of a stator carrying a single-phase exciting winding and a rotor which has a closed type armature winding with a commutator and brushes. The brushes on the commutator are short circuited. In the repulsion-start induction-run motor, the action of repulsion motor is combined with that of a 1-phase induction motor.This motor is started as a repulsion motor with a corresponding high-starting torque. At some predetermined speed, a centrifugal switch short-circuits the commutator segments so that the motor operates as a 1-phase induction motor.The centrifugal device is fitted on the rotor shaft of the motor. When ... Read More

In the repulsion induction motor, a high starting torque is due to repulsion motor action. When it is running, the repulsion-induction motor functions through a combination of repulsion motor and induction motor action.Construction of Repulsion Induction MotorThe construction of a 2-pole repulsion induction motor is shown in the figure.It consists of a stator which carries a single distributed winding fed from a 1phase supply. The rotor of the repulsion-induction motor has two independent windings placed one over the other.The inner winding is a squirrel cage winding with rotor bars permanently short-circuited.The outer winding is a repulsion commutator armature winding which ... Read More

The printed circuit board (PCB) motor consists of a rotor in the form a disc which is made up of non-magnetic and non-conducting material. Hence, the printed circuit board motor is also called as disc armature motor. The basic construction of a printed circuit board motor is shown in the figure.The whole armature winding of the motor and the commutator are printed in copper on both sides of the rotor disc. The brushes are placed around the inner periphery of the rotor disc.The disc armature of the motor is placed between two sets of permanent magnet poles which are mounted ... Read More

A permanent split capacitor (PSC) motor is a type of single-phase induction motor. The circuit diagram of a permanent split-phase motor is shown in the figure below. The permanent split-phase induction motor consists of a squirrel cage rotor and the stator has two windings, viz. starting or auxiliary winding and main or running winding. This motor has one capacitor "C" which is connected in series with the starting winding of the motor. This capacitor is permanently connected in the circuit both at starting and running conditions of the motor.As the capacitor is permanently connected in the circuit and it splits ... Read More

The performance analysis of a single-phase, single-winding induction motor can be done with the help of the equivalent circuit that is shown in the figure. There are both forward and backward components of power and torque is present in the motor.Here, the torque of the backward field is in the opposite direction to that of the forward field and hence the total air-gap power in a single-phase induction motor is given by, $$\mathrm{𝑃_{𝑔} = 𝑃_{𝑔𝑓} − 𝑃_{𝑔𝑏} … (1)}$$Where, Pgf is the air-gap power for the forward field and is given by, $$\mathrm{𝑃_{𝑔𝑓} = {{𝐼}^{2}_{𝑚}}\:𝑅_{𝑓}}$$And Pgb is the air-gap power ... Read More

The equivalent circuit parameters of a single-phase induction motor can be determined from the blocked rotor and no-load tests. Except, the capacitor-run motor, the blocked rotor and no-load tests are performed with auxiliary winding kept open.Blocked Rotor Test on Single-phase Induction MotorIn the blocked rotor test, the rotor of the motor is blocked, i.e., remains at rest. A reduced voltage is applied to the stator so that the rated current flows in the main winding. The voltage, current and power are measured.Vsc, Isc and Psc are the voltage, current and power under the blocked rotor conditions. With the rotor blocked, ... Read More

A linear induction motor (LIM) is an induction motor that converts electrical energy input into linear or translational motion instead of rotational motion as in the case of a conventional induction motor.In a linear induction motor, the stator and the rotor are known as primary and secondary respectively. The secondary of the linear induction motor consists of a flat aluminium conductor with a ferromagnetic core. If the primary of the linear induction motor is connected to a three-phase supply, a traveling flux wave is produced which travels along the length of the primary.Due to the relative motion between the traveling ... Read More

A permanent magnet DC (PMDC) motor is a type of DC motor whose field poles are made up of permanent magnets. The cross-sectional view of a 2-pole permanent magnet DC Motor is shown in Figure-1In a PMDC motor, the permanent magnet poles are radially magnetised and mounted on the inner periphery of the stator of the motor. The stator also serves as a return path for the magnetic flux. The rotor of the PMDC motor has a conventional DC armature with commutator and brushes.In a permanent magnet DC motor, the torque is produced by the interaction between axial current carrying ... Read More