Leave a Reply Cancel reply Your email address will not be published. It resembles the stator winding of 2 pole , split phase ac motor. We will explain and discuss the construction of this type of motor.
And their ability to produce high torque at low speeds makes them suitable for applications such as blenders and portable drills. Universal motors work with voltages of direct current or alternating current.
Speed control of universal motor Speed control of universal motor is best obtained by solid-state devices. The frames of universal motor are usually made up of high quality aluminium , rolled steel and cast iron.
This phenomenon takes place especially at huge loads. Universal motors are high speed , small size motors as compared to other motors of same output. The inductor winding of the universal motors is usually bipolar, with two inductor coils. The commutation on ac is much poorer than on dc , due to eddy current induced in the short circuited armature coils.
The universal motor is undoubtedly the most used motor in the household appliance industry.
If we use wide brushes then the short circuited current is excessive, and motor starting torque is reduced. The Universal motor is used for the purposes where speed control and high values of the speed are necessary.
The power factor becomes low due to large reactance of the field and armature winding. The use of these motors in alternating current is very widespread due to the higher starting torque with respect to that of the induction motors and due to its high rotation speed, which allows to reduce its size and its price. These are: The factors that determine the speed for any dc motor are the same as those for ac series or universal motors i.
An universal motor is a specially designed series wound motor, that operates approximately at the same speed and torque, on either AC or DC voltage. For an engine of this type to be able to work with alternating current , it is necessary that the stacking of its inductor the core of the electromagnets is made of magnetic sheet to avoid losses in the iron. The construction of the universal motor is same as that of the series motor.
But for some specific applications , it is desirable to introduce a motor that operates in ac and dc supply both. Instead line voltage is varied.
Suppose you have provided supply voltage across the Field coil and Armature coil, from the same voltage source. The motor efficiency becomes low due to hysteresis and eddy current effects. The direction of rotation is reversed by reversing the current in the field circuit.
Higher number of turns in the armature to compensate for the decrease in flow due to the lower number of turns of the inductor. They react on each other to produce an unidirectional torque. Because, the reluctance voltage drop is present on ac but not in DC. The universal motor operates in direct current exactly like a serial motor.