What is the principle of universal motor?
The working principle of the universal motor is like a DC series generator. When the current flows into the field winding, it generates an electric field. The same current is still emanating from the armature conductors. When a current conductor is put in an electric field, a mechanical force is encountered.
What are the characteristics of universal motor?
Universal motors have high starting torque, can run at high speed, and are lightweight and compact. They are commonly used in portable power tools and equipment, as well as many household appliances. They’re also relatively easy to control, electromechanically using tapped coils, or electronically.
What are the two types of universal motor?
Two types of universal motors are in use, namely, non-compensated and compensated. The non-compensated motor is usually built with concentrated or salient poles (Fig. 2). On the other hand, the compensated motor has distributed field windings (main field and compensating winding).
What are applications of universal motor?
There are various applications where universal motors are used, such as power drills, wash machines, blowers and kitchen appliances, etc. And they are also used for numerous different purposes where speed control and high qualities of speed are necessary.
Why capacitor is used in universal motor?
As opposed to an AC motor using only a motor start capacitor, which creates a pulsating magnetic field during normal operation, AC motors using a motor start capacitor and a motor run capacitor create a rotating magnetic field during normal operation.
Why is it called a universal motor?
Universal Motor is a special type of motor that can run on a DC supply or a single-phase AC supply. Since it can run both on AC and DC, it is called a universal motor.
What are the methods of speed control of universal motor?
Three methods of controlling the speed of a universal electric motor were discussed. These are the resistance control method, the field tapping method, and the centrifugal switch method. In the resistance control method, a variable resistance in series with the motor is used to set the RPM.
What is power factor of universal motor?
between 0.7 and 0.9
1.1 Universal motor The machine has a “series” speed-torque characteristic, the no-load speed being limited by mechanical losses. The power factor is between 0.7 and 0.9 (mainly the result of armature inductance), but this is of no significance in small ratings.
How is torque produced in a universal motor?
When a current carrying conductor is placed in an electromagnetic field, it experiences a mechanical force. Due to this mechanical force, or torque, the rotor starts to rotate. The direction of this force is given by Fleming’s left hand rule. When fed with AC supply, it still produces unidirectional torque.
What is the advantage of universal motor?
One main advantage of the Universal motor is its high power density. It’s not uncommon for a Universal Motor to have over twice the continuous output power as an equally-sized AC motor. Additionally, its low cost, portability, and ability to run without a control make it worth looking at.