DC controls adjust speed by varying the voltage sent to the motor (this differs from AC motor controls which adjust the line frequency to the motor). Typical no load or synchronous speeds for an AC fractional horsepower motor are 1800 or 3600 rpm, and 1000-5000 rpm for DC fractional hp motors.
On which factors the speed of a DC motor depends?
The above equation shows that the speed depends upon the supply voltage V, the armature circuit resistance Ra, and the field flux Ф, which is produced by the field current. In practice, the variation of these three factors is used for speed control.
What are the factors on which speed of motor depends?
The electric motor speed depends on both the applied voltage and the number of turns of its coil. The more turns the motor has the higher the strength of the rotor magnetic field if the current is maintained constant.
What parameter controls the speed of a DC motor?
Thus, the speed of a DC motor can be controlled in three ways: By varying the supply voltage. By varying the flux, and by varying the current through the field winding. By varying the armature voltage, and by varying the armature resistance.
What is the need of speed control in DC motor?
DC Motors plays an important role in energy conversion process. It is a machine which converts electrical energy into mechanical energy. In mechanical system, speed varies with number of task so speed control is necessary to do mechanical work in a proper way. It makes motor to operate easily.
How can I reduce the speed of a 12v DC motor?
A couple of things you can do:
- Use gears to change ratio of speed, which is what you’re going to do. …
- Use a stepper motor, which are commonly used for high-torque, low RPM applications.
- Find some sort of PWM control circuit to slow it down, although you probably won’t be able to get it down to 5-10RPM.
How do you calculate the speed of a DC motor?
conductors in armature. Hence, speed of a DC motor is directly proportional to emf of rotation (E) and inversely proportional to flux per pole (φ). N=120f/P.
Can we increase the RPM of motor?
Yes, but with a small amount above the maximum speed under normal rated conditions. Increasing the speed can be achieved by increasing the supply frequency as the speed and frequency are directly proportional; however, there are two constraints.
What are the two factors influencing the speed of induction motor?
The speed of an AC motor depends on the frequency of the input power and the number of poles for which the motor is wound.
What are the parameters of DC motor?
The parameters under consideration are the motor armature-winding resistance and inductance, back e.m.f. constant, motor torque constant, moment of inertia, and the viscous friction.