What are the factors affecting torque in dc motor?
What are the factors affecting torque in dc motor?
Apart from the current through the coil the torque depends on the magnetic field strength. Usually DC motors have permanent magnets ( most commonly used are AlNiCo or SmCo magnets), a higher grade or strength of permanent magnets (like NdFeB) will produce a much higher torque.
Why does an electric motor lose torque?
When the rotor rotate, there is a change in magnetic flux, causing what we call back EMF. This back EMF “oppose” the voltage we applied to the motor, thus reducing the current in the winding. Higher RPM means higher rate of change in magnetic flux, means lower current and torque.
How do you increase the torque of a DC motor?
If the speed is to remain constant then the back-emf must also remain constant. Then the only way to increase torque is to increase the armature current and the only way to increase the armature current is to increase the supply voltage. This in effect is how a speed controller works.
Can a motor lose torque?
over time, motors will lose some of their torque as the magnets weaken from being subjected to heat.7 ene 2010
Do DC motors have a holding torque?
Normal DC motors and servo motors do not have much torque at low speeds. Suitable for applications with high holding torque. Stepper motors can be easily controlled with microcontrollers such as the ATmega chips that are readily available on Arduino development boards.1 abr 2019
How is torque controlled in a DC motor?
The torque (and speed) of a DC motor are both controllable. The torque is controllable up to the maximum rated torque of the motor, and is controlled by varying the armature (and if a shunt wound motor, the field) current. Maximum sustainable torque is achieved at full rated current on the armature (and field).7 dic 2015
What is the torque of a motor?
Torque: The torque output of a motor is the amount of rotational force that the motor develops. The torque of a small electric motor is commonly measured in either inch pounds (in-lbs), Newton meters (N-m) or other directly converted units of measure.
What is torque and what is the source of torque in DC motor?
By turning on and off coils in sequence, a rotating magnetic field can be created. These rotating magnetic fields interact with the magnetic fields of the magnets (permanent or electromagnets) in the stationary part of the motor (stator) to create a torque on the armature which causes it to rotate.
Why is torque important in DC motors?
Many applications require a high starting torque. The D.C. motor, by its very nature, has a high torque vs. speed characteristic, enabling it to deal with high resistive torques and absorb sudden rises in load effortlessly; the motor speed adapts to the load.
How torque is produced in a DC motor?
When a DC machine is loaded either as a motor or as a generator, the rotor conductors carry current. These conductors lie in the magnetic field of the air gap. Thus each conductor experiences a force. ... Hence torque is produced at the circumference of the rotor and rotor starts rotating.20 mar 2013
Does DC motor have more torque?
DC motors can provide a more constant torque over the speed range, and generally provide faster response to load changes that AC motors.
Do DC or AC motors have more torque?
AC motors are generally considered to be more powerful than DC motors because they can generate higher torque by using a more powerful current. However, DC motors are typically more efficient and make better use of their input energy.