What are the factors that decide the speed of a DC machine?

What are the factors that decide the speed of a DC machine?

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 important factors to be present in order for a DC motor work?

When selecting a DC motor for a given application, two factors must be taken into consideration: 1) The allowed variation in speed for a given change in load. 2) The allowed variation in torque for a given change in load.

Why do we select 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.

What are the factors to be considered when purchasing motor for machine drive?

When selecting a motor or drive, there are many aspects of the hardware to take into consideration. There are a number of important characteristics to think about including the actions that you need your motor to be able to perform, the location that the motor will be in, compatibility, sustainability, and cost.

What are the factors that affect the speed of a DC motor explain how the speed can be controlled above and below base speed?

Thus, the speed of a DC motor can control in three ways: By varying the flux, and by varying the current through field winding. By varying the armature voltage, and the armature resistance. Through the supply voltage.

What factors affect the rotational speed of a simple DC motor?

The rotating speed of an electric motor depends on two factors: its physical construction, and the frequency (Hz) of the voltage supply.

What are the factors that influence the torque of DC motor?

The torque is dependant on how large a magnet field the engine generates, and this is mostly dependant on the current it draws and the number of turns in the coil. So the thickness of the wire has no effect except if it affects the resistance and therefore the current drawn.

How are DC motors specified?

Key criteria for selecting a DC motor includes first finding out what voltage is readily available for the application and what physical size the motor needs to be. Speed and torque can then be considered once these first two parameters are determined. Voltage availability is a critical element in motor selection.

What are the specifications of DC motor?

Motor Specifications

• Standard 130 Type DC motor.
• Operating Voltage: 4.5V to 9V.
• Recommended/Rated Voltage: 6V.
• Current at No load: 70mA (max)
• No-load Speed: 9000 rpm.
• Loaded current: 250mA (approx)
• Rated Load: 10g*cm.
• Motor Size: 27.5mm x 20mm x 15mm.

How do you choose a DC motor for a robot?

10 Steps to Choosing the Right Motors for Your Robotic Project

1. Step 1: Determine the total weight and traction requirements.
2. Step 2: Calculate the traction wheel rotation speed.
3. Step 3: Calculate the traction motor power/torque.
4. Step 4: Calculate the lifter motor rotation speed.

What are the factors based on which motors are selected for industrial application?

Industrial motor selection depends on many facets including application, operational, mechanical, and environmental issues. Users should determine whether the application is constant or variable speed or if position control is required.

What controls the speed of a DC motor?

What are the guiding factors for selection of number of Poles?

Mention guiding factors for the selection of number of poles. Ø The frequency should lie between 25 to 50 Hz. Ø The value of current per parallel path is limited to 200A, thus the current per brush arm should not be more than 400A. Ø The armature mmf should not be too large. The mmf per pole should be in the range 5000 to 12,500 AT.

How to choose the diameter of the commutator?

The diameter of the commutator is chosen as 60 to 80\% of armature diameter. The limiting factor is the peripheral speed. The typical choice of commutator diameter for various voltage ratings are listed here:

What is the brake mode of DC machine?

Ø Brake mode: The machine works as a generator and the electrical power developed is either pumped back to the supply as in regenerative braking. 12. State use of a yoke in a D.C. machine. The yoke serves as a path for flux in D.C. machine and it also serve as an enclosure for the machine.

What is the function of interpoles in DC machines?

The interpoles are used in D.C. machines to neutralize the cross magnetizing armature mmf at the interpolar axis and to neutralize the reactance voltage in the coil undergoing commutation. 30. State the relation between the armature and the commutator diameter for various ratings of D.C. machines.