# Frequent question: How do you drive a DC motor?

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## How does a DC drive work?

DC drives. DC drives are DC motor speed control systems. Since the speed of a DC motor is directly proportional to armature voltage and inversely proportional to motor flux (which is a function of field current), either armature voltage or field current can be used to control speed.

## What is a DC motor and how does it work?

The DC motor is a machine that transforms electric energy into mechanical energy in form of rotation. Its movement is produced by the physical behavior of electromagnetism. DC motors have inductors inside, which produce the magnetic field used to generate movement.

## What can a DC motor be used for?

Small DC motors are used in tools, toys, and appliances. The universal motor can operate on direct current but is a lightweight brushed motor used for portable power tools and appliances. Larger DC motors are currently used in propulsion of electric vehicles, elevator and hoists, and in drives for steel rolling mills.

## How do you control the speed of a DC motor?

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 is the disadvantages of DC drive?

Frequent starting, braking and reversing. The disadvantage of D.C. drives is the presence of a mechanical commutator which limits the maximum power rating and the speed.

## Which motor is used in DC drive?

The main components of a DC drive system are shown in figure below. DC Drive Input: Some thyristor based DC drives operate on a single phase supply and use four thyristors for full wave rectification. For larger motors, three phase power supply is needed because the waveforms are much smoother.

## What is the principle of DC motor?

Working principle of DC motor

A current-carrying conductor, when kept in a magnetic field, gains torque and develops a tendency to move. In short, when electric fields and magnetic fields interact a mechanical force arises. This is the principle on which the DC motors work.

## How much does a DC motor cost?

DC motors are quite affordable and usually cost less than \$25. Between \$6 and \$85: Vibrating motors can be found for under \$85. Between \$12 and \$45: This price range is where you can purchase a brushless motor. Between \$13 and \$125: Stepper motors are the most expensive motors.

## How does a 12v DC motor work?

In a DC motor, the stator provides a rotating magnetic field that drives the armature to rotate. A simple DC motor uses a stationary set of magnets in the stator, and a coil of wire with a current running through it to generate an electromagnetic field aligned with the centre of the coil.

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## What are the 4 types of DC motor?

There are 4 main types of DC motors:

• Permanent Magnet DC Motors. The permanent magnet motor uses a permanent magnet to create field flux. …
• Series DC Motors. In a series DC motor, the field is wound with a few turns of a large wire carrying the full armature current. …
• Shunt DC Motors. …
• Compound DC Motors.

## Which is not part of a DC motor?

The correct answer to the question will be compass i.e compass is not a part of a DC motor. Various parts of a DC motor are coil of wire, armature, field magnets, brushes and commutator. … The brushes connected to the coil provides the current through a split ring called commutator.

## How do you identify a DC motor?

Look for the commutator & brushes and salient field system to confirm. (iii) has 5 terminals, then it is a AC synchronous motor (3 for stator and 2 for field). Look for 2 slip rings for rotor dc supply. (iii) has 4 terminals, then it may be a DC motor, in which case look for the commutator & brushes to confirm.

## How do you slow down a 12v DC fan?

Get a three 1.8 ohm 2 watt resistors, connect them in parallel and put them in series with your fan (put them in the air stream of the fan to help cool them). That should slow your fan down and reduce the load.

## How do I control my 12v fan speed?

All we need to do is insert a rheostat or variable resistor in the 12V wire to the fan. The rheostat should be rated at least 3 Watt, (for fans up to 10Watt), and have a resistance of 20 – 50 Ohms. If you are using this mod on your CPU fan then use the 20 ohm rheostat to prevent fan stall at the slowest speed setting.

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