Saturday, February 25, 2012

The DC Motor Principle and How it works? Video


An educational video regarding the DC Motor Principle and video demonstration illustrates How it works?

DC Motor Principle 1
An educational video regarding the DC Motor Principle



DC motors - how is it made? How it works?
In this video, i break apart DC motor model and then i rebuilt it from a scratch, to explain how a DC motor is made. This video is part of the theory "How DC Motors Work.



DC Motor
A direct current (DC) motor is a fairly simple electric motor that uses electricity and a magnetic field to produce torque, which turns the motor. At its most simple, a DC motor requires two magnets of opposite polarity and an electric coil, which acts as an electromagnet. The repellent and attractive electromagnetic forces of the magnets provide the torque that causes the DC motor to turn.
If you've ever played with magnets, you know that they are polarized, with a positive and a negative side. The attraction between opposite poles and the repulsion of similar poles can easily be felt, even with relatively weak magnets. A DC motor uses these properties to convert electricity into motion. As the magnets within the DC motor attract and repel one another, the motor turns.
A DC motor requires at least one electromagnet. This electromagnet switches the current flow as the motor turns, changing its polarity to keep the motor running. The other magnet or magnets can either be permanent magnets or other electromagnets. Often, the electromagnet is located in the center of the motor and turns within the permanent magnets, but this arrangement is not necessary.
To imagine a simple DC motor, think of a wheel divided into two halves between two magnets. The wheel of the DC motor in this example is the electromagnet. The two outer magnets are permanent, one positive and one negative. For this example, let us assume that the left magnet is negatively charged and the right magnet is positively charged. Electrical current is supplied to the coils of wire on the wheel within the DC motor. This electrical current causes a magnetic force. To make the DC motor turn, the wheel must have be negatively charged on the side with the negative permanent magnet and positively charged on the side with the permanent positive magnet. Because like charges repel and opposite charges attract, the wheel will turn so that its negative side rolls around to the right, where the positive permanent magnet is, and the wheel's positive side will roll to the left, where the negative permanent magnet is. The magnetic force causes the wheel to turn, and this motion can be used to do work.
When the sides of the wheel reach the place of strongest attraction, the electric current is switched, making the wheel change polarity. The side that was positive becomes negative, and the side that was negative becomes positive.
The magnetic forces are out of alignment again, and the wheel keeps rotating. As the DC motor spins, it continually changes the flow of electricity to the inner wheel, so the magnetic forces continue to cause the wheel to rotate.
DC motors are used for a variety of purposes, including electric razors, electric car windows, and remote control cars. The simple design and reliability of a DC motor makes it a good choice for many different uses, as well as a fascinating way to study the effects of magnetic fields

Thursday, February 23, 2012

The AC Motor Principle and 3D Animation Video



An educational video regarding the AC Motor Principle and 3D Animation demonstration illustrates the operation of an AC motor

The Motor Principle : Electromagnetism
An educational video clip regarding the motor principle in electromagnetism

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Induction : Electromagnetism
An educational video clip regarding induction through electromagnetism




Electric Motor Principle
video describes the components and how electric AC motor work



AC Electronic Motors
AC electronic motorsAC electronic motors are synchronous motors based on the principle of frequency control with self-timing. The essence of the principle is to control the stator's magnetic field vector according to the rotor position.Such motors are sometimes called commutatorless DC motors as the controller of such motor is usually powered from DC voltage while its rotor speed depends on supply voltage.So we can see that such motor works as a direct current motor. Its design is similar to that of AC synchronous motor. Its magnetic rotor rotates in a stator with a three-phase winding. Supply voltage of the motor windings is formed in accordance with the rotor position.A commutator is used in DC motors for this purpose while AC electronic motors have a semiconductive commutator for that.The motor has the following operating principle. The controller commutates stator windings so that the stator's magnetic field vector is always perpendicular to the rotor's magnetic field vector.By using pulse-duration modulation the controller regulates current which flows through the windings. That means it regulates the stator's magnetic field vector and thus the moment affecting the rotor.The sign at the angle between the vectors determines direction of the moment affecting the rotor. Such motors were designed to improve properties of DC motors. Their main advantage is that they don't have rotary contacts. This significantly increases their lifespan. Such types of motors find various applications - from house appliances to rail transport.



  Electric Motors and Drives, Second Edition 
Written for non-specialist users of electric motors and drives, this book explains how electric drives work and compares the performance of the main systems, with many examples of applications. The author's approach - using a minimum of mathematics - has made this book equally popular as an outline for professionals and an introductory student text.

3D Animation AC Motor
3D Animation video shows the components and operation of a motor.



AC Motor Animation Video
video shows the components of AC induction motor



Operating an AC Three-Phase Induction Motor
This Demonstration illustrates the operation of an induction motor. You can create a voltage imbalance or a phase shift in the three-phase source. This will result in a change in speed of the rotor that represents a change in developed torque.

Friday, February 3, 2012

Magnetic field in a solenoid Theory, Experiment and Animation Video



Magnetic field in a solenoid Animation Video
Animation showing the direction of the magnetic field in a solenoid and how an electric current flowing in a coil produces a magnetic field.

Magnetic field in a solenoid
A solenoid coil carries an electric current symbolized by several little red spheres in motion. A green arrow shows the direction of magnetic field inside the coil. For other physics animations



Magnetic Field due to a Current in a Solenoid
Animation showing the direction of the magnetic field in a solenoid.



DSN Animation: What is a Solenoid Valve?
This Design Squad Nation animation shows how an electric current flowing in a coil produces a magnetic field. Explains how a solenoid uses a changing magnetic field to move a rod back and forth to do mechanical work, such as opening and closing a valve.



Magnetic Field Viewer
Allows manipulation of iron fillings without the mess.

Theory on Magnetic Field of Solenoid Video
Video describing theory on Magnetic Field of Solenoid.

Theory on Magnetic Field of Solenoid, Free IIT-JEE Coaching, AIEEE Tricks, NEET Preparation, MPPET
IIT JEE study material and free video tutorials for students of grade X, XI, XII and droppers who are aspiring for engineering and medical entrance exams. This video tutorial is on the magnetic field of a solenoid. The magnetic field just outside the solenoid is zero in the case of infinitely long solenoid. However the magnetic field will exist when you measure it at distance from the surface. To find the magnetic field in a certain path for a solenoid with finite length will be illustrated in this free video lecture for IIT preparation.



Magnetic Field of General Solenoid 1
This video shows how to derive the general magnetic field of a solenoid anywhere along the axis of the solenoid including its inside and at its edge, as well as how to approximate the answer to a long solenoid and apply it to a magnet.



Magnetic Field of General Solenoid 2
This video shows how to derive the general magnetic field of a solenoid anywhere along the axis of the solenoid including its inside and at its edge, as well as how to approximate the answer to a long solenoid and apply it to a magnet. (Part 2)



Magnetic Field of a solenoid Experiment
Video shows experiment of solenoid and explaining the electromagnet formed by a solenoid


Magnetic Field of a solenoid Experiment
Video shows experiment of solenoid



Solenoid - Electromagnet
explaining the electromagnet formed by a solenoid, effects are permanent on a steel ruler.



Electromagnetic induction
Electromagnetic induction. A changing magnetic flux induces a current into a coil.
Demo 1: As the magnet is moved in, the magnetic flux through the solenoid changes and an induced current appears (Faraday's law). The faster the magnet the higher the induced current. If the solenoid is approached first with the other magnetic pole, the direction of the induced current changes. When the magnet is moved away from the solenoid the direction of the current changes again.