Assignment1: Electromagnetic Applications
ECE 170L
Intro. to Electro. Fields
Instructor: Dr.Mohammed Abdulmjid
Student’s Names:
Bashayr Almuwaylihi , Shaddin AlZaid
Student’s ID:
S13105900, S14209168
Table of Contents:
Introduction ……………………….…….…………………2
Maglev -Train ……………….………………..…………..…3
Loudspeaker ………………………………….….….………6
Electrical bell …………………………………………………7
Computer Hardware and Memory Storage Devices …………….8
Electric generator……..………………………………..……9
Microphones …………..……………………………….…10
Microwave …………..………………………………..……13
References .………………………………………………..16
Electromagnetic fields were discovered in the 19th century, when physicists noticed that electric sparks could be copied at a distance, with wireless communication. Electromagnetic field, its generated when the particles charged such as electrons. Sometimes electromagnetic field referred as an EM field. Charged particles in motion produce magnetic fields. When the velocity of a charged particle changes, an EM field is produced. In this research you will find some application for the electromagnetic waves.
1- Maglev-Train:

Figure (1): Maglev-Train Principe.

Maglev (derived from magnetic levitation) is a transport method that uses magnetic levitation to move vehicles without contacting the ground. By reducing friction by a great extent and allowing very high speeds. In itself, maglev technology includes no moving parts. A vehicle travels along a good way using magnets to create both lift and propulsion.

There are three components to this system:
Electrical power source (large).

Metal coils padding a guide way or track.

Large directing magnets attached to the underside of the train.

The two notable types of maglev technology are:
1-Electromagnetic suspension (EMS):
Figure 1 shows a system that is done by a German scientist. Its system is called Tran rapid. It uses EMS technology. EMS is electromagnetic suspension altering. EMS systems use the attractiveness of magnets. The same pole in the magnets attracted to each other, so the stator and support magnets are attracted in figure 1. Because of that the train to not land on the track. It regulates the power of the magnetic field produced by electromagnets that levitate an object. There is a guidance magnet on the side of the track that prevents the train from moving side to side. So the train in the picture can’t touch any side of the track levitating in the air because of the magnetic force keep the train to the middle.

Figure (2): Maglev-Train Principe.

Electrodynamics’ suspension (EDS):
EDS is Electrodynamics suspension. The maglev train travels at high speeds over the coils, the magnet that superconducting on the side of the train induce the current from the coils. A magnetic field is generated as shown in the picture on top of figure 2. It’s working as an opposing pole of the magnetic field on the front of the train, because of that the train can move without any other force while the train is levitating on the track. The magnetic field on the back of the train will push the train by changes to the same pole of the magnetic field. Now the train has no friction that makes it goes smooth and fast.

Figure (3): Maglev-Train Principe.

A lot of systems use loudspeaker for example: TV. The main function of speaker converts electrical signals into audio sounds. This device consists of an electromagnet which is attached to the cone surrounded by the magnetic flux that being produced by the permanent magnet. When the current reaches the magnet, creating a magnetic field causing an attract and repel movement pumping the sound waves.

Figure (4): Loudspeaker Principe.

How does a loudspeaker work?
In figure (3), when a fluctuating electric current flow through the coil (orange), it becomes a temporary electromagnet, attracted and repelled by the permanent magnet (blue/red). As the coil moves, it moves the cone (gray) back and forth, pumping sound waves (light blue).

3-Electrical bell:
Electric bells used in many systems for example:- Alarming system. It’s works based on electromagnetic coils are used to move the striker against the bill to make sound. The sound is produced by electromagnetic coils which move the striker against the bell. When the striker moves toward the bell, the electrical contact will break and the electromagnet will be demagnetized. After striking the striker it has returned to its original position, thus the cycle will continue until the switch is in the open position.

How does an electric bell work?
An electric bell contains an electromagnet, contain a coils of insulated wire wound round iron rods. When an electric current flow over the coils, the roads will be magnetic and attract a piece of iron attached to a clapper. Then the clapper hits the bell and makes it ring.

Figure (6): An electric bell’s electromagnet is activated by an electric current passing through the coils of wire.

4-Computer Hardware and Memory Storage Devices:
Magnetic storage is one of the most affordable ways to store large data and has been implemented using magnetic tape and floppy disks. The data are stored in electromagnetic format in the form of bits and bytes. The data in the form of zero and ones. The two types of magnetic polarities represent either zero or one. The computer hardware contains a magnetic tape and it works on the electromagnetic principle. In addition to tat the olden day VCR’s and VCP’s are having huge rolls of magnetic tapes, which contain the data in it. And the computer and Televisions it uses a high current electromagnets to produce a beam of electrons.

Figure (7): Storage Devices examples.

How does a Magnetic Storage Work?
A magnetic disk’s medium have an iron particles, which can be polarized when given a magnetic charge the 1 (one) or 0 (off) direction. 0 and 1 which in turn represent each bit of data that the CPU can recognize. To create magnetic charges on the medium a disk drive uses read/write heads containing electromagnets.

5- Electric Generator:
A generator is a device that converts mechanical to electrical energy.
Sources of mechanical energy include:
Gas turbines water turbines.

Steam turbines.

Internal combustion engines and even hand cranks.

Figure (8): Electric Generator.

The work of the electrical generator mechanism:
When a spin file around the magnetic field (or magnets on file) produce electrical energy and this is known as electromagnetic induction and is used in rotation file or magnet alternator bike mechanical energy. The power plants are used renewable energies like the water and the wind , and it would be large turbines to convert the power of the water flow into electricity.

Microphones: 6-
Microphones are devices that translates vibrations of the sound in air and acoustical energy are converted to electrical energy.

From the operation principles there are three main types of microphones which are:
Dynamic (moving-coil)
1) Dynamic microphones:
Dynamic microphones composed of a diaphragm suspended in front of a magnet to which a coil of wire is attached.

The location of the coil is between the gaps of the magnet, the coil move in the gap due to the vibration of the diaphragm and that result an AC to flow
Coils of wire are used to increase the magnitude of the induced voltage and current.

Figure (11): Dynamic microphones work.

The coil-diaphragm structure mass blocks its fast movement at high frequencies
A resonant peak is usually found at around 5kHz, making it a favorite with vocalists.

Very strong (wide range used for kick-drums).

2) Ribbon microphone:
It composed of a thin strip of conductive corrugated metal (ribbon) between magnetic plates.

Ribbon vibration according to the acoustic wave induces a current.

The transformer is needed to step the small electrical output.

Ribbon lightness guarantees a flat frequency response for mid and high frequencies up to 14kHz. It resonates at very low frequencies (around 40Hz).

It is very accurate and well suited for the recording of acoustic instrument

Figure (12): Ribbon microphones work.

3) Condenser microphones:
A capacitor is an electrical device for storing electrical charge between two closely spaced conductors (plates).

Capacitance (C) measures how much charge (Q) is stored for a given voltage (V), such that C = Q/V.

Capacitance is inversely proportional to the distance (d) between plates.

Figure (13): Condenser microphones work.

•In condenser mics, diaphragm is the front plant which vibrates with the sound. The charge (Q) is fixed, thus changes in the distance (D) between plates result on changes of voltage (V).

•Condenser mics can be very high quality.

•The diaphragm can be very light, rendering a flat frequency response (with a small resonance peak at above 12kHz).

•Output of condenser mics is more higher than for dynamic mics.

•High output makes it more robust to noise.

•A source of power to charge the capacitor.

Microwave: 7-
Microwaves are electromagnetic waves that move through space at the speed of light. Its invisible so, we can’t see microwaves. Microwaves are shorter than radio waves. Microwaves are longer than infrared radiation

Figure (14): The electromagnetic spectrum.

Microwaves are sandwiched between radio waves and infrared light on the electromagnetic spectrum. The microwaves used in cooking around 12 centimeters, or a little wider than the diameter of a baseball.

The Microwave Oven:

Figure (15): Microwaves generated from electricity inside the microwave oven by component called the magnetron. A transformer converts the standard household electricity from a wall socket of 120 volts to about 4,000 volts or higher to power the magnetron. The voltage heats a filament at the center of the magnetron, ebullience off electrons.

Figure (16): The electrons would go out in straight line to the anode, or positive terminal, that surrounds the filament, but two ring magnets bend the electrons back toward the filament and they fly in a circular path.

Figure (17): Microwaves are created as the electrons whip past cavities in the anode.

Figure (18): Microwave Oven.

Figure (19): Microwave Oven.

1-Maglve -Train: Loudspeaker:
3- Electromagnetic ball: Computer Hardware and Memory Storage Devices: Electric generator: microphone:
Juan Bello _Microphones.

7- Microwave: