Physics Project workF.M Transmitting circuit

T.Y. Bsc Physics

3/30/2015

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Sr.No.

Description Page no.

1 Description 32 History

Modulation Types of modulation

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3 Making of F.M circuit Components Circuit diagram Making Working

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4 Formula and frequency analysis 105 Types of antennas

Yagi-Uda antenna Low power half wave sleeve dipole antenna High gain professional panel antennas PCS FM DIPOLE

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6 Applications Any Audio Home Televisions Cars iPod & MP3 Players Christmas Lights Fitness Centers Council Home Stereos Sirius XM Radios Drive-In Movies Correctional Facilities Karaoke Computers Internet Radio House Parties Tour Guides & Bus Tours DVD Players iPhone & Smartphones Dance Parties Group Meetings & Presentations As Transducer

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7 Legal Restrictions 168 Special thanks 169 Reference 17

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The project is about how to use Frequency Modulating (F.M.) with Hartley oscillator. In this circuit we use some necessary component like transistor, resistor, capacitor & inductor. The working principle of the circuit is to modulate the frequency of input signal with appropriate power and then transmit it with desire frequency.

The tank circuit is give appropriate signal and we can use this as a carrier .When battery is connected with it capacitor is charged after charging of capacitor this gives a energy to inductor and then inductor converts this energy in to magnetic energy and then oscillations of tank circuit are run forward and it gives electro-magnetic waves is fed into the transistor collector and modulation occurs of signals which are biased on base of the transistor. This modulated wave is fed to the antenna with the help of capacitor. .

In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves. In addition to their use in broadcasting, transmitters are necessary component parts of many electronic devices that communicate by radio, such as cell phones, wireless computer networks; Bluetooth enabled devices, garage door openers, two-way radios in aircraft, ships, and spacecraft, radar sets, and navigational beacons. The term transmitter is usually limited to equipment that generates radio waves for communication purposes; or radiolocation, such as radar and navigational transmitters. Generators of radio waves for heating or industrial purposes, such as microwave ovens or diathermy equipment, are not usually called transmitters even though they often have similar circuits.

The term is popularly used more specifically to refer to a broadcast transmitter, a transmitter used in broadcasting, as in FM radio transmitter or television transmitter. This usage usually includes both the transmitter proper, the antenna, and often the building it is housed in.

A transmitter can be a separate piece of electronic equipment, or an electrical circuit within another electronic device. A transmitter and receiver combined in one unit is called a transceiver. The term transmitter is often abbreviated "XMTR" or "TX" in technical documents. The purpose of most transmitters is radio communication of information over a distance. The information is provided to the transmitter in the form of an electronic signal, such as

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an audio (sound) signal from a microphone, a video (TV) signal from a video camera, or in wireless networking devices a digital signal from a computer. The transmitter combines the information signal to be carried with the radio frequency signal which generates the radio waves, which is often called the carrier. This process is called modulation. The information can be added to the carrier in several different ways, in different types of transmitter. In an amplitude modulation (AM) transmitter, the information is added to the radio signal by varying its amplitude. In a frequency modulation (FM) transmitter, it is added by varying the radio signal's frequency slightly. Many other types of modulation are used.

The antenna may be enclosed inside the case or attached to the outside of the transmitter, as in portable devices such as cell phones, walkie-talkies, and garage door openers. In more powerful transmitters, the antenna may be located on top of a building or on a separate tower, and connected to the transmitter by a feed line, that is a transmission line.

In far of years abut an era of first world war there is a great shortage of communication occurs so in those days the scientists think that the communication of the radio modulation can be very help full, So then can research on the modulation and transmitting of various waves but the input waves are to weak for transmitting at long distances.

So the scientists develop some ideas in which they can made the input signals strong by modulation in which they can superimpose weak input signals from mike on the carrier signals and then they transmitting the at various distances.

The first primitive radio transmitters (called Hertzian oscillators) were built by German physicist Heinrich Hertz in 1887 during his pioneering investigations of radio waves. These generated radio waves by a high voltage spark between two conductors. These spark-gap transmitters were used during the first three decades of radio (1887-1917), called the wireless telegraphy era. They couldn't transmit audio and instead transmitted information by telegraphy, the operator spelling out text messages in Morse code. Two short-lived competing transmitter technologies came into use after the turn of the century, which were the first continuous wave transmitters: the Alexanderson alternator and Poulsen arc transmitters, which were used into the 1920s. But all these early technologies were replaced by vacuum tubetransmitters in the 1920s, because they were inexpensive and produced continuous waves, which could be modulated to transmit audio (sound) using amplitude modulation (AM) and frequency modulation (FM). This made possible commercial AM radio broadcasting, which began in about 1920. The current form of FM transmission was invented by Edwin Armstrong in 1933, and the first FM radio station was licensed in 1937. The development of radar during World War II was a great stimulus to the evolution of high frequency transmitters in the UHF and microwave ranges, using new devices such as the magnetron, klystron, and traveling wave tube. In recent years, the need to conserve

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crowded radio spectrum bandwidth has driven the development of new types of transmitters such as spread spectrum.

In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.

In telecommunications, modulation is the process of conveying a message signal, for example a digital bit stream or an analog audio signal, inside another signal that can be physically transmitted. Modulation of a sine waveform transforms a baseband message signal into a pass band signal.

In the modulation there is various types as under:-

(1) Frequency modulation: -

In this type f modulation there will be changing in the frequency of carrier wave with respect to the input signal. Then this signal can be strong and being able to transmute at long distance.

In telecommunications and signal processing, frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. (Compare with amplitude modulation, in which the amplitude of the carrier wave varies, while the frequency remains constant.)

In analog signal applications, the difference between the instantaneous and the base frequency of the carrier is directly proportional to the instantaneous value of the input-signal amplitude.

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Digital data can be encoded and transmitted via a carrier wave by shifting the carrier's frequency among a predefined set of frequencies—a technique known as frequency-shift keying (FSK). FSK is widely used in modems and fax modems, and can also be used to send Morse code.[1] Radio teletype also uses FSK.[2]

Frequency modulation is used in radio, telemetry, radar, seismic prospecting, and monitoring newborns for seizures via EEG.[3] FM is widely used for broadcasting music and speech, two-way radio systems, magnetic tape-recording systems and some video-transmission systems. In radio systems, frequency modulation with sufficient bandwidth provides an advantage in cancelling naturally-occurring noise.

(2)Amplitude modulation: -

In this type of modulation the carrier waves can be super imposed on the input signals which are produced with the help of the mike etc. .In this type the amplitude of carries waves can be changed with respect to the input signal .Then this amplitude modulated waves can transmitted with the help of the transmitting antenna.

Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. In amplitude modulation, the amplitude (signal strength) of the carrier wave is varied in proportion to the waveform being transmitted. That waveform may, for instance, correspond to the sounds to be reproduced by a loudspeaker, or the light intensity of television pixels. This technique contrasts with frequency modulation, in which the frequency of the carrier signal is varied, and phase modulation, in which its phase is varied.

AM was the earliest modulation method used to transmit voice by radio. It was developed during the first two decades of the 20th century beginning with Reginald Fessenden's radiotelephone experiments in 1900. It remains in use today in many forms of communication; for example it is used in portable two way radios, VHF aircraft radio and in computer modems.[citation needed] "AM" is often used to refer to medium wave AM radio broadcasting.

(3) Phase modulation:- In this type of modulation the

phase of carrier waves is changed with respect to the input signals and then they are transmitted.

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PM changes the phase angle of the complex envelope in direct proportion to the message signal.

Suppose that the signal to be sent (called the modulating or message signal) is

and the carrier onto which the signal is to be modulated is

Annotated:

Carrier (time) = (carrier amplitude)*sin(carrier frequency*time + phase shift)

This makes the modulated signal

This shows how modulates the phase - the greater m(t) is at a point in time, the greater the phase shift of the modulated signal at that point. It can also be viewed as a change of the frequency of the carrier signal, and phase modulation can thus be considered a special case of FM in which the carrier frequency modulation is given by the time derivative of the phase modulation.

The modulation signal could here be

In our circuit we use Frequency modulation to drive our signal at various signal and then receiving with the help of receiver circuit. (Here we use mobile fm for receiving purpose)

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(1) 0.1µF(104) (2) 0.1µF(104)(3) 680pF(681)(4) 30pF(30)(5) 10pF(10)(6) 0.1µF(104)(7) 30pF(30)(8) 0.1µF(104)

(1) 2.2KΩ (2) 22KΩ(3) 2.2KΩ

(1) Q1=9108(N-P-N)

5.5Tesla (3-Turns of 0.1mm copper awg wire)

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In the making of F.M. circuit firstly we use input as mike or any audio signal are fed to it .This signals are filtered by the capacitoec2 and then provided in to the base of the transistor. To reduce noise we can change the value of c2 for better performance.C1 removes further noise from battery and gives smooth dc. As well as c1 the working of C8 is also same. The capacitor C4 is the by pass capacitor. The working of this capacitor is that this bypass the ac signals so high voltage drop is made and less power loss. The resistors R1 and R2 and Capacitor C3 are for transistor biasing. The inductor is of 5.5T and is made by 0.3mmdia of copper wire of five turns. The capacitor C6 and inductor makes tank circuit. The tank circuit is produces necessacory ac signal for carrier purpose .The CapacitorC5 and C4 are for phase

change and bypass. The

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coupling capacitor c7 is connected with antenna. With the help of antenna we can transmit our signal .The length of antenna is making by use of formula as λ/4.Whereλ is the wavelength of transmitted signal. The battery of 9v is connected for supply .We can join ac to dc adapter but for that we can use filter circuit for smooth dc for better result .We can use 9018 transistor because the stability of this is quite high.

A radio transmitter is an electronic circuit which transforms electric power from a battery or electrical mains into a radio frequency alternating current, which reverses direction millions to billions of times per second. The energy in such a rapidly reversing current can radiate off a conductor (the antenna) as electromagnetic waves (radio waves). The transmitter also impresses information, such as an audio or video signal, onto the radio frequency current to be carried by the radio waves. When they strike the antenna of a radio receiver, the waves excite similar (but less powerful) radio frequency currents in it. The radio receiver extracts the information from the received waves. A practical radio transmitter usually consists of these parts:

A power supply circuit to transform the input electrical power to the higher voltages needed to produce the

required power output.

An electronic oscillator circuit to generate the radio frequency signal. This usually generates a sine wave of

constant amplitude often called the carrier wave, because it serves to "carry" the information through space. In most modern transmitters this is a crystal oscillator in which the frequency is precisely controlled by the vibrations of a quartz crystal.

A modulator circuit to add the information to be transmitted to the carrier wave produced by the oscillator. This

is done by varying some aspect of the carrier wave. The information is provided to the transmitter either in the form of an audio signal, which represents sound, a video signal, or for data in the form of a binary digital signal.

In an FM (frequency modulation) transmitter the frequency of the carrier is varied by the modulation signal.

An RF amplifier to increase the power of the signal, to increase the range of the radio waves.

An impedance matching (antenna tuner) circuit to match the impedance of the transmitter to the impedance

of the antenna (or the transmission line to the antenna), to transfer power efficiently to the antenna. If these impedances are not equal, it causes a condition called standing waves, in which the power is reflected back from the antenna toward the transmitter, wasting power and sometimes overheating the transmitter.

In higher frequency transmitters, in the UHF and microwave range, oscillators that operate stably at the output frequency cannot be built. In these transmitters the oscillator usually operates at a lower frequency, and is multiplied by frequency multipliers to get a signal at the desired frequency.

When we provides the supply to the capacitor of tank circuit it will charge at maximum and the it pass the energy to the inductor which is connected in parallel with it the inductor can convert electrical energy into magnetic energy and then after the capacitor makes magnetic in to electrical and this pulse is transmitted to the collector of transistor. The input signal by filtering with filter circuit is comes at base and then by suitable biasing at emitter the amplified signal corresponding to the base input signal is made. The signal at emitter terminal is weak so bypass capacitor bypass it and there is greater voltage drop across emitter output the out put of signal it fed to the antenna by suitable filter capacitor. The output frequency can be adjusted by changing the value as capacitor of inductor. The output frequency can be calculated by the formula as given under:-

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And the value o frequency can be easily changed with the help of variable capacitor. And then it is filtered and fed to the various types of antennas as practical purpose the some usual antennas are as listed below:-

. .

A Yagi-Uda antenna, commonly known simply as a Yagi antenna, is a directional antenna consisting of multiple parallel dipole elements in a line,[1] usually made of metal rods.[2] It consists of a single driven element connected to the transmitter or receiver with a transmission line, and additional parasitic elements: a so-called reflector and one or more directors.[3][4][5][6][2] The reflector element is slightly longer than the driven dipole, whereas the directors are a little shorter.[6] This design achieves a very substantial increase in the antenna's directionality and gain compared to a simple dipole. .

The antenna was invented in 1926 by Shintaro Uda of Tohoku Imperial University, Japan,[4] with a lesser role played by his colleagueHidetsugu Yagi.[3][7] However the "Yagi" name has become more familiar with the name of Uda often omitted. This appears to have been due to Yagi filing a patent on the idea in Japan without Uda's name in it, and later transferring the patent to the Marconi Company in the UK.[8] Yagi antennas were first widely used during World War II in radar systems by the British, US and Germans.[7] After the war they saw extensive development as home television antennas.

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Surprisingly good FM antenna at incredible cost. Perfect for small FM stations complete with mounting bracket. Easily mounts to your balcony, any metal construction or antenna mast on your roof. Recommended for PCI MAX with or without 15W booster.

Technical specifications:- Frequency range: 88-110MHz- Gain: 0dBd (dipole)- Bandwidth: 20 MHz- Max. power: 25 Watts min (change connector above 15W)- Polarization: Vertical- Weight: 2kg- Length: 150cm- Connector: F (replace with PL259, BNC or N for more power)

Broadband Directional Panel , very sturdy construction, made of hot dipped galvanized steel. Suitable for high power radiating systems. All insulators are made of PTFE with stainless steel screws. All metallic parts are electrically grounded offering excellent protection against lightning. Both vertical and horizontal polarization are available. When panels are mounted on the four sides of a square tower a circular radiation pattern can be obtained. This is what the big boys use in their setups, usually there are at least 4 such pannels on the tower and the number can be much higher (8,12 or more panels).

Technical specifications (For all models):- Frequency Band: 87.5-108 MHz- Impedance: 50 Ohm

Base station antenna, Mono-band- Unity-gain, Horizontal or Vertical polarization- Directional (if Horizontal) or Omnidirectional (if Vertical)- High power handling capability- Made of aluminium alloy 6063 T-832

And you can use copper wise for rural use……

Any Audio

Use virtually any audio source you can imagine from CD players, Cassette Tape Players, MP3 Players, Boom boxes, old stereo systems, you name it.

If it has an audio out port, chances are you can broadcast it!

Home

Transform your home into a concert hall when you utilize our FM transmitters with your home audio system. Fill your home with your favorite audio source for endless hours of listening pleasure.

Televisions

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Broadcast the sound from your television set to any FM radio in static-free clarity. Our transmitter will connect with your television set and broadcast the sound to any FM radio.

Cars

Enjoy your favorite music while traveling on the road or during the morning and afternoon commute. Compatible with your laptop, smart phone and Apple device, our transmitter will broadcast your audio source to the cars radio without an auxiliary input.

iPod & MP3 Players

Broadcast your MP3 audio to any FM radio when you integrate an FM transmitter from Whole House. Now you can take the audio from your MP3 player and broadcast it any FM radio.

Christmas Lights

Imagine filling the hearts of thousands with joy this holiday season, when you integrate a transmitter with your holiday light show. As people walk and drive by your holiday light show, they’ll be amazed by your clever engineering and choreographed light show.

Fitness CentersTransmitter integrates seamlessly with your audio equipment and creates a better environment for membership.

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Council

Translate sermons into a different language and assist hearing impaired members of your council with our FM transmitter. A transmitter will allow your congregation to hear the sermon through headphones and an FM radio.

Home Stereos

Listen to your favorite music from your stereo throughout your backyard without having to move a single piece of audio equipment. Just imagine no more blasting the speakers and rattling the windows to hear your music.

Sirius XM Radios

If you enjoy satellite radio then you can use our FM transmitter to broadcast the audio to any FM radio. This means you can avoid the hassle of having to move and setup the satellite radio every time you want to listen to it in another room.

Drive-In Movies

Make your own drive-in movie in minutes. All you need is a projector, DVD player and a wall or sheet to play the movie on and you’re set. Watchers can either drive their car up or just bring their own FM radio.

Correctional Facilities

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Correctional facilities have used FM transmitters to reduce prison noise in common areas for years. The television audio is broadcast from a transmitter to the prisoners’ hand-held FM radio. The prisoner listens to the television audio in their headphones, which reduces the noise.

KaraokeNow you can practice your favorite songs in true karaoke fashion. When you use the Whole House FM transmitter with a Lavalier microphone, you can broadcast your voice to any FM Radio.

Computers

Our transmitter can connect to any PC or Mac computer easily through the headphone jack to play your computer’s music files through any FM radio. You can even power the transmitter with the computer USB port.

Internet Radio

It really doesn’t matter if you listen to Pandora or internet radio on your smart phone or computer. You can now broadcast Pandora to any FM radio within a 150 feet with the Whole House FM Transmitter, just plug your smart phone or laptop into one and you will be able to listen to Pandora anywhere, as long as you have and FM radio.

House Parties

Make your next house party and pool party even better by being able to have music playing throughout your entire complex and by the pool so everyone feels they are a part of the same party and not left out.

Tour Guides & Bus Tours

Tour guides across the globe use the Whole House FM Transmitter® 3.0 to bring their tours to life. With an FM transmitter, they give their voice wheels and allows it travel to the ears of their tour. Since it’s portable and battery powered, all you need is some FM radios and your tour will hear your every word.

DVD Players

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Broadcast audio from your DVD player to any FM radio by using the RCA Stereo Audio Jack we provide. Works great for those portable DVD players you can use while traveling because the audio can now be broadcast through the car’s FM radio.

iPhone & Smartphones

Of course you can use it with more than just an iPhone, and in fact all other smart phones work just as well. With an internet connection you can broadcast not only your phone conversation (great for in the car or an ad hock conference call) but also for streaming music or MP3 files you have through the phone.

Dance Parties

Your party can be a huge success when you use a FM Transmitter to broadcast the music to the dancers/ party goers. This gives you total mobility and speed to quickly and easily create that party atmosphere you want to make it a huge success… And you can do it on the fly in minutes!

Group Meetings & Presentations

With the built in microphone port you will be able to broadcast your presentation to the participants. An FM transmitter work amazingly well when a PA system is missing or fails. It will prevent your big meeting or event from falling apart at the last second when things go awry. It’s always better to be safe than sorry.

We can use this at many many more by connecting inductor with a long pole we can use it transducer and we can measure longitudinal displacement.In with our circuit run at desire frequency of L-C values when the pole which is connected with the inductor in press the inductor changes its direction. So there will be change in L and hence circuit will produce another frequency. By using this feature of circuit we can measure weight, linear displacement and can transmit it wirelessly without using any further circuitry.

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In most parts of the world, use of transmitters is strictly controlled by law because of the potential for dangerous interference with other radio transmissions (for example to emergency communications). Transmitters must be licensed by governments, under a variety of license classes depending on use: (broadcast, marine radio, Airband, Amateuretc.), and are restricted to certain frequencies and power levels. In some classes each transmitter is given a unique call sign consisting of a string of letters and numbers which must be used as an identifier in transmissions. The operator of the transmitter usually must hold a government license, such as a general radiotelephone operator license, which is obtained by passing a test demonstrating adequate technical and legal knowledge of safe radio operation.

An exception is made allowing the unlicensed use of low-power short-range transmitters in devices such as cell phones, cordless telephones, wireless microphones, walkie-talkies,Wifi and Bluetooth devices, garage door openers, and baby monitors. Although they can be operated without a license, these devices still generally must be type-approved before sale.

Joshi sir Makvana sir Bakotra sir Patel sir

And hall of Bahauddin science college physics staff.

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Text book of solid-state physics. www.circuitstoday.com www.wikipedia.com www.allaboutelectronics.com