ACKNOWLEDGEMENTI would like to express my sincere, humble and deep sense of gratitude to Mr. J.P. Sharma for his invaluable guidance, help, encouragement, & criticism along with his valuable experiences which he gained by various projects, industrial work. This work could not have been completed without his constant guidance and advice. His perception and devotion to quality work has inspired me a lot.I would like to extend my gratitude to the people who helped me a lot during my project work. I am highly thankful to Mr. J.P.Sharma for providing useful suggestions and information.I would also like to thank Mr. J.P.Sharma.I appreciate the cooperation extended to me by the teaching and teaching supporting staff members of Department of Electronics & Communication Engineering, I apologize to those whose help is not acknowledged.

Jitender kumarShiv Kumar SainiSushil Kumar

INTRODUCTION

A motion detector is a kind of security system that uses sensing ability in the form of sensors to detect movement and and this usually triggers an alarm, or sometimes activate another circuit. However, motion detectors are normally used to protect indoor areas, in this, conditions can then be controlled more closely. Detectors for use in homes for security purpose usually detect movement in a closed space area of little feet-by-feet. Detectors for large range warehouses can protect areas with dimensions as large as 24mx37m . The motion detector is normally useful in places like museums where important assets are located. As such, motion detectors can detect break-in at vulnerable points. Such points include walls, doors windows and other openings. Special motion detectors can protect the inside of exhibit cases where items such as diamonds arc placed. Others can be focused on a narrow area of coverage, somewhat like a curtain, that projected in front of a painting to detect even the slightest touch.Motion detector systems use a variety of methods to detect movement. Each method has advantages and disadvantages. Motion detectors can be categorized into two major types these are namely: (1) Passive detectors. (2) Active detectors. Passive detectors are detectors which do not send out signals but merely receive signals, such as change in temperature, change in light intensity and so on. Most infrared detectors are passive detectors. While Active detectors are detectors which send out waves of energy and receive waves reflected back from objects. Any disturbance in the reflected waves caused by example a moving object will trigger an alarm. Microwave and ultrasonic detectors are examples of active detectors. Man and animal or moving object produces sound. The sound is created as a result of their physical movement, which might be low or fast movement, and also depends on the medium that create the sound. However, these movements can be detected by using an ultrasonic sensor. The ultrasonic sound waves are sound waves that are above the range of human hearing and, thus, have a frequency above about 20khz. Any frequency of above 20kz is considered ultrasonic . In general, an ultrasonic sensor typically comprises of one or more ultrasonic transducer which transforms electrical energy into sound and vice-versa, a casing which encloses the ultrasonic transducer, connectors, and if possible some electronic circuit for signal processing. Nowadays there are numerous of the commercial ultrasonic motion detectors, basically the main aim of this work is to design and construct a simple and cheap ultrasonic motion detector system which is aimed at detecting the physical movement of human, animal, or anything that moves. The design is to improve the use of sensor in detecting motion. In general, it is aimed at reduction of the cost to design, develop or construct an ultrasonic motion detector. Human, animal or anything can produce sound. This sound is creating by the physical movement whether the movement is fast or slow depends on the medium that create the sound. Eventually these movements can be detected by using an ultrasound sensor. Ultrasonic sound waves are sound waves that are above the range of human hearing and, thus, have a frequency above about 20,000 hertz. Any frequency above 20,000 hertz may be considered ultrasonic. An ultrasonic sensor typically comprises at least one ultrasonic transducer which transforms electrical energy into sound and, in reverse, sound into electrical energy, a housing enclosing the ultrasonic transducer or transducers, an electrical connection and, optionally, an electronic circuit for signal processing also enclosed in the housing. Ultrasonic sensors have typically been used in applications such as detecting and identifying solid objects, measuring the shape and orientation of a work piece, detecting possible collisions between objects to avoid the collisions, room surveillance, flow measurement, and determining a type of material by measuring the absorption of sound. By combining parts of electronic to the ultrasonic sensor it become an ultrasonic motion detector. A motion detector is an electronic device that detects the physical movement in a given area and transforms motion into an electric signal. The motion detector may be electrically connected to devices such as security, lighting, audio 2 alarms. Motion sensors are usedin a wide variety of applications. Motion detectors are mainly used in for security systems.Now days in the market there are many kind of ultrasonic motion detector sell, basically this project is to design an ultrasonic motion detector use to detect physical movement of human, animal, or anything that move. The design is to improving the use of sensor in detecting motion. Also to reduce the cost to built an ultrasonic motion detectorProject name:- ULTRA SONIC SENSER CIRCUITUltrasonic sensors use sound waves rather than light, making them ideal for stable detection of uneven surfaces, liquids, clear objects, and objects in dirty environments. These sensors work well for applications that require precise measurements between stationary and moving objects. Overview:-

Inexpensive motion detector used to control lightingAn electronic motion detector contains an optical, microwave, or acoustic sensor, and in many cases a transmitter for illumination. However, apassivesensor only senses a signal emitted by the moving object itself. Changes in the optical, microwave, or acoustic field in the device's proximity are interpreted by the electronics based on one of the technologies listed below. Most inexpensive motion detectors can detect up to distances of at least 15 feet (5 meters). Specialized systems are more expensive but have much longer ranges. Tomographic motion detection systems can cover much larger areas because the radio waves are at frequencies which penetrate most walls and obstructions, and are detected in multiple locations, not just at the location of the transmitter.Motion detectors have found wide use in domestic and commercial applications. One common application is activation of automatic door openers in businesses and public buildings. Motion sensors are also widely used in lieu of a trueoccupancy sensorin activating street lights or indoor lights in walkways (such as lobbies and staircases). In such "Smart Lighting" systems, energy is conserved by only powering the lights for the duration of a timer, after which the person has presumably left the area. A motion detector may be among the sensors of aburglar alarmthat is used to alert the home owner or security service when it detects the motion of a possible intruder. Such a detector may also trigger asecurity camerain order to record the possible intrusion. Sensor technology:-

Infrared detector mounted on circuit board, along with photoresistive detector for visible light .There are several motion detection technologies in wide use.Passive infrared (PIR)Passive infrared sensors are sensitive to a person's skin temperature through emittedblack body radiationatmid-infraredwavelengths, in contrast to background objects at room temperature. No energy is emitted from the sensor, thus the name "passive infrared" (PIR). This distinguishes it from theelectric eyefor instance (not usually considered a "motion detector"), in which the crossing of a person or vehicle interrupts a visible or infrared beam.Microwave:-These detect motion through the principle of Dopplerradar, and are similar to aradar speed gun. Acontinuous waveofmicrowave radiation is emitted, and phase shifts in the reflected microwaves due to motion of an object toward (or away from) the receiver result in aheterodynesignal at lowaudio frequencies.Ultrasonic:-An ultrasonic wave (sound at a frequency higher than a human can hear) is emitted and reflections from nearby objects are received. Exactly as in Doppler radar, heterodyne detection of the received field indicates motion. The detecteddoppler shiftis also at low audio frequencies (for walking speeds) since the ultrasonicwavelength of around a centimeter is similar to the wavelengths used in microwave motion detectors. One potential drawback of ultrasonic sensors is that the sensor can be sensitive to motion in areas where coverage isn't desired, for instance, due to reflections of sound waves around corners.Such extended coverage may be desirable for lighting control, where the point is detection of any occupancy in an area. But for opening an automatic door, for example, one would prefer a sensor selective to traffic in the path toward the door.Tomographic motion detectorTomographic motion detection systems sense disturbances to radio waves as they pass from node to node of a mesh network. They have the ability to detect over complete areas because they can sense through walls and obstructions.Video camera software With the proliferation of inexpensivedigital camerascapable of shooting video, it is possible to use the output of such a camera to detect motion in its field of view using software. This solution is particularly attractive when the intention was to record video triggered by motion detection, as no hardware beyond the camera and computer is required. Since the observed field may be normally illuminated, this may be considered anotherpassivetechnology. However it can also be used in conjunction withnear-infraredillumination to detect motion in the "dark" (that is, with the illumination at a wavelength not detected by the human eye)

2. ULTRASONIC MOTION DETECTORS:-

Generally, there exist numerous of motion detector, but of our interest is the ultrasonic motion detectors due to its numerous advantage over other types of detectors. For example, having fast response time and very sensitive, no physical contact required by the object, being environmentally friendly and reliable, and above all utilizing ultrasonic waves that are not visible and audible to human. Ultrasonic motion detectors are electrical devices, which use ultra-sound (that is, sound of very high frequency) to detect motion. In such a detector a transmitter emits a sound of a frequency which is normally too high for the human ear to hear. When a receiver picks up the sound waves that is reflected from the area under protection, it sends it to an appropriate circuit for further action (normally an audio circuit). In the case of motion of human or target in the space between the receiver and transmitter, further change, or shift in the frequency of sound is experienced , a circuit in the device detects any unusual shift in frequency, which is normally noted due to predefined frequency. A small shift in frequency, such as that produced by an insect or rodent, is ignored. When a noticeable shift is observed, such as a large shift produced by a moving person, the device triggers the alarm. HISTORY:-observing Prior to World War II, sonar, the technique of sending sound waves through water and the returning echoes to characterize submerged objects, inspired early ultrasound investigators to explore ways to apply the concept to medical diagnosis. In 1929 and 1935, Sokolov studied the use of ultrasonic waves in detecting metal objects. Mulhauser, in 1931, obtained a patent for using ultrasonic waves, using two transducers to detect flaws in solids. Firestone (1940) and Simons (1945) developed pulsed ultrasonic testing using a pulse-echo technique. Shortly after the close of World War II, researchers in Japan began to explore the medical diagnostic capabilities of ultrasound. The first ultrasonic instruments used an A-mode presentation with blips on an oscilloscope screen. That was followed by a B-mode presentation with a two dimensional, gray scale image. Japan's work in ultrasound was relatively unknown in the United States and Europe until the 1950s. Researchers then presented their findings on the use of ultrasound to detect gallstones, breast masses, and tumors to the international medical community. Japan was also the first country to apply Doppler ultrasound, an application of ultrasound that detects internal moving objects such as blood coursing through the heart for cardiovascular investigation. Ultrasound pioneers working in the United States contributed many innovations and important discoveries to the field during the following decades. Researchers learned to use ultrasound to detect potential cancer and to visualize tumors in living subjects and in excised tissue. Real-time imaging, another significant diagnostic tool for physicians, presented ultrasound images directly on the system's CRT screen at the time of scanning. The introduction of spectral Doppler and later color Doppler depicted blood flow in various colors to indicate the speed and direction of the flow.. The United States also produced the earliest hand held "contact" scanner for clinical use, the second generation of B-mode equipment, and the prototype for the first articulated-arm hand held scanner, with 2-D images.

How the ultrasonic sensor works?

The ultra sonic circuit is adjusted in such a way as to stay in balance as long the same as the output frequency of the transmitter. If there is some movement in the area covered by the ultrasonic emission.the signal that is reflected back to the receiver becomes distorted and the circuit is thrown out of balance. The circuit works from 9-12 VDC and can be used with batteries or a power supply.ULTRASONIC MOTION DETECTOR:-The ultrasonic motion detector is a project that uses an ultrasonic sensor as its base to detect movement or moving object in small places. It is design to be a low cost ultrasonic motion detector. The transmitter sensor use to generate signal in that area. When the signal is block by moving or movement the receiver will gets the signal and amplifies the signal using transistor. The transistor is use as an amplifier to the receiver circuit. The Led and buzzer in the circuit use to see if there is movement detect by the sensor. The relay use to trigger another circuit when there is movement detects. The signal generate by the sensor is about 40khz. This is a fully hardware design project plus it is built to be a portable ultrasonic motion detector. The circuit consists of the following major blocks.1. Transmitter 2. Receiver3. Transistor Amplifier Circuit4. Op amp Amplifier5. Op amp Comparator 6. Pi Filter7. Schmitt Trigger8. Darlington pair Amplifier Block Diagram:-Before starting with actual circuit design, we must first understand the basic principles behind the technology that is used this project. The project methodology flow chart is shown below

Figure 3.1 Flow design of the circuitThe flow design of the circuit consist of

1. Finding the right transmitter and receiver sensor for the circuit.

2. Designing the amplifier/receiver circuit

3. Design the transmitter circuit

4. Using simulation to verify the design.

5. Implementation on board.

Figure:- Block Diagram of ultrasonic Sensor CircuitBlock diagram description:-Ultrasonic sensor consist the following circuit in block diagram.1. Amplifier circuit.2. Hex buffer circuit 3. Sensor circuit.Amplifier circuit For the amplifier in this project, the transistor is use to act as amplifier. The basic transistor amplifier circuit is use act as an amplifier method to amplifying. H9013 series of transistor is use because the transistor is the general transistor use in amplifying concept. It is a BJT type of transistor. When the receiver sensor receive signal it will send the signal to the transistor to be amplified. In this project five transistors is use to amplified the signal send by the receiver sensor. The type of design for the transistor is a common emitter amplifier. Base from the design the input signal that come from the base of transistor will be amplified and produce at the collector transistor a larger output signal and the output will be more on positive side signal. Mean that the transistor will amplify current from a small input current to a high output current. It is use also to trigger the relay connected to it. Variable resistor is use to control the level of signal or the sensitivity signal send by the receiver sensor. Mean if no setting are made by the variable resistor the sensor is highly sensitive, even the air counts as a motion parts thus we will get false trigger by the circuit.

Figure:- Basic design of amplifers.

Hex buffer circuit

This circuit consist a buffer, crystal and transmitter sensor in it. The crystal is use to drive the transmitter sensor into a steady frequency stability. It will ring the transmitter to continuous transmitting frequency. A voltage applied across the crystal will cause mechanical movement within the crystal. If an AC voltage is applied across the crystal, the crystal will begin to vibrate. Thus in this circuit it the buffer act as a driver to make sure that the sensor transmit the frequency. The crystal or XTAL is a 40 kHz in frequency. The buffer or hex inverter use in the circuit is single supplies IC mean single supply needed to make it work. It is use to change from high to low level logic conversion. The IC is HD4069UBP hex buffer converter. The supply can be 9Vdc or 12Vdc. It is 14 pin IC. In this project the pin 1 until pin 6 uses for the transmitter sensor to drive the frequency, the other pin use to drive transistor to supply enough current for the relay to energize.

Figure:- Top view of HD4069UBP buffer IC.

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Figure:- Transmitter Circuit Design

Sensor circuit (Transmitter and Receiver):-

Use to transmit and receive signal and send to the circuit. The sensor in this circuit is an ultrasonic sensor. The frequency generate by the sensor 40kHz. The transmitter and receiver must be equal in frequency to make the circuit function. When power supply is given to the circuit, the transmitter will transform the electrical energy to sound wave and transmit it to the air. Thus when the sound wave or signal is blocking by something or someone, the signal will be detected by the receiver. Crucial thing is finding the right sensor for the right circuit. Moreover the sensor cannot be place to far from each other.

Fiqure:- Sensor (Transmitter and Receiver)

Ultra Sonic Detector ConstructionThe board is made of a thin insulating material clad with a thin layer of conductive copper that is shaped in such a way as to form the necessary conductors between the various components of the circuit. The use of a properly designed printed circuit board is very desirable as it speeds construction up considerably and reduces the possibility of making errors. In order to solder a component correctly you should do the following. Clean the component leadswith a small piece of emery paper. Bend them at the correct distancefrom the components body and insert the component in its place on the board. You may find sometimes a component with heavier gauge leadsthan usual, that are too thick to enter in the holes of the p.c. board. In this case use a mini drill to enlarge the holes slightly. Do not make the holes too large as this is going to make soldering difficult afterwards. Take the hot iron and place its tip on the component leadwhile holding the end of the solder wire at the point where the lead emerges from the board. The iron tip must touch the lead slightly above the p.c. board. When the solder starts to melt and flowwait till it covers evenly the area around the hole and the flux boils and gets out from underneath the solder. The whole operation should not take more than 5 seconds. Remove the iron and allow the solder to cool naturally without blowing on it or moving the component. If everything was done properly the surface of the joint must have a bright metallic finish and its edges should be smoothly ended on the component lead and the board track. If the solder looks dull, cracked, or has the shape of a blob then you have made a dry joint and you should remove the solder (with a pump or a solder wick) and redo it. Take care not to overheatthe tracks as it is very easy to lift them from the board and break them. When you are soldering a sensitive componentit is good practice to hold the lead from the component side of the board with a pair of long-nose pliers to divert any heat that could possibly damage the component. Make sure that you do not use more solderthan it is necessary as you are running the risk of short-circuiting adjacent tracks on the board, especially if they are very close together. When you finish your work cut offthe excess of the component leads and clean the board thoroughly with a suitable solvent to remove all flux residues that may still remain on it. There are quite a few components in the circuitand you should be careful to avoid mistakes that will be difficult to trace and repair afterwards. Solder first the pins and the IC sockets and then following if that is possible the parts list the resistors the trimmers and the capacitors paying particular attention to the correct orientation of the electrolytic. Solder then the transistors and the diodestaking care not to overheat them during soldering. The transducers should be positioned in such a way as they do not affect each other directly because this will reduce the efficiency of the circuit. When you finish soldering, check your work to make sure that you have done everything properly, and then insert the ICs in their sockets paying attention to their correct orientation and handling IC3 with great care as it is of the CMOS type and can be damaged quite easily by static discharges. Do not take it out of its aluminium foil wrapper till it is time to insert it in its socket, ground the board and your body to discharge static electricity and then insert the IC carefully in its socket. In the kit you will find a LED and a resistor of 560 which will help you to make the necessary adjustments to the circuit. Connect the resistor in series with the LED and then connect them between point 9 of the circuit and the positive supply rail (point1).Connect the power supply across points:- 1 (+) and 2 (-) of the p.c. board and put P1 at roughly its middle position. Turn then P2 slowly till the LED lights when you move your fingers slightly in front of the transducers. If you have a frequency counter then you can make a much more accurate adjustment of the circuit. Connect the frequency counter across the transducer and adjust P2 till the frequency of the oscillator is exactly the same as the resonant frequency of the transducer. Adjust then P1 for maximum sensitivity. Connecting together pins 7 & 8 on the p.c. board will make the circuit to stay triggered till it is manually reset after an alarm. This can be very useful if you want to know that there was an attempt to enter in the place which are protected by the radar.

Figure:- Ultra Sonic Motion Detector Circuit

Figure:-Circuit Diagram Of Ultra Sonic Motion Detector

The circuit consists of the following component1. Transmitter. 2. Receiver.3. Transistor Amplifier Circuit.4. Op amp Amplifier. 5. Op amp Comparator. 6. Pi Filter.7. Schmitt Trigger.8. Darlington pair Amplifier.9. Resistor.10. Capacitor.11. IC circuit.12. Transducer.13. Diode.14. Sensor (Transmitter and Receiver).

Figure:- Component used in Ultrasonic sensor circuit.

Transmitter:- Inelectronicsandtelecommunicationsatransmitterorradio transmitteris anelectronic devicewhich, with the aid of anantenna, producesradio waves. The transmitter itself generates aradio frequencyalternating current which is applied to the antenna. When excited by this alternating current, the antenna radiatesradio waves. In addition to their use inbroadcasting, transmitters are necessary component parts of many electronic devices that communicate byradio, such ascell phones,wireless computer networks bluetoothenabled devices,garage door openers,two-way radios in aircraft, ships, and spacecraft,radarsets, and navigational beacons. The transmitter circuit consists of mainly an astable multivibrator circuit using IC 4093. The capacitor and resistor values are adjusted to obtain a frequency of 40 kHz which is fed to the ultrasonic transmitter. The transmitter produces ultrasonic waves of 40 kHz frequency which travel around the room, get reflected and fall on the receiver.U2C forms a 40 KHz oscillator. This oscillator is connected to U2D and U2E while the inverted oscillator signal (U2B) goes to U2A and U2F. These parallel gates provide more current and drive the ultrasonic transmitter. Note that it may take a couple of seconds after the power is applied for the oscillator to stabilize.Figure:- Ultrasonic Transmitter.Receiver:- Ultrasonic Receiver which will detect the signal from the Ultrasonic Transmitter once it bounces off from an object. The combination of these two sensors will allow the aerial robot to detect objects in its path and maneuver around the objects. These sensors will be attached in front of the plane.OR The receiver is an ultrasonic transducer. After transmission, the signal gets reflected from the surroundings. This signal is received at the receiver transducer and is then sent to process for the presence of motion. Q1 and Q2 amplify the reflected 40 KHz signal picked up by the ultrasonic receiver by 2500. Q2 is capacitively coupled to the voltage doubler formed by D1 and D2. The rectified signal is connected to the negative input of voltage comparator U1A. R12 (the Sensitivity potentiometer) sets the threshold voltage for U1A. When the threshold voltage is exceeded, the open collector output of U1A goes high-impedance. This enables the 70 Hz oscillator formed by U1B.When this oscillator is on, the LED glows and the one-shot formed by U3 is repeatedly triggered. The output duration of the one-shot is set by R16 and C11 and is equal to 1.1*R16*C11 seconds. U3's output turns on Q3. As a result, K1 closes its normally open contacts. C13 dampens the inductive kickback when K1 is turned off, preventing the circuit from triggering due to this noise source. The unit is powered by a 12 VDC 200mA unregulated wall transformer. U4 provides a regulated 9VDC to power the circuit. Device pinouts are shown in Figure 2. The 40 KHz transmitter and receiver are mounted 4" apart on a piece of perfboard.

Figure:- Ultrasonic Transmitter and Reciver.

Figure:- Ultrasonic Reciver.Resistor:- Aresistoris apassivetwo-terminalelectrical componentthat implements electrical resistanceas a circuit element. Resistors act to reduce current flow, and, at the same time, act to lower voltage levels within circuits. In electronic circuits resistors are used to limit current flow, to adjust signal levels,biasactive elements, terminatetransmission linesamong other uses. In the ultrasonic sensor circuit many resistors are used.Name of the resistor which are used in ultrasonic sensor circuit is below.1. R1= 180kohm2. R2=12kohm3. R3,R8=47kohm4. R4=9kohm5. R5,R6,R16=10kohm6. R7,R10,R12,R14,R17=100kohm7. R9,R11=1mohm8. R13,R15=3mohm

Figure:- Circuit Layout of Sensor

These are those resistor which are mainly used in ultrasonic sensior circuit.Acapacitor(originally known as acondenser) is apassivetwo-terminalelectrical componentused to storeenergyelectrostaticallyin anelectric field. The forms of practical capacitors vary widely, but all contain at least twoelectrical conductors(plates) separated by adielectricinsulaton. The conductors can be thin films, foils or sintered beads of metal or conductive electrolyte, etc. The nonconducting dielectric acts to increase the capacitor's charge capacity. A dielectric can be glass, ceramic, plastic film, air, vacuum, paper, mica, oxide layer etc. Capacitors are widely used as parts ofelectrical circuitsin many common electrical devices. Name of the resistor which are used in ultrasonic sensor circuit is below.1. C1=10uf/16v2. C2=47uf/16v3. C3=4,7pf4. C4,C7=1nf5. C5=10nf6. C8,C11=4,7uf/16v7. C9=22uf/16v8. C10=100nf9. C12=2,2uf/16v10. C13=3,3nf11. C14=47nfThese are the those capacitor which is used in ultrasonic sensor.

Figure:- CapacitorIC CIRCUIT:-Anintegrated circuitormonolithic integrated circuit is a set ofelectronic circuiton one small plate ("chip") ofsemiconductor material, normallysilicon. This can be made much smaller than adiscret circuit made from independentelectronic components. ICs can be made very compact, having up to several billiontransistorsand other electronic componentsin an area the size of a fingernail.

Figure:-Motion Sensor CircuitTransistor Amplifier Circuit

The first part of the receiver circuit consists of an amplifier section using a BC547. The ultrasonic waves from the transmitter get reflected and fall on the receiver. The receiver is connected to an amplifier circuit having a gain of 20. The amplitude of waves falling on the receiver is very small, the amplifier amplifies the noise.Op-amp Amplifier:- Anoperational amplifier("op-amp") is aDC-coupledhigh-gainelectronic voltageamplifierwith adifferential inputand, usually, a single-ended output.In this configuration, an op-amp produces an output potential (relative to circuit ground) that is typically hundreds of thousands of times larger than the potential difference between its input terminals.Operational amplifiers had their origins inanalog computers, where they were used to do mathematical operations in many linear, non-linear and frequency-dependent circuits. The popularity of the op-amp as a building block inanalog circuitsis due to its versatility. Due tonegative feedback, the characteristics of an op-amp circuit, itsgain, input andoutput impedance,bandwidthetc. are determined by external components and have little dependence on temperature coefficients or manufacturing variations in the op-amp itself.The LM741 series are general purpose operational amplifiers which feature improved performance over industry standards like the LM709. They are direct, plug-in replacements for the 709C, LM201, MC1439 and 748 in most applications. The amplifiers offer many features which make their application nearly foolproof: overload protection on the input and output, no latch-up when the common mode range is exceeded, as well as freedom from oscillations. This is the second stage of the amplifier section. This part further amplifies the noise received by the ultrasonic receiver. This also integrate the output of the amplifier.The amplifier's differential inputs consist of a non-inverting input (+) with voltageV+and an inverting input () with voltageV; ideally the op-amp amplifies only the difference in voltage between the two, which is called thedifferential input voltage. The output voltage of the op-ampVoutis given by the equation:

Where Ais theopen-loopgain of the amplifier (the term "open-loop" refers to the absence of a feedback loop from the output to the input.

Figure:-Circuit diag. of Op amp

Figure:- op-amp amplifierOp amp Comparator

One input consists of the shifted, negative clipped amplified output of the Opamp amplifier and the positive clipped amplified output. The output of the comparator is by default high and when the positive clipped portions exceed the negative clipped part due to noise, the Opamp inverts. Inelectronics, acomparatoris a device that compares twovoltagesorcurrentsand outputs a digital signal indicating which is larger. It has two analog input terminalsandand one binary digital output. The output is ideally

A comparator consists of a specialized high-gaindifferential amplifier. They are commonly used in devices that measure and digitize analog signals, such asanalog-to-digital converters\(ADCs), as well asrelaxation oscillators. Anoperational amplifier(op-amp) has a well balanced difference input and a very highgain. This parallels the characteristics of comparators and can be substituted in applications with low-performance requirements.In theory, a standard op-amp operating in open-loop configuration (without negative feedback) may be used as a low-performance comparator. When the non-inverting input (V+) is at a higher voltage than the inverting input (V-), the high gain of the op-amp causes the output to saturate at the highest positive voltage it can output. When the non-inverting input (V+) drops below the inverting input (V-), the output saturates at the most negative voltage it can output. The op-amp's output voltage is limited by the supply voltage. An op-amp operating in a linear mode with negative feedback, using a balanced, split-voltage power supply, (powered by VS) has its transfer function typically written as:. However, this equation may not be applicable to a comparator circuit which is non-linear and operates open-loop (no negative feedback).

Pi-filter

Thecapacitor-input filter, also calledpifilter due to its shape that looks like theGreek letterpi, is a type ofelectronic filter.The pi-filter converts the fluctuating ac noise into dc and feeds into the Op amp comparator.Thecapacitor-input filter, also called thepi filterdue to its shape that looks like theGreek letter, is a type ofelectronic filter. Filter circuits are used to remove unwanted or undesired frequencies from a signal.

Figure:- Pi Filter Circuit

A simple pi filter, containing a pair of capacitors, an inductor, and a load.A typical capacitor input filter consists of a filter or reservoircapacitorC1, connected across the rectifier output, aninductorL, in series and another filter or smoothing capacitor, C2, connected across the load, RL. A filter of this sort is designed for use at a particular frequency, generally fixed by the AC line frequency and rectifier configuration. When used in this service, filter performance is often characterized by itsregulationandripple. The capacitor-input filter operates in three steps:1. ThecapacitorC1 offers lowreactanceto the AC component of the rectifier output while it offers infinite resistance to the DC component. As a result the capacitorshuntsan appreciable amount of the AC component while the DC component continues its journey to the inductor L.2. TheinductorL offers high reactance to the AC component but it offers almost zero resistance to the DC component. As a result the DC component flows through the inductor while the AC component is blocked.3. ThecapacitorC2 bypasses the AC component which the inductor had failed to block. As a result only the DC component appears across the load RL.The component value for the inductor can be estimated as an inductance that resonates the smoothing capacitor(s) at or below one tenth of the minimum AC frequency in the power supplied to the filter (100 Hz from a full-wave rectifier in a region where the power supply is 50Hz). Thus if reservoir and smoothing capacitors of 2200 microfarads are used, a suitable minimum value for the inductor would be that which resonates 2200 microfarads (F) to 10 Hz, i.e. 115 mH. A larger value is preferable provided the inductor can carry the required supply current.

Figure:- Schmitt Trigger CircuitSchmitt trigger:-The next part of the receiver circuit is the Schmitt trigger.The Schmitt trigger is acomparator application which switches the output negative when the input passes upward through a positive reference voltage. It then usesnegative feedbackto prevent switching back to the other state until the input passes through a lower threshold voltage, thus stabilizing the switching against rapid triggering by noise as it passes the trigger point. In this circuit the motion caused by the object causes distortion at the receiver output. The comparator output is by default high. When the noise levels detected are substantially high, the comparator inverts itself and the trigger is triggered. The output is fed to a Darlington pair. The Schmitt trigger is acomparator application which switches the output negative when the input passes upward through a positive reference voltage. It then usespositive feedbackof a negative voltage to prevent switching back to the other state until the input passes through a lower threshold voltage, thus stabilizing the switching against rapid triggering by noise as it passes the trigger point. That is, it provides feedback which is not reversed in phase, but in this case the signal that is being fed back is a negative signal and keeps the output driven to the negative supply voltage until the input drops below the lower design threshold. Schmitt trigger devices are typically used insignal conditioningapplications to remove noise from signals used in digital circuits, particularly mechanicalswitch bounce. They are also used inclosed loopnegative feedbackconfigurations to implementrelaxation oscillators, used infunction generatorsand switching power supplies.

Fiqure:- schmitt trigger

Fiqure:- component list of ultrasonic sensor.Darlington pairThis is a very high current gain section which when turned on by the trigger from the Schmitt trigger, starts conducting and the buzzer and led goes on.Transistors are an essential component in a sensor circuit. Usually transistors are arranged as a pair, known as a darlington pair.It is very important that you can identify this arrangement of transistors and state clearly why they areused.A darlington pair is used to amplify weak signals so that they can be clearly detected by another circuit or a computer/microprocessor.

The circuit below is a temperature sensor. When the temperature drops below zero the LED lights. This type of system is often seen in a car and warns the driver of the possibility of icy conditions. The two transistors are known as a darlington pair. Without a darlington pair the circuit would probably fail. The circuit opposite is a Darlington Pair driver. The first transistors emitter feeds into the second transistors base and as a result the input signal is amplified by the time it reaches the output.The important point to remember is that the Darlington Pair is made up of two transistors and when they are arranged as shown in the circuit they are used to amplify weak signals

Fiqure of Darlington pairWORKING OF THE CIRCUITAs it has already been stated the circuit consists of an ultrasonic transmitter and a receiver both of which work at the same frequency. They use ultrasonic piezoelectric transducers as output and input devices respectively and their frequency of operation is determined by the particular devices in use.The transmitter is built around two NAND gates of the four found in IC3 which are used here wired as inverters and in the particular circuit they form a multivibrator the output of which drives the transducer. The trimmer P2 adjusts the output frequency of the transmitter and for greater efficiency it should be made the same as the frequency of resonance of the transducers in use. The receiver similarly uses a transducer to receive the signals that are reflected back to it the output of which is amplified by the transistor TR3, and IC1 which is a 741 op-amp. The output of IC1 is taken to the non inverting input of IC2 the amplification factor of which is adjusted by means of P1. The circuit is adjusted in such a way as to stay in balance as long the same as the output frequency of the transmitter. If there is some movement in the area covered by the ultrasonic emission the signal that is reflected back to the receiver becomes distorted and the circuit is thrown out of balance. The output of IC2 changes abruptly and the Schmitt trigger circuit which is built around the remaining two gates in IC3 is triggered. This drives the output transistors TR1, 2 which in turn give a signal to the alarm system or if there is a relay connected to the circuit, in series with the collector of TR1, it becomes activated. The circuit works from 9-12 VDC and can be used with batteries or a power supply.IC CIRCUIT:- Anintegrated circuitormonolithic integrated circuit is a set ofelectronic circuitson one small plate ("chip") ofsemiconductor material, normallysilicon. This can be made much smaller than adiscrete circuit made from independentelectronic components. ICs can be made very compact, having up to several billiontransistorsand other electronic componentsin an area the size of a fingernail. The width of each conducting line in a circuit can be made smaller and smaller as the technology advances; in 2008 it dropped below 100nanometerand now is tens of nanometers.

Figure of ic circuitPCB DESIGN

Figure of pcb design of ultrasonic circuit

APPLICATIONS :-

The motion detector circuit has a number of uses.

1. As burglar alarm: The circuit can be used as an alarm system in homes, shops and even automobiles. The device is small, sensitive and has a low cost. This can be used in homes and shops to guard safes and other valuables\

2. .As a people counter device:Apeople counteris a device used to measure the number and direction of people traversing a certain passage or entrance per unit time. The resolution of the measurement is entirely dependent on the sophistication of the technology employed. The device is often used at the entrance of a building so that the total number of visitors can be recorded.The motion detector can be used in daytime to count the number of people entering a shop by attaching a counter circuit and can be converted into a burglar alarm at night by minimum modifications.

3. As High Security Safe Alarm:When integrated with a high security safe it can trigger an alarm even in the event of a minute movement. Hence it can serve the purpose of handling attempted robberies on high security vaults.

4. Motion Sensing Camera Trigger:As the name suggests the device can be used to trigger cameras to automatically operate the presence of motion in surroundings. This can be used in wildlife photography and security cameras.