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.

INTRODUCTIONHuman, 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 detectorThe circuit consists of the following major blocks1.Transmitter2.Receiver3.Transistor Amplifier Circuit4.Opamp Amplifie5.Opamp Comparator6.Pi Filter7.Schmitt Trigger8.Darlington pair Amplifier

1.TransmitterThe 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.2.ReceiverThe 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.

3.Transistor Amplifier CircuitThe 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.4.Opamp AmplifierThe 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 amplifier5.Opamp ComparatorOne 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.

6.Pi-filterThecapacitor-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 Opamp comparator7.Schmitt triggerThe 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.8.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 ledgoes onC10 - 100 nFC12 - 2.2 uF/16VC13 - 3.3nFC14 - 47nFTR1, TR2, TR3 - BC547 , BC548P1 - 10 KOhm trimmerP2 - 47 KOhm trimmerIC1, IC2 - 741 OP-AMPIC3 - 4093 C-MOSR TRANSDUCER 40KHzT TRANSDUCER 40KHzD1, D2, D3, D4 - 1N4148Technical Specifications - CharacteristicsWorking voltage: 12V DCCurrent: 30 mA

COMPONENTS LISTR1 - 180 KOhmR2, R12 - KOhmR3, R8 - 47 KOhmR4 - 3.9 KOhmR5, R6, R16 - 10 KOhmR7, R10, R12, R14, R17 - 100 KOhmR9, R11 - 1 MOhmR13, R15 3.3 KOhmC1, C6 - 10uF/16VC2 - 47uF/16VC3 - 4.7 pFC4, C7 - 1 nFC5 - 10nFC8, C11 4.7 uF/16VC9 - 22uF/16V

WORKING 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 signalthat 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.APPLICATIONSThe 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.

Mobile Controlled Home Appliances without MicrocontrollerSometimes unfortunately we may forget switch off the appliances while going to the outside and we face the problems to switch off these devices when we are out of home. To solve these types of problems this article explains you how to design a simple circuit, which will on the devices remotely and devices will off automatically after the specified time interval. Till now we have seen so many circuits to control the devices or appliances from the remote place but the main advantage of this circuit is simple because we are not using any microcontroller in this circuit and it uses the components which are easily available in the market. We have already seenHow DTMF Controlled Home Automation System Circuit Works using Microcontrollerin the earlier post.MobileControlled Home Appliances Circuit Principle:The main principle used in this circuit is DTMF communication. DTMF is acronym for Dual-Tone Multi-Frequency. When you make a call to customer care service they will ask you to press the numbers to provide the appropriate services. If you think about how they are recognizing the pressed number then DTMF comes on the picture.If you press the button in your mobile phone then a tone is generated with 2 frequencies. These 2 frequencies of the tone are row and column frequencies of that particular button. For example if you press the button 1 then a tone generated with the sum of 697 Hz and 1209 Hz. The below table show you the row and column frequencies of a DTMF keypad.

These generated tones are decoded at switching centre to determine which button is pressed. Now we have to use this DTMF tones to control the devices from remote area. To decode these DTMF tones at receiver we need to use a DTMF decoder. Decoder IC converts these tones into the digital form. For example if you press number 5 in mobile keypad then the output of DTMF decoder is 0101.

Circuit Components: MT8870 DTMF decoder NE555 timer IC 5V relay 230V, 50 Hz AC motor BC548 transistors 2 3.579 MHz crystal Pot 4.7M ohm 2.5mm audio jack red LED Electrolytic capacitor 470uF 1n4007 Diodes 5 0.1uF Ceramic capacitors 3 Resistors (1/4 watt) 150k, 1k, 390k, 10k, 100k, 2.2k, 1M, 220 Connecting wires Bread boardMobile Phone Controlled Home Automation System Design without Microcontroller:The main components in this circuit are MT8870 DTMF decoder and 555 timer. Here 555 timer operates in monostable mode. When you make a call to the mobile which is connected at the receiver end, MT8870 IC provides high pulse at 15thpin after receiving a valid signal. Now if you press 7 from the mobile the output decoder IC will trigger the 2ndpin of 555 timer. As a result the output at 3rdpin of 555 timer becomes high, so that transistor Q2 starts conducting because of this LED and device on. The device on time can be varied by varying the Pot RV1 and capacitor C4. The device on time can be calculated using the formulaTime = 1.1 * RV1 * C4 sec.In the above circuit device become on only when all the outputs of DTMF decoder (pin 11, pin12, pin13 and pin15) are high. To make all the outputs of DTMF decoder high we need to press number 7 from the dialed mobile.How to OperateDTMFControlled Home Automation System without Microcontroller?1. Give the connections as per the circuit diagram.2. While giving the connections, make sure that there is no common connection between AC and DC supplies.3. Solder a two pin connector to the audio jack4. Insert the audio jack to the receiver mobile and keep the receiver mobile in auto answer mode.5. Receiver mobile should be in general profile and keypad tones should be in sound mode.6. Now make a call to the receiver mobile as it is in the auto answer mode it will pick up the call automatically.7. When ring stops press number 7 in your mobile, now you can observe that both LED and device will on for some time and switches off.DTMFControlled Home Automation System without Microcontroller Circuit Advantages: We can avoid the wastage of power We can control the devices from long distances alsoDTMF Mobile Controlled Home Appliances Circuit Applications:1. Used to control the home appliances2. We can control the robot using this technology3. This circuit is used to control the water tank motor by setting the on timeCircuit Limitations: Security is not provided, anyone can control by making a call to the receiver mobile Number of devices which we can connect to the circuit is limited.