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Security alarm


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Our third year analog project

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Security alarm

  1. 1. PROJECT REPORT ON “SECURITY ALARM” Submitted By VISHRAM ANANT (24), JOEL MENDONCA (33),GLEVITA MENDONSA (34), JAESON NAZARETH (36) Under The Guidance Of Prof: ManaliTayade Department of Electronics & Telecommunication Xavier Institute Of Engineering, Mahim. MUMBAI UNIVERSITY, MUMBAI 2012-2013
  2. 2. CERTIFICATE This is to certify that this Project Report entitled “SECURITY ALARM” Is satisfactorily completed by VISHRAM ANANT (24), JOEL MENDONCA (33), GLEVITA MENDONSA (34), JAESON NAZARETH (36) Of T.E(E.X.T.C) class as specified in syllabus. This report represents their bonafide work in year 2012-2013.Prof. ManaliTayade Prof. SupravaPatnik(Project Guide) (H.O.D. –EXTCDepartment)Prof. Y.D. Venkatesh (External Examiner) (Principal)
  3. 3. Security Alarm Joel Mendonca, GlevitaMendonsa, Vishram Anant, Jaeson Nazareth. Electronics and Telecommunication Engineering Xavier Institute of Engineering, MahimAbstract- This design provides an inexpensive yet effective B. WORKINGform of protection against intruders as well as it can beeasily used during festivals for novel applications. When a The circuit consist of a transformer which is a stepray of light is interrupted, the power output is switched on down transformer. It gives 12V supply to allfor a variable duration of 5-55 seconds to operate the components on the circuit. Besides there arerelay components like Relay switch, IC 555 used as a monostablemultivibrator, LDR (Light Dependent I. INTRODUCTION Resistor) which serves as the primary component of theThe circuit illustrated here is used as an Burglar alarm. LDR circuit whose role will be given in kept at such a place that when thief enters our house then ashadow will fall on the LDR. A small beam of light source is 1.IC 555-The operation and output of the 555also needed to supply continuous signal to LDR. For best Monostable is exactly the same as that for theLight source we can use Laser diode which will work for few transistorised one. The difference this time is that theKMs. For home use Infra Red LED’s will be good and will be two transistors have been replaced by the 555 timertricky to thief and works with same efficiency at night. device. Consider the 555 Monostable circuit belowII CIRCUIT DIAGRAM Fig 1. Circuit Diagram A. COMPONENTS USED Fig 2. Working of monostable IC 555 The components used are :IC 555 When a negative ( 0V ) pulse is applied to the triggerCentre tap X’former 230-12V input (pin 2) of the Monostable configured 555 TimerLDR oscillator, the internal comparator, (comparator No1)Transistor T1,T2 BJT 547 detects this input and "sets" the state of the flip-flop,T3 BJT 557 changing the output from a "LOW" state to a "HIGH"Diode D1, D2 Zener diode state. This action inturn turns "OFF" the dischargeR1,R2,R3,R4,R5,R6,R7 transistor connected to pin 7, thereby removing theC1,C2,C3 short circuit across the external timingBulb 11 watts capacitor, C1.This action allows the timing capacitor toRelay switch start to harge up through resistor, R1 until the voltage across the capacitor reaches the threshold (pin 6)Potentiometer voltage of 2/3Vcc set up by the internal voltage divider network. At this point the comparators output goes "HIGH" and "resets" the flip-flop back to its original
  4. 4. state which inturn turns "ON" the transistor and multiple operating coils are used to protect electricaldischarges the capacitor to ground through pin 7. This circuits from overload or faults; in modern electriccauses the output to change its state back to the original power systems these functions are performed by digitalstable "LOW" value awaiting another trigger pulse to instruments still called "protective relays".start the timing process over again. Then as before, the Small "cradle" relay often used in electronics. TheMonostableMultivibrator has only "ONE" stable "cradle" term refers to the shape of the relays armature.state.The Monostable 555 Timer circuit triggers on a A simple electromagnetic relay consists of a coil ofnegative-going pulse applied to pin 2 and this trigger wire wrapped around a soft iron core, an iron yokepulse must be much shorter than the output pulse width which provides a low reluctance path for magnetic flux,allowing time for the timing capacitor to charge and a movable iron armature, and one or more sets ofthen discharge fully. Once triggered, the 555 contacts (there are two in the relay pictured). TheMonostable will remain in this "HIGH" unstable output armature is hinged to the yoke and mechanically linkedstate until the time period set up by the R1 x C1 network to one or more sets of moving contacts. It is held inhas elapsed. The amount of time that the output voltage place by a spring so that when the relay is de-energizedremains "HIGH" or at a logic "1" level, is given by thefollowing time constant equation. there is an air gap in the magnetic circuit. In this condition, one of the two sets of contacts in the relay2.Relay switch-A relay is an electrically operated pictured is closed, and the other set is open. Otherswitch. Many relays use an electromagnet to operate a relays may have more or fewer sets of contactsswitching mechanism mechanically, but other operating depending on their function. The relay in the pictureprinciples are also used. Relays are used where it is also has a wire connecting the armature to the yoke.necessary to control a circuit by a low-power signal This ensures continuity of the circuit between the(with complete electrical isolation between control and moving contacts on the armature, and the circuit trackcontrolled circuits), or where several circuits must be on the printed circuit board (PCB) via the yoke, whichcontrolled by one signal. The first relays were used in is soldered to the PCB.long distance telegraph circuits, repeating the signal When an electric current is passed through the coil itcoming in from one circuit and re-transmitting it to generates a magnetic field that activates the armature,another. Relays were used extensively in telephone and the consequent movement of the movableexchanges and early computers to perform logical contact(s) either makes or breaks (depending uponoperations. construction) a connection with a fixed contact. If the set of contacts was closed when the relay was de- energized, then the movement opens the contacts and breaks the connection, and vice versa if the contacts were open. When the current to the coil is switched off, the armature is returned by a force, approximately half as strong as the magnetic force, to its relaxed position. Usually this force is provided by a spring, but gravity is also used commonly in industrial motor starters. Most relays are manufactured to operate quickly. In a low- voltage application this reduces noise; in a high voltage or current application it reduces arcing. 3.LDR-A photoresistor or light dependent resistor Fig 3. Relay Switch (LDR) is a resistor whose resistance decreases with increasing incident light intensity; in other words, itA type of relay that can handle the high power required exhibits photoconductivity.Aphotoresistor is made of ato directly control an electric motor or other loads iscalled a contactor. Solid-state relays control power high resistance semiconductor. If light falling on thecircuits with no moving parts, instead using a device is of high enough frequency, photons absorbedsemiconductor device to perform switching. Relays by the semiconductor give bound electrons enoughwith calibrated operating characteristics and sometimes energy to jump into the conduction band. The resulting
  5. 5. free electron (and its hole partner) conduct electricity, components, EAGLE already supplies thethereby lowering resistance. Device Set so we don’t have to spend timerecreating devices from scratch every time we wish to use it. First things first, look through yourdesign and list all of the components that you expect to use and look through the libraries that comeprepackaged with EAGLE. Fig 4.LDRA photoelectric device can be either intrinsic orextrinsic. An intrinsic semiconductor has its owncharge carriers and is not an efficient semiconductor,for example, silicon. In intrinsic devices the only FIG 5. Schematic of security Alarmavailable electrons are in the valence band, and hence B. BOARDthe photon must have enough energy to excite the Creating the board from a schematic is one ofelectron across the entire bandgap. Extrinsic devices the easiest tasks with EAGLE.have impurities, also called dopants, added whose The Board command creates a new windowground state energy is closer to the conduction band; with all the parts arranged next to a default board outline. All the nets from the schematicsince the electrons do not have as far to jump, lower are shown as air wires. The Move commandenergy photons (that is, longer wavelengths and lower allows you to pick up each part and move it tofrequencies) are sufficient to trigger the device. If a its desired position. You can also move entiresample of silicon has some of its atoms replaced by groups of parts. The right mouse button rotatesphosphorus atoms (impurities), there will be extra the current part or group.electrons available for conduction. This is an example The Ratsnest command recalculates the airof an extrinsic semiconductor.Photo resistors are wires.Manual routing is done with the Route command. You simply pick up anbasically photocells. air wire, adjust the angle with the right mouse button, and select the layer with the center III. TECHNOLOGY USED button. Via will be added automatically asIC 555 is used in monostable state and triggers needed. You can also let the Auto router dotheRelay circuit. the routing. A. SOFTWARE USED 1. Schematic Designed on Eagle 2. Board prepared on EagleEAGLE(Easily Applicable Graphical Layout Editor) IV. PCB LAYOUT A. SCHEMATIC Library CreationEAGLE only knows of components that exists in its libraries, if it isn’t contained in one of themany default libraries you will have to create the device yourself. For standard components andmany typical
  6. 6. Etching at ambient temperature might take over an hour, it is better to heat up the etching solvent to about 35-45 degrees Celcius. The etching solution heating up could be done in a magnetron, this takes about 40 to 60 seconds in a 850W magnetron depending on the initial temperature of the etching solution (hint: first try this with just water to determine the timer setting of the magnetron). The etching - rocking the etching tray - takes about 15-30 minutes at this temperature. If you have a heated, air-bubble circulated etching fluid tank available, this is probably the fastest way to etch. At higher temperatures the etching performance decreases. The etching process isC. PCB UV Exposure an exothermic reaction, it generates heat. Take The protective plastic layer is removed - care, cool your etching tray when necessary! peeled back - from the photosensitive PCB. You should minimize the amount of copper to The toner side of the greased layout is placed etch by creating copper area in your PCB on the copper of the PCB. Captured air- layout as much as possible. When starting the bubbles are gently pressed away from etching process and little to etch it is difficult underneath the layout. The PCB with the to keep the etching solution at 35-45 degrees layout is now covered with an appropriate Celsius. It helps to fill for example the kitchen sized windowpane and placed on a piece of sink with warm water and rock the etching plain polished tile or marble. The tile or tray in the filled kitchen sink. marble absorbs the heat coming from the UV bulb, which is significant. Three to four minutes 300W bulb UV exposure from a V. CONCLUSION distance of 30-40 cm will do the photo The LDR and R1 form a potentialdivider. With light process. Take care when finished and focused on LDR, the resistance of LDR becomes very removing the PCB, it gets hot! low – of the order of 500 ohm to 1k.Hence, the voltage across R1 is sufficient to keep T1 in conduction whichD. PCB Development in turn keeps T2 in conduction. Underthis condition IC The PCB is developed with a 1% solution of 555 is triggered. The output of themonostable stage is sodium hydroxide NaOH. You can make this low and relay is unable to trigger.When the beam is solvent by adding 10 gram of sodium interrupted momentarily by the coin orby an intruder hydroxide pellets to 1 litter of water and mix it the resistance of LDR suddenly rises to 1M.Now the until everything is dissolved. Use a brush to voltage across R1 is insufficient to keep T1 speed up the developing and clean the PCB inconduction and hence T1 and T2 are cut off and the during this process if the PCB is still greasy bulb glows. due to the applied sunflower-seed oil. The developing process takes about 1 minute. It is ACKNOWLEDGMENT sometimes difficult to guess when the It is our privilege to acknowledge with deep sense of developing is finished. The traces should gratitude to our project guide, Prof. Manali Tayade become clear and the exposed photosensitive for her valuable suggestions and guidance throughout layer has dissolved (during the brushing you our course of study and timely help given to us in the see darker `cloud coming off the PCB completion of our project. surface). We are highly obliged to the entire staff of Electronics and Telecommunication Department for their kind helpE. PCB Etching
  7. 7. and co-operation. We also take this opportunity tothank all my colleagues for offering all possible help. REFERENCES 1. 2. 3. 4. 5. 6. 7.