Super Sensitive Intruder Alarm

Super Sensitive Intruder AlarmIn the project first I pass on have do research for deuce-ace or more travel which have at least three active divisors. I will do the research by using the internet, books, magazines etcetera After the research I will choose the set which I think is simple and easy for me to do my project on. I will do further research on the chosen circuit to understands how it scarpers and how the components work. So when I start to making the project I will be commensurate to deal with the faults if I find whatsoever in the circuit.Circuit 1 Fire s brookdaliseThis circuit is used is used when a fire occurs. The circuit relies on the smoke produced in the event of fire. The light which f completelys on LRD decreases when the smoke passes between bulb and LDR. This increases the confrontation of the LDR and the potentiality increases at the base of transistor. and so the supply to COB is complete to set forth the alarm. The sensitivity of the circuit is the distance between bulb LDR and it can also be preset panorama of VR1.Reference http//english.cxem.net/home/home36.phpCircuit 2 Fire alarmThe 555 snipr (IC1) is an oscillator at audio frequency which is configured to run freely. The T1 and T2 (transistors) build IC1 value. The pin 3 of IC1 is couples to the base of transistor, which makes the speaker to make the alarm go off. The thermistor is the key to the alarm. Also when the justification is low and the temperature is high the alarm will sound. The frequency of NE555 depends on the values of resistances R5 and R6 and capacitance C2. The circuit can be office staffed from a 6V battery or a 6V power supply. The thermistor can be attach on a heat resistant material like mica to prevent it from damage due to excessive heat. The LED acts as an indication when the power supply is switched ON.Reference http//www.circuitstoday.com/2008/04/30Circuit 3 super sensitive intruder alarmIn this circuit the alarm will set off when the shadow of an intruder passing few meters nearby the circuit is enough to trigger the alarm. IC2 uA 741 is wired as sensitive comparator its set point is by R6 and R7. The potential drop divide by LDR and R9 is given at non inverting pin of IC2. When at that place is an intruder near by or close to the LDR the shadow will make the resistance to increase. In that case the voltages at the inputs of comparator will be different and the out put of IC2 will be low. There fore the Q1 will turn on. This makes a forbid going pulse to trigger the IC1 which is wired as a mono-stable multi-vibrator. The out put of IC1 will be amplified by Q2 (SL 100) to produce alarm. The LDR can be housed in a dark tube to increase sensitivity. The sensitivity is very important here. If you can non adjust the required sensitivity properly, use one LOW resistance (1K) POT in series with R9 for fine adjustment.Reference http//www.circuitstoday.com/super-sensitive-intruder-alarmChoosing circuitThe circuits ha ve done research on be very simple and interesting. The circuit I am going to do for my project is the intruder alarm circuit. The components in the circuit are simple and I have used them in the past. I understand how the components work and how the components behave so it will be easy for me to make the circuit. I can also make the other two circuits save they are not as simple as the intruder alarm circuit and they have components which havent used before.Components listLABELCOMPONENTSQUANTITYR1, R2, R3 R51k ohm impedances4R41M resistor1R6 R710 k ohm resistors2R8LDR1R947k potential meter1D1LED1IC2Operational amplifier uA7411IC1555 timer1Q1PNP transistor BC 1571Q2NPN transistor SL1001C1Capacitor 0.01 uF1C2Capacitor 10 uF 25v1K1Buzzer1Three subsystems and active component sSubsystem 1 Operational amplifier uA741An operational amplifier is usually said as an op-amp. Its a DC coupled high-gain electronic voltage amplifier, with deferential inputs barely its usually a sing le output controlled by negative feed hold which determines magnitudes of its output voltage gain, and has high input impedance, low output impedance. Used with split supply, usually +/- 15V.The most green and most famous op-amp is the mA741C or just 741, which is packaged in an 8-pin mini-DIP. The integrated circuit contains 20 transistors and 11 resistorsPin layoutFeatureLarge input voltage aimNo latch-upHigh gainShort-circuit protection no frequency compensationSubsystem 2 PNP transistorTransistor PNP it consists of two P-N junctions transistor back to back like thisThe arrows are there to represent the conventional flowing of current from positive(p) to negative. Some semiconductors have an excess of electrons, n-type material that is due to doping of the semiconductors, plot of ground others have a deficiency of electrons called holes, they are found in P-type materials.When base emitter voltage is about 0.7 v, thats when the transistors conducts. Current are controlled by transistors devices. The bigger the base-emitter current, the bigger the collector-emitter current. The transistors are used as an amplifier or a solid state switch.Pin layoutSubsystem 3 NE555 timer555 timers is an extremely stable regulator which is capable of producing precise time delays. In the time delay process the time is controlled by one outdoor(a) resistor and capacitor. The frequency and the cycle are controlled by two external resistors and one capacitor for a stable operation as an oscillator. The output can drop down to 200mA.FEATURESTurn-off time less than 2 msMax. in operation(p) frequency greater than 500 kHzTiming from micro irregulars to hoursOperates in both a-stable and mono-stable modesHigh output currentAdjustable duty cycleTTL compatibleTemperature constancy of 0.005% per CPin configurationSpecificationInput voltage 0-9VOutput source sound and lightNum of functions 1Product design Intruder alarmReliability good qualityTechnical functionality Sens e shadows of intruderProcess The circuit is able to sense intruders shadow and make the alarm go off. exfoliation of operation NormalSize length 20cm x 8 cm, height 2cmCapability It only takes 1 actionCost 5Quality standards has to represent the health and safety act of 1974Legislation Health and safety at work act 1974Timescales 18 weeksPhysical and human resource implications the circuit that can be built manually. It will be built Using breadboards and components or with the use of circuit wizard.Other componentsLED When LED is forward bias whence it going to emit lights and converts electrical energy to light.CapacitorThe capacitor is a component to stores up electronic charge and releases when its needed. Capacitor comes in massive range of sizes and types for to be used in adaptable power, conditioning, smoothing and isolating signals. They are made from various materials and all the electronic system uses them.Capacitor Symbol = C, Unit = Farads maneuver Symbol = Q, Unit = CoulombsPotential difference = V, Units = VoltsThe capacitor can charge and discharge quickly. Its made of two plates separated by an insulator or air. When a plate is charged the other plate is charged oppositely. The charge can build up and remain after the current is gone.Materials in capacitor6 volt batteryTwo large electrolytic capacitors, 1000 F minimum (Radio Shack catalogue 272-1019, 272-1032, or equivalent)Two 1 k resistors iodine toggle switch, SPST (Single-Pole, Single-Throw)ResistorA resistor is a passive electrical component which controls the flow of current. There are two types of resistor one is called inflexible resistor and the other is called variable resistor. The resistance of a resistor is measured in ohms and it can be measured by colour coding spate and measurement.Potentiometer (pot)This type of variable resistor with 3 contacts (a potentiometer) is usually used to control voltage. It regulates the voltage in the circuit.Light dependent resisto r (LDR)Its an electrical component which converts brightness (light) to resistance. The LDR depends on the intensity of light for its value.BuzzerIts an electrical device that produces and buzzing sounds when a signal has been received.Testing the circuitI first built the circuit on circuit wizard. I put all the components out the page first then I connected all the components and added ground to the circuit. then I played the circuit which shows the circuit is working perfectly because the Led lit up and the buzzer went off when I turned on the circuit. This shows that all the components are working correctly and there are no faults in the circuit.Safe working proceduresEvery activity must be carried out in accordance with a developed Safe Working Practice.This will be validated by means of a Risk Assessment.The control measures identified in the risk assessment shall form the basis for the written Safe Working Practice.Consider what must be done before the task starts, How the ta sk is done, what prep is neededWhat competence is required or certification?The action to be taken when the task is complete.Five steps for risks assessment and hazardIdentify the hazards wire cutter frizzy edgesLong nose pliers sharp edgeComponents sharp edge from componentsDecide who might be harmed and howThe person who is using equipment will get hurt by cutting them themselves andThe people who are around the work could get hurt by leaning on to a sharp component.Evaluate the risks and decide on precautionThe risks are very similar, there are all involved with sharp edges. The user of the equipment could get hurt by losing concentration and accidently cut their finger. The precautions would be to always have full concentration when cutting wires and the user should make sure they are careful when cutting the wires and keeping their fingers away from the sharp edges.Record your findings and implement themThe results of my risk assessment are that most people are cutting th eir fingers as they cut the wires. The reason crumb that is people are not concentrating when using the wire cutters and pliers. To avoid these risks there should not be more then two people in the workshop. When there are lots of people in the workshop the users could lose their concentration easily.Review your assessment and update if necessaryTo review the risk assessment I have decided to update the wire cutter with a wire cutting machine so when people use it they wont cut their fingers.PPEPPE refers to cautionary clothing and other devices that are designed to protect an individual while in potentially dangerous areas or performing potentially hazardous operations. Examples of PPE complicate gloves, hard hat, steel toed boots, and safety glasses.Making the subsystemsThis is the first subsystem where the operational amplifier uA741 is. It also had LDR, pot and two resistors. I connected the circuit with dusky fit to the negative and red wiring to the positive.This is my se cond subsystem where the BC157 NPN transistor is at. It also had components such as resistors and LED. As I connected the first subsystems wiring with black to negative and red to positive I continued to follow the same procedures.This is my third subsystem where the 555 timer is at. It also has components such resistors, transistors, capacitors and a buzzer. I connected the circuit with black wiring to the negative and red wiring to the positive.Testing the circuitsThe method I used to test my circuit is voltmeter, logic probe and oscilloscope. I used the voltmeter to retick the circuit has correct reading on each outputs and inputs. I used the logic probe to test the circuit by checking if the circuit has the correct readings. And I used the oscilloscope to make a sine wave when the alarm goes off.Firstly I tested my subsystem which had some faults in it. The faults which did not give any reading on the voltmeter, was some wires were misplaced. So after I correct my mistake the c ircuit was working the out of the circuit was an LED which lit up and I got reading on the voltmeter.In the first cooking stove the LED is lit up and the voltmeter reading is 1.88v but when the LDR I covered on the image on the right the LED switches off and the voltmeter reading decreases to 1.31v. The readings on the voltmeter, and LED switching on and off shows that the circuit is working correctly.My second subsystem had faults with it which I could not find a solution to it. I tried testing it with voltmeter and logic probe but the result was negative. So I decided to put my second subsystem with my third subsystem. I connected both circuits together and put the power on to find out that the buzzer is working but the Led wasnt illume up. I tried regenerate the LED quit few times to if the Led had a fault with it. I also had some minor problems with the change shape but that was simple enough to fix.Putting all subsystem togetherI started to put the subsystems together by fi rstly connecting all three breadboards together, and then I connected to the power supply to one of the breadboard. I had to connect all three circuits so I cut out some wires and connected positive to positive and negative to negative so all the circuits are connected.So now to test the circuit I put the power supply on and then connected a voltmeter to check all the components in the circuit are working correctly. Then I connected the buzzer which was buzzing but did not stop until I disconnected the circuit and the LED did not light up either. To find the faults I went over the circuits to check for any faults. I did find some faults but they were just simple wring problems which I fixed with ease but the circuit still not work. After replacing some components the circuit was still not working. After doing all the tests I could do I decided to take out the second subsystem because it did not work when I was testing it but it worked with the third subsystem. As I removed the secon d subsystem the circuit started to work. I then check it with voltmeter to make sure the circuit was working correctly. The Led lit up too and went off when I covered the LDR.