CHAPTER ONE 1.0 INTRODUCTION ION
The need for having home protection protection has always been of great importance. But in recent times, considering a dramatic rise in petty crimes like robbery and theft, the need has been more strongly felt to have a fool proof protection of the belongings and the family members. Home security has come a long way in the last few decades. Initially security was in the hands of guards who manuall manually y provi provided ded survei surveilla llance nce during during the night night in the earlie earlierr days, but it was not fool proof as it was only normal for a security man to have momentary lapses in concentration. The guard was also susceptible to sleep at times. It was then that home alarm system systems s based based upon upon electr electronic onic circui circuits ts we were re develo developed ped which which proved to be highly reliable and were appreciated by the people as they were relieved from constant monitoring of their homes. A shadow alarm, as dened by Trimmer, H. illiam !"#$"% is a system designed to detect intrusion & unauthori'ed entry & into a building or area by generating or giving o( an alarm whenever a shad shadow ow fall falls s on it. it. )ecu )ecuri rity ty alar alarms ms ar are e used used in resid esiden enti tial al,,
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comm commer erci cial al,, indu indust stri rial al,, and mili milita tary ry prop proper erti ties es for for prot protec ecti tion on against burglary !theft% or property damage, as well as personal protection against intruders. )hadow alarms are widely used for security purposes. )hadow sensors are widely used to detect the movement of a person in a conned area. *any circuits published earlier have a serious drawback that only one light dependent resistor !+-% is used for shadow detection. In this proect work, we shall describe a simple but improved circuit of a smart shadow sensor alarm, which can register a shadow when there is a light di(erence. Here, two /mm +-s are used with the popular 0p1 amp +*23"45 to drive an active pie'o1sounder when a 6valid7 shado shadow w is dete detect cted ed.. The The whol whole e shad shadow ow sens sensor or cir circuit cuit can can be powered from four "./8 AA cells !984%, or similar dc supply sources. It can be easily installed on the windows and doors of buildings and o:ces. The opto1sensitive device sounds an alarm whenever a shadow falls on it. )o it can be used at night by shopkeepers to protect the valuables in their showrooms. A dim lighting in the room is necessary to detect the moving shadow. It does not re;uire an aligned light beam to illuminate the photo1 sensor.
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comm commer erci cial al,, indu indust stri rial al,, and mili milita tary ry prop proper erti ties es for for prot protec ecti tion on against burglary !theft% or property damage, as well as personal protection against intruders. )hadow alarms are widely used for security purposes. )hadow sensors are widely used to detect the movement of a person in a conned area. *any circuits published earlier have a serious drawback that only one light dependent resistor !+-% is used for shadow detection. In this proect work, we shall describe a simple but improved circuit of a smart shadow sensor alarm, which can register a shadow when there is a light di(erence. Here, two /mm +-s are used with the popular 0p1 amp +*23"45 to drive an active pie'o1sounder when a 6valid7 shado shadow w is dete detect cted ed.. The The whol whole e shad shadow ow sens sensor or cir circuit cuit can can be powered from four "./8 AA cells !984%, or similar dc supply sources. It can be easily installed on the windows and doors of buildings and o:ces. The opto1sensitive device sounds an alarm whenever a shadow falls on it. )o it can be used at night by shopkeepers to protect the valuables in their showrooms. A dim lighting in the room is necessary to detect the moving shadow. It does not re;uire an aligned light beam to illuminate the photo1 sensor.
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Accor ccordi ding ng to )chat chat', ', av avid A., et al !"## !"##$% $%,, a shad shadow ow detector e;uipment will do e=actly the way it is named & detect a shadow or movement within the range of its set sensitivity and subse;uently raise an alarm. 5eedless to say these are used for secur securin ing g re rest stri rict cted ed 'one 'ones s or simp simply ly for for moni monito tori ring ng unwa unwant nted ed occupations. 4ompared to other types of popular security devices and concepts, a shadow detector alarm is comparatively more reasonable and accurate. This is simply because the operating prin princi cipl ples es of thes these e devi device ces s mak make them them dete detect ct only only genu genuin ine e intrusions and only around the restricted area, so whenever an alarm is sounded through it, you can be certain that an inltration has taken place. This shadow alarm system uses u ses I4 4A>">?, one of the most common 0perational Ampliers which was wired in an inverting mode and used as the tone generator and amplier to obtain ma=imum audible sound. The rst chapter of this proect talked talked about the introduction, the concept of the system and also the aims and obective of the proect among other things. 4hapter two is about the review of
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past literature and work done on the proect under consideration. 4hapter three is about the construction in full while 4hapter four is on result analysis. 4hapter ve is conclusion, recommendation and -eferences. 1.1 BACK BACKGR GROU OUND ND OF THE THE STUD STUDY Y
The twentieth century also saw maor developments in security security alarm alarm technology technology.. 0nce 4alahan@s 4alahan@s emergen emergency cy call bo= bo= design had become more a(ordable after the second world war, more control points could be used for medical services, police and re departments, thus improving the security of the population nationw nationwid ide e !Ter !Terranc rance e Hughes Hughes,,
and
#?s
were
particularly
marked
by
growing
demo democr crat ati' i'at atio ion, n, in whic which h secu securi rity ty alar alarm m syst system ems s beca became me a standa standard rd featur feature e of buildi building ng securit security y. inally inally,, the rst rst wirele wireless ss alar alarm m syst system ems s came came on the the mark market et and and re revo volu luti tioni oni'e 'ed d alar alarm m technology as well as on a practical level & until the unavoidable tangle of cables eventually passed away. )everal other ideas and methods have been proposed and used as solutions to curb cases
3
of intrusi intrusions ons and subse; subse;uen uentt theft thefts s into into re resid sident ential ial and o:ce o:ce building. )ome of such methods include having human sentries, employing security outts, =ing barbed wire fences, etc. 0ther methods abound but one observable problem with these devices were that hat they hey proved to be ine(ective in detecting and and appr appreh ehen endi ding ng intr intrud uder ers s who who took took adva advant ntag age e of laps lapses es in the the security methods to perpetrate crime. This proect work therefore seeks to critically look at these already e=isting devices and their mod modes of ope opera rattion ion wit with the inte intent ntio ion n of nd nding ing out out thei theirr limi limita tati tion ons s and and pro( pro(er er a bett better er desi design gn that that can can comf comfort ortab ably ly surmount the observed limitations of the former systems. +ooking at the high cost of losses which could be and is usually incurred alwa always ys when when thie thieve ves s brea break k in and and stea steall from from our our homes homes and and o:ce o:ces, s, it is pert pertiinent nent we look look at a solut olutio ion n which hich has has the the capa capabi bili lity ty of prev preven enti ting ng intr intrus usio ions ns and and thef thefts ts than than prov provid idin ing g solutions after a theft must have already occurred. 1.2 STA STATEMENT TEMENT OF THE THE PROBLE PROBLEM M
It is worthy to note that despite the so many e(orts aimed at apprehending criminals who intrude into our homes and privacy,
/
none of them has been able to prevent crime. The monitoring cameras and other such gadgets and devices have only served to provide information as to how a crime was committed. But how these theft incidents could be nipped in the bud and prevented is another thing these devices has not and could not do. And then we nd out that many times even when the information on crime is provided, nothing is done to apprehend the culprits. It is no longer enough for us to ust have information on a crime, the problem then is to nd ways to prevent these crimes from happening in the rst instance. This solution then, is what this proect seeks to provide. 1.3 OBJECTIVE OF THE STUDY
ohn . enkins !% wrote that a few years ago, precisely in
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window will nd it virtually impossible to break into the house due to the claw1like steel bars. In addition, any attempt to force entry that is detected is forwarded to an alarm control panel, which then reliably sets o( a loud alarm and the o(ender is forced to escape. But the Daw in the above described device however, is that there is no denite di(erence between the shadow cast by an intruder and that of a small animal. The aim and obective of this proect work is to design a device which can comfortably detect a human shadow as distinct from shadows cast by little animals and trees. This is going to be achieved by using a moving and si'eable shadow as the reference shadow of the device. This proect has the capability of reducing burglary and unauthori'ed intrusion to its barest minimum, thereby giving property owners a sense of security and comfort even when they leave their premises and homes. 1.4
SIGNIFICANCE OF THE PROJECT
This device functions as an electronics watch dog. This device functions as a maor security alarm that can be used in
2
residential, commercial, industrial, and military buildings to protect properties against burglary !theft% or property damage, as well as personal protection against intruders. 1.5 SCOPE OF THE STUDY
)cope is used here to indicate the depth into which this study intends to go in e=amining the role smart security devices and gadgets play in ensuring the safety of lives and property of individual in buildings such as residential buildings, o:ce buildings, shopping malls, supermarkets, social events centres, churches and educational institutions, etc. In one aspect, this proect is going to e=amine the di(erent models of security devices, methods and solutions already in use, and the ways in which the shadow detector can be incorporated so as to bring lasting solution to burglary thefts. 0n the other aspect, it is going to look for ways the device can be e(ectively utili'ed to provide a better solution to crime prevention. 1.7 LIMITATION OF THE STUDY
A careful review of the di(erent crime and intruder prevention devices and models shows that there e=ist minor and $
maor di(erences in the operational mode of already e=isting devices. )ome smart security devices are ;uite distinct from others in so many aspects. 0ne of the problems encountered in this proect work is that even the shadow of big animals can also trigger the device ust as the shadow of human being can as well. This obviously posed a limitation in evaluating the e(ectiveness of usage of the device. However, an attempt was made to make the sensitivity of the device intelligent enough so as to take notice of shadows only as large as that of humans. Another limitation encountered in this study is that a comprehensive documentation has not yet been made with respect to the construction and e(ective use of shadow detector circuit. E(orts however were made to gather the little bits of information on the proect together and use them as secondary materials upon which the evaluation of the present system and its construction and usage are based. 1. DEFINITION OF TERMS
In the course of carrying out a research on a proect such as this, there is need for careful denition of the operative words
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used in the proect and its report. This is so as to minimi'e the possibility of ambiguity in discussions as the study progresses. In the light of the above therefore, attempt will be made to dene keywords as used in this proect. The words to be dened then are as followsF I!"#$%&# A'(#)F An intruder alarm is a system designed to
detect intrusion & unauthori'ed entry & into a building or area. B$#*'(#+, Burglary is the crime of breaking into and entering the
dwelling of another with felonious intent, whether or not the felony is actually perpetrated. S&!-#-F )ensors are devices which detect intrusions. )ensors
may be placed at the perimeter of the protected area, within it, or both. E'&/"#/ F&!/&F )ecurity electric fences consist of wires that
carry pulses of electric current to provide a non1lethal shock to deter potential intruders. Tampering with the fence also results in an alarm that is logged by the security electric fence energiser, and can also trigger a siren, strobe, andGor notications to a control room or directly to the owner via email or phone.
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CHAPTER TO LITERATURE REVIE 2.0 REVIE OF THE SYSTEM
)everal works have been done by various authors and scholars on this topic and several other related topics. This chapter reviews previous e(orts made in the construction and design of a shadow detector circuit. 0ne of such works was done by the aduna )tate Cniversity, 4omputer )cience epartment. Their proect was on 6automatic alarm of various kinds7. In the proect, they wrote about the intruder alarm and its design, as
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well as its construction. The modes of operation, limitations, etc. were talked on. There are very few reviews on the topic though. escribing the shadow alarm detector, Trimmer, H. illiam !"#$"% postulated that shadow alarm devices are usually used for protection against theft. He went ahead to dene the device as a compact shadow alarm unit that sounds an alarm when a shadow falls on it. This compact shadow alarm unit is capable of sensing a moving shadow in a restricted area, and can be easily installed on walls, windows or doors to protect valuables from theft. 4onstant lighting however is re;uired in the conned area to detect the moving shadow. riting also on the issue of shadow alarms and security, eber, Thad +. !"#$/% mentioned other individuals such as arl Ben', the owner of *ercedes Ben' and Henry ord, the owner of ord cars who saw the need for this alarm in the 2?s and $?s and started using these alarms in their products. Today, most cars in the world come with this shadow alarm and even more advanced security systems. Therefore, it can be said that house shadow alarms are the basis of all car security systems.
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2.1 HISTORICAL BACKGROUND OF INTRUDER ALARM
According to alker, Jhilip !"#$/%, intruder alarms have been around for thousands of years. The most basic alarm used by ancient humans was the dog. It would protect property and guard against people who were attempting to take valuables. He further said that the rst electro1magnetic alarm system in the world was patented on <" une "$/> in the name of a man called Augustus -ussell Jope, an inventor from )ommerville in Boston. Cp until then, people had mainly relied on the loud chatter of their startled geese, the integrity of their guard dogs or mechanical ringing to catch any intruders on their property. 0ver time, humans used other tricks like chimes to warn them against burglars. *odern
intruder
alarms, however, are
far
more
elaborate and use advanced forms of technology. The second half of the "#th century was a period of great innovation in the security industry according to -amsey, Anthony ! by a Bostonian inventor named Augustus -ussell Jope. According to him, Augustus created a pro=imity
">
sensor for doors and windows by connecting them to a parallel circuit, a simple device which rang a bell. *uch like alarm systems today, Jopes alarm could not be turned o( simply by shutting the door or window that tripped itK Augustus eventually sold his invention to Edwin Holmes, who created the rst modern alarm company, the Holmes Electric Jrotection 4ompany. Jope@s battery1operated gadget may seem very simple from today@s point of view but it proved e=tremely e(ective against intruders. It reacted to the closing of an electric circuitF doors and windows were connected as independent units by a parallel circuit. If the door or a window was opened and the electric circuit closed, the sudden Dow of current caused one of the attached magnets in the system to vibrate. The electro1 magnetic vibrations were transmitted to a hammer which then struck a brass bell. The special feature of Jope@s invention was that the alarm could not be switched o( by merely closing the windows or doors. A switch spring mounted in the wall above the door kept the current interrupted in this case as well, so that the bell could keep ringing.
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espite the pioneering work of Jope, most individuals usually assume that someone else, namely Edwin Holmes was the father of the modern alarm system. *aking the clarication however, Atss, -. 5andakumar !"##$% said that Edwin Holmes was a businessman and founder of the rst company for electrical alarm systems, who had in fact bought the rights to Jope@s invention in "$/2. Loing further, Atss, -. 5andakumar !"##$% continued that it was him !Edwin Holmes% who then led the way in the business of electro1magnetic alarm technology with his 6Holmes Electric Jrotection 4ompany7. Another milestone in the history of modern alarm systems according to ohn . enkins !
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electric alarm systemsM enkins went on to e=plain that the connection came about by the president of the company who soon funded the production of the stock ticker, Elisha Andrews, who was now 4alahan@s boss. The poor man was taken by surprise in his home one night by a burglar and seriously robbed. )hocked by the incident, 4alahan felt obliged to protect his boss from such dangers in future. His plan was to t each of the fty neighbours in the pro=imity of Andrew@s house with one emergency call bo= and one bell and then to connect the houses to one another. or each household call bo=, a certain number of bell rings was determined that could distinguish the houses in the event of a burglary. If an alarm rang in house A, houses B and 4 would know that house A was probably being burgled. hile he was working on the rst emergency call apparatus, 4alahan
had
another
decisive
ideaF
burglaries
occurred
particularly fre;uently in cities & if his system were to not only trigger an alarm but also provide a service then an emergency central station was necessary which could react to incoming calls for help. He began by dividing 5ew Nork 4ity into districts which
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were all to be connected up to a central monitoring station. In the event of an incoming emergency call, a messenger boy would be sent out to promptly arrange help for that particular district. The advantage of the call bo=es was that they re;uired very little maintenance. They were run on the mains supply from the local central station. In "$2", 4alahan helped form the American istrict Telegraph !AT% company. The company was highly successful and held o:ces in Brooklyn, 5ew Nork, Baltimore, Jhiladelphia and 4hicago from "$2/. 4alahan@s emergency call bo=es became standard use for police and re services, as well as for messenger services. By the end of the "$2?s, two thirds of all stock sold was made via messenger boys from AT. Another innovator of alarm technology worth mentioning was Ale=ander Lraham Bell. Although Ale=ander is best known for his development of the rst working telephone, few know that he used this same technology to create the rst version of a central monitoring station. riting on Ale=ander Lraham Bell and this innovation, Aii, 5. 4lifton !
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branches together. The "$??s had been a period of deadly bank robberies, and bank managers were desperate to gure out some way to protect their customers valuables. The switchboard made bank robbery a far more di:cult proposition for a couple of reasonsF irst , bank sta( could immediately notify the other four branches that a robbery was in progress, which meant law enforcement had a chance of arriving in time to apprehend the bank robbers. )econd, bank employees could describe the robbers physical appearance over the phone, which made it easier for law enforcement to nd them and post anted posters if the robbers managed to get away. hile burglar alarm technology has developed signicantly since the "#th century, it is still based on the basic principles innovated by Augustus Jope and Ale=ander Bell. All maor alarm companies, including *iac Alarm, make use of pro=imity sensors in the windows and doors as the rst line of defense against potential burglars, and alarm systems transmit information to a central monitoring station that can dispatch law enforcement ;uickly and e(ectively.
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ortunately, technological advances have made security systems more reliable than a brass bell and a magnet, and way more secure than sliding a big rock in front of your door but we should be mindful of how much we owe to the innovators that have made families around the world safer than ever before.
2.2 REVIE OF THE INFRARED DETECTOR
The infrared sensor, being one of the primary and most important components of the shadow detector circuit shall be brieDy discussed in this section. According to 5afees, Ahmed A. et al, the history of the infrared
detector
started
with
Herschels
e=periment
with
thermometer on ebruary ""th, "$??. They postulated that infrared detectors are in general used to detect, picture, and measure patterns of the thermal heat radiation which all obects
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emit. At the beginning, their development was connected with thermal detectors, such as thermocouples and bolometers, which are still used today and which are generally sensitive to all infrared wavelengths and operate at room temperature. The second kind of detectors, called the photon detectors, was mainly developed during the Pm. After orld ar II, infrared detector technology development continued to be primarily
driven
by
military
applications.
iscovery of variable band gap Hg4dTe ternary alloy by +awson and coQworkers in "#/# opened a new area in I- detector technology and has provided an unprecedented degree of freedom in infrared detector design. *any of these advances were transferred to I- astronomy from epartments of efence research. +ater on civilian applications of infrared technology are fre;uently called 6dualQuse technology applications.7 0ne should point out the growing utilisation of I- technologies in the civilian
sphere based on the use of new materials and technologies, as well as the noticeable price decrease in these high cost technologies. )wetha -. et al !
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The most basic alarm consists of one or more sensors to detect intruders, and an alerting device to indicate the intrusion. However, a typical premises security alarm employs the following componentsF
•
P#&)-&- /!"#' $!" !J4C%, A'(#) C!"#' P(!&' !A4J%,
or simply (!&'F The SbrainS of the system, it reads sensor inputs, tracks armGdisarm status, and signals intrusions. In modern systems, this is typically one or more computer circuit boards inside a metal enclosure, along with a power supply.
•
S&!-#-F evices which detect intrusions. )ensors may be
placed at the perimeter of the protected area, within it, or both. )ensors can detect intruders by a variety of methods, such as monitoring doors and windows for opening, or by monitoring
unoccupied
interiors
for
motions,
sound,
vibration, or other disturbances.
•
A'&#"!* %&/&-F These indicate an alarm condition. *ost
commonly, these are bells, sirens, andGor Dashing lights.
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Alerting devices serve the dual purposes of warning occupants of intrusion, and potentially scaring o( burglars. These devices may also be used to warn occupants of a re or smoke condition.
•
K&+(%-F )mall devices, typically wall1mounted, which
function as the human1machine interface to the system. In addition to buttons, keypads typically feature indicator lights, a small multi1character display, or both.
•
I!"&#/!!&/"!- between components. This may consist
of direct wiring to the control unit, or wireless links with local power supplies.
•
S&/$#"+ %&/&-F evices to detect thieves such as
spotlights, cameras lasers. In addition to the system itself, security alarms are often coupled with a monitoring service. In the event of an alarm, the premises control unit contacts a central monitoring station. 0perators at the station see the signal and take appropriate action, such as contacting property owners, notifying police, or
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dispatching private security
forces.
)uch
signals may
be
transmitted via dedicated alarm circuits, telephone lines, or Internet. 2.3.1
•
TIMELINE OF SECURITY ALARM INVENTIONS
In "$/<, Edwin Holmes invented the rst electric alarm system in Boston. The basic design featured a tripwire that electrically powered a solenoid that struck a gong when it was set o(. He started a business with the concept and moved to 5ew Nork.
•
In "#?/, the American Telephone and Telegraph 4ompany purchased
the
Holmes
business.
Csing the
advanced
electrical grid that was established in 5ew Nork, the company linked the personal burglar alarms to police and re departments. •
)tarting in the "#2?s, a number of alarm systems came e;uipped with motion sensors. These used basic ultrasonic technology that were emitted from a sensor and reDected back. Any change in sound would cause the system to go o(.
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2.3.2 •
IMPROVEMENTS
uring the "#$?s, improvements to motion sensors merged with other technologies. *otion sensors began to use infrared technology to avoid false positives and also superior electrical components to establish full home protection systems.
2.3.3 •
INTEGRATION
Throughout the "##?s, the prices on home security systems fell. *any companies o(ered free installation packages with a monthly fee. The system was integrated with not only safety services, but also phone support from the company itself.
4HAJTE- TH-EE 405)T-C4TI05 *ETH00+0LN >.? )N)TE* B+04 IAL-A* )hadow alarms are widely used for security purposes. escribed here is a simple but improved circuit of a smart shadow sensor alarm, which can register a shadow when there is a light di(erence. A shadow alarm is a device that generates an alarm whenever a shadow falls on it. This shadow alarm circuit can sense a moving shadow in a conned area. It can be used to protect things from theft. hen somebody approaches the unit, it
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will give a loud alarm to abort the attempt of theft. The circuit uses the light sensing property of the Jhoto diode. This proect can be easily installed on windows and doors. This block diagram demonstrates the principle of operation of a simple shadow alarm using photodiode. The block diagram is as shown belowF
F*$#& 1, Block diagram of the shadow detector circuit 3.1 SHADO ALARM CIRCUIT DIAGRAM
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F*$#& 2, 4ircuit diagram of the shadow detector 3.2 PRINCIPLE OF OPERATION OF THE DEVICE
The circuit uses the light sensing property of the JI5 Jhotodiode. The p1n unction of the photo diode gives light current when it is forward biased. I4" is designed as a voltage comparator. Its non inverting input is connected to a potential divider -" and 8-. By adusting 8-, input current to pin> can be set to a reference level. The inverting input of I4" is connected to a photo diode. I4 4A>">? is a "/ *H' Bi*0) 0perational amplier with *0)ET inputs and bipolar output. The inputs contain *0)ET transistors to provide very high input impedance and very low input current as low as "?pA. It has high speed of performance and suitable for low input current applications. 4A>">?A and 4A>">? are op amps that combine the advantage of both 4*0) and bipolar transistors. Late1protected J14hannel *0)ET !J*0)% transistors are used in the input circuit to provide very1high1input impedance, very1low1input current and e=ceptional speed performance. The use of J*0) transistors in the input stage results in common1mode input1voltage capability
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down to ?./8 below the negative1supply terminal, an important attribute in single1supply applications. A 4*0) transistor1pair, capable of swinging the output voltage to within "?m8 of either supply1voltage terminal !at very high values of load impedance%, is employed as the output circuit. The 4A>">? )eries circuits operate at supply voltages ranging from /8 to "98. They can be phase compensated with a single e=ternal capacitor, and have terminals for adustment of o(set voltage for application re;uiring o(set1null capability. Terminal provisions are also made to permit strobing of the output stage. The 4A>">?A o(ers superior input characteristics over those of the 4A>">?. 5ormally in the light !as set by 8-% Jhotodiode gives voltage to pin< of I4". )ince this voltage is higher than the voltage set by 8at pin> ,output of I4" remains low keeping +E and bu''er o(. hen a person approaches the photodiode, the shadow causes a reduction in current through the photodiode so that voltage at pin< decreases below that of pin>. 0utput of I4" then goes high and Bu''er sounds.
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N"&F The circuit triggers when the light intensity changes
without a shadow. It is better to keep the unit in a place where constant light is available 3.3 SYSTEM OPERATION
This shadow alarm circuit can sense a moving shadow in a conned area. It can be used to protect things from theft. hen somebody approaches the unit, it will give a loud alarm to abort the attempt of theft. The circuit uses the light sensing property of the Jhoto diode. 3.4 POER SUPPLY UNIT
F*$#& 3, iagram of the power supply unit of the device
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A regulated #8G/??mA power supply that can be used for powering the basic re alarm circuit and its modied versions is shown above. Transformer T" is a <>?8 primary, "<8 secondary, /??mA step down transformer. " is a "A bridge which performs the ob of rectication. 4apacitor 4" lters the rectier output and 4< is the A4 by1pass capacitor. I4" !2$?#% is a #8 =ed positive voltage regulator. The output of the rectierUlter section is connected to the input of 2$?/ and a regulated steady #8 is obtained at its output. )" is the 05G0 switch. " is a /??mA safety fuse. 3.5 FUNCTION
OF
THE
MAJOR COMPONENTS OF
THE
DEVICE 3.5.1
PHOTODIODE
A photodiode is a semiconductor device that converts light into current. The current is generated when photons are absorbed in the photodiode. A small amount of current is also produced when no light is present. Jhotodiodes may contain optical lters, built1in lenses, and may have large or small surface areas. Jhotodiodes usually have a slower response time as their surface >"
area increases. The common, traditional solar cell used to generate electric solar power is a large area photodiode.
F*$#& 4, iagram showing a photodiode
Jhotodiodes are similar to regular semiconductor diodes e=cept that they may be either e=posed !to detect vacuum C8 or V1rays% or packaged with a window or optical ber connection to allow light to reach the sensitive part of the device. *any diodes designed for use specically as a photodiode use a JI5 unction rather than a p&n unction, to increase the speed of response. A photodiode is designed to operate in reverse bias.
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Jhotodiode is a p&n unction or JI5 structure. hen a photon of su:cient energy strikes the diode, it creates an electron1hole pair. This mechanism is also known as the inner photoelectric e(ect. If the absorption occurs in the unction@s depletion region, or one di(usion length away from it, these carriers are swept from the unction by the built1in electric eld of the depletion region. Thus holes move toward the anode, and electrons toward the cathode, and a photocurrent is produced. The total current through the photodiode is the sum of the dark current !current that is generated in the absence of light% and the photocurrent, so the dark current must be minimi'ed to ma=imi'e the sensitivity of the device 3.5.2
CAPACITOR
It is a passive component with two terminals and used to store charges. 4apacitors are made up of two conductors which are separated by the dielectric medium Dows in between. It works when the potential di(erence applied across the conductors polari'e the dipole ions to store the charge in the dielectric medium.
>>
F*$#& 5, iagram of a capacitor
There are two types of capacitors & i.
Jolari'ed & They have polarity means U and1 sign marked on it. It is mainly used to store the charges. Before troubleshooting the circuit capacitors must be fully discharged as they have charges store in it.
ii.
5on1polari'ed & They dont have a polarity and can be mounted in any of the way. They are generally used to remove the noises present during the conversion of A4 into 4.
3.5.3
RECTIFYING DIODE
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A rectier is an electrical device that converts alternating current !A4%, which periodically reverses direction, to direct current !4%, which Dows in only one direction. The process is known as rectication. Jhysically, rectiers take a number of forms, including vacuum tube diodes, mercury1arc valves, copper and selenium o=ide rectiers, semiconductor diodes, silicon1 controlled
rectiers
and
switches.
Historically,
other
even
silicon1based
synchronous
semiconductor
electromechanical
switches and motors have been used. Early radio receivers, called crystal radios, used a 6cats whisker7 of ne wire pressing on a crystal of galena !lead sulphide% to serve as a point1contact rectier or 6crystal detector7.
F*$#& , -ectifying diodes in a rectier circuit
-ectiers have many uses, but are often found serving as components of 4 power supplies and high1voltage direct current
>/
power transmission systems. -ectication may serve in roles other than to generate direct current for use as a source of power. As noted, detectors of radio signals serve as rectiers. In gas heating systems Dame rectication is used to detect presence of Dame. Because of the alternating nature of the input A4 sine wave, the process of rectication alone produces a 4 current which, although unidirectional, consists of pulses of current. *any applications of rectiers, such as power supplies for radio, television and computer e;uipment, re;uire a steady constant 4 current !as would by produced by a battery%. In these applications the output of the rectier is smoothed by an electronic lter to produce a steady current.
3.5.4
I.C. CA3130 OPAMP
4A>">?A and 4A>">? are op amps that combine the advantage of both 4*0) and bipolar transistors. Late1protected J14hannel *0)ET !J*0)% transistors are used in the input circuit
>9
to provide very1high1input impedance, very1low1input current, and e=ceptional speed performance. The use of J*0) transistors in the input stage results in common1mode input1voltage capability down to ?./8 below the negative1supply terminal, an important attribute in single1supply applications.
F*$#& 7, 4ircuit diagram of the 0p Amp APPLICATIONS
i.
Lround1-eferenced )ingle )upply Ampliers
ii.
ast )ample1Hold Ampliers
iii.
+ong1uration TimersG*onostables
iv.
High1Input1Impedance 4omparators !Ideal Interface with igital 4*0)%
v.
High1Input1Impedance ideband Ampliers
>2
vi.
8oltage ollowers !e.g. ollower for )ingle1)upply GA 4onverter%
vii.
8oltage -egulators !Jermits 4ontrol of 0utput 8oltage own to ?8%
viii.
Jeak etectors
i=.
)ingle1)upply ull1ave Jrecision -ectiers
=.
Jhoto1iode )ensor Ampliers
3.5.5
LIGHTEMITTING DIODE !LED%
A light1emitting diode !+E% is a semiconductor light source. +Es are used as indicator lamps in many devices and are increasingly used for general lighting. Appearing as practical electronic components in "#9<, early +Es emitted low1intensity red light, but modern versions are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.
>$
F*$#& , +ight Emitting iodes and its symbol
hen a light1emitting diode is switched on, electrons are able to recombine with holes within the device, releasing energy in the form of photons. This e(ect is called electroluminescence, and the color of the light !corresponding to the energy of the photon%
is
determined
by
the
energy
band
gap
of
the
semiconductor. An +E is often small in area !less than " mm <%, and integrated optical components may be used to shape its radiation pattern. +Es have many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller si'e, and faster switching. However, +Es powerful enough for room lighting are relatively e=pensive,
and
management
re;uire
than
more
compact
precise
current
Duorescent
lamp
and
heat
sources
of
comparable output. +ight1emitting diodes are used in applications as diverse as aviation
lighting,
automotive
lighting,
advertising,
general
lighting, and tra:c signals. +Es have allowed new te=t, video displays, and sensors to be developed, while their high switching
>#
rates are also useful in advanced communications technology. Infrared +Es are also used in the remote control units of many commercial products including televisions, 8 players and other domestic appliances. +Es are also used in seven1segment display.
3.5.
RESISTORS
It is a passive component having two terminals that are used to manage the current Dow in the circuit. A current that Dows via a resistor is directly proportional to the voltage that appeared into the resistor. A resistor in its denition is an electrical and electronic component that o(ers opposition to the Dow of electrical current. It also acts as a pre1load on the voltage supplies to a system i.e. causes an initial voltage drop across it this is a pre1load component. It is often called a bleeder resistor because it provides the following advantages. -esistors are of two types &
3?
i.
i=ed -esistor & having a =ed value of resistance
ii.
8ariable -esistor & whose value of resistance can be changed for e=ample if we have a resistor of / then the value of resistance will vary from ? to / k.
8alue of resistance can be calculated with the help of a multimeter or with the color code which is visible on the resistor. ".
It improves voltage regulation of the supply by acting as a pre1load on the supply, thereby causing an initial voltage drop. In this way di(erence between no1load and full1load is reduced hence improving the regulation of the system.
<.
It improves ltering action
>.
It also provides safety to the technician handling the e;uipment when power supply is switched o( by providing a path for the ltering capacitor to discharge through it, and that is why it is called bleeder resistor. ithout the resistor, the capacitor will retain its charges for ;uite a very long time even when the power supply is switched o(. This high
3"
voltage is always a problem to electrical electronic engineers working on e;uipments. TYPES OF RESISTOR
8ariable -esistor -heostat -esistor Jotentiometer -esistor i=ed -esistor T(6'& 1.0, A "(6'& -8!* "& #&--"# /'$# /%&
40+0C-
I-)T BA5
B+A4
)E405 BA5 W
?
B-05
"
?
-E
<
??
0-A5LE
>
???
NE++0
3
????
L-EE5
/
?????
B+CE
9
??????
8I0+ET
2
???????
L-EN
$
????????
HITE
#
THI- BA5
T0+E-A54E
"?
X
X"Y X
?????????
L0+
W
W
V?."
)I+8E-
W
W
V?.?"
X/Y X"?Y
3<
The symbol is as shown belowF
CHAPTER FOUR TEST AND RESULT ANALYSIS 4.1 CONSTRUCTION PROCEDURE
In building this proect, the following procedures were properly considered and observed.
3>
i. ii.
Assembling of the entire materialsGcomponents needed. -esistance check of the components bought, with the help of the ohmmeter before making the necessary connection with
iii.
the components. rafting out a schematic diagram on how to arrange the
iv. v.
materialsGcomponents. Testing the completed system to see if the design works and inally, implementation of design of the proect. Having procured all the materials, we proceeded into
arranging the components onto the 8ero board. 4are was taken not to lay the I.4. directly on the bread board since the heat the soldering iron emits while soldering could damage it. After every other soldering, the I.4. was then properly soldered. The components were all soldered onto the board after which the circuit was correctly conrmed done. 4.1 ASSEMBLING OF THE DIFFERENT SECTIONS
Having provided
the casing and
having nished
the
construction of the sections of this system, the assembling into the casing followed. The sections were properly laid out and assembled into the casing where the general coupling and linkages into the peripheral devices took place.
33
inally, the indicator was brought out to indicate when the system is powered. A switch was as well brought out for powering the system. The sensor and power indicator were also brought out from the casing. 4.2 MOUNTING PROCEDURE
The transformer was bolted directly to the bottom of the case. This was followed by mounting of the power section of the circuit board. A gap was made between one mounting and the successive ones. This is necessary to avoid overcrowding. The vero board was also mounted at the upper side of the case. The resistors, transistors, and other components used were mounted on the vero board. All the accessories were tightly =ed to avoid slack that may result in the malfunction of the system. 4.3 CASING AND PACKAGING
All the components were soldered onto the 8ero Board. After which a case was gotten where the entire circuit was mounted followed by other e=ternal components such as indicators, sensors, and switches.
3/
4.4 PACKAGING
This is a very important aspect of the design work. It is the appearance given to the nal work. After soldering on the vero board, we did not leave the work as it wereR it has to be cased. Jackaging could serve two maor functions. ".
)erve to protect the components used for the design.
<.
)erve to make the nished work look attractive.
A portable plastic casing covered with leather was used in packaging the work. The plastic case was chosen because of its poor conduction of heat and electricity.
The dimension and
design of the bo= was arrived at after considering various factors such as the width and length of the vero board The dimensions for the casing areF +ength
11 >"./ cm and <9./cm
Height
11 "3.cm
The vero board and the transformer are held rmly by bolts and nuts. 4.5 TESTING 39
Testing is one of the important stages in the development of any new product or repair of e=isting ones. Because it is very di:cult to trace a fault in a nished work, especially when the work to be tested is too comple=. or the purpose of this proect, two stages of testing were involved i. Jre1implementation testing ii. Jost1implementation testing. 4.5.1 PREIMPLEMENTATION TESTING
It is carried out on the components before they are soldered to the veroboard. This is to ensure that each component is in good working condition before they are nally soldered to the board. The components used in this design are grouped into two.
−
iscrete components e.g. resistors, light emitting diodes, capacitors, transistors. Etc.
−
Integrated circuit components.
32
The discrete components were tested with a milliammeter by switching
the
meter
to
the
re;uired
value
and
range
corresponding to each discrete component to check for continuity. 4.5.2
POSTIMPLEMENTATION TESTING
After implementing the circuit on a proect board, the di(erent sections of the complete system were tested to ensure that they were in good operating condition. The continuity test carried out is to ensure that the circuit or components are properly linked together. This test was carried out before power was supplied to the circuit. inally, after troubleshooting had been done on the whole circuit, power was supplied to the circuit. 8isual troubleshooting was also carried out at this stage to ensure that the components do not burn out. The circuit was tested in the day time, for that reason, a dark obect was allow to pass through the sensor !+-% and the alarm was observed triggered and when the black obect was removed the alarm was observed to have gone 0.
3$
4. RESULTS OBTAINED
The results obtained during the construction states after necessary troubleshooting were satisfactory. The system was able to respond to its operation.
3#
4HAJTE- I8E 4054+C)I05 A5 -E40**E5ATI05 /.? 4054+C)I05 )ecurity alarms are system designed to detect intrusion & unauthori'ed entry & into a building or area. )ecurity alarms are used in residential, commercial, industrial, and military properties for protection against burglary !theft% or property damage, as well as personal protection against intruders. 4ar alarms likewise protect vehicles and their contents. Jrisons also use security systems for control of inmates. )ome alarm systems serve a single purpose of burglary protectionR combination systems provide both re and intrusion protection. Intrusion alarm systems may also be combined with closed1circuit television surveillance systems to automatically record the activities of intruders, and may interface to access
/?
control systems for electrically locked doors. )ystems range from small, self1contained noisemakers, to complicated, multi1area systems with computer monitoring and control. )hadow sensors are widely used to detect the movement of a person in a conned area using photodiode.
5.1 RECOMMENDATION
This proect is designed to be used in our homes, o:ces and industries or any other place where there is need for protection of properties against theft. It is recommended that work should be done on the implementation and integration of this device into the security network in our homes and industries.
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-EE-E54E) Tian, )un, N Tang, Tricolor attenuation model for shadow detection. IEEE Trans Image Jrocess 1!"?%, <>//&<>9> !
!)cottsdale, Ari'ona, C)A,
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A +eone, 4. istante, )hadow detection for moving obects based on te=ture analysis. Jattern -ecognit 40!3%, "<<<& "<>> !>2&">3< !%. * Nang, +o, 4 4hiang, Tai, *oving cast shadow detection by e=ploiting multiple cues. IET Image Jrocess 2!<%, #/&"?3 !
invariant
color
features.
4omput
8is
Image
Cnderstand 95!<%, <>$&/&/2 !
!)prings, 4olorado, C)A,
Conference
on
Computer
ision
and
Pattern
!ecognition !auai, Hawaii, C)A,
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Huang, 4 4hen, *oving cast shadow detection using physics1 based features. IEEE Conference on Computer ision and Pattern !ecognition !*iami, lorida, C)A, "?&
<>"2 5 Brisson, A Zaccarin, +earning and removing cast shadows through a multi1distribution approach. IEEE Trans JA*I 29!2%, "">>&""39 !
)iala, * 4hakchouk, 0 Besbes, 4haieb, *oving shadow detection with support vector domain description in the color ratios space. International Conference on Pattern !ecognition !4ambridge, C, $3&>$2
A oshi, 5 Japanikolopoulos, +earning to detect moving shadows in dynamic environments. IEEE Trans JA*I 30!""%, !
single
image.
IEEE
International
4onference
on
4omputer 8ision 1, Beiing, 4hina 3$?&3$2 !
IEEE
Conference on Computer ision and Pattern !ecognition
!*iami, lorida, C)A,
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A *akarau, - -ichter, - *\ller, J -einart', Adaptive shadow detection using a blackbody radiator model. IEEE Trans Leosci -emote )ensing 49!9%, <<&>>/
- Luo, [ ai, Hoiem, )ingle1image shadow detection and removal Computer
using
paired
ision
and
regions.
IEEE
Conference
on
Pattern
!ecognition !)prings,
4olorado, C)A, >&
APPENDI: 1
40*J-EHE5)I8E 4I-4CIT IAL-A* 0 THE )HA0 ETE4T0- E8I4E
//
