Super sensitive intruder alarm

Super sensitive intruder alarm

1. Super Sensitive Intruder Alarm
Introduction:
Frailty and wrongdoing comprise a portion of the serious issues confronting our prompt society
today. Individuals live with dread of being assaulted by robbers, miscreants and hoodlums. In
spite of all the exertion, assets and time that has been given to the improvement of instruments
that will diminish wrongdoing rates and make the world a more secure spot to live, these issues
are as yet on the increment. These brought about the requirement for an expanding improvement
in the innovation of caution frameworks which uses different standards like infrared movement
identification, light (photograph) touchy electronic gadgets, etc. Indeed, even with the
presentation of these alert frameworks which have decreased incredibly the degree of frailty,
there is as yet an issue of bogus caution which should be limited. To adequately lessen the degree
of weakness and stay away from bogus alerts which can make pointless distress, a touch actuated
security framework is required. This framework in the event that appropriately planned will give
security and guarantee cautions are initiate just when an unapproved individual attempt to access
the ensured territory or gadget by contacting the passageway or then again some other piece of
the device. An caution is an uproarious commotion or sign for alarming or advising individuals
regarding threat or an issue. An alert framework is in this way a security framework that creates
a type of sound to caution individuals of a specific threat. The advancement of caution
frameworks began with the making of man. Man required giving ready data and received a type
of flagging, outcry and yelling. This was subsequently supplanted by applauding and beating of
gongs by local pro claimers to caution the local area to scatter data in the early African culture.
Every one of these techniques of raising alarm were rough, temperamental and wasteful. With
the headway in science and innovation, these unrefined strategies for producing alert were
supplanted by electronic alert frameworks in the late eighteenth century.
Super sensitive is a framework intended to recognize interruption – unapproved passage – into a
structure or other region. Security cautions are utilized in private, business, modern, and military
properties for insurance against burglary or property harm, just as close to home assurance
against interlopers. Security cautions in neighborhoods show a connection with diminished
robbery. The alert frameworks fill a solitary need of theft security; blend frameworks give both
fireand interruption insurance.
On the before days guard would be recruited to deal with property and offer required security in
the home. A few homes additionally had canines that would be utilized uniquely around evening
time. These two should give security to our kin even without the house proprietor. Nonetheless,
employing a gatekeeper was not a viable strategy since a large portion of them would be
murdered in the line of working obligation. In some cases canine would assault even guests
while some guardians plundered property. This circuit is utilized to caution the client when any

2. individual goes into the home. On the off chance that there is any individual before IR sensor, it
produces an information signal. These information signals are given to the speaker to alarm the
client. The shadow of any individual close by the circuits is sufficient to trigger the caution.
Super Sensitive Intruder Alarm is a ultra touchy interloper caution circuit chart. Here the
shadow of the interloper going through couple of meters close by can trigger this circuit to create
an alarm. Here the work is performed through a LDR (Light Dependent Resistor).Thus this
circuit was set up in such a manner so Op-amp was made to trigger the NE 555 to deliver a
progression of clock beat waveform which was wired in methods for monostable Multivibrator
mode. Now let us see the activity of this straightforward Intruder caution circuit.
Problem Statement:
In Kuwadzana territory in Harare there is an expansion in robbery cases in houses and
organizations. Because of the present circumstance a need has emerged to limit wrongdoing
cases in houses and organizations by executing a home security framework that cautions the
capable authorities.
SOLUTION:
This circuit is designed to alert the user when an intruder enters into the home. If there is any
obstacle in front of IR sensor, it generates an interrupt signal. This interrupt signal is given to the
speaker to alert the user.
Super Sensitive Intruder Alarm Circuit Principle:
IR transmitter consistently discharges the IR (Infrared) beams which must be gotten by IR
beneficiary. When there is a deterrent before IR sensor, the sent IR beams are reflected back to
the IR collector. The yield of Op-Amp is high when IR beneficiary gets the reflected IR beams.
This yield of operational amplifier is associated with the RESET pin of 555 timer.
The yield of 555 timers is low when input voltage at pin four is high, at that point 555 clock
creates the recurrence which can be changed by the estimation of the resistors R1, R2 and
capacitor C3.
Obstruction Present → IR Receiver Receives IR Rays→ Operation amp
Output High → 555 RST Pin High → Speaker Produces the Sound.
No Obstacle → IR Receiver doesn't Receive the Rays → Op-amp Output Low → RST Pin
Low → No Sound
The yield of NE555 is sifted by the 1uFcapacitor and took care of to the speaker.

3. Numerous IR sensors are utilized in house at better places and the yield of these sensors is given
to the RESET pin of regular 555 clock. At the point when any sensor distinguishes any
individual, the reset pin of 555 timer turns out to be high and speaker will produce the sound.
Super Sensitive Intruder Alarm Circuit Diagram:

Circuit Components:
 NE555 timer
 LM358 op-amp
 Pot – 10k, 4.7k
 IR transmitter
 IR receiver
 Red led
 Ceramic capacitors – 0.1uF, 0.01uF
 Electrolytic capacitor – 1uF, 16v
 Resistors – 10k, 100, R4,R5
 2 resistors – 330 ohm
 Speaker
 Battery

4. SYSTEM DESIGN AND IMPLEMENTATION
Proposed Model:
In this circuit the alert will set off when the shadow of an interloper passing couple of meters
close by the circuit is sufficient to trigger the caution. IC2 uA 741 is wired as delicate
comparator; its set point is by R6 and R7. The voltage partition by LDR and R9 is given at non
altering pin of IC2. When there is an interloper close by or near the LDR the shadow will make
the protection from increment. All things considered the voltages at the contributions of
comparator will be unique and the out put of IC2 will be low. There front the Q1 will turn on.
This makes a negative going heartbeat to trigger the IC1 which is wired as a mono-stable multi-
vibrator. The out put of IC1 will be enhanced by Q2 (SL 100) to deliver alert. The LDR can be
housed in a dull cylinder to build affectability. The affectability is vital here. On the off chance
that you can't change the necessary affectability appropriately, utilize one LOW opposition
(~1K) POT in arrangement with R9 for fine change. The circuit is two sections and its
transmitter and the beneficiary is nothing yet a laser diode driven by a battery and it's connected
to the diode. To guarantee that the current remains in the diode a 5V or 7.5V and its applied to
the diode. These laser diode can be the one regularly utilized in laser pointers radiating in red.
This would be more economical simple than getting one.
Equipment Implementation:
555 Timer:
In that 555 timer goes about as a free running oscillator. It will generate the recurrence when info
is high heartbeat ii will at asa RESET pin. The produced recurrence of 555 timer is varying by
resistor esteems R4, R5 or by fluctuating the capacitor esteem C3.
Here Pin two and pin six of 555 timer are shorted to permit the setting off after each planning
cycle. In these circuit of capacitor C3 is charges through the resistors R4,R5 and its releases
through the resistor R5.
LM358 Op-Amp:
LM358 IC comprises of two operational intensifiers. Each Op-amp has two information sources
(modifying and non – reversing) and one yield. The operation – amp yield is high when non-
reversing voltage is more noteworthy than the rearranging voltage and it is low while
transforming voltage is more prominent than non altering voltage

5. .
LM358 Op-Amp
IF V1>V2 then OP = HIGH
IF V2>V1 then OP = LOW
The operational – amp output is high when non-inverting voltage is greater than the inverting
voltage and it is low.
IR Transmitter:
The working voltage of transmitter is around 2 to 3V, to drop the leftover voltage we associate a
resistor in arrangement with IR drove.
IR Receiver:
It is constantly utilized backward predisposition. It nearly goes about as a shut circuit when it
gets IR beams and it has high obstruction when it doesn't get any IR beams.
At first the Comparator utilized here was associated through non rearranging mode. The set place
of this Comparator was is through R6&R7.The voltage partition by LDR and R9 was given at the
non-transforming pin of the IC2.At backup mode these two voltages are set equivalent by
changing R9.The yield of the comparator will be high during this time so Transistor Q1 will be
off hence the voltage trigger given to the IC555 will be positive and there will be no caution.
At the point when an Intruder goes through that way the interlopers shadow will make cause the
opposition of the LDR to increase. Now the voltages given at the contribution of both the

6. terminal will be distinctive in this comparator the contrast between the voltages will be
intensified since the increment in obstruction will make the yield of the comparator to go to the
negative immersion giving low output. This makes the Q1 on. Therefore it allows a negative
going heartbeat to trigger to the Monostable multi vibrator. This makes the IC555 to create
nonstop square wave structures and it was then enhanced by the semiconductor Q2 to deliver the
caution sound. This circuit will be exceptionally amusing and simple to execute appreciate doing
it.
Stages of Implementation
The system design was implemented in three units These units are:
(A) The power supply unit
(B) The trigger unit
(C) The alarm/amplifier units
Power supply unit
The power supply unit is a 2-way programmed power supply framework. It gets contribution
from the two mains supply and battery supply. The two free stockpile frameworks are associated
with a transfer switch which goes about as a programmed change over change to turn on any of
the accessible information supply to the primary circuit. The power supply unit gives power
supply to the next two units of the circuit.
Operation of the Power Supply Unit It consist of 4 stages for rectification of 240V (A.C)
mains supply to 12V (D.C), a battery supply and a relay switch.
 Transformer stage
 Rectifier stage
 Filter stage
 Regulator Stage
The Trigger Unit
The trigger unit consist of 3 major components which areNE555 timer (IC2), Transistor (TR1)
and a relay (RLY2). The 555 timer (IC2) produces a trigger current which comes out through its
pin 3 whenever pin 2 is activated through the sensor. Pins 4 and 8 are connected to positive
power supply while pin 1 is grounded. R3 and C2 determines the time out period of the 555
timer (i.e. the period at which the alarm sound) while R4 determines the sensitivity of the sensor.
The output from pin3 (trigger current) is amplified by transistor (Tr1). R5 act as base resistor to
Tr1 which is operating in common emitter mode. The output current from transistor (Tr1) causes

7. the relay (Rly2) to operate thereby switching on the alarm/amplifier unit to power supply for
duration of time determined by the time out period of the 555 timer (IC2). D7 acts as a
commutation diode protecting the transistor (Tr1) from Back-EMF generated by the relay coils.
The 555 timer in this unit operates in a mono stable mode.
The Alarm Unit
It consists of 3 basic components which are; Two 555 timers IC3 and IC4 operating in a stable
mode to produce a sire sound and a power transistor (Tr2) used for further amplification of the
audio output. IC3 operates at a high frequency of about 481Hz, and act as a voltage controlled
oscillator, while producing a square wave. This forms the basic tone of the siren sound system.
IC4 produces another square wave much lower frequency of about (0.5Hz) this lower frequency
alters the rhythm of the steady tone from IC3 to the desired siren sound. The output of IC4 (i.e.
it’s pin3) is actually coupled through R9 to control the voltage terminal of IC3. The low
frequency (0.5Hz) output from IC4 is used to modulate the high frequency (481Hz) produced by
IC3 thereby alternating the frequency of operation of IC3 to produce a siren sound instead of a
continuous 481Hz tone. The final siren note is available at pin3 of IC3 but its maximum current
(as calculated on Section 3.3.3) is 0.038A. This current is not sufficient for 5w, 8ohms speaker.
The pin3 output of IC3 is therefore fed to the transistor Tr2 for further amplification enabling it
to power the speaker thereby producing a very loud audible siren sound.
How to Operate Super Sensitive Intruder Alarm Circuit?
 Give the associations as per the circuit chart.
 Associate 5V stockpile to the circuit.
 Presently place the deterrent before IR sensor then speaker creates the sound.
 Eliminate the impediment now you won't get any solid.
 Detach the battery from the circuit.
Applications:
This circuit is used in houses and offices for security purpose.
Limitations:
This circuit delivers the sound if there is any non-living thing before IR sensor.

8. Advantages:
It is Simplicity of establishment. The successful capacity to be utilized inside and outside. It very
well may be utilized as caution for the house/organization limits. It is utilized as a typical force
outlets and phone jacks in the event that it utilized inside. Can be utilized as home security
framework and can be utilized in Museums, Banks, Offices for safe gatekeeper numerous
significant things.
Disadvantages:
It tends to be enacted when something living and enormous bird sitting on the divider. They are
more costly when contrasted with basic security caution frameworks.
System Design Analysis
The Power Stage
A 240/18v transformer was chosen because its rating is capable of meeting the current demand
of the circuit and it is protected by the 1A fuse against excess current. The limiting resistor (R1)
for the LED1 was calculated as:
LED current
(7)Where VCC = supply voltage = 18V,
VLED = 2.2,
ILED = maximum allowable current across the LED = 35mA.
mA V R 35 18( )2.2 1 − = A V 0.035 8.15 = R1 = 451 43.
Ω The preferred resistor value closest to 451.43Ω is 470Ω . Therefore 470Ω were adopted in the
design. Current drawn by LED1 Ω = 470 18V = 038.0 MA The peak inverse voltage (PIV)
obtainable at the secondary terminal transformer is twice the terminal voltage VS .
That is: PIV = 2 x Vs = 2 x 18 = 36V. At the full bridge rectifier circuit IN4001 diode was used
because its PIV which is 50V is greater than the PIV of the secondary of the secondary terminal
which is 36V[13].
This was done to avoid damage to the diodes in case reverse operation occurs. The value of the
filter capacitor C1 was obtained as:
fyR C 4 3 1 = (8) (For full wave rectifier circuits)

9. where:
f = frequency of ripple voltage = 50Hz y = ripple factor = 5% = 0.05 12 R = resistance of the
regulator = I V (9) V = Constant output voltage from the regulator = 12v,
I = Constant output current from the regulator = 500mA = 0.5A = = 24Ω 0.5 12 R 4 3 24 50
05.0 1 x x x x C = , 415.692 1 C = C x LEDcurrent 6 .2 4056 10 − = , C = 405.2 6. xµF A 2200
µF was used in the design because it is the closest value of a standard capacitor of 405.2 6. xµF .
The current limiting resistor for LED2 is calculated as shown
below: LEDcurrent Voltagedrop R2 = ( ) ( ) 2 I LED
Vcc V LED R − = Where
VCC = supply voltage = 12V,
VLED = 2.2, I (LED) = 0.01A (Chosen to limit the amount of current consumed by the LED) A
V R 0.01 12( )2.2 2 − = ,
A V R 0.01 8.9 2 = R2 = 980Ω The preferred resistor value closest to 980Ω is 1KΩ . Therefore
1KΩ resistor was adopted as R2 in the design.
Current drawn by LED2 = 1000Ω 12V = 012.0 A = 12mA 3.3.2. The Trigger Stage The timeout
period (T) and the frequency (f) were determined by the values of R4 and C2 as follows: (1.1 ) 3
2 T = R xC (10)
But R3 = 220KΩ = 220 x 103Ω,
C2 = 47µF = 47 x 10-6F T (1.1 220x10 220x47x10 sec) s
3 −6 = = x sec)34.101.1( s = 374.11 sec s ≈ 11sec s T f 1 = 11.374 1 = = 09.0 Hz 13
The values of R4 and C2 were chosen in such a way that they can produce an approximate
period of 11secs delay.
The basis resistor R5 for transistor Tr1 was chosen as a result of the following calculations: B
BE I Vcc V R − 6 = (11)
Where VCC = supply voltage = 12V,
VBE = Base emitter voltage = 0.6(see appendix III) IB = Base current IB = IC/gain Supply
voltage, Gain = 25 (hFE) IC = collector current = maximum Relay current = A Coil sis ce Supply
Voltage 03.0 400 12 Re tan = = I B .0 0012A 25 03.0 ⇒ =
= To ensure that the current is sufficient to drive the transistor into saturation, the quantity of the
current is doubled i.e. I B = .0 0012x2 = 024.0 A 0.0024 4.11 0.0024 12 6.0 5 = − R = 47050Ω ≈

10. 7.4 ΩK A 7.4 ΩK resistor was chosen to serve as the base resistor (R6) to the transistor because
it is the closet value of standard resistor value to 47050Ω . 3.3.3.
The Alarm/Amplifier Stage Design calculation for this unit was done in three stages.
Stage 1: This is the high frequency oscillator stage. The period (TH) and frequency (fH) for this
stage were calculated as follows:
TH = t1 + t2 (12) t1
= 0.693 x C4 (R7 + R8)
But C4 = 0.01µF = 0.01 x 10-6F R7 = R8 = 100KΩ =100 x 103Ω
Therefore, t1 = 0.693 x 0.01 x 10-6(100 x 103 + 100 x 103 )
= 0.693 x 0.01 x 10-6 x 200 x 103 = 1.386 x 10-3secs t2= 0.693 x 100 x 103 x 0.01 x 10-6
t2= 0.693 x 10-3 3 -3 H 1 2
∴T = t + = t 1.386 x 10 + 0.693x 10 = 2.079 x 10-3secs = 2.079msecs
3 097.2 10 1 1 − =
= T x F H H = 481Hz
14 Duty cycle = 100% 097.2 10 38.1 10 3 3 1 x x x T t H − − =
= 66.95%
The value of C4, R7 and R9 were manipulated in order to get the desired frequency that will
modulate the low frequency oscillator (IC2) to give the desired tone.
Stage 2: This is the low frequency oscillator stage. The period (TL) and frequency (FL) for this
were calculated as follows: = + (13) t1 = 0.693 x C6 (R11 + R12)
But C6 = 47µF = 47 x 10-6F R11 = 1KΩ = 1 x 103 Ω
Therefore, t1 = 0.693 x 47 x 10-6 (1 x 103 + 22 x 103 ) = 0.693 x 47 x 10-6 x 23 x 103 =
10741.003x 10-3secs = 1.041secs t2 = 0.693 x C6 xR12 t2 = 0.693 x 47 x 10-6 22 x 103 t2 =
995.74 x 10-3 = 0.0996secs 1 2 T t t ∴ L = + = 1.041 + 0.996 = 2.037secs 037.2 1 1 = = L L T F
= 0.491Hz
Duty cycle = x100% 2.037 1.0411 T t L 1 = = 51.1% The values of C6, R11 and R12 were
manipulated in order to get the desired frequency that will modulate the high frequency oscillator
(IC3) to give the desired tone.

11. Stage 3: This is the audio amplifier stage. It is this stage that gives the final power output to the
speaker. The actual power output by the transistor (Tr2) was calculated as follows:
Power output = IE x VCC (14) Where VCC = supply voltage = 12v, IE = Emitter current But
IE = (1 + gain) x IB Gain = 100 (hFE) I B 038.0 A 300 4.11 300 12 6.0 = = − = IE = (1 + 100) x
0.038 = 0.418A, and Substituting back into to Eqn. (14), P 418.0 x12 ⇒ OUT = = 5.016
Watts ≈5Watts This means that the amplifier stage of the alarm unit (Tr2) gives an output of
5Watts. Therefore a 5Watts, 8Ω speaker was chosen at the output stage for maximum power
transfer.
Testing and Results
In testing the designed and constructed system, four basic steps were taken. These steps are
sequentially listed below as:
Step 1: To ensure that all the components to be used are functionally operating, they were first
tested with a digital multi meter and failed ones replaced before finally soldering them on the
vero board.
Step 2: To ensure that there was no breakage in the circuit path on the veroboard, immediately
after soldering on veroboard, the circuit path was tested using the Digital Multi-meter. This was
done to also ensure continuity of circuit on the veroboard.
Step 3: Using Circuit Maker 6 (Student Edition), the circuit was simulated. The result obtained
from the simulation closely corresponds to the desired result, with only some slight variations.
Step 4: The period of time for the alarm sound (Time out period) was manually tested. This was
achieved using Digital Stop Watch and the result obtained was found to be 10.60 seconds. The
value obtained from the manual testing closely agrees with that obtained in the design
specifications i.e. 11.37 seconds.
Discussion of Results
The main reason for testing all the components before they were finally soldered on the
veroboard is to avoid the painstaking effort it will take to dis-solder faulty components at the end
of the day. From the continuity test carried out on the veroboard to check the circuit path, it was
discovered that the circuit was in a perfect working condition as continuity was ensured.
Simulation of the circuit design was also done as mentioned earlier, with the sole objective of
comparing the results obtained from design calculations to that obtained from simulation. The
two results when compared closely correspond with only a very slight discrepancy in values.

12. Conclusion:
It can be concluded that the sole aim of carrying out the design, analysis and implementation of a
super sensitive intruder alarm systems and simple and reliable touch sensitive security system
was achieved, in that the aim was to develop a cheap, affordable, reliable and efficient security
system, which was successfully realized at the end of the design process. One factor that
accounts for the cheapness of the product was the proper choice of components used. The ones
that were readily available were used, while a close substitute was found for those that were not
readily available. The reliability of the entire alarm system was considered by the integration of
an automatic change over switch into the power supply unit such that the A.C mains supply and
the battery are cold redundant. Thus, this guarantees constant supply of power to the main
circuit. The efficiency of the entire system was put into consideration by the use of transistor in
the common collector mode to couple the output of the circuit to the speaker. The system was
tested and found to be working to specifications and predictions. Summarily, a cheap and
reliable way of checking the activities of burglars and intruders has been successfully developed,
which is the aim of the research. We can conclusively say therefore, that the benefits of having
this burglar alarm system cannot be overemphasized. In future, we shall find a way of
improving the system by interfacing the alarm system with the microcomputer to boost the
effectiveness of the entire system or integrating a digital door lock.
References:
“False alarm”, http://www.alarm.org/false/tips/dealer tip/dealer tip.html
British Security Industry Association (BISA), “Journal on security system section strategy for intruder
alarm system”, April 2005. Page 1-3
Thomas Petruzzelis, “The alarm, sensor and security circuit book”, TAB Books. Imprint of McGrawhill
San Francisco, U.S.A. Reprinted 1994, Page 5-7
“History of Security Alarms”, http://www.icee.org/organization/history center/fire alarm.html
Pascoe, T.; Lawrence, G.”Are intruder alarm systems effective as crime prevention
measures”onAerospace and Electronic Systems Magazine, IEEE
“Seismic intruder alarm “can recognise footfalls Electronics and Power in Google.
Chunlei Zhu; Qing-Jie Kong; Zhou, L.; Gang Xiong; Fenghua Zhu,” Sensitive keyword spotting
for voice alarm systems” on Service Operations and Logistics, and Informatics (SOLI), 2013
IEEE International Conference.

13. Lovecek, T.; Velas, A.; Kampova, K.; Maris, L.; Mozer, V.”Cumulative probability of detecting
an intruder by alarm systems” on Security Technology (ICCST), 2013 47th International
Carnahan Conference on 2013.
Reliable and Error Detection Architectures of Pomaranch for False-Alarm-Sensitive
Cryptographic ApplicationsVery Large Scale Integration (VLSI) Systems, IEEE Transactions on
2015.
https://prezi.com/gncgpbktkb8l/super-sensitive-intruder-alarm/
https://www.electronicshub.org/super-sensitive-intruder-alarm/
https://www.coursehero.com/file/52579870/PROJECT-TITLEdocx/