1) The circuit described is a simple anti-theft alarm that sounds if someone attempts to snatch a bag or suitcase it is placed in.
2) It works by using a plug and socket - when the plug is detached from the socket, such as if the bag is snatched, it triggers an alarm using integrated circuits.
3) The alarm is loud to draw attention, simulating a police horn for about a minute, allowing time to catch the thief.
MOBILE BUG ; ACTIVE CELL PHONE DETECTOR USING CMOS & BIPOLAR TRANSISTORSShahrukh Javed
DESCRIPTION
Cell Phone Detector this handy, pocket-size mobile transmission detector can sense the presence of an activated mobile cell phone from a distance of one and-a-half meters.
The circuit can detect the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. The moment the Bug detects RF (radio frequency transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks. The alarm continues until the signal transmission ceases. This project provides a simple circuit to detect the presence of an activated cell phone by detecting these signals.
NOTE Circuit will not detect if the mobile is switched off.
TEAM MEMBER
SHAHRUKH JAVED
SYED MOULA
For more log on to: http://shahrukhjaved.webs.com/apps/blog/
E-mial: shahrukh.tjit14@gmail.com
MOBILE BUG ; ACTIVE CELL PHONE DETECTOR USING CMOS & BIPOLAR TRANSISTORSShahrukh Javed
DESCRIPTION
Cell Phone Detector this handy, pocket-size mobile transmission detector can sense the presence of an activated mobile cell phone from a distance of one and-a-half meters.
The circuit can detect the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. The moment the Bug detects RF (radio frequency transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks. The alarm continues until the signal transmission ceases. This project provides a simple circuit to detect the presence of an activated cell phone by detecting these signals.
NOTE Circuit will not detect if the mobile is switched off.
TEAM MEMBER
SHAHRUKH JAVED
SYED MOULA
For more log on to: http://shahrukhjaved.webs.com/apps/blog/
E-mial: shahrukh.tjit14@gmail.com
AUTOMATIC DOORBELL WITH OBJECT DETECTION USING ULTRA SONIC TRANSMITTER AND RE...AKSHAT GANGWAR
We all have a doorbell at our homes. When a visitor comes to our house, he searches for the doorbell switch and then rings it to let us know his presence. If the who came to our house cannot find the doorbell or else if the person is so short that he cannot reach the doorbell, what can be done? How will it be if we use an automatic doorbell which rings as soon as a person arrives at our place? There are no more hassles. The person who comes to our house need not search for the doorbell and press it any more. If we install this automatic doorbell using object detection circuit, the circuit will automatically sense the presence of the person and it rings the doorbell.
This circuit operates using a pair of ultrasonic transmitter and receiver modules which are used to detect the person and then if the person is detected, the doorbell is automatically turned ON when the person is in-front of the door.
The ultrasonic transmitter operates at a frequency of about 40 Kilo-Hertz. That means it continuously transmits the ultrasonic waves of about 40KHz. The power supply should be moderate such that the range of the transmitter is only about one or two meters. If the transmitting power is less than one meter, then there is a chance that the person who is one meter away is not detected. Also, if the range is set to be very large, then it may lead to false triggering, meaning that, the objects far away from our door are considered as the visitors and the alarm rings. This can be a nuisance for us if the alarm rings for every object or person far away. So, to avoid both the problems, the transmitting power is kept to an optimum level.
The ultrasonic receiver module receives the power at the frequency same as that of the transmitter’s so that noise will be eliminated and we get less false triggering. The sensitivity of the receiver can be tuned by using the 500K-ohm variable resistor arranged as a pot in the circuit. By tuning this properly, we can achieve the desired results. The output of our circuit is given to a buzzer circuit which acts as a doorbell in our case. The receiver in this circuit uses IC LM324 which is internally has four op-amps. Out of the four op-amps, we are using only four of them and leaving the other one unused as it is not much required in our case. The three op-amps are used in cascaded arrangement to provide high gain as well as noise free output.
Smart Autonomous Mobile detector RobotPunit Tiwari
SMART AUTONOMOUS MOBILE DETECTOR ROBOT
-This device can notice the use of GSM mobile phone in mobile restricted areas such as Examination hall or confidential rooms etc.
-It is just like a sniffer mobile that can sense the activity of mobile phone from a distance of 5 meters or more.
A security alarm based on infrared radiations.
555 Timer used in this process.
Comparator, Photodiode, Resistors, Capacitors, and Buzzer are used.
Complete working Of circuit.
You can learn about ECG AMPLIFIER, INSTRUMENTATION AMPLIFIER, ECG AMPLIFIER DIAGRAM, VALUE OF RC TIME CONSTANT ?, DRIVEN-RIGHT-LEG SYSTEM, EQUIVALENT CIRCUIT FOR THE INPUT OF AN ECG AMPLIFIER, Method to increase input impedance, Active filters, FREQUENCY RESPONSE, LOW PASS FILTER, HIGH PASS FILTER, BAND PASS FILTER, Resonant frequency, Quality factor or Q factor
VIDEO LINK: https://youtu.be/sBG17ffSh40
Refer this link to get idea about instrumentation amplifier
https://youtu.be/-j8ePvHOuGk
AUTOMATIC DOORBELL WITH OBJECT DETECTION USING ULTRA SONIC TRANSMITTER AND RE...AKSHAT GANGWAR
We all have a doorbell at our homes. When a visitor comes to our house, he searches for the doorbell switch and then rings it to let us know his presence. If the who came to our house cannot find the doorbell or else if the person is so short that he cannot reach the doorbell, what can be done? How will it be if we use an automatic doorbell which rings as soon as a person arrives at our place? There are no more hassles. The person who comes to our house need not search for the doorbell and press it any more. If we install this automatic doorbell using object detection circuit, the circuit will automatically sense the presence of the person and it rings the doorbell.
This circuit operates using a pair of ultrasonic transmitter and receiver modules which are used to detect the person and then if the person is detected, the doorbell is automatically turned ON when the person is in-front of the door.
The ultrasonic transmitter operates at a frequency of about 40 Kilo-Hertz. That means it continuously transmits the ultrasonic waves of about 40KHz. The power supply should be moderate such that the range of the transmitter is only about one or two meters. If the transmitting power is less than one meter, then there is a chance that the person who is one meter away is not detected. Also, if the range is set to be very large, then it may lead to false triggering, meaning that, the objects far away from our door are considered as the visitors and the alarm rings. This can be a nuisance for us if the alarm rings for every object or person far away. So, to avoid both the problems, the transmitting power is kept to an optimum level.
The ultrasonic receiver module receives the power at the frequency same as that of the transmitter’s so that noise will be eliminated and we get less false triggering. The sensitivity of the receiver can be tuned by using the 500K-ohm variable resistor arranged as a pot in the circuit. By tuning this properly, we can achieve the desired results. The output of our circuit is given to a buzzer circuit which acts as a doorbell in our case. The receiver in this circuit uses IC LM324 which is internally has four op-amps. Out of the four op-amps, we are using only four of them and leaving the other one unused as it is not much required in our case. The three op-amps are used in cascaded arrangement to provide high gain as well as noise free output.
Smart Autonomous Mobile detector RobotPunit Tiwari
SMART AUTONOMOUS MOBILE DETECTOR ROBOT
-This device can notice the use of GSM mobile phone in mobile restricted areas such as Examination hall or confidential rooms etc.
-It is just like a sniffer mobile that can sense the activity of mobile phone from a distance of 5 meters or more.
A security alarm based on infrared radiations.
555 Timer used in this process.
Comparator, Photodiode, Resistors, Capacitors, and Buzzer are used.
Complete working Of circuit.
You can learn about ECG AMPLIFIER, INSTRUMENTATION AMPLIFIER, ECG AMPLIFIER DIAGRAM, VALUE OF RC TIME CONSTANT ?, DRIVEN-RIGHT-LEG SYSTEM, EQUIVALENT CIRCUIT FOR THE INPUT OF AN ECG AMPLIFIER, Method to increase input impedance, Active filters, FREQUENCY RESPONSE, LOW PASS FILTER, HIGH PASS FILTER, BAND PASS FILTER, Resonant frequency, Quality factor or Q factor
VIDEO LINK: https://youtu.be/sBG17ffSh40
Refer this link to get idea about instrumentation amplifier
https://youtu.be/-j8ePvHOuGk
In an extremely mechanized world such as today’s it is necessary to make our life better, convertible and economical. This is the purpose for which the Electronic house is developed. This project proposes the development of security system for farm houses and residential houses. It is used to develop security system for houses and to save electric power.
Timer with audible warning with circuit Diagram Team Kuk
From detectors to automobiles, audible alarms (also known to be called buzzers) have become a part of our everyday life. Some of the uses of these alarms are innocuous such as in a microwave oven. However, in some applications such as in a smoke detector or medical equipment, a person’s life may depend upon the audible warning sound. In all cases, the equipment designer should consider the desired characteristics of the audible alarm at the initial design-planning phase to obtain satisfactory performance and avoid costly redesign. The first characteristic for a designer to consider is the type of sound such as a continuous, intermittent or specialty sound. Other critical criteria include sound level, frequency, current draw, quality, mounting configuration, cost, and availability
1. CIRCUIT IDEAS
ANTI-BAG-SNATCHING ALARM SAN
I THE
O
D. MOHAN KUMAR the voltage at the non-inverting input is (IC3) gets the supply voltage at its pin 5.
higher than at the inverting input and the IC UM3561 is a complex ROM with
H
ere is a simple alarm circuit to output of IC1 is high. an inbuilt oscillator. Resistor R8 forms
thwart snatching of your valuables The output from pin 6 of IC1 is fed to the oscillator component. Its output is fed
while travelling. The circuit kept trigger pin 2 of IC NE555 (IC2) via coupling to the base of single-stage transistor am-
in your bag or suitcase sounds a loud capacitor C1 (0.0047 µF). IC2 is configured plifier BD139 (T1) through resistor R9 (1
alarm, simulating a police horn, if some- as a monostable. Its trigger pin 2 is held kilo-ohm).
one attempts to snatch your bag or suit- high by resistor R4 (10 kilo-ohms). Nor- The alarm tone generated from IC3 is
case. This will draw the attention of other mally, the output of IC2 remains low and amplified by transistor T1. A loudspeaker
passengers and the burglar can be caught the alarm is off. Resistor R6, along with is connected to the collector of T1 to pro-
red handed. capacitor C3 connected to reset pin 4 of duce the alarm. The alarm can be put off
In the standby mode, the circuit is IC2, prevents any false triggering. Resistor if the plug is inserted into the socket
locked by a plug and socket arrangement R5 (10 mega-ohms), preset VR (10 mega- again. Transistor T1 requires a heat-sink.
(a mono plug with shorted leads plugged ohms) and capacitor C2 (4.7 µF, 16V) are Resistor R7 (330 ohms) limits the cur-
into the mono-jack socket of the unit). timing components. With these values, the rent to IC3 and zener diode ZD1 limits
When the burglar tries to snatch the bag, output at pin 3 of IC2 is about one minute, the supply voltage to IC3 to a safe level
the plug detaches from the unit’s socket which can be increased by increasing ei- of 3.3 volts. Resistor R9 limits the cur-
to activate the alarm. ther the value of capacitor C2 or preset VR. rent to the base of T1.
The circuit is designed around op-amp When there is an attempt at snatch- The circuit can be easily constructed
IC CA3140 (IC1), which is configured as ing, the plug connected to the circuit de- on a vero board or general-purpose PCB.
a comparator. The non-inverting input taches. At that moment, the voltage at Use a small case for housing the circuit
(pin 3) of IC1 is kept at half the supply the inverting input of IC1 exceeds the and 9V battery. The speaker should be
voltage (around 4.5V) by the potential voltage at the non-inverting input and sub- small so as to make the gadget handy.
divider comprising resistors R2 and R3 of sequently its output goes low. This sends Connect a thin plastic wire to the plug
100 kilo-ohms each. The inverting input a low pulse to trigger pin 2 of IC2 to and secure it in your hand or tie up some-
(pin 2) of IC1 is kept low through the make its output pin 3 high. Consequently, where else so that when the bag is pulled,
shorted plug at the socket. As a result, the alarm circuit built around IC UM3561 the plug detaches from the socket easily.
FEBRUARY 2004 ELECTRONICS FOR YOU