Cell phone detector
This handy pocket-size mobile transmission detector or sniffer can sense the presence of an activated mobile cell phone from a distance. So it can be used to prevent use of mobile phones in
examination halls, confidential rooms, etc. It is also useful for detecting the use of mobile phone for spying and unauthorized video transmission. The circuit can detect the incoming and outgoing
calls, SMS and video transmission even if the mobile is kept in the silent mode. Assemble the circuit on a general purpose PCB as compact as possible and enclose in a small box like junk mobile case. As mentioned earlier, capacitor C3 should have a lead length of 18mm. Use of a short telescopic type antenna .Use the minimum 12V battery of a remote control and as mall gadget pocket size. The unit will give the warning indication ofsomeone uses a cell phone
As increase in the technology in the world using the electronic equipment are being used in a Wrong way like in the examination halls and confidential rooms. Cell Phones are used to perform various malpractices, use of cell phones have led to usage of various things. It has become easier for the data to circulate without the permission of the creator.Copying,cheating rates have increased significantly because of the usage of cell phones. To Avoid thiswe Are introducing this project called Cell Phone Detector. The most common electronic equipment used now-a-days is Cell Phone or Mobile Phone.
With advancement in communication technology, the requirement of cell phones has increaseddramatically. A cell phone typically transmits and receives signals in the frequency range of 0.9 to 3GHz. This project provides a simple circuit to detect the presence of an activated cell phone by detecting these signals. This handy pocket-size mobiletransmission detector or sniffer can sense the presence of an activated mobile cell phone from some short distance. Our project provides a simple circuit to detect the presence of an activated cell phone by detecting these.
When a call is coming to the mobile phone, the transmitter inside it becomes activated. The frequency of the transmitter is around 900MHz.The coil L1 picks up these oscillations by induction and feds it to the base of Q1. This makes the transistor Q1 activated.Since the Collector of Q1 is connected to the pin 2 of IC1 (NE555) , the IC1 is triggered to make the LED connected at its output pin (pin 3) to blink. The blinking of the LED is the indication of incoming call. The authors have discussed the techniques for detecting cellular phones. The device examines the existing technology currently available on the market, they have discussed about the existing design that utilizes mostly discrete components, and a design approach using a down converter in conjunction with a bandpass filter. The existing technologies available on the open market are examined and discussed. These technologies are not adequate, because they are inaccurate and expensive. The first signal detection technique, an existing design utilizing discrete components is difficult to implement. They are very affordable to construct, but require precision tuning. This design is analyzed and found to be inaccurate. The second signal detection technique, a design using a down converter, voltage controlled oscillator (VCO), and a bandpass filter was investigated for cellular phone detection. The performance of this technique through hardware and computer modeling is discussed and the results are presented. The new system is accurate and a practical solution for detecting cellular phones in a secure facility
Mobile phone uses RF with a wavelength of 30cm at 872to2270MHz.That is the signal is High frequency with huge energy. When the mobile phone in active, it transmit the signal in the form of sine wave which passes through the space. The encode audio/video signal contain electromagnetic radiation which is picked up by the receiver in the base station. The transmitter power of the modern 2G antenna in the base station is 20-100watts Radio Frequency detection simply consists of intercepting a sinusoidal signal passing through space. On average, mobile phone frequencies operate with a wavelength of 30cm between 872 and 2170 MHz. This means that when the device is activated the signal has high frequency and energy. Global System of Mobile Communication (GSM) digital phone transmissions are allocated two frequency bands: one at 900MHz and the second at 1800MHz. Within each band there are roughly 100 carrier frequencies on 200kHz spacing. Mobile-phone uses RF ranging from 700 to 2600 MHz in the GSM (Global-System of Mobile communication) and LTE (Long Term Evolution) bands, that is the signal is high-frequency with hugeenergy. When a mobile-phone is active, it transmits the signal in the form of sinusoidal-wave which passes through the space. The encoded audio/video signal contains electromagnetic- radiation which is picked up by the receiver in the basestation. 
List of Components
In this circuit we have used a CA3130 OP-Amp IC for detecting incoming or outgoing signal around it. Op-amp non-inverting end is connected to Vcc through 2.2M resistor and it is also connected to the ground through 100K resistor and 100uF Capacitor. Its inverting terminal is feedback from its output through a 2.2M resistor for amplify the signal. Two 100nF capacitors are connected between inverting and non-inverting terminal, working as loop antenna for the system. Two 100nF capacitors are connected in series between Pin 1 and 8 of op-amp to boost the gain of the current to voltage converter at its output pin. Output of this op-amp is connected at the base of NPN transistor namely BC547 through a 1k resistor and a LED is connected at its emitter for indication. And a 9 volt battery is used for powering the circuit. A buzzer can also be used for sound indication.. This circuit consist an op-amp with some active passive components. An LED is used for indication of presence of cell phone. Op-amp is configured as Frequency Detector or Current to Voltage Converter and its output is connected to a LED r using NPN and PNP transistors. Working of Mobile Detector is simplE.Two 100nF capacitors (C2 and C3), in parallel, are used for detecting RF signal from Mobile Phone. These capacitors are working as loop antenna for the system. When there is any call or SMS then capacitors in parallel detect the data transmission frequencies or RF signal and output of op-amp goes high or low (fluctuating) due to generated current at the input side of op-amp. Due to these fluctuations, LED turns on and off through NPN transistor according to the signal’s frequency. Now PNP transistor is also triggered with the same frequency and LED starts blinking until data Transmission gets finished.
1) It can be used to prevent use of Mobile phone in examination halls, confidential rooms etc.
2) It is also useful for detecting the use of mobile phones for spying and unauthorized video Transmission.
3) It is useful where the use of mobile phones is prohibited like petrol pumps and gas stations.
As soon as the cell phone detector detects the signal that has been transmitted be the phone while receiving a call or amessage the led starts blinking.This will help to identify the presence of cell phones by detecting the presence of the signaltransmissions and the output given by the LED.
This pocket-size mobile transmission detector or sniffer can sense the presence of an activated mobile cell phone from a distance of one and a half meters. So it can be used to prevent the use of
mobile phones in examination halls, confidential rooms, etc. It is also useful for detecting It is also useful for detecting the use of mobile phones for spying and unauthorized video transmission.
1) Active Cell Phone Detection And Display Using Atmega-8 Microcontroller -Tanvi Deshpande & Nakul Jadhav
2) Design And Testing Of Mobile-PhoneDetectors- Edwin Ataro
3) Diana Starovoytova Madara Simiuy Sitati Design And Testing Of Mobile-PhoneDetectors- Tesfamichael Molla
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