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  2. 2. o Introduction o Design Objectives o Equipments o Frequency Range Detector o Working Principle o Basic block diagram o Circuit Design o Components Description- Op-Amp IC1 CA3130 NE555 Timer Capacitors Resistors Transistors o Applications o Conclusion o Future Plan
  3. 3.  Main scope of project is to sense the presence of an activated mobile phone from a distance of one-and-a-half meters to prevent the use in the examination halls, confidential rooms etc.  RF detector using tuned LC circuits is formed for detecting signals in the GHz frequency.  Transmission frequency of mobile phone ranges from 0.9 to 3 GHz.  As the cell phone sends or receives a message or call, it sends off a signal. This signal is detected by our circuit and will cause the LED to blink and buzzer to sound.  This simple circuit can detect any cell phone activities like sending or receiving calls or SMS, or any type of data transmission.  The aim of the circuit is to receive the RF signal from mobiles & detects its presence by alarming the sound.
  4. 4. The main objective includes building a mobile detector to locate a phone within one and a half radius and to jam GSM signal within 5 to 10 meters radius.
  5. 5. Resistors Capacitors Transistors Op-Amp LED IC 555Timer Piezo buzzer Battery 5 inch Antenna On-Off Switch
  6. 6.  The transmission frequency of mobile phones ranges from 0.9 to 3 GHz with a wavelength of 3.3 to 10 cm. So a circuit detecting gigahertz signals is required for a mobile bug.  The lead length of the capacitor is fixed as 18 mm with a spacing of 8 mm between the leads to get the desired frequency.  The disk capacitor along with the leads acts as a small gigahertz loop antenna to collect the RF signals from the mobile phone.
  7. 7.  We use a disk capacitor C4(220nF), which will capture the signals from the active cell phone transmission. The disk capacitor along with its leads form a small gigahertz loop to catch the signals.  The IC CA3130 is an op-amp, that is used in this circuit as a current to voltage converter. The capacitor C4 leads are the input for the IC1.  The IC1 provides the base voltage to the transistor Q1.  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 transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks.  We are using a 5 inch antenna.
  8. 8.  OP AMP IC1 CA3130 Op-amp IC CA3130 (IC1) is used in the circuit as a current-to voltage converter ..
  9. 9. NE555 TIMER IC A555timer in mono-stablemodealongwith a high gainopamp isused to detect Giga Hertz induced signals soproduced by an active cell phone with in closer proximityt o sound a buzzeralarm.
  10. 10. TRANSISTORS One transistor is used, BC548 It is a CMOS version using gate- protected p-channel MOSFET transistors in the input to provide very high input impedance, very low input current and very high speed of performance..
  11. 11. RESISTORS 15 kΩ, 12 kΩ, 1 k Ω, 100kΩ, 2.2 MΩ. Total six resistors are there. 15 k Ω is connected with pin no 6 and 12 k Ω is connected with pin no 2 of the NE555 timer.
  12. 12. CAPACITORS 0.01 µF, 4.7 µF, 0.1 µF, 0.22 µF, 22 pF, 47 pF, 100 µF. How does it work?  To detect the signal , the sensor part should be like an aerial..  The capacitor creates the fields, store the energy and transfers this energy in the form of mini current to the input of the IC1 which will upset the balanced input of IC1 and converts the current into output voltages..
  13. 13. 1) It can be used to avoid the usage of mobile phones in examination halls,seminar halls,quizzes etc. 2) It can be used to avoid video transmission in a secret or private meeting. 3) It can be used for military and civil defense purposes to detect mobile phones by increasing its radius of range. 4) It can be used in hospitals and airplanes where,mobile signals interfere with the electronic equipment which may have fatal consequences.
  14. 14. • This cell phone detector circuit can sense the presence of an activated mobile cell phone from a distance of one and-a- half meters.. • This cellular phone detector can detect any activity of a mobile phone : incoming or outgoing SMS , video transmission or voice transmission.. • This cellular phone detector electronic circuit diagram can be used to verify the presence of an active cellular phone in the tested area..
  15. 15.  Over the allotted period we were able to progress with our circuitry but it is far from complete.  So in future we expect to complete the circuit and implement a cellular detector through our circuit.