• Design And Construction Of A Remote Controlled Tri–band Frequency Jammer.

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    • Initially, when the circuit is just powered on, the Q0 output of the CD4017 decade counter goes high. The counter increments for each low-to-high going pulse arriving at its CLK pin (14). When the first pulse arrives, Q0 goes Low and Q1 is turned High. This activates the relay and the AC appliance connected to it is turned on. The status LED connected to Q1 also glows to indicate the appliance is switched on. When the user presses a key again, the second pulse arriving at the CLK line increments the counter by 1. This makes Q1 back to Low (which means the relay is deactivated and the appliance is turned off) and Q2 is pulled High. Since Q2 is wired to the Reset input, the second key press actually brings the CD4017 IC back to the power-on-reset conditions with Q0 High. Thus, it basically operates as an ON/OFF toggle switch controlled with any key of an infrared remote.
      The power supply for the circuit can be derived from the mains AC itself using a step down transformer and a bridge-rectifier circuit. For +5 V power supply, the LM7805 regulator IC is used.

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    • ABSRACT - [ Total Page(s): 1 ]ABSTRACT COMING SOON ... Continue reading---

         

      APPENDIX A - [ Total Page(s): 1 ]APPENDIX AList of Components•    Vero Board •    Connecting wire •     Power Switch •     30 Amps Fuse •     Soldering Lead •    Soldering Iron •     LEDs •     240V/ 60V Transformer •     12 volts D.C battery •    • IN9004, IN4004.1 diode, •     750 Ω, 750.1Ω, 100Ω, 1KΩ, 2KΩ, 22KΩ, 100KΩ, 1KΩ, 2KΩ, 22kΩ resistors •     555 timer •      ... Continue reading---

         

      APPENDIX B - [ Total Page(s): 2 ] ... Continue reading---

         

      CHAPTER ONE - [ Total Page(s): 2 ]CHAPTER ONEINTRODUCTION1.1    BACKGROUND OF THE STUDYA mobile phone jammer or signal blocker is an instrument used to prevent cellular phones from receiving signals from base stations. The process of blocking the receiver to receive a transmitted signal is called Jamming of the signal. The jammer effectively disallows cellular phone signal when activated. These devices can be used in practically any location, but are found primarily in places where a phone call would be particularly disruptiv ... Continue reading---

         

      CHAPTER TWO - [ Total Page(s): 3 ]CHAPTER TWOLITERATURE REVIEW AND THEORETICAL FRAMEWORK2.1    INTRODUCTIONWireless networking plays an important role in achieving ubiquitous computing where network devices embedded in environments provide continuous connectivity and services, thus improving human’s quality of life. However, due to the exposed nature of wireless links, current wireless networks can be easily attacked by jamming technology. Jamming can cause Denial-of- Service (DoS) problem which may result in several o ... Continue reading---

         

      CHAPTER FOUR - [ Total Page(s): 5 ]The bar chart in figure 4.9 above shows the jamming strength of the jammer at  Eigbejila, Odota and Garin Alimi area of Ilorin west Local government area kwara State, Nigeria. It is obvious from table 4.2 above that as the distance between the cell phone and the base station increases, the effective jamming distance increases. This is due to the fact that the amount of power reaching the cell phone from the base station decreases as the cell phone moves farther from the base station and vice ve ... Continue reading---

         

      CHAPTER FIVE - [ Total Page(s): 1 ]CHAPTER FIVECONCLUSION, CHALLENGES, RECOMMENDATION 5.1    ConclusionsThis project is very useful for mobile phones restricted places such as private meetings, examination hall, defense establishments, military camp, Hospitals; Petrol pumps, Libraries etc.  This device can scramble/jam mobile devices in a given area within the operating frequency range of   800MHz - 2100MHz at the range of 2-7 meters. The designed device works in Tri-band. It jams the GSM 800 band, GSM 1800 band and the add ... Continue reading---

         

      REFRENCES - [ Total Page(s): 1 ]REFERENCES1.    Science Journal of Physics ISSN: 2276-6367 http://www.sjpub.org/sjp.html.2.    Radio Jamming", Wikipedia Foundation, Inc. 2012. 3.    "Electronic Warfare", Wikipedia Foundation, Inc. 2012. 4.    "Electronic Counter-Countermeasures", Wikipedia Foundation, Inc. 2012. 5.    Scourias, John (1997): Overview of the Global System for Mobile Communications, University of Waterloo.6.    "Mobile Phone Jammers", Wikipedia Foundation, Inc. 2012.7.    Semiconductor device ... Continue reading---