Introduction - This circuit can detect the use of a gsm mobile in mobile restricted areas . The circuit can detect mobile in silent mode and also detect the use of bluetooth, sms, call etc. For example 1> examination halls . 2> high security area . 3> IN sensitive religious areas. 4>IN defence.
BFR96 BFR96 Is also called as RF & MICROWAVE DISCRETE or LOW POWER TRANSISTORS. Features · High Current-Gain – Bandwidth Product, fT = 4.5 GHz (typ) @ IC = 50 mA · Low Noise Figure – NF = 2.4 dB (typ) @ f = 0.5 GHz · High Power Gain – Gmax = 14.5dB (typ) @ f = 0.5 GHz
BFR96 DESCRIPTION: Designed primarily for use in high-gain, low noise, small-signal amplifiers. Also used in applications requiring fast switching times.
Diode Specifications Limit specifications Maximum forward continuous current The product of forward voltage drop and current through the diode is the power dissipation of the diode. Power dissipation results in a temperature rise. The maximum temperature that a diode can operate is around 125 C although some parts can operate at over 150 C. It is always good to operate any component below its maximum rated temperature. Be very aware that the specification assumes that the diode is operated with an infinite heat sink attached. No such heat sink exists and you must de-rate the specification based upon the actual heat sink characteristics and ambient temperature. This very important step is often overlooked and the result is diode failure from overheating even if the diode is operated below the specified maximum.
Diode specification- 2 Maximum forward surge current This specification generally applies to power rectifier diodes and addresses the turn-on transient current when large filter capacitors have to be rapidly charged. This specification is usually several times higher than the continuous current rating but only applies if the duration is brief.
Diode specification-3 Maximum forward peak current This specification generally applies to power rectifier diodes and addresses the fact that conduction through the diode is only for a small percentage of the total AC cycle time. As an example, a one ampere DC average current might require brief peak currents of ten amperes or more. The peak currents cause local hot spots which can damage the diode if they exceed the maximum temperature.
Diode specification-4 Maximum reverse voltage In the reverse direction the diode is an insulator but only if the reverse voltage is not too high. There is some voltage at which the diode structure breaks down and considerable reverse current can result which will usually destroy the diode instantly. The rating is often given as PIV for Peak Inverse Voltage. It is always a good idea to choose a diode with a significantly higher PIV rating than the maximum reverse voltage it will experience as this p r o v i d e s a s a f e t y ma r g i n .
Diode specification-5 Reverse recovery time Because of some complex physics, a diode that has been conducting in the forward direction will briefly conduct in the reverse direction. This results in extra heat being generated in power rectifiers and limits how high the AC frequency can be.
Diode specification-6 Maximum junction temperature This is the maximum temperature that the diode junction should be operated at. It is often in the 125 to 150 C range.
Range of mobile sniffer It can detect the activity of the phone from a distance Of eight metres or more. If two identical units of this sniffer are placed in the room, the range can be extended to a radius of 15 -16 metres.
What new thing we learn Duration of these project we learn following- 1> work as a team mate. 2>use bread board. 3> connections. 4> proteus. 5> good soldering.
Resistor Specifications Resistors have two main parameters. The first is its resistance in ohms. The second is its power rating in watts. There are other specs such as maximum working voltage but its power rating and resistance value are the most important in car audio systems.
Resistor Specifications-2 If an ideal piece of wire (no resistance) is connected to the ideal battery and there would be an infinite amount of current flow through the wire. In the real world, the battery (like your car battery) would force enough current through the wire and create enough heat in the wire to, at the very least, melt/burn the insulation off of the wire and more than likely incinerate anything that comes in contact with it.
Resistor Specifications-3 RESISTOR COLOR CODES The most common resistors have a tolerance of plus or minus 5%. These resistors have 4 color bands. The first 2 color bands give the first 2 digits of the resistors value. The 3rd band give the number of 0s added to the first 2 digits. If the third band is gold, you multiply the first 2 digits by .1. If it is silver, multiply by .01. The fourth band gives the tolerance. Gold is a 5% tolerance. Silver is 10%. The tolerance band is generally set off from the other bands. The other bands are generally set close together.
WORKING of mobile sniffer The sniffer keeps monitoring the RL level in the area which gives warning indication . The circuit is designed as a sensitive RF detector. RF signal` diode IN34 forms the major element. Along with resistor R1 and capacitor c2, the diode pick s up RF energy in the area. In the standby mode, the output of the diode is around 0.6 milli volt, which rises to 60 millivolts when it receives the high energy radiation from the mobile phone.
IC2 LA4440-2 Features • Built-in 2 channels (dual) enabling use in stereo and bridg amplifier applications. Dual : 6W×2 (typ.) Bridge : 19W (typ.) • Minimun number of external parts required. • Small pop noise at the time of power supply ON/OFF and good starting balance. • Good ripple rejection : 46dB (typ.) • Good channel separation. • Small residual noise (Rg=0).
IC2 LA4440-3 Features• Low distortion over a wide range from low frequencies to high frequencies. • Easy to design radiator fin. • Built-in audio muting function. • Built-in protectors. a. Thermal protector b. Overvoltage, surge voltage protector c. Pin-to-pin short protector
Since the voltage level from the sensor diode Is too weak, three –stage amplification is provided to give the warning indication through the speaker. output pulses from the sensor diode (1N34) are preamplified by transistor BFR96(T1). It is an RF/microwave lowpower transistor with high current gain and bandwidth.
It has a high power gain of 14.5 db at 0.5 ghz. Resistor R2 maintains the feedback and capacitor C4 keeps the collector voltage of T1 steady for maintaining the amplification. The preamplified signals are fed to the second amplifier stage built around IC TL071(IC1). It is a low noise , JFET-input op-amp with low input bias input and offset current. The BIFET technology provides fast slew rates to 1c1. here ic1 is designed as an inverting amplifier with resistor combination of r4 and r5 as potential divider to set half supply voltage to its non-inverting input.
The inverting input of ic1 receives the preamplified signals from t1. variable resistor vr1 adjusts the feedback of the inverting amplifier and hence its gain. The amplified signals from ic1 pass through capacitor c5 and diode D2 into volume control VR2 . It also receives the signals from unit 2 identical to unit 1 through capacitor c6 and diode D3. from volume control vr2, power amplifier ic2 gets the amplified signals. Ic la4440 (ic2) is a two channel audio power amplifier with inbuilt dual channels for streo and bridge amplifier applications. In dual
Mode it gives 6w, and in bridge mode the output is 19w. It has good ripple rejection of 46db, small residual noise built-in over –voltage and surge- voltage protection, and pin –to –pin protection . Here ic2 is wired in bridge config uration using only one input. Normally, a feeble hissing noise is heard from the speaker, indicating that the sniffer is active. The hissing noise is due to the detection of RF
In the area. Its loudness can be adjusted using vr2 . When a mobile phone is activated with in the range of eight metres, a loud motor- boating sound is heard through the speaker. This is due to a very high RF activity during the activation of the mobile phone. The sound is louder if the mobile phone is with a radius of two metres.
Limitation of direct powersupply. Power to the circuit is derived from a 12v, 4.5AH rechargeable battery, as AC power supply may generate audible disturbances in the circuit.
Improvement- 1> the size of our project is large but not complicated The following changes make project small- 1>Replace of power supply and use of battery . 2> Replace the loudspeaker and use buzzer. 3>use of best antenna which has small size and good range. So these changes make mobile sniffer pocket size.
HELP taken 1> we take help our guide 2> proteus 3>www.google.com 4> electronic for you.