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Cell phone detector circuit

Updated: Nov 30, 2023

Cell phone Locator is a circuit that can detect the presence of any enacted PDA close by and gives a sign of initiated PDA close around of it. Essentially Cell finder is a Recurrence Indicator or a Current to Voltage Converter Circuit which gets frequencies around 0.8 - 3.0GHz (Portable band frequencies). RL tuned circuit (Resistor-Inductor circuit) isn't reasonable for recognizing the RF signals in GigaHertz range.


This Cell phone Identifier Circuit can recognize approaching/active calls, informing, video transmission and any SMS or GPRS utilizes inside the scope of 1 meter. This circuit is exceptionally valuable to identify PDAs at Wireless limited places like Test corridors, meeting rooms, emergency clinics and so on. It is additionally helpful in distinguishing the unapproved use or spying utilizing stowed away Mobile phone. It can distinguish the RF Transmission from the Cell Phone and triggers Bell to deliver blare sound, regardless of whether the telephone is kept on Quiet mode and this caution keeps signaling till the presence of RF signals.


Circuit Explanation


In this circuit we have involved a CA3130 Over powered Amp IC for distinguishing approaching or active sign around it. Operation amp non-upsetting end is associated with Vcc through 2.2M resistor and it is additionally associated with the ground through 100K resistor and 100uF Capacitor. Its reversing terminal is criticism from its result through a 2.2M resistor for intensify the sign. Two 100nF capacitors are associated among reversing and non-modifying terminal, filling in as circle recieving wire for the framework. Two 100nF capacitors are associated in series between Pin 1 and 8 of operation amp to help the addition of the current to voltage converter at its result pin.


Result of this operation amp is associated at the foundation of NPN semiconductor in particular BC547 through a 1k resistor and a Drove is associated at its producer for sign. A ringer is likewise utilized for sound sign by utilizing a PNP semiconductor specifically BC557. What's more, a 9 volt battery is utilized for driving the circuit. Rests of associations are displayed in the Circuit Outline beneath.

Required Components:


1. Op-Amp CA3130

2. 2M resistor (2)

3. 100K resistor (1)

4. 1K resistor (3)

5. 100nF capacitor (4)

6. 22pF capacitor (2)

7. 100uF capacitor

8. Bread board

9. 9 Volt Battery

10. Battery Connector

11. LED

12. Transistor BC547

13. Transistor BC557

14. Connecting wires

15. Buzzer

16. Antenna


Working Explanation


This circuit comprise an operation amp for certain dynamic uninvolved parts. A Drove and signal are utilized for sign of presence of cellphone. Operation amp is designed as Recurrence Identifier or Current to Voltage Converter and its result is associated with a Drove and signal utilizing NPN and PNP semiconductors.


Working of Portable Finder is basic. Two 100nF capacitors (C2 and C3), in equal, are utilized for recognizing RF signal from Cell Phone. These capacitors are filling in as circle radio wire for the framework. At the point when there is any call or SMS then capacitors in equal identify the information transmission frequencies or RF sign and result of operation amp goes high or low (fluctuating) because of created current at the info side of operation amp. Because of these variances, Drove turns on and off through NPN semiconductor as per the sign's recurrence. Presently PNP semiconductor is additionally set off with a similar recurrence and bell begins signaling until information transmission gets wrapped up.


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