This handy mobile bug or cell phone detector, pocket-size mobile transmission detector or sniffer can sense the presence of an activated mobile cellphone from a distance of one and-a-half metres. 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 unauthorised video transmission.
The circuit can detect both 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. The alarm continues until the signal transmission ceases.
Cell Phone Detector Circuit Schematic
An ordinary RF detector using tuned LC circuits is not suitable for detecting signals in the GHz frequency band used in mobile phones. 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.
Here the circuit uses a 0.22μF disk capacitor (C3) to capture the RF signals from the mobile phone. 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.
Cell phone RF radiation detector Video
and another video from Sufyan Ghori
Op-amp IC CA3130 (IC1) is used in the circuit as a current-to-voltage converter with capacitor C3 connected between its inverting and non-inverting inputs. 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. The output CMOS transistor is capable of swinging the output voltage to within 10 mV of either supply voltage terminal.
Capacitor C3 in conjunction with the lead inductance acts as a transmission line that intercepts the signals from the mobile phone. This capacitor creates a field, stores energy and transfers the stored energy in the form of minute current to the inputs of IC1. This will upset the balanced input of IC1 and convert the current into the corresponding output voltage.
Capacitor C4 along with high-value resistor R1 keeps the non-inverting input stable for easy swing of the output to high state. Resistor R2 provides the discharge path for capacitor C4. Feedback resistor R3 makes the inverting input high when the output becomes high. Capacitor C5 (47pF) is connected across ‘strobe’ (pin 8) and ‘null’ inputs (pin 1) of IC1 for phase compensation and gain control to optimise the frequency response.
When the cell phone detector signal is detected by C3, the output of IC1 becomes high and low alternately according to the frequency of the signal as indicated by LED1. This triggers monostable timer IC2 through capacitor C7. Capacitor C6 maintains the base bias of transistor T1 for fast switching action. The low-value timing components R6 and C9 produce very short time delay to avoid audio nuisance.
Assemble the cell phone detector 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 18 mm with lead spacing of 8 mm. Carefully solder the capacitor in standing position with equal spacing of the leads. The response can be optimised by trimming the lead length of C3 for the desired frequency. You may use a short telescopic type antenna.
Use the miniature 12V battery of a remote control and a small buzzer to make the gadget pocket-size. The unit will give the warning indication if someone uses mobile phone within a radius of 1.5 meters.
Check the related posts for more mobile phone detectors.
Last members who liked this article
mbkakumargaurcheri-anMahayaavinashmeDanielaebizeJKPieGuyTrailCree
i tried out this circuit,but it works only for 50 cms or less.have any suggestions for the improvement of the circuit????
I did the circuit for my project, it worked! mine can detected about 9 feet. But 12V voltage make the circuit become too sensitive, it will trigger even if you switch on your room lamp, so I reduce the voltage to 9V and it work fine! I built it on the PCB.
But remember to insulate the antenna, I used the middle part of TV antenna’s cable – the white one with insulation.
Actually the circuit is taken from Electronic For You Magazine from India..
Bye from Malaysia….
hi Faudzee,
I tried this circuit. But it wont work for me.. I think the problem is present in the capacitor. Please give me some comments about the capacitor
hi
i designed d same circuit
it worked but range is too small, it’s only 15 cm.
what should be done to increase it..
Moreover
can ny1 pls tell me detaled working f d ckt along with purpose f each component and design steps 4 same.
I need 2 prepare project report so plz help..
otherwise atleast tell me source whr i can get more details @ same ckt.
w8ng 4 rply…
hv a gr8 dy byeeeeeeee
hey faudzee….can u mail me all d requirmnts documentation!!…lyk wat kinda capacitors 2 b used preferable…and all oder things…
i will b highly obliged if u do!!…thank u
hello!
i am ajendra and i work on this program with my friend jaydeep we compleat this program.it is very easy to make
my contect no. is +91 *9426318602
by!by!by! friend!
hi..
i have done all circuitary with 10 volt battery…buzzer beeps even no transmission is there or cell phones r switched off….led flashes on switching on power ….can u help me out with this trouble????
……contact me at vand.gupta089@gmail.com
sir i got the output for this circuit ,but it works only when the moble in operation .
I would like to known basic working of IC CA3130 ,and what its function in this circuit
I want pcb layout of this circuit to complete the project.
If you have pcb layout then send me on:-gauravkpatil.973@rediffmail.com
Please help me.
For details of the circuit, contact me
Circuit published in Electronics For You magazine from India.
D.Mohankumar
hi
i am doin the circuit with my friend and would like to know the basic functioning of ic ca3130. wish to hear from you. bye…….
sir im havin problems wid de circuit..de alarm goes off as soon as de circuit is given power..also i wud like to have de design details of de circuit..please help!!!!
sir which kind of antenna should be used to improve the range of the instrument
sir,will you please tell me all design equations and working of each part,mainly use of capacitor after the antenna and working of ca3130.
please send me mail on harshal_chimu@rediffmail.com
I’m in the U.S.A. I am an electronics engineering student. I was wondering if there is a way for me to get the PCB details for this circuit
Respected sir,
I am an Engg. student. I am doing the project on mobile bug. can you please tell me the design of the circuit components especially the ic ca3130; and the antenna specifications?
If you can provide me with any documentation,please kindly forward to my mail ravikiran2mahesh@gmail.com.
Thanking you in advance,
Ravi kiran.
Even i tried to make the circuit. The first confusion i have is that of the capacitor. I cant find the same capacitors with 8mm lead spacing and 16mm lead length as mentioned in the circuit. Can you please give the model number for the capacitor.
Somebody please help. Thank You.
hi friends,
This project will not work for me. It is very difficult to buy the ic3130. I am trying to finish the work. Please give me any comments.
hello sir,i am doin tis project wit my frnd i got the output for this circuit it works even when the mobile is keep at silent mode…
I would like to known basic working of IC CA3130 ,and what its function in this circuit. Please let me know about tis very soon.
pls help i doin this project
91 9629049030
i have lay out digram of mobile bug,contect me 9893130732
HELLO, I am student of B.Tech electronics.I need every information abt MOBILE BUG Like PCB LAYOUT,PROJECT REPORTS etc.& how can I extend its radius to bug mobile.Please give me information.My email is MAHESH_6298 @YAHOO.COM & My mobile no. is 9371494051
FRNDS.I WANT TO KNOW HOW MUCH IT COSTS TO PREPAIRE THIS PROJECT???? PLZ HELP ME SOON
what type of power supply i must use???
hi! i M ajendra you use 12v bettery supply
thanks
my no is +91 9426318602
i done this project.it works,but range is very less,how to increase it?can u please tell me all design equations & detail opration of ca3130 & purpose of capacitor after the antenna.please reply as soon as possible.
hii……plssssss help me.we’re doing this as our mini project.we don’t know wat kind of antenna shold be used to improve the range of this bug.now our circuit will detect mobile signals only to a few cms..pls give a soln to dis problem immediately.we want to submit dis within 2 days.
hi..,im doing mini project on mobile bug..,i want to increase the redius which is now its 1.5m..,i want to extend then wt i ve to do?
sir i am working on this project. i wanna know more details about this.
like
i couldn’t get ic ca3130, will simple op-amp work?
what type of antenna should i use?
plzzz reply
ankit.8.baheti@gmail.com
if anyone can help……plz help me.
iam also on this project i want its lay out diagram plz can you send me it on my email? i want to precise that iam french speaker and i just try my best to speak and write english. please also tell me all design equations and working of each part,mainly use of capacitor after the antenna and working of ca3130.
hi friends,
i am doing project. what type of antenna can i use for this circuit. pls send me!
i want to do this project can u give some more information so as to understand it better please
FRNDS.I WANT TO KNOW HOW MUCH IT COSTS TO PREPAIRE THIS PROJECT???? PLZ HELP ME SOON 9329816097
Please My Project is on mobile bug. I wish that you help me with recent update on the project topic. thanks
hi umadi……… vl u plz fwd me d updates of MOBILE BUG
can u send me detial workig of this circut and student of QAU. i will be very thankful to u.
can u send me detial workig of this circut i am student of QAU. i will be very thankful to u.
Reply
Hi, I am doing my semestral project on mobile bug because I found out that it is quite interesting. Can u send me the documentation that are related to the project and updates on this project? Thanks.
i am doin my mini project on mobile detector can you send me the documentation of this project…..?
and can we increase the range of this mobile detector???
I don’t know about disk capacitor.
Ceramic capacitor. Is it right?
im doing project on this please send me documentation on this
i also need cell phone jammer documentation
Are you guys able to do a bit of the work yourself?
There is a nice schematic posted and it only requires a good hand full of components.
So get up and do your own work for your own university grade!
hi…
am doing my miniproject on mobilebug….
if u hav documentation pls fwd to my mail…
especially its advantages n applicatns,omer_sohel@yahoo.com
please how cAn i know the original TS555CN IC
PLS CAN U SEND ME THE CIRCUIT DIAGRAM OF CELL PHONE DETECTOR
IT IS FOR PROJECT
ABEG OOO
im doing my project on this please send me documentation on this
hi miss.tejaswini could u plz fwd me tha document on MOBILE BUG.2 MY MAIL “”"”srinivas13389@gmail.com”"”
thanks in advance
sir presently iam doing mini project on mobile bug sir plz could u help and sent documentation for this project
hi friend could u plz forward me the documentation on mobile bug to mpl_srinivas@yahoo.co.in
CAN U SENT ME THE LAY OUT OF IC CA3130 ANDIC NE555
plz i need the documentation of mobile bug….im doing my miniproject an mobile bug…plz send it me on abdulmuqeet_19@yahoo.com
I LIKE HOW, THE ONE, ONLY CALL, CAN BE CAPTURED, THE ONLY IMEI THE ONLY, JUST ONE NUMBER OF MOBILE PHONE GSM, I CAN USE SNIFFER ETHEREAL OR CAIN AND ABEL OR WIRESHARK
iam doing mini project on cell phone detector.can u able 2 send all documentation regarding this topic
this is raj kumar. i already have done the cell phone detection project…if u want details u can mail me raj_kumar999@yahoo.com
I am going to do a project about cellphone detector.Please send all document and cost about it.
HI I M DOING MY MINI PROJECT ON MOBILE BUG CIRCUIT.CAN U PLS FORWARD THE DOCUMENTATION TO MY MAIL.krashmirao_89yahoo.com
i m doing mini project on mobile detector.pls send me the documentation.my id is krashmirao_89@yahoo.com
i am doing this project could u please forwar me details of the circuit
search in google
The documentation is already here you dumbasses! So stop asking for it, your not going to get it!
hey ppl….dis is a very gud ckt..,bt im js not being able 2 gather info needed for me 2 complete dis as my mini project….,plss do help me out wit all d details u cud provide me wid…….!! plssss..,, i need em urgently..,
This is my circuit. You will get more information through my mail mohanuc@gmail.com.
D.Mohankumar
can u plz send me information about this project….???
plssss snd me all d details about d prj 2 my email:kamawl_scorpion@yahoo.co.in
plssss do help me buddy……..
how to increase the area?what is the frequency range??
hi
i m doing my btech
and in our college
we have to make one mini project
which can be useful to our college
this mobile detecter can be useful to me
but i m not getting enough specification of this one
so can u plz provide me some stuff
it will be greatfull to me
thank u
hi…i have just finished this design..it is working properly…if you have any problem consult with me……….
Can we increase the range by attaching the RF amplifier instead of antenna???
Do reply fast..
Hi kuldeep im a b.tech(ece) final year student and i want to develop a mobile detector for my minor project.so can you provide me with the details of the mobile detector?Plz contact me at Taran.3087@gmail.com
Hye Kuldeep
I’m BE student..
I’m also run this project for my final year project..
My project should being detected when the cellphone are switch OFF and switch ON..
So I need to share your information about this matter..
Email me : pau_gbest@yahoo.com.my
I really need your help
hi
i’m doing project on cellphone detector.i need clear circuit diagram and component required for this circuit.
Hi kuldeep,
Did this ckt really work?What antenna should be used.Can you help me out
hi
i m doing BE
and in our college
we have to make one mini project
which can be useful to our college
this mobile detecter can be useful to me
but i m not getting enough specification of this one
so can u plz provide me some stuff
it will be greatfull to me
thank u
pls send me the details and specifications of IC3130 which is used as current to voltage converter in mobile bug project to ramya1490@yahoo.com
hey i have just started with this project…i got the 1st half result ie the LED is working but theres some problem with the buzzer circuit…it continuosly sounds even when there is no signal….i think theres some problem with the monostable IC circuit….
can’t we use a suitable amplifier circuit instead of the IC NE555 circuit?????
what type of antena is used for this circuit?can u plz specify its name?
n plz do send me any additional information about this project…???
I have just started with this project…i got the 1st half result ie the LED is working but theres some problem with the buzzer circuit…it continuosly sounds even when there is no signal….i think theres some problem with the monostable IC circuit….
can’t we use a suitable amplifier circuit instead of the IC NE555 circuit?????
what type of antena is used for this circuit?can u plz specify its name?
n plz do send me any additional information about this project…???
plz send me the details to my id…sonujigsy@yahoo.in
can u plz send me the circuit image and its connections as well as the type & number of components used my mail id is
ashishbansal_hacker@yahoo.co.in
hello,kuldeep,i m a final year student,i was asked to increase the range of mobile bug detector to 5m range,how is it possible,kindly mail me,regarding my prob,it wil be a great support to me,dear
wil it work for any activated mobile or for incoming or outgoing calls
It will detect incoming,outgoing,SMS,Video
signals of an activated mobile phone even in
the silent mode.Phone should not be in the off
mode.
Cell phone detector IS VERY GOOD.
I FOUND THAT THIS IS VERY USEFUL FOR ME
I WANT TO BUY THIS
PLEASE GIVE ME THE PROCEDURE TO BUY
Hi,am working on this as my project.I need the block diagram stage by stage and the write up.Pls send to my e-mail noheem_ashafa@yahoo.com
I just built this and would like to point out that it only triggers when there’s activity on the phone, such as when it’s receiving SMS or about to ring. It doesn’t detect the presence of the phone otherwise.
hi
i m doing my BE
and in our college
we have to make one mini project
which can be useful to our college
this mobile detecter can be useful to me
but i m not getting enough specification of this one
so can u plz provide me some stuff
it will be greatfull to me
thank u
hello,frnd,i m a final year student,i was asked to increase the range of mobile bug detector to 5m range,how is it possible,kindly mail me,regarding my prob,it wil be a great support to me,dear
workig very good in a small region
am interested with the circuit,please tell me how in can increase the range and how to detect.
i need report of this project
hi myself shreya…2nd yesr BE…..
intrsted in dis project….want 2 kno all about it..!!
any via for hw can v increase d range?…i will b highly obliged if i get all d specifications ab t d components and increasin d range…….send it 2 m_simple2001@yahoo.com
Hi,am working on this as my project.I need the block diagram stage by stage and the write up.can i implement dis on orcad????
my email id is tusharsrk@gmail.com
Hi,am working on this as my project.I need the block diagram stage by stage and the write up.my id is tusharsrk@gmail.com
advantages & disadvantages & application of
Cell phone detector or sniffer
can any one tell me the principle it works on?
pls am workin on this for a project. hw can i increase the the area covered n if possible nos of fones detected. pls send the write ups to my mail. sofelsbaba@yahoo.com. 10x
HELP!!!!
need detail abtract, explaining working of each component briefly
i can solve ur problem
please do tell me more about this project plsss,….
i need help before 6th of oct
please
send all information related to cell phone detector…
hai,risha i have done this mobile bug as my mini project its working if u need specification just mail me
rishi please help me out we need to defened this project tomorrow it is not working can you help me out? i think there is a problem in the antenna what antenna should we use?we obeyed all the instructios here an still it only beeps for a while not that long..please help me T_T
can u tell me how to design the capacitor c3
i.e. the lead length of the capacitor as 18mm and with the spacing of 8mm between the leads… moreover it’s said that c3 conjunction with lead inductance acts as transmission line….
SO HOW TO DESIGN THE C3 PART???
and how to increase the working region???
!!!HELP ME AS SOON AS POSSIBLE!!!
i want a full circuit diagram of mobile phone
hii….
i m working on dis project , but i need more theory about the components of dis project.
helloo i m shyam i want to take ur help in this project ?? will u help me plz??
hi! i done this project if you have any doubt then call me this is my no +919510079083
hii….
i m working on dis project , but i need more theory about the components of dis project.
hy bdy.. its great to know that u hav done with it … congratulatins but im getting problem with this the ckt is nt workin at all… please send me the documentatn of dsk capacitor and the type of antenna u used…. bye
Thanks
D.MOHANKUMAR
i want this project, but is it easy to assemble? i need your reply.. ynx
Yes.It is an interesting and useful project. Careful construction on a common PCB will give good result.
D.MOHAN KUMAR
the ciruit realy worked
amazing thx for it
so thxxxxxxxxxxxxx
The project is very nice….
hi! i made this project sucessfully.
if have any doubt then call me on this no +919510079083
hi…
can u send me the theory explanation for this project…AjithT002@gmail.com this is profile… i also need site to get the data sheet about the IC CA3130…
hi pls can i get to knw more on the IC CA3I30 cuz i cnt find it here in malaysia..plz rply to my mail snowboy3k@yahoo.com
Those who sucessfully done this project can u send all the documentation to tmac_yu@hotmail.com so that i can know wad is the problem with my circuit…
I cant make my circuit run at all…
i need all the info for this project especially on the antenna part and c3…
i dont quite understand about those….
PLz help me as im using this project as my final year project…
do email me at tmac_yu@hotmail.com
thnx ^_^
i complete whole ckt and all other parts are ready but it is not working
i m doubtful about c3 disk capacitor
i have used one but either it disk or other type .{rectangular/thin box type in shape}
pLz help me as im using this project as my third year project
plz.send me all documents related this project on my id hirenraval90@yahoo.in
Hi every1 ds is very gud ckt im workin on it bt i thought of making some modifications like expand da distance upto 3meters and expand da frequancy 2 include CDMA frequancy band so if any1 can help me i’ll b really glad and thankful
plz contact me at refsam@yahoo.com
Hi my self ashok. I have finished this project succesfully. I want to expand its merits like this device detects the switch on mobiles within a meeting room or exam hall. If any one has any suggesion plz contact with me.
I am happy to know that you have completed my circuit Mobile bug successfully.
D.Mohankumar
interesting project I loved building this worked perfectly.
Go ahead. Try to construct the circuit perfectly as per the description given. Definitely it will give a good result.
D.MOHAN KUMAR
what cn i do to increase the range of the circuit of mobile bug
With this design maximum range of the circuit will be around 1 meter depending on the output power of the mobile phone.Experimentation is necessary to increase the range.
D.MOHAN KUMAR
did you find what you needed to increase the range. could you share it please?
hey guys,
i have implemented the circuit,
but the problem is, that the LED glows and buzzer sounds even though there’s no mobile phone 1.5 meters near it!
so i think the activation of LED and buzzer is not depending on the activation of mobiles, it’s constantly ON!!!
how do i rectify it??
i m waiting for ur reply…
I already placed the construction details of the circuit and problems during assembling and trouble shooting methods. See the post.
D.MOHAN KUMAR
those who have done this plz do a favour and send me all info abt this at vand.gupta089@gmail.com
PLZ…..
SEND ME DOCUMENTS & PPT REGARDING MOBILE BUG PROJECT ON MY ID hirenraval90@yahoo.in
send today because monday is last day for my seminar
thnx….
buddy im also working on this project n searching for ppt .if you find it plzzzzzzzzzzzz forward this to me.if i got it then i will definately send it to u.9971778084
helo
i m working on dis project , i need more details and theory about the components of dis project. plz i really need it cuz coming wk is my last wk on it..i do appreciate if i wil get it..forward to my mail snowboy3k@yahoo.com
i am student of fybcs plz tell me about this project.i want to do hobby project in college plz send me more information about this project or any one
Give your mail ID
D.Mohan kumar
i can’t get the ic ca3130. can you sugest ic equalent to that.
CA 3130 is a commonly available OpAmp. No other IC will work.
D.MOHANKUMAR
Itis a commonly available OpAmp. No other IC will work.
D.MOHANKUMAR
hi friends
you can contact me on my id for word document & power point presentation on mobile bug
hirenraval90@yahoo.in
Hi i m working on this project. i had assembled all the parts properly but it is still not working can anyone help me. when i turned it on, it doesn’t detect any signal . i had checked with my multimeter there is no variation in the voltage across pin 2 & 3 of opamp. I had by mistake remove the connection of capicantance c4 and resistance r2 from the ground then opamp gives an output of 1.9v continuously and also detects the Rf signal over a 10cm range only but 555 ic still doesn’t work. so plz help me.
Give your Mail ID
D.MOHANKUMAR
lookin 4 more project like this to do cuz i need to submit all to schl as a Proposal..pls do mail to snowboy3k@yahoo.com if u knw anyone..thanks
i want more detail about dis project
My mobile phone detector is not working.please help.It’s very urgent
I would like a copy of the circuit and instructions on creating it and using it.
jim
sir iam working on this cell phone detector project in my college. But it was not works. so please give me the full details about this circuit. please it’s urgent.
MOBILE BUG
Purpose of the circuit
This circuit is intended to detect unauthorized use of mobile phones in examination halls, confidential rooms etc. It also helps to detect unauthorized video and audio recordings. It detects the signal from mobile phones even if it is kept in the silent mode. It also detects SMS.
CONCEPT
Mobile phone uses RF with a wavelength of 30cm at 872 to 2170 MHz. That is the signal is high frequency with huge energy. When the mobile phone is active, it transmits the signal in the form of sine wave which passes through the space. The encoded audio/video signal contains electromagnetic radiation which is picked up by the receiver in the base station. Mobile phone system is referred to as “Cellular Telephone system” because the coverage area is divided into “cells” each of which has a base station. The transmitter power of the modern 2G antenna in the base station is 20-100 watts.
When a GSM (Global System of Mobile communication) digital phone is transmitting, the signal is time shared with 7 other users. That is at any one second, each of the 8 users on the same frequency is allotted 1/8 of the time and the signal is reconstituted by the receiver to form the speech. Peak power output of a mobile phone corresponds to 2 watts with an average of 250 milli watts of continuous power. Each handset with in a ‘cell’ is allotted a particular frequency for its use. The mobile phone transmits short signals at regular intervals to register its availability to the nearest base station. The network data base stores the information transmitted by the mobile phone. If the mobile phone moves from one cell to another, it will keep the connection with the base station having strongest transmission. Mobile phone always tries to make connection with the available base station. That is why, the back light of the phone turns on intermittently while traveling. This will cause severe battery drain. So in long journeys, battery will flat with in a few hours.
AM Radio uses frequencies between 180 kHz and 1.6 MHz. FM radio uses 88 to 180 MHz. TV uses 470 to 854 MHz. Waves at higher frequencies but with in the RF region is called Micro waves. Mobile phone uses high frequency RF wave in the micro wave region carrying huge amount of electromagnetic energy. That is why burning sensation develops in the ear if the mobile is used for a long period. Just like a micro wave oven, mobile phone is ‘cooking’ the tissues in the ear. RF radiation from the phone causes oscillation of polar molecules like water in the tissues. This generates heat through friction just like the principle of microwave oven. The strongest radiation from the mobile phone is about 2 watts which can make connection with a base station located 2 to 3 km away.
How the circuit works?
Ordinary LC (Coil-Capacitor) circuits are used to detect low frequency radiation in the AM and FM bands. The tuned tank circuit having a coil and a variable capacitor retrieve the signal from the carrier wave. But such LC circuits cannot detect high frequency waves near the microwave region. Hence in the circuit, a capacitor is used to detect RF from mobile phone considering that, a capacitor can store energy even from an outside source and oscillate like LC circuit.
Use of capacitor
A capacitor has two electrodes separated by a ‘dielectric’ like paper, mica etc. The non polarized disc capacitor is used to pass AC and not DC. Capacitor can store energy and pass AC signals during discharge. 0.22 capacitor is selected because it is a low value one and has large surface area to accept energy from the mobile radiation. To detect the signal, the sensor part should be like an aerial. So the capacitor is arranged as a mini loop aerial (similar to the dipole antenna used in TV).In short with this arrangement, the capacitor works like an air core coil with ability to oscillate and discharge current.
How the capacitor senses RF?
One lead of the capacitor gets DC from the positive rail and the other lead goes to the negative input of IC1. So the capacitor gets energy for storage. This energy is applied to the inputs of IC1 so that the inputs of IC are almost balanced with 1.4 volts. In this state output is zero. But at any time IC can give a high output if a small current is induced to its inputs. There a natural electromagnetic field around the capacitor caused by the 50Hz from electrical wiring. When the mobile phone radiates high energy pulsations, capacitor oscillates and release energy in the inputs of IC. This oscillation is indicated by the flashing of the LED and beeping of Buzzer. In short, capacitor carries energy and is in an electromagnetic field. So a slight change in field caused by the RF from phone will disturb the field and forces the capacitor to release energy.
ROLE OF IC CA 3130
This IC is a 15 MHz BiMOS Operational amplifier with MOSFET inputs and Bipolar output. The inputs contain MOSFET transistors to provide very high input impedance and very low input current as low as 10pA. It has high speed of performance and suitable for low input current applications.
RANGE OF THE CIRCUIT
The prototype version has only limited range of 2 meters. But if a preamplifier stage using JFET or MOSFET transistor is used as an interface between the capacitor and IC, range can be increased.
Dear sir,
I m building a project on mobile bug so plz get me available the details for the report
regds:
SIDDHANT MITTAL
sir,i m working on this project,but i was asked to increase the range uptp 5 metres,n i m not able to get it,kindly grace me,in response to my problem
hi am working on this project….i need detailed discription and block diagrm..and also working of each block….i do have some doughts…? will it work only when we make a call or sending an sms…? will it show any indication whn cell is on within the range..? do reply plz….am in need of reply…plz..do reply..
Details are in the same post. If you want any more points contact dmohankumarwc@gmail.com
D.MOHANKUMAR
hi….friends…am working on mobile bug project…i need more info about it and also its working in a clear manner…plz do help me…its urgent…mail me throu rubyroobs@yahoo.co.in
vl d normal opamp work…r should v use only ic ca3130…?help me
No other IC will work in this circuit.Only CA 3130 will work
D.MOHAN KUMAR
if the mobile is switched it will detect or not
No. It won’t detect switched off mobile phones.
It will detect the active phones while there is incoming or outgoing signals ….
sorry, if the mobile is switched off it will detect or not
The detector will sense the RF signal only if the Mobile is switched on.Even in the silent mode it will work.
vl d mobile bug works widout monostable timer n buzzer?if not,wat is its role in dis ckt..reply me plz….
this circuit is projected it is very good circuit and also good project for clases.
by moification it can be used for the cell phone activated switch,
yasi
hi..can you please explain the design on the basis of values of the resistor and capacitors chosen for it..also the purpose of using r1 and c4 in the circuit..
Details of the circuit is given in the same page as a reply
dmohankumarwc@gmail.com
hi am working on this project….i need detailed discription and block diagrm..and also working of each block….i do have some doughts…? will it work only when we make a call or sending an sms…? will it show any indication whn cell is on within the range..? i was asked to increase the range uptp 5 metres,n i m not able to get it,kindly grace me,in response to my problem.
Check the related posts and reply
D.Mohankumar
sir,i want more detail about dis project
the antennae connection details??
troubleshooting tips??
my id: bibin.paul.c@gmail.com
sir,
can u send me the detailed documents with PCB layout, design of the circuit.
Iam working on this project.
send me to: gafed05@gmail.com
thank you sir this very usefull in my school but how can i increase range of this
we are constructing the mobile phone detector,so please provide PCB layout of the ckt.
And please tell me where to connect mosfet transister to increase the range of the ckt.
Details of the Project are in the post
i am going to mini project on mobile dector .pls send details and doumentation”how do implement this project? pls needful sir pls……………………
I have selected phone detector as my project.
send me as much information as available .
the main problem is coming with
antenna and c3 capactor.
I didn’t get the use of this two receiver
C3 is the common 0.22 uf disc capacitor. It is easily available. Antenna can be a small telescopic antenna used in pocket radio.If these are not available in your place,you can procure both the components from junk circuit boards
i want to make a working project on cell phone jammer .can some1 help me…….mail to jaspratapsingh@gmail.com
hello sir,
i have taken mobile bug as my mini project. i got the components but i am unable to design pcb layout using orcad . if possible please send me the pcb layout . its VERY VERY urgent
thanks sir ur ideas were helpful
hello sir
i am doing this as mini project. I want to know that whether the lead spacing of 8mm for capacitor can be made through wire or its spacing is from the body of capacitor.
0.22 disc capacitor is a long lead one. If the leads are short, solder two pieces of trimmed leads of resistor to increase the length. Total lead length must be 18mm from the base of disc and spacing between the leads must be 8 mm to get the required frequency
Sir, I just wanna ask u about the C3 capacitor….u said that the spacing between leads shud be 8 mm…. The problem is 8mm is from the top of capacitor??? or is it the spacing between holes where capacitor is to be mounted is to be of 8 mm ??
Silly Question….but the Important one !!
Please mail me the pictorial representation !! Thanx
It is not a silly question. It is important to get desired frequency. As you said 8 mm is the distance between the soldering points and 18 mm is the height of the capacitor leads
pls give me the PCB layout ASAP… THX!
I am making the minor project of “Mobile Bug” Plz send me all the information an layout diagram of mobile bug ,,,
plz send me all documantation at my email address”"guru296403@gmail.com”"
plz plz plz its urgent for me…..
send me soonn….
please send me the all nokia cell phone circuit diagram and components names
what is the use of r4,r5,r6,c8,c9 in the circuit of cell phone detector
what is the use of r4,r5,r6,c8,c9 in the circuit of cell phone detector. thanks
All these are components around the monostable timer
pls send me links to report on mobile bug
See the next pages.You will get mail address
i need d details of mobile bug as im doing project on it
plz help
See older comments
and how to detect d direction of mobile…
sir plz mail me d details of mobile bug
my mail id is harishiyer.312@gmail.com
can you provide the complete details about the mobile bug
iam on this project i want its lay out diagram plz can you send me it on my email
hi
i m doing project on MOBILEBUG please send all documentation to snp450@gmail.com
Give your mail ID
D.MOHANKUMAR
mail to dmohankumarwc@gmail.com