/Schematics/Everything else/GSM phone ring detection

This circuit was designed to detect when a call is incoming in a cellular phone (even when the calling tone of the device is switched-off) by means of a flashing LED.
The device must be placed a few centimeters from the cellular phone, so its sensor coil L1 can detect the field emitted by the phone receiver during an incoming call.


Part list

R1____________100K 1/4W Resistor
R2______________3K9 1/4W Resistor
R3______________1M 1/4W Resistor
C1,C2_________100nF 63V Polyester Capacitors
C3____________220µF 25V Electrolytic Capacitor
D1______________LED Red 10mm. Ultra-bright (see Notes)
D2___________1N5819 40V 1A Schottky-barrier Diode (see Notes)
Q1____________BC547 45V 100mA NPN Transistor
IC1____________7555 or TS555CN CMos Timer IC
L1_____________Sensor coil (see Notes)
B1_____________1.5V Battery (AA or AAA)

Author (sent by): Red circuits

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Rating: (2.89, votes 2186)


Date: 26-03-2007

Lokalna verzija ove stranice: Detekcija emitovanja mobitela


Bookmark and Share Comments (16)

comment [6]

Trax, kako ne? Na koliko radi volta?

comment [5]

LED se pali ako se ne varam na 1.7 V, posto je u kolu timer oscilacije koje proizvodi na elektrolitskim kond podici ce napon za sqrt(2) sto je nekih 2.12 V. ispravite me ako negdje grijesim... IP:

comment [4]

Nije tacno da obicna LE dioda radi na 1,5V.
IP: n/a

comment [3]

pulsiranjem mozes dobiti vise volti od samog ulaza IP:

comment [2]

Obicna LE dioda radi na 1,5 volta, a ona FLASH na 2-2,5 volta

comment [1]

Ovo je zanimljivo, samo - mene kopka jedna cinjenica. Svi znamo da LED-ica radi na oko 2 do 2,5 V a napajanje je ovdje 1,5 V . . . ??? IP:

Comment page: <12

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