i want the working principle of mobile incoming call indicator
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working principle of mobile incoming call indicator
Purpose
This circuit can be used to escape from the nuisance of mobile phone rings when you are at home. This circuit will give a visual indication if placed near a mobile phone even if the ringer is deactivated. 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.
Device operation
When a call is coming to the mobile phone, the transmitter inside it becomes activated. The frequency of the transmitter is around 900MHz.The coil L1 picks up these oscillations by induction and feds it to the base of Q1. This makes the transistor Q1 activated.Since the Collector of Q1 is connected to the pin 2 of IC1 (NE555) , the IC1 is triggered to make the LED connected at its output pin (pin 3) to blink. The blinking of the LED is the indication of incoming call.
The signal detected by the sensor coil is amplified by transistor Q1 and drives the monostable input pin of IC1. The IC's output voltage is doubled by C2 & D2 in order to drive the high-efficiency ultra-bright LED at a suitable peak-voltage.
Introduction:
Hello friends, are you searching for one good mini project for your submissions? If your answer is yes, then your search will end here. Today I am going to make a circuit that will indicate an incoming or outgoing call or massage from your mobile phone. Yes you can do such awesome mini project with some simple electrical components within no time. Let us start making our “Mobile incoming call indicator” mini project.
Components Used:
IC 1 = NE555 (Timer IC)
Resistors
Capacitors
Transistor : Q1 = BC548
LED
6V DC Battery
Diode: 1N5819
Description:
In this mini project we are going to make a simple circuit that will detect a mobile phone. In this mini project we have used a LED which will glow instantaneously when mobile phone rings.