Cellular Phone Detector


Posted on Jan 26, 2013

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.


Cellular Phone Detector
Click here to download the full size of the above Circuit.

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. N




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

SMS through Telephone with AT89S8252
Line-activated-solid-state-switch
200mA/Hour 12V NiCAD Battery Charger
Phototransistor for High Impedance Voltmeter
MSF Radio Receiver
ICL7107 / ICL7106 - Digital Voltmeter
FM remote Encoder/Decoder
Iso buffer serial to parallel converter
By the high-power switching power supply L4970A



Top