detect mobile

[hamid9543]

i need to circuit for detect mobile .can anybody help me?

[looser]

hamid9543

If you intend to turn on or off something in a meter range to your cellphone you just need say 2 inch of wire as an antenna and a diode detector to drive a plastic case darlington transistor .
This than can drive a high impedance relay with ease.

[igq]

Hi, looser.
Can you show a circuit?

[alpaslan]

Use google with "RF sniffer" or "GSM Sniffer". You find lot of simple examples.

[hamid9543]

thx.
but i neet to circuit for detect mobile in meter rang

[looser]

\ı/
 l                                   o  6-12v
 l                                   l
 l                                   l
 l                                relay
 l      1n4148                   l c
 l-------l>ı--------------l<
                     l               l e
                     l               l
              2n2  =              l
                     l               l
                     l               l
                    gnd          gnd

better the relay resistance be greater than 700 ohm.... 1k
use hi gain darlington transistor.
if you cant find than you can use two regular plastic transistor as darligton

beware that your cellphone will sometime talk to the network stating he is ready to serve and stop. So for every relay trigger do not expect  you will receive a call.