Friday, April 12, 2013

Telephone Call Recorder

Today cellphone has turn out to be a vital part of our are livings. It is the most broadly used communication device in the world. Owing to its large popularity & popular use, there come ups a necessity for name recording units, which find software in call cent-res, inventory broking companies, police, administrative centers, homes, and so forth. Here they are describing a name recorder that makes use of only some sections. But in an effort to keep in mind its working, should first have the elemental information of usual cellphone wiring in addition to a stereo plug.

In India, land-line rings primarily use RJ11 wiring, which has wires-tip and ring. While tip is the positive wire, ring is the poor. And collectively they full the phone circuit. In a cellphone line, voltage between tip and ring is round 48V DC when handset is on the cradle(idle line). In order to ring the phone for an incoming name, a 20Hz AC current of round 90V is superimposed over the DC voltage already current within the idle line. The bad wire from the cellphone line goes to IN1, whereas the certain wire goes to IN2. Further, the negative wire from OUT1 and the certain wire from OUT2 are linked to the phone. All the resistors used are zero.25W carbon film resistors and the entire capacitors used are rated for 250V or more.