Telephone Call Recorder

Today phone has change into an essential component of our lives. It is essentially the most extensively used communique tool on the earth. Owing to its big reputation & in style use, there arises a necessity for name reporting gadgets, which find application in name cent-res, inventory broking corporations, police, offices, homes, and so on. Here they are describing a name recorder that makes use of just a few phases. But with the intention to remember its working, must first have the basic knowledge of standard phone wiring as well as a stereo plug.

In India, land-line rings essentially use RJ11 wiring, which has wireless-tip & ring. While tip is the certain wire, ring is the terrible. & together they full the cellphone circuit. In a phone line, voltage between tip & ring is around 48V DC when handset is on the cradle(idle line). In order to ring the telephone for an incoming name, a 20Hz AC current of round 90V is superimposed over the DC voltage already present in the idle line. The poor wire from the phone line goes to IN1, whereas the positive wire goes to IN2. Further, the poor wire from OUT1 & the certain wire from OUT2 are linked to the phone. All the resistors used are zero.25W carbon movie resistors & the entire capacitors used are rated for 250V .

The poor terminal of To AUX IN is linked to pin one of the crucial stereo jack while the certain terminal is hooked up to pins two and three of the stereo jack. This stereo jack, in turn, is related to the AUX IN of any documenting device, any suchs pc, audio cas-setts participant, CD participant, DVD player, and so on. Here they will be connecting it to a pc. When a call comes in, around 90V AC current at 20Hz is superimposed over the DC voltage already present within the idle line.

This current is transformed in to DC through the diodes & fed to resistor R1, which cut backs its magnitude & feeds it to LED1. The present is additional scale backd in magnitude by using the resistor R2 & fed to the suitable & left channels of the stereo jack, that are connected to the AUX IN port of a computer. Audio fileing application,can be used to file the decision. When a call is available in, needs to launch the audio documenting software and start documenting.

For phone documenting, basically connect the stereo jack to the AUX IN port of the PC. Install the Audacity audio recorder . Run the executable Audacity file. By & huge window, you'll discover a drop-down box within the top right corner. From this box, make a selection the AUX choice. Now you are ready to report any name. As soon as a name is readily available in, press the record button current within the Audacity primary window & then choose up the telephone receiver & answer the name. Press the stop button one time the decision ends. Now go to the file menu & choose the Export as WAVE choice & save the file in a desired location.

You may exchange the price of resistor R2 if you require to vary the output volume. You can use a variable resistor in collection with R2 to range the amount of the output. The recorded audio clip may additionally be edited the usage of different choices in the Audacity application. You can gather the circuit on a general-purpose PCB & enclose it in a small cupboard. Use an RJ11 connector & stereo jack for connecting the phone set & laptop (for call reporting). Phone twines can be utilized to connect to the telephone line & the circuit. Use of a shielded cable is beneficial to reduce disturbances in the fileing. These will also be scale backd by way of growing the price of R2 to about 15 kilo-ohms.