Currently become very popular handsets with tastaturen (touchtone) dialing and melodic signal the calling device. Great the number of vehicles produced in South-East Asia and sold now at affordable prices. The proposed device allows you to use it on paired telephone lines.
In telephone exchanges, where the automation elements are walking seekers, electromagnetic relay and coordinate multiple connectors, used station device pairing phones and subscribers set consoles diode separation circuits. The use of bollards was caused the lack of subscriber lines and allowed to connect to the PBX for more telephones (SLT).
When making a call from the PBX, depending on the polarity on the wires total the subscriber line, open the diodes corresponding to the selected line, and works a call. To discharge the capacitor in the circuit of diode call blockers provided with a discharge circuit, since the capacitor cannot discharge through station device PBX because of the diodes. These bollards are designed for connection with THE Electromechanical calls. As a rule, they do not provide sufficient discharge of the coupling capacitor in the circuit of the calling device e-TA. Charged capacitor creates additional resistance in the circuit of the calling device and the latter is not triggered.
To solve this problem will help console, the diagram of which is shown.
In the time of reducing the voltage unipolar ringing signal to its lower level transistor VT1 is opened due to the voltage dividing capacitor, consequently, it is opened and the transistor VT2, which closes the conclusions of the TA. The coupling capacitor is fully discharged through the transistor VT2, and calling device is ready to receive the next pulse of the signal tone.
The device can be mounted in the housing of the telephone Jack.
The console allows you to include in the coupled telephone line answering machines, radiodigital, faxes, modems.
Author: A. Poroshenko, Chistopol, Tatarstan