SU1288930A1 - Device for automatic disabling of call signal - Google Patents

Abstract

Invention m. B. used in control systems for the operation of household appliances or in medicine for recording cardiograms on a subscriber telephone line; m is additional to the author. St. No. 1238262. Functionality is explored; the possibilities are one by one, while providing the ringing signal of the transmission of additional information. N cTp-BO contains a two-half-period bridge rectifier 1, consisting of DIODES 2--5, an optocoupler 6, a capacitor 7, resistors 8-11, a pnp-transistor 12, an additional two-wave rectifier 13, states of diodes 14–17, a pn-transistor 18, actuators block 19, resistor 20 and block 21 delays, content diode 22, field-effect transistor 23. capacitor 24, cut 1 stor 25. I ill. y 00 00 so oo NJ

Description

The invention relates to the field of telephony, can be used in home appliance control systems or in medicine for recording patient cardiograms on subscriber telephone lines and is an improvement on the device by author. St. No. 1238262.

The aim of the invention is to extend the functionality by providing simultaneously with the disconnection of the ring signal, the transmission of additional information.

The drawing shows a structural electrical circuit of the automatic call disconnection device.

The proposed device contains a two-half-period bridge rectifier 1, consisting of the first, second, third and fourth diodes 2-5, the optocoupler 6, the capacitor 7, the first, second, third and fourth resistors 8-11, p-p-p- a transistor 12, an additional full-wave bridge rectifier 13, consisting of five, sixth, seventh and eighth diodes 14-17, an additional pnp-transistor 18, an executive unit 19, an additional resistor 20 and a delay unit 21 containing a diode 22, a field-effect transistor 23, a capacitor 24. a resistor 25.

The device automatically disconnect the call works as follows.

In the initial state, the DC supply voltage of the line goes to the first diagonal of the additional full-wave bridge rectifier 13, providing the corresponding constant supply to the amplifier delay unit 21 on the pn-transistor 2 pn transistor 18 regardless of polarity of the linear wires.

In the initial state, the amplifier and the electronic key are closed and in the state of maximum resistance, practically without loading the PBX line. The field-effect transistor 23 of the delay unit 21, having a low-level potential, is initially open, providing a low-level potential based on a pnp-transistor 12, but due to the significant resistance value of the additional resistor 20 in the drain circuit, it also practically does not load the line.

When a subscriber call arrives, the alternating current from the subscriber telephone line through the coupling capacitor 7 goes to the first full-wave bridge rectifier 1, from which output the rectified current limited by the first resistor 8 flows through the light-emitting diode of the optocoupler 6, opening the photodiode of this optocoupler, and Through the separation diode 22, an instantaneous charge of the capacitor 24 occurs, the high potential of which closes the field effect transistor 23.

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As a result, the pn-p-transistor 12 is opened and translates the additional pn-p-transistor 18, which was previously in the state of minimum resistance, providing a short circuit of the subscriber line, imitating the subscriber's response.

After receiving information about the loop closure (subscriber response), the PBX switches off the call signal, as a result of which the rectified current stops flowing through the light emitting diode of the optocoupler 6. At the same time, the photodiode of the indicated optocoupler closes.

After the termination of the ringing signal and the closure of the photodiode of the optocoupler 6, the high potential at the capacitor 24 and the gate of the field-effect transistor 23 of the delay unit 21 retains the closed state of the field-effect transistor 23, which provides a high potential at the base of the transistor 12, which keeps the additional pnp-transistor 18 in the state of minimum resistance, keeping the closed state of the loop of the subscriber telephone line.

The high potential of the capacitor 24 on the gate of the field-effect transistor 23 of the time delay unit 21 is reduced, as a gradual discharge of the kgl-dengator 24 occurs through the resistance of the resistor 2K i; with a certain of its .loiio. ituri e.ib pnp-transistor 18 trans.hodgggg, in a high resistance state, which leads to the opening of the pc circuit and disconnecting the} 1I1o device from the subscriber. Yufoshy line.

Thus, when a call arrives, the handset is lifted and the connection is established by closing the loop, as well as the connection is held in time when the call is discontinued and then disconnected automatically from the PBX subscriber line.

Claims (1)

Invention Formula Automatic call off device by aut. St. No. 1238262, characterized in that, in order to extend the functionality by providing simultaneously with the disconnection of the ringing signal of transmitting additional information, an execution unit, a delay unit and an additional resistor are introduced, the cathode of the fifth diode connected to the collector of the additional pnpn transistor through the executive unit, and the anode of the photodiode of the optocoupler is connected to the base of a pnpn transistor through a delay unit, the output of which through an additional resistor is connected to the cathode of the fifth diode, while the block is decelerated contains a diode and a field effect transistor, the gate of which is connected to the cathode of the diode and 1288930 34 through parallel connected condensate delay unit whose input is the torus and the resistor with the source of the field trans-anode of the diode, and the source of the field-effect transistor a resistor whose drain is connected to the anode of the seventh diode.