SU720827A1 - Tone signal receiver - Google Patents

Description

- -.one

The invention relates to communication technology and can be used for receiving dialing and calling signals, including automatic long-distance telephone communication.

A known receiver of tone signals comprising a series-connected limiting amplifier and a resonant amplifier, a detector, a DC amplifier whose output is connected to the first input of the And element, and an executive unit 1.

However, the known receiver tonal signals does not provide the stability of the duration of dialing signals when changing the size of the received signal.

The purpose of the invention is to provide protection against false positives.

To do this, a first-stage trailing edge detachment unit, a trigger, a first one-shot, and a trigger are entered into the tone receiver, which contains a series-connected amplifier-organizer and a resonant amplifier, a detector, a DC amplifier whose output is connected to the first input element I, and an executive unit. series-connected

the front edge of the sending unit, the second one-shot and the second block of the falling edge of the send; block selection of the rear edge of the parcel, the output of which is connected to

the second trigger input, the output of the second block of the falling edge of the parcel is connected to the third trigger input and to the second input of the element I, the output of which is connected to the first input of the execution unit through the first one-shot; the trigger output is connected to the second input of the execution unit.

The drawing shows a structurally electronic, trichesk scheme of the proposed device. Tone Receiver Diagram

contains the amplifier-limiter 1, the resonant amplifier 2, the detector 3, the amplifier 4 DC, element 5 And, the Executive unit 6, the first block 7 of the selection of the falling front of the parcel, the trigger 8,

the first one-shot 9, the block of the selection of the leading edge of the parcel, the second one-shot of the 11, the second block 12 of the marking of the trailing edge of the block.

The device works as follows.

The input modulated dialing or calling signal with a carrier frequency of 2100 Hz is amplified and limited by amplifier 1 and extracted by resonant amplifier 2, detected by detector 3, amplified by direct current amplifier 4 and generated in a direct dialing or calling packet.

The differential of the leading edge of the package, formed by the block 10 of the selection of the leading edge of the package, triggers the second one-shot 11, which generates a pulse with a duration equal to about half the duration of sending the dialing number.

The differential of the falling edge of this pulse, formed by the second block of the detachment of the falling edge of the parcel, is fed to the second input of element 5 I, and to the first input of element 5 I a pulse is sent from the DC amplifier 4. At the output of element 5, and only if signals are present at both inputs, a short pulse coincides in time with the falling edge of the second one-oscillator 11. Thus, protection against false alarms from short interference signals and speech currents is implemented. The pulse from the output of the element 5 And starts the first one-shot 9, which produces a pulse with a duration equal to the standard duration of the parcel dialing. This pulse is applied to the second input of the execution unit 6.

When receiving signals with a duration greater than the duration of the dialing number (call signal), an I1 pulse from the DC amplifier 4 is fed to the information input of the trigger 8. The differential edge of the second one-oscillator 11 is fed to the synchronization input of the trigger 8 and allows the signal from the amplifier 4 constant to pass current through the trigger 8 to the first input of the execution unit 6. At the end of the call, the differential of the falling edge of the call is made, which is set up by the first block 7 of the falling edge. the package, is fed to the second input of the trigger 8 and resets it; the output of the trigger 8 stops the signal to the first input of the execution unit. a 6.

The use of the proposed device provides protection against spurious triggers of the dialer receiving device and the call from the noise generated by the talk currents, as well as the formation of a standard pulse duration when receiving a number, regardless of the distortion of their duration while passing through the communication channel. In addition, the proposed device allows reception of dialing and calling parcels having a duration much longer than the duration of sending a dialing number, which improves the operational capabilities of the receiver; performance on IM ensures the stability of the circuit, high reliability, low weight and size, which distinguishes it from the prototype.

Claims (1)

Invention Formula A tone receiver containing a series-connected limiting amplifier and a resonant amplifier, a detector, a DC amplifier whose output is connected to the first input of the AND element, and an executive unit, characterized in that, in order to provide protection against false positives, the first block is inserted the selection of the falling edge of the premise, the trigger, the first one-shot and the series-connected selection block of the leading edge of the send, the second one-shot and the second block of the falling edge of the send; the output of the resonant amplifier is connected via a detector to the input of a direct current amplifier, the output of which is connected to the first trigger input, to the input of the front edge of the parcel and the input of the first block of the rear edge of the parcel, the output of the second block the selection of the falling edge of the parcel is connected to the third input of the trigger and to the second input of the element I, the output of which through the first one-vibrator is connected to the first input of the execution unit, while the output of the trigger connected to the second input of the executive unit.  Sources of information taken into account during the examination 1. USSR Author's Certificate No. 464978, cl. H 04 Q 1/46, 1974 (prototype).