SU1656690A1 - Device for two-side amplification of voice frequency - Google Patents

Abstract

This invention relates to a telephone communication technique. The purpose of the invention is to increase stability in the work by eliminating self-excitation. The device contains differential transformers (T / 1 and 2, two-wire lines 34 and 5 6 of communication T 7, a decoupling capacitor 8 and amplifiers 9 and 10. A large margin of stability in the operation of the device is ensured by the fact that only negative feedback. This does not cause the device to exit from the state of stability when the wires are broken or short-circuited in the communication line and allows you to keep the communication in the remaining sections of the communication line (if it is broken at any point) Self-excitation is eliminated by it neither the Introduction T 2 and 7, a capacitor 8 and an amplifier 10 January yl. + S YO

Description

The invention relates to a telephone communication technique and can be used to amplify telephone signals transmitted over a two-wire, mainly cable line.

The goal is to increase stability at work by eliminating self-excitation.

The drawing shows the structural electrical circuit of the device for two-way amplification of the tonal frequency

The device contains the first differential transformer 1, the second differential transformer 2, the first and second two-wire lines and 5-6, the coupling transformer 7, the decoupling capacitor 8, the first and second amplifiers 9 and 10.

The first differential transformer 1 has the first 11-12, the second 13 14,

the third 15-16 windings, the average conclusions 17 and 18, respectively, the first and second windings

The second differential transformer 2 has the first 19-20, the second 21-22, the third winding 23-24, the middle terminals 25 and 26, respectively, of the first and second windings.

The coupling transformer 7 has an input winding 27-28 and an output winding 29-30.

A device for two-way amplification of the tonal frequency works as follows.

When transmitting signals from a two-wire line 3, the current from the terminals of the first winding 11 and the second winding 13 passes to the middle terminals 17, 18 of the differential transformer 1 and further to the input winding 27-28 of the coupling transformer 7. From the terminals of the output winding 29-30 of the coupling transformer 7 signal goes to the input

ate oh oh oh

The amplifiers 9, 10 and amplified are fed to two-wire lines 3-6 through the leads of the third winding 15-16 of the differential transformer 1, as well as the leads of the third winding 23-24 of the differential transformer 2.

Similarly, the process of amplifying and transmitting signals occurs when they are received from any other direction due to the symmetry of the circuit. In this case, the transmission of signals from two-wire line 3 to two-wire line 4 and from two-wire line 6 to two-wire line 5 (and vice versa) occurs with a large attenuation. The latter is provided by the properties of differential transformers 1, 2. The presence in the input winding 27-28 of a coupling transformer 7 and a decoupling capacitor 8 makes it possible to remotely supply the amplifiers 9, 10 by transmitting 3 6 DC current through a two-wire line. The electrical connection of the outputs of the amplifiers 9, 10 to the two-wire lines 3, 5 through the third windings 15-16 and 23-24 of the differential transformers 1, 2 eliminates the need for additional DC power supplies.

The device provides the effect of negative resistance in the direction of the two-wire line from which the signal is received, due to which in that line, in particular, at the terminals of the signal source there will be an adequate increase in the signal level. If the device is switched on in the middle of the line, the transfer characteristics between the transmission direction pairs (on the two-wire lines 3 and 6, as well as 4 and 5) are fully identical.

The device provides independent gain control and correction of the frequency response between the transmission directions (two-wire line 3, 6 and two-wire line 4, 5). It is obvious that the connection between the two-wire lines 3-4 is carried out due to the electrical connection between the windings of the differential transformer 1, the TQ same thing happens between the two-wire lines 5-6. When using the device, only two or three transmission directions on the terminals of unused two-wire lines are set to balanced circuits. In this case, if only two transmission directions are used, for example, via two-wire lines 3 and 6 or 4 and 5, then due to the large stability margin and self-excitation of the device, instead of balanced circuits, it is sufficient to establish active resistances. A large margin of stability of the device is provided for

due to the fact that the chain is always saved

Claims (1)

only negative feedback. This does not cause the device to exit from the state of stability when the wires are broken or short-circuited in the communication line and allows you to keep the communication in the remaining sections of the communication line (if it is broken at any point). Apparatus of the Invention A device for two-sided amplification of a tone frequency, comprising a first amplifier, a first differential transformer with three windings, the first winding of which is connected in series to the first wire of the first two-wire line, the second winding of the first differential transformer is connected in series to the second wire of the first two-wire line, characterized in that, in order to increase stability in work by eliminating self-excitation, a second amplifier was introduced about it, a coupling transformer with two windings, a decoupling capacitor and a second differential transformer with three windings, the first and second windings of which are connected in series to the first and second wires of the second two-wire line, respectively, the middle terminals of the first and The second windings of the first differential transformer are connected to the corresponding middle terminals of the first and second windings of the second differential transformer and to the corresponding terminals of the input winding of the coupling transformer, the output windings of which are connected to the inputs of the first and second amplifiers, the outputs of which are connected to the third winding, respectively the first and second differential transformers, and the input winding of the coupling transformer is divided by an isolating capacitor. o / 5 u sh VjtJLJL 1 I about