DE1218505B - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

H03k

German class: 21 al -36/12

Number: 1218 505

File number: St 23357 VIII a / 21 al

Filing date: February 13, 1965

Opening day: June 8, 1966

The invention relates to a method and a circuit arrangement for the transmission of primarily bipolar Signals over a PCM connection.

In pulse code modulation (PCM) connections in which the signal to be encoded has both polarities may have, such as B. in telephone systems, it means a simplification, if one is only unipolar Encoding and transmitting signals.

For this purpose, the respective sign of the input signal part to be coded must first be determined. There are already arrangements for pulse code modulation 'known in which by means of one of code clock pulses controlled gate circuit such a determination is made. This is used with the known Arrangement, however, essentially to a DC voltage level shift of the signal to be coded to make further decisions about it during a coding period can determine whether the signal is above or below a certain DC voltage level. To the ao With the known arrangement, positive or negative PCM pulses are transmitted, depending on the polarity of the signal.

In contrast to this, according to the invention, the signal becomes after the sign of an input signal part is converted into a signal of uniform polarity by adding a signal part opposite polarity electrically inverted. The positive or negative amplitude of the Input signal part amplified and depending on a characterizing the polarity of the respective input signal part first signal a unipolar, the amplitude value characterizing second signal is formed, and the first signal is also transmitted as an additional code to the encoded second signal.

It is therefore the task of the circuit arrangement according to the invention, after determining the sign convert the signal parts into a signal with uniform polarity.

The circuit arrangement according to the invention has an input via which electrical signals of positive or negative polarity can be received, and a trigger stage which assumes its first or second state, depending on whether the input signal is positive or negative. The circuit arrangement also has switching means between said input and an output which generate an output signal of uniform polarity from a positive or negative input signal, the amplitude of which depends on the amplitude of the input signal. The flip-flop can also be connected to a further output of the circuit arrangement and circuit arrangement for
Transmission of primarily bipolar signals via a
PCM connection

Applicant:

Standard Elektrik Lorenz Aktiengesellschaft,

Stuttgart-Zuffenhausen, Hellmuth-Hirth-Str. 42

Named as inventor:

John Clifford Price, Harlow, Essex

(Great Britain)

Claimed priority:

Great Britain 18 February 1964 (6704) - -

to output a signal to indicate the polarity of the input signal.

The invention is to be explained further below with reference to the drawings.

F i g. 1 shows the block diagram of a first embodiment of the circuit arrangement according to the invention;

F i g. 2 shows the block diagram of a second embodiment of the circuit arrangement according to the invention;

Fig. 3 shows the circuit diagram of a third embodiment the circuit arrangement according to the invention.

In all three embodiments, a first output signal is generated, which characterizes the sign and a second output signal of uniform polarity representing the amplitude of an input signal which can be of either polarity and from an analog signal of a speech component in a time division multiplex (PCM) telephone connection consists.

The invention is not intended to be limited to this one application.

In FIG. 1, the signal generator 1 and the channel gate 2 belong to the system mentioned. Every signal part from channel gate 2 is connected via the working resistor 3 and via the input terminals 6 and 7 a flip-flop 4 and an amplifier 5 at the same time fed. The input terminal 7 is at ground potential.

609 578/473

Claims (1)

3 4 The flip-flop 4 is passed on as a function of the polarity of an operating resistance 23, as it is brought into its one or subsequent coding in a multichannel different position given the larity of the input signal part, and one or the other system is known.
The output of flip-flop 4 is excited accordingly. The one with the high-resistance constant current source The output of the amplifier 5 feeds the primary 5 of the transistor 26 connected transistors 24 and winding of a transformer 8, which divides the flowing current between the 25 normally evenly Fixing circuits 9 and 10 have a secondary winding. When an input signal is applied, this owns with center tap. ■ Current distribution depending on the polarity of the input signal Let it be assumed that the starting point changed in one direction or another. at signal that the amplitude of the input signal part io positive input signal leads the transistor 24 always positive. The output signal more and the transistor 25 less current, with negative appears between the output terminals 11 and 12, tive input signal, the transistor 25 leads more Terminal 11 is with the center tap of the secondary and transistor 24 less current, winding of the transformer 8 connected, terminal The transistors 27 and 28 are connected to the collector 12 is at earth potential. __ 15 of transistor 24 and transistors 29 and 30 The sign of the input signal part is connected to the collector of transistor 25, output signal appears between the transistors 28 and 29 have a common Output terminals 13 and 12. Terminal 13 is with the same working resistance 31. connected to the output of flip-flop 4, which is excited. is when the input signal part is positive. It is connected in 20 stronger links, it contains the transistor In this case, therefore, assume that a marker is ren 32 and 33 and controls the transistors 34 and 35 or a binary L signal at the output has a positive Schmitt trigger. Input signal part indicates during a gap The Schmitt trigger is normalized by the Tranoder a binary 0 signal at the output a negative transistor 36 and 37 blocked, which is another member of the Indicates input signal part. This arrangement is 25 form circuit. During the switch-on period chosen arbitrarily and can be exchanged. one channel is the base of transistor 37 across Each input signal part is fed via the amplifier line 38 from the common control circuit Ker 5 is fed to the transformer 8, and a time-shifted pulse is fed to it every second. This will With the transformer winding, a voltage with an erroneous tilting is avoided, which would otherwise be caused by induced by the polarity of the input signal part. To 30 the occurrence of switching peaks at the beginning of a next the fixing circuits are ineffective and the channel period could occur. Secondary winding is isolated. If the flip-flop 4 The output of the Schmitt trigger is via the Resistance 39 in the collector circuit of transistor 35 corresponds to the polarity of the signal supplied has taken one position or the other is achieved. This exit is connected to the bases of the tran- the corresponding fixing circuit connected via an output transistor 28 and 30; exceeds his potential The output of the flip-flop 4 is excited and applies the potential associated with it to the bases of the transistors 27 nete end of the secondary winding to ground potential and 29, then transistors 28 and 30 fixed. As a result, the connections 11 and appear conductive, otherwise the transistors 27 and 12 an output signal pulse, which determines the size of the introductory 29, characterizes the output signal part. 40 In any case, the larger der flows through this In this way, the fixing circuit 9 is excited, the collector currents of the transistors 24 and 25 via the when the input signal is positive while the common working resistance is 31. Fixing circuit 10 is energized when the input Um between the output terminals 40 and 41 a signal is negative. It can be seen that the unipolar output signal can be obtained for which only output signal always has the same polarity if the 45 the amplitude of the amplitude of the input Input signal is positive or negative. signal depends, another switching element with the In the arrangement according to FIG. 2, two in transistors 42 and 43 are used.
Series-connected capacitors 14 and 15 instead of the common working resistance 31 of the transformer 8 in FIG. 1 used to generate the uni-base signal fed to transistor 42 with a polar output signal that compares the magnitude of the 50 to a potential that characterizes the input signal from the potentiometer. The output terminal 44 of the base of the transistor 43 is supplied. At 11 it must be ensured between the two capacitors 14 and 15 that the transistor 42 is connected to the signal. The with F i g. 1 corresponding value zero current leads, the current across the elements have the same reference numerals, the resistance 45 a way to gain the negative potential of the sign of the input signal 55 offered. The characterizing output signal corresponds to the signal characterizing the sign is F i g. 1 type described. between the output terminals 46 and 47. The capacitors 14 and 15 are charged with the type that compare with the Schmitt trigger output polarity of the input signal. are bound. If the input signal is positive, the current through the resistor 39 is the magnitude of the input signal 60, and the potential-characterizing, unipolar output pulse abutment of terminal 46 is given the potential of when one of the fixing circuits 9 or 10, terminal 47 is raised,
is excited via the flip-flop 4 by the corresponding capacitor via the associated fixing patent claims:
circuit is discharged. 65 In the arrangement according to FIG. 3, one-first method for the transmission of primarily bipolar transmission other signal parts that follow different signals, e.g. B. speech vibrations, about a Channel gates 20, 21, 22 arrive, one after the other via PCM connection, in which the polarity of the the first signal characterizing the respective input signal part is formed, characterized in that that the positive or negative amplitude of the input signal part is amplified and depending on the first signal, a unipolar second signal characterizing the amplitude value is formed, and that the first signal as an additional code to the coded second signal is transmitted. 2. Circuit arrangement for carrying out the method according to claim 1, characterized in that the input (6) is connected to an amplifier (5) and to a flip-flop (4) which corresponds to the polarity of the input signal part on one (4 a) or the other Output (4 b) carries a signal that the two outputs of the flip-flop are each connected to a fixing circuit (9, 10) which, depending on the position of the flip-flop, one or the other end of the tapped secondary winding of a located in the output circuit of the amplifier Connect the transformer (8) to ground, and that the tap of the secondary winding is connected to the output (11) which leads to the input of the coding circuit. 3. Circuit arrangement according to claim 2, characterized in that one output (z. B. 4 a) of the flip-flop is also connected to an output (13) which forwards the signal indicative of the polarity of the input signal part to the coding circuit. 4. Circuit arrangement according to claim 2 and 3, characterized in that the transformer (8) is replaced by two capacitors (14, 15) with a center tap. 5. Circuit arrangement for performing the method according to claim 1, characterized in that that the input with a transistor pair connected in the manner of a differential amplifier (24, 25) is connected, the collector circuits of which via two further transistor pairs (27, 28 and 29, 30) to a (for the transistors 28 and 29) common working resistance (31) and two separate load resistors work that of the magnitude of the amplitude of the input signal forming, common working resistor (31) via a further pair of transistors (42, 43) with the the unipolar output signal emitting output (40) of the circuit is connected and that the input also via a transistor pair (32, 33) acting as an amplifier with an as Schmitt trigger acting transistor pair (34, 35) is connected to one of a synchronization operated switch (transistor pair 36, 37) is connected so that it is offset in time to the control pulses opening the channel gates (20, 21, 22) the sign of the input signal part emits characteristic signal to an output (46). Considered publications:
German interpretative document No. 1070 224. 1 sheet of drawings 609 578/473 5.66 © Bundesdnickerei Berlin