SU1439752A1 - Correcting device - Google Patents

Abstract

The invention relates to telecommunications and can be used in television, telephone and digital transmission systems, mainly c. cable connecting lines The purpose of the invention is to enhance the functionality of the correction device. The corrective device contains a potentiometer 1, resistors 2 and 3, two-terminal 4 and 5 impedance transformers 6, a matching device 7 and a high impedance device 8. Two-terminals 4 and 5 monotonously raise high frequencies in the interval of several g; frequencies and can be used to match and correct linear cable distortions. The choice of two-terminal 4 and 5 corrects or synthesizes any given linear distortion. A constant increase in their magnitude is fulfilled by a transformer 6, and an adjustable increase by a potentiometer 1. The goal is achieved by correcting or synthesizing arbitrary linear distortions with the help of resistors 2 and 3 and a two-port 5 introduced. 1 sludge; x (L

Description

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The invention relates to telecommunications and can be used in television, telephone and digital transmission systems, mainly in cable connection lines.

The purpose of the invention is to expand the functionality by correcting or synthesizing arbitrary linear distortions.

The drawing shows a structural electrical circuit of the correction device.

Corrective device contains potentiometer 1 with resistance R and adjustment weight p, resistor 2 with resistance R or R / a and resistor --3 with resistance (la), two-terminal 4 and 5 complex resistance Z and Z (/ Z, in addition, transformer 6 with a transformation ratio n, a matched device with resistance R is represented by position 7, and high-resistance (resistance much larger than R) is represented by position 8,

The device works as follows.

The operation of the correction device is considered in the modes when the high-resistance device 8 is either the output of the current generator or the input of the voltage amplifier.

Potentiometer 1 with resistance R resistor 2 with resistance R or with resistance R / a, shunted through transformer 6 by resistor 3 with resistance (la), whose resistance, reduced to the primary winding of the transformer, is equal to R, and bipolar 4 and 5 of complex resistance K and Zij R / Z form an aperiodic two-port constant resistance resistor R, matching resistance R connected to the filter of the input or output of the device 7, Since the device 8 connected to the filter high-resistance switch Ator 6 and retraction movement of the potentiometer 1 does not violate the above matching. The complex resistance of two-terminal 4 and 5 is back proportional to Z ;, Zji R. As one decreases, the other increases.

At frequencies when the resistance module of the two-terminal 4 impedance Zij. Much more resistance R, and two-pole 5

the complex resistance Z is negligible, the action of the two-pole 4 can be neglected, and the two-pole 5 short-circuits the resistor 2, the windings of the transformer 6 and the resistor 3 through it. At the same time, the position of potentiometer 1 determines the level of the signal during transmission from matching device 7 to high impedance device 8, or dividing the current - its branching into the shoulders of potentiometer 1 - during transmission from high-resistance device 8 to matching device 7. In the latter case, in the upper polo enii potentiometer 1 to the input resistance R negotiated device 7 is supplied with a maximum of half of the current output unit 8, the remaining half of the current passes through the potentiometer 1,

At frequencies when the resistance of the two-pole 4 impedance Zg is negligible than the resistance R, and the two-pole 5 of the complex resistance Z is much larger, potentiometer 1 is shorted and the signal transmission level does not depend on its installation. When transmitting a signal from a matching device 7 to a high-resistance device 8, the entire voltage of the signal of device 7 is allocated to the primary winding 1 of the transformer, which is equal to n times the voltage of the secondary winding II, i.e. in (l + u) times more enters the high-impedance input of the device 8.

When a signal is transmitted from the high impedance output of the device 8 to the input of the matched device 7, the signal current through the secondary winding II of the transformer 6 and the resistor 3 folds with c times higher with the primary winding I of the transformer and (1 + n) times parallel to the input of the device 7 with resistance R, B - as a result, the signal current flows to the input of the device 7 from the device 8, which is (1 + n) / 2 times the current signal from the output of the device 8.

Between the indicated frequencies, the voltage and current of the signal vary between the limiting values, respectively, inversely proportional to the changes with the frequency of the two-terminal impedances 4 and 5. In the upper position of the drainage potentiometer .1

accordingly, the transmission direction either increases the voltage or the signal current by (I + n) times at the frequencies at which) 7. (; I, and weakens, is equal to the weight p of the resistance of the lower arm of potentiometer 1 at the frequencies at which | Zi | jZtl. The attenuation of the signal potentiometer 1

input relative lift is increased by a potentiometer 1 ..

15

is measured, is (1 + n) times and its increment is exceeded (1 + n) / p times, as a result, the ratio of the filter elements Z Zj, R ensures the matching of the resistance R of the device 7, the choice of circuits and element ratings of two-terminal 4 and 5 sets type of corrected and synthesized linear distortion of Kenya. Potentiometer 1 introduces their adjustable relative increment of 1 / p times. When using transformer 6, their value is increased (1 + n) times. With p 5, linear distortions of 20 lg (l + 5) "15.6 dB are synthesized and corrected. By adjusting the potentiometer 1, they can be increased practically by another (10-15) dB

In order to reduce the transformer power, when transmitting from the high resistance device 30 of the device 8 to the device 7 to be matched, only resistor 3 () with resistance is left in the filter, and vice versa - only resistor 2 () with resistance R,

In addition, the resistance R of the input or output of the device 7 is matched. Small linear distortions are corrected or synthesized without transformer 6 and its resistor 3 () shunt. In this case, the movable tap: the potentiometer 1 and the device 8 are connected directly.

Claims (1)

20 claims A correction device containing a potentiometer connected in series with a resistance R, 25 equal to the one to be matched, and a two-terminal impedance Z, a transformer, the primary winding of which is connected in parallel with the outputs of the two-terminal impedance Z. and the secondary winding with a transformation ratio p one output connected to a movable output of a potentiometer, characterized in that, in order to 35 extend the functionality by correcting or synthesizing arbitrary linear distortions, In the particular case where a two-pole resistor with a resistance of NIC 4 is entered, it is a PVa capacitor, a resistor with resistance C, and a two-pole 5 - a choke 40 (l-a), where, and a two-pole the impedance Zj, while a resistor with resistance R / a is connected in parallel to a two-terminal impedance Z, 45 a resistor with resistance (l-a) is connected in parallel to the secondary with an inductance of 1 R C, which corresponds to 2 R, the weakening of low frequencies by potentiometer 1 introduces a rise of high frequencies within a decade of frequencies by 1 / p, which, when using a transformer 6, increases by another (1 + n) times. Bipolar 4 and 5 monotonously raise the high frequencies in the interval of several decades of frequencies and can be used, for example, to match 50 winding of the transformer, and the first and second outputs of the two-terminal impedance are connected respectively to the first and second fixed terminals of the potentiometer. and correction of linear cable distortions. Thus, the choice of two-terminal 4 and 5 impedance corrects or synthesizes any given linear distortion. A constant increase in their magnitude is performed by transformer 6, re In addition, the resistance R of the input or output of the device 7 is matched. Small linear distortions are corrected or synthesized without transformer 6 and its resistor 3 () shunt. In this case, the movable tap: the potentiometer 1 and the device 8 are connected directly. Invention Formula A corrective device containing a potentiometer connected in series with a resistance R equal to that matched, and a two-terminal impedance Z, a transformer, the primary winding of which is connected in parallel with the outputs of the two-terminal impedance Z., and the secondary winding winding of the transformer, and the first and second outputs of the two-terminal impedance are connected respectively to the first and second fixed terminals of the potentiometer.