SU464061A1 - Automatic gain control device - Google Patents

Description

one

The invention is related to the field of automation rad1K) of those 1 systems.

A device for automatic gain control is known, which contains a series of loop-connected adjustable amplifiers with an extreme auto-tuning unit, an amplitude detector, a comparator, an add-subtracting logic, and a digital integrator made, for example, in the form of a reversible binary counter and a transformer code-voltage.

In order to increase stability, a multivibrator is additionally introduced into the proposed device, the output of which is connected to the control input of the logic circuit for addition and subtraction and the input of the reversible binary counter, and the input to the output of the reverse of the extreme auto tuning unit.

The drawing shows a functional diagram of the proposed automatic gain control device.

The device contains an IOLOS filter I, an adjustable amplifier 2, an amplitude detector 3, a direct current amplifier 4, an extreme auto tuning unit 5, which includes a ring switch, trigger 6, integrator 7, reverse trigger 8, coincidence circuit 9, comparator 10, scheme 11 of storing extremum n multivibrator 12.

The structure of the proposed device includes

2

also a digital integrator 13, made, for example, in the form of a reversible binary counter n code-voltage converter, standby multivibrator 14, Schmitt trigger 15, comparator 16 and logic addition-subtraction circuit, which consists of two coincidence circuits 17 and 18 and multivibrator 19 .

The proposed device works as follows.

The input of the comparator is the voltage of the envelope f / o and the constant voltage, which determines the level of the output signal. Matching circuit 18 is turned on and off when

f / oi f / o-fA,

where A is the comparator insensitivity.

In the maximum signal search mode, the extreme tuning unit changes the control voltage from zero to the maximum value. During the reorganization of the bandpass filter 1, the envelope voltage increases, which leads to the operation of the coincidence circuit 18 and a change in the control voltage. Since the digital integrator 13 in the analysis works only for summation, at the end of the reorganization of the band-pass filter, the adjusting voltage adjusts the gain of the amplifier 2 by receiving the maximum signal.

When the control pair is re-modified, the extremum of the bend around the maximum signal is captured. During the tracking of the extremum, the extreme auto-tuning unit operates in the auto-oscillation mode.

The signal level during the tracking process generally changes. As the sigpal increases, the gain decreases automatically. In order to deplete the gain adjustment in the event of a decrease in the signal, a reverse impulse goes to the waiting multivibrator 14, which puts the digital integrator 13 into the subtraction mode and turns on the combination circuit 17.

Upon termination of the reverse impulse, the device automatically switches the integrator to the add mode, at which the envelope voltage results in a bo level. For the time of gain correction, trigger 15 is energized with a blocking voltage, which prohibits the reverse of the extreme autotune unit during the transient process.

Thus, the considered scheme provides self-tuning of the gain when searching for the maximum signal and changing it at the extremum of the automatic tuning system.

PRED. M et inventions

An automatic gain control device containing a band-wired adjustable amplifier connected in series with an extreme auto-tuning unit, an amplitude detector, a computer, a logic circuit for addition and subtraction, and a digital integrator made, for example, in the form of a reversible binary counter and converter code - voltage, characterized in that, in order to increase stability, a waiting multivibrator is additionally introduced, the output of which is connected to the control input of the logic circuit of addition-calculation Tanya and the input of the reversible binary counter, and the input - with the output of the reverse of the block of extreme self-tuning.