SU859961A1 - Device for tolerance checking of amplitude-frequency characteristici of four-terminal metworks with automatic control of amplification - Google Patents

Description

connected to the output of the second amplifier with automatic gain control and with the input of a bandpass filter, the first output of which is connected to the second inputs of the comparison elements by the maximum and minimum signals, and the second output of the bandpass filter is connected to the control input of the second amplifier with automatic gain control, whose input connected to the input of the device.

The drawing shows a block diagram of the device.

The device contains a sensor 1 test signals, an adder 2, a control unit 3, a first amplifier with AGC, a generator 5 of the reference frequency; the second amplifier 6 with AGC, a barrier filter 7, a band-pass filter 8, a comparison element 9 on a signal maximum, a comparison element on a signal minimum 10, a controlled attenuator 11, an OR element 12, an indicator 13, an output 14 and an input 15 of the device.

The device works as follows.

After the START command is issued, the control signals from the control unit 3 are fed to the controlled attenuator 11 and the test signal sensor 1 (DIS). In this case, the first of the DIS signals goes to the adder 2, to the second input of which through the amplifier 4 with AGC receives a signal from the generator 5 of the reference frequency, the attenuation value of the quadrupole at which pin ta is zero (zero), the amplifier 4 with AGC ensures the output constant the signal level at the input of the adder 2. From the input of the adder, a two-frequency signal is fed to the output 14 of the device and then to the input of a controlled quadrupole and from the output of the latter to the input 15 of the device and then to the input of the amplifier 6. From the output of the amplifier 6 signal 8 is supplied to the bandpass filters 7 and barrage which is performed by frequency division signals. The feedback of the output of the band-pass filter 8 to the second input of the amplifier with AGC 6 ensures the constancy of the output level at the reference frequency, relative to which the frequency response is measured. The reference frequency sig from the output of the bandpass filter 8 is fed to the first inputs of the elements of comparison 9 and 10, to the second inputs of which, through the control attenuator 11, test signals with a sequentially varying frequency are received.

The Kazkda frequency of the sensor 1 of the test signals corresponds to a fully controlled attenuator 11 with a certain voltage dividing ratio, which is set so that if the attenuation at this frequency corresponds to the norm.

the level at the second (signal) inputs of the elements 9 and 10 of the comparison will be equal to the level coming from the output of the bandpass filter 8 to their first inputs and the operation of the comparison circuits will not occur-.

In the case of attenuation at different frequencies, the specified response requirements of the elements of comparison 9 and 10 do not occur. If the attenuation at a given frequency is

is greater than the norm, then the comparison element 9 by the maximum will work, and if the attenuation at a given frequency is less than the norm, the comparison element 10 will operate at the minimum.

5, the output signals of the comparison elements are transmitted to the OR element 12, and then to the indicator 13. Due to the OR element 12, the alarm NOT NORM occurs when one of the comparison elements is triggered. This signaling on the indicator appears only after the arrival of a delayed control pulse from the control unit 3, which ensures the elimination of

5 false positives caused by transients in the controlled quadrupole and in the device nodes.

Claims (2)

1. Author's certificate of the USSR 531100, cl. G 01 R 27/28, 1973. 2. Technique of film and television. 1973, 10 (prototype). g