SU476521A1 - Frequency response meter - Google Patents

Description

one

The invention relates to radio metering technology and can be used in the development of instruments for studying the amplitude-frequency characteristics (AFC) of quadrupoles.

A measurer of amplitude-frequency characteristics is known, containing a series-connected modulating voltage generator, a generator of oscillating frequency (GCH), a quadrupole under study and a logarithm, and an oscillographic indicator, the signal input of which is connected to the output of the logarithm, and the input of the horizontal deviation signal to the output of the modulating voltage generator.

A disadvantage of the known device is the complexity of the HF channel, the presence of a wideband HF switch in it, and low measurement performance, especially with small frequency sweeps.

In order to improve the accuracy and performance of measurements, the proposed multivibrator, a control circuit, a key diagram, an integrating device, a comparator and a reversible counter, as well as a reference voltage source and a reference pulse generator are introduced into the proposed frequency response meter. An additional generator output of a modulating voltage is connected to the input of a standby multivibrator and a second control circuit input, an additional output of the control circuit is connected to the control input of the reversible counter, the output of the logarithm of the key circuit, to the other input of which a signal is output from the source the reference voltage, and the control input of the comparator is connected to the output of the reference pulse generator.

FIG. 1 shows the block diagram of the proposed frequency response meter; in fig. 2 - voltage diagrams at different points of the meter circuit.

The amplitude-frequency characteristics meter contains a GKCH 1 connected to a modulating voltage generator 2. The GKC 1 output is connected to the input of a logarithm 4 of the oscillographic indicator 5 and a signal input of the key circuit 6 through the quadrupole 3 under study. Auxiliary output The modulating voltage generator 2 is connected to the waiting multivibrator 7 and the control circuit 8, which are interconnected.

The control circuit 8 is connected to the key circuit 6 and the reversible counter 9, between which the integrating device 10 and the omparator 11 are connected in series. The key circuit 6 is also connected to the output of the reference voltage source 12, and the comparator is connected to the reference pulse generator 13.

Izmeritel frequency response works as follows.

At the output of the surge switch 1 of the LOD, the effect of the modulating voltage of the generator 2 appears to be garliuic oscillations, which, after passing through the quadrupole 3 under study, enter the logarithm -4. The device 4 logarithms and detects the signal iodine to it. The output signal of the logarithm device 4 is fed to the input of the vertical defaults of the indicator 5.

The modulating voltage generator 2 generates a saw-tooth voltage with two tunable steps (Fig. 2, a) both at the GKC 1 and at the input of the horizontal deviation of the indicator 5. As a result, on the screen of the indicator 5 an image of the AHC with two points is observed.

Simultaneously with the coil voltage, the generator 2 generates trigger pulses (FIG. 2, c) to the waiting multivibrator 7 and the control circuit 8. The latter generates control pulses (FIG. 2, h) to start the reversing counter 9 and switching pulses for the key circuit 6 which transmits to its output the voltage from the output of the device 4 (Fig. 2, b), the reference voltage of the direct current of the protective device (Fig. 2, e). The output of the key circuit is fed to the integrating device 10, which is a dual integrator. The output voltage (Fig. 2, b of the integrating device 10 is fed to a comparator 11, producing rectangular pulses of the same amplitude with a duration equal to the duration of the decay of the pulses at the output of the integrating device 10, which are then converted into a burst of pulses using the generator of reference pulses 13 (Fig 2). These bursts of impulses arrive at the reversible counter 9, which during the first step works on addition, during the second step -

ia subtraction. The resulting difference in the number of pulses is equal to the ratio of the amplitudes at the given points. Then, under the influence of an indication pulse (Fig. 2, / 1h), the measurement result is displayed and, finally, a pulse (Fig. 2, hi

resets the counter. Therefore, for one sweep period it is possible to uniquely determine the ratio of the amplitudes of any two points of the frequency response.

Subject invention

A meter of amplitude-frequency characteristics containing serially connected modulating voltage generator, 1 oscillator of oscillating frequency, investigated quadrupole and logarithm, as well as an oscillographic indicator, whose sigal input and switch are to the output of a logarithm, and the input of the horizontal deviation signal

To the output of a modulating voltage generator, characterized in that, in order to improve the accuracy and performance of measurements, a series-connected standby multivibrator, control circuit, key circuit, integrator, comparator and reversible counter, as well as a reference voltage source and generator are introduced into it reference pulses, with the additional output of the modulating voltage generator connected to the input of the waiting multivibrator and to the second input of the control circuit, an additional output of the control circuit and connected to the control input of the reversible counter logarithmic output device coupled to the signal input of the key circuit, the other input of which is fed the signal output from the reference voltage source, and a control input connected to the output komiaratora reference oscillator

pulses.