SU805206A2 - Automatic meter of four-terminal network band-width - Google Patents

Description

The invention relates to a measuring technique and can be used in instruments for automatic measurement of the four-pole network bandwidth. According to the main auth. No. 437984, a device is known for automatically measuring the bandwidth of a quadrupole band, comprising a series-connected sawtooth voltage generator, a frequency control unit, a sweeping frequency generator, a grid driver, frequency tags, an electronic key and a counter l. The drawback of the device is the low accuracy of the transmission band measurement due to the absence of non-vernier frequency marks. The purpose of the invention is to improve the accuracy of the measurement of the bandwidth. The goal is achieved in that the device for automatic measurement of the quadrupole bandwidth contains a series-connected sawtooth generator, a frequency control unit, a oscillating frequency generator, a frequency marker grid former, a first electronic key, a first counter, and the oscillator frequency output the quadripole under study is connected to the first input of the indicator, the second input of which is connected to the output of the sawtooth generator, and the output is connected A second electronic key, a second counter, an input for a grid of frequency labels of smaller discreteness / two triggers, an adder and a block for deceleration of the scanning speed are entered, with the output oscillator frequency generator via series-connected shaper of a grid of frequency labels of smaller discreteness and the second electronic key is connected to the counting input of the second counter, the output is meat which is connected to the input of the second transfer count, and the reversing input connected to the output of the first flip-flop, a first input of which is connected to one of the pulse isolation unit outputs a reference band, and a second input connected to a first control input

the second electronic key, with the output of the frequency tag grid generator and the first input of the second trigger, the second input of which is connected to the second control input of the second electronic key and the output of the adder, the inputs of which are connected to the corresponding electronic key outputs, and the second output The trigger through the slowdown speed sweep unit is connected to the input of the sawtooth generator.

Figure 1 shows the block diagram of the device; in fig. 2 - time diagrams of signals.

The device contains a sawtooth voltage generator 1 (GPN), a frequency control unit 2, a frequency generator 3 (frequency response generator) 3, a frequency marker grid former 4, the first electronic key 5, the first counter b, the quadripole 7 under investigation, indicator 8, the selection unit 9 band count pulses, the second electronic key 10, the second counter 11, the generator 12 of the grid of frequency labels menyii discreteness, the first trigger 13, the second trigger 14 the adder 15 and the block 16 slowing down the scanning speed.

The device works as follows.

The frequency of the hoop 3 is tuned to the required limits by the output voltage of the frequency control unit 2 with a period set by GPN 1. The frequency response of the quadrupole 7 under investigation is reproduced on the display of the indicator 8, the output of which produces a square pulse, the front and the slope of which are formed at the moments of the switching frequency of the hoop. 3, respectively, through the initial and final frequencies of the counted bandwidth of the four-pole 7; At the same time, at the outputs of block 9, the selection of pulses for counting the strip. a pulse is generated and a pulse of the end of the reference strip. A start pulse is directly connected to the accumulator 5 and 10 through the adder 15, allowing the passage of the frequency mark pulses from the formers 4 and 12 to the counting inputs of counters b and 11, respectively. At the same time, trigger 14 is shifted by the same impulse, including the raververt speed deceleration unit 16, in which case the frequency sweep rate of the hopper 3 is reduced and thus the quality of the pulses of the tags is reduced. discreteness at the output of the generator 12. Counter 11 counts the pulses in the summation mode specified by the output level of the flip-flop 13 until a pulse 4 of the mark appears at the output of the generator

the discreteness with which the key 10 is closed and the flip-flop 14 is transferred, turning off the deceleration unit 16. Next, only counts of greater discreteness are counted by counter b until the output of the circuit of the output 9 of the pulse of the end of the counting band by which the key 5 is closed, the key 10 is opened, the flip-flop 13 is thrown, including the slowdown unit 16, and flip-flop 14, which translates the counter 11 to pulse subtraction mode. Next, only counts of smaller discreteness are counted by counter 11 until a pulse of higher increments of the mark of greater discreteness appears at the output of shaper 4, which closes key 10, flips trigger 13, turns off deceleration unit 16, and flips counter 1 of forward pulse counting. As a result of the cycle of the algorithm, counters 6. and 11 are written down the numbers, the sum of which is proportional; measurable band

transmission. In this case, if the number of deductible pulses arriving at counter 11 exceeds the number of previously totalized pulses, the unit of the highest bit is borrowed

from counter 6 at the entrance of the transfer.

The accuracy of the frequency measurement is increased by a number of times, equal to the ratio of the frequencies: 1x intervals between larger marks and discreteness, while the measurement time is increased almost indefinitely.

Claims (1)

1. USSR author's certificate 437984, cl. G 01 R 29/00, 1974 (prototype). I I I { n