SU705360A1 - Digital central frequency meter - Google Patents

Description

(54) DIGITAL MEASURING MEDIUM FREQUENCY

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The invention relates to measuring equipment and can be used to register random impulse streams from ionizing radiation detectors.

A medium frequency meter is known, built on the principle of a tracking frequency counter, containing a rib counter, a x5da multiplier converter, a frequency divider, logic elements, and a control unit 1.

The disadvantage of the meter is a significant measurement error when changing the range.

Another digital average frequency meter is known, which contains a decoder, a divider h: asthoty, a reversible counter divided into two parts, the outputs w of the lower-order bits of which are connected to the first. the inputs of the frequency divider gates, and the outputs of the higher-order dbv through the decoder are connected to the inputs of the gates of the ten-day multiplier. The output of the ten-day multiplier is connected to the input of a frequency divider connected by its outputs to the second inputs of a frequency divider. The output of the frequency divider valves is connected to the first

the input of the coincidence circuit, the second input of which is connected to the output of the decade multiplier valves, and the output of the coincidence circuit is connected to the input of the subtraction of the reversible counter 2,

In such a meter with automatic measurement range switching. the inconvenience of presenting the measured value is due to the fact that

0 it displays information in binary. The disadvantage of the digital meter is also the fact that when the measured value changes from a range to a range

5 fluctuation of readings related to the number of the measurement range, which reduces the measurement accuracy.

The purpose of the invention is to improve the accuracy of the range of the laugh

0

To do this, a digital average frequency meter containing a decoder connected through a series-connected decade multiplier and a frequency divider with one of

5 groups of inputs of the frequency divider valve unit, another group of inputs of which is connected to the first outputs of the lower bits of the reversible counter. ka, the coincidence element, one of the inputs of which is connected to the input of the frequency switch, the other with the output of the valve block of the frequency divider, and the output with the input of the reversible counter, the second output of the reversible counter is connected to the input of the decoder, the first, second and third additional elements of the coincidence are entered , moreover, the inputs of the first and second additional elements of coincidence are connected respectively to the outputs (ni-l) IP1-GO of the bits of the reversible counter, the outputs of the first and second additional elements of coincidence, and one of the inputs (rii-i) -ro bit a reversible counter connected sootoetstvenno to the inputs of the third extension elementasovpadeny whose output is connected to the input 9 (w-l) -ro discharge and one of the inputs senior n bits down counter, a second input coupled with rhodom Im-th discharge down counter. ;. - .-. ; .

The drawing is structural. scheme of a digital meter of average frequency;;

Digital meter of the average frequency with automatic switching. . . ranges consists of a decoder 1, a frequency divider 2, a block 3 of a valve of a frequency divider, a reversible counter 4, a decade multiplier 5. Match element b, First, second and third additional match elements 7, 8 and 9,;

The device works as follows. .

To the input And reversible counter 4, divided into two parts of the CP and p. input impulses are received. Input. the pulses are recalculated in m lower-order bits of the reversible counter 4. The higher bits n are meant for measuring the range of the input frequency. . The codes of both parts vn and h of the reversible counter 4 are sent in power to the inputs of the valve block of frequency divider 3 and to the decoder 1. The decoder i is right handled by the decade multiplier 5 in such a way that the pulses of the reference clock are: stoty, Pr (5 one; through gates 5, the frequency divider 2 is supplied to YHOD; frequency divider code 2 arrives at the other inputs of frequency divider valve block 3, where it is compared with reversible counter code 4, and the output signal from frequency divider gates 3 controls the coincidence element in a way that is fixed In the current mode, the input subtraction (Calc.) of the reversible counter, 4, receives signals with a frequency equal to the code of the reversible counter 4. In this case, the input frequency will be equal to the feedback frequency (rial output of the coincidence element 6), . When it changes

the input part of the frequency range for one range of overflow (increase in frequency) or borrowing (with decreasing frequency) is sent to the higher bits of the reversible counter, and thus the code of the ranges changes by one in one direction or the other. At the same time, the overflow signal is fed to the input of setting the number 1 of the discharge of the 4f reversible counter, which allows forming the recording mode of the unit to the hi-th bit. Thus, after increasing the input frequency and moving it to a higher range, the counter of the reversing counter 4, the number corresponding to the measured value is immediately set, and not the higher bits - the measurement range code. ....

As the input frequency decreases, the z.impulse is made from the (lin-l) -ro input. At the same time, the first, second, and third additional elements of coincidence 7, 8, and 9 produce signals of the codes of bits, corresponding values (m-1-OOOl and (vn-0000), respectively. Thus, when the input frequency decreases, its transition to a lower range produced with a shift (hysteresis) by one decimal order. Such a construction of the average frequency meter allows you to present the measured value in the tenth numeral system, and eliminate the uncertainty of its representation at the boundaries of the measurement ranges when the input hour changes then you.

Claims (1)

1.ABTopckoe certificate of the USSR №194185, cl. GOITJ 23/02, 1967. 2, USSR Author's Certificate No. 337938, cl. GOIR 23/02, 1972, (prototype),