SU696388A2 - Mean frequency meter - Google Patents

Description

I

The invention relates to a measurement technique and can be used for measuring the average frequency of a random sequence of pulses in instruments for recording ionizing radiation.

Known average frequency meter containing connected to the blocking key counter-register formed by triggers, the counting inputs of which are interconnected through the first group of logic circuits AND, connected by their other inputs to the outputs of previous triggers, the separate inputs of which are connected in pairs to the corresponding outputs of subsequent triggers through the second group of logic circuits I. The shift-register-bus bus connects the other inputs of the logic circuits AND of the second group with a clock generator, which through The time delay device (one-shot) is connected to the blocking key and the counting inputs of the triggers of the information output unit, the potential inputs of which are connected to the corresponding triggers of the counter-register 1.

The known device has high accuracy and good reproducibility, simply in realizing, stability in time and temperature changes, but has a linear dependence of the output readings on the average frequency of the input pulses, which limits its scope.

In a series of cJiyiaeB, it is necessary to have a meter with a non-linear (for example, quadratic) dependence on the input-output, i.e. I possess the ability of adaptive compression of 1 information.

Such a need arises, in particular, when operating under conditions of a large dynamic range of the measured frequency or in cases when information needs to be transmitted over a communication channel with limited bandwidth (for example, when logging wells).

The aim of the invention is the extension of functionality, which is expressed in the course of obtaining a non-linear dependence of the input-output meter of the average frequency.

The goal is achieved by the fact that the average frequency meter containing a clock pulse generator, a counter-register, the control input of which is connected to the counting inputs of the information output unit through the delay element and to the control input of the key, the output of which is connected to the counting input of the counter register, the potential outputs of the information output unit are connected to the potential outputs of the counter-register, a controlled frequency divider is entered, and (The counting input of the controlled frequency divider is connected to the generator output KTOV pulses, the control input of the counter-register is connected to the output of the controlled frequency divider, the potential inputs of which are connected to the forward potential outputs of the counter-register. The block diagram of the average frequency meter is shown in the drawing. -register 2, the potential outputs of which are connected to the corresponding potential inputs of the information output unit and 3, and the direct potential outputs of the counter-register 2 are also connected to the corresponding outputs entsialnym inputs controllable frequency divider 4. Counting input ugfavl emogo frequency divider coupled to the output clock generator 5 and the output - to the control input of the register-counter and via the delay element 6, - a calculating unit input information and output a control input of the key. The meter works as follows. The input pulses with an average frequency p are fed through the key 1 to the counter-register 2. By setting the current value of the number N; recorded in the counter-register 2, the value of the division factor from the controlled frequency divider 4 is set. This is done by supplying code bits from the direct potentiometer 1x outputs of the counter-register 2 to the potential inputs of the controlled divider 4. After time С m. К О ОМ1 where С - is the value of the division factor of the controlled frequency divider 4; clock frequency 5; v ", the proportional coefficients, the pulse from the output of the controlled frequency divider 4 triggers delay element 6, the pulse which locks key 1 and the input pulses to the counter-register 2 stops and shifts the contents of the counter-register 2 by one bit to the left. The back of the pulse front of the delay element 6 Information is rewritten from the counter-register. 2 to the output information block 3. At the end of this pulse, key 1 is opened and counter-register 2 again counts the input pulses, the number of which is added to the result of the previous count and shift, and the code of the total number controls the divider 4. After several count cycles and shift the number N is rewritten in the information output unit 3; The UGT is proportional to the square root of the average frequency of the input pulses. According to the author's testimony, for the average frequency meter, the number recorded in the counter-register after several cycles can be represented as NI N424, where NI, Nj.j, N, 2 counts in adjacent time intervals T; nj, nj-i, p | -2 is the frequency of the input pulses in adjacent time intervals T; n is the average value of the measured frequency. Enter the place of a constant interval T, the interval whose duration is inversely proportional to the number recorded in the counter, i.e. T -, where K is the proportionality coefficient, for a steady state output value N - y-hCK / N-) N, - | K-fi. That is, if the duration of the time interval during which the accumulation of pulses in the counter-register occurs is inversely proportional to the number recorded in the counter-register, then the set value (recorded in the counter after several cycles) is proportional to the square root of the average frequency of the input pulses. Due to the quadratic dependence of the input - output of the meter, the information is adaptively compressed, which makes it possible to use the meter in conditions of a large dynamic range of measured frequencies in telemetry systems with limited bandwidth of the communication channel. The frequency divider plays essentially the role negative feedback element. Obviously, by specifying certain transfer functions of this processing link, it is possible to obtain various dependences of the input - output meter. I The above described case of a quadratic input – output dependence is. the simplest. If you use a more complex transfer function feedback type

T - N-e

then the meter will have a logarithmic input-output relationship.

Claims (1)

Invention Formula Average frequency but auth. St. No. 392433 characterized in that In order to expand its functionality, a controlled frequency divider is introduced into it, the counting input of which is connected to the output of the clock pulse generator, the control input of the counter-register is connected to the output of the controlled frequency splitter, potential inputs of which are connected to the forward potential outputs of the counter-register . Sources of information taken into account in the examination 1. Copyright USSR N 392433, cl. G 01 T 1/17, 1971. L I A of f.-