SU189946A1 - DIGITAL DEVICE FOR MEASURING TIME INTERVALS - Google Patents

Description

Known digital time interval measurement devices containing an input driver, outputting rectangular pulses, a pulse counter, a fixed reference frequency generator, frequency dividers with an input valve, a valve control device, a delay device specifying the device reset time before measurement, have a manual selection of measurement limits.

The proposed device is equipped with a device for selecting measurement limits, consisting of a comparator unit, the input of which is connected to one of the outputs of a pulse counter, and an output to the input of a limit counter, controlling the keys at the outputs of the frequency dividers and a collective circuit that connects the outputs of the specified switches and skips exemplary frequencies at the pulse counter input, which automates the process of measuring time intervals by automating the selection of measurement limits.

The drawing shows a functional diagram of the proposed device. (For example, the circuit is designed to measure time intervals in three bands).

4 at the input of frequency dividers 5, a control device 6 controlling the valve, a delay device 7 defining the device reset time before the measurement.

5 In addition, the device includes a device for selecting measurement limits, a niee of comparison block 8, used to set the limit numbers of each of the limits and to compare the number of 2 pulses recruited by the counter with the limit numbers of the corresponding ranges, the limit counter on the flip-flops 9 and 10, which is intended to control the keys //, 12 and 13 at the outputs of frequency dividers 5 corresponding to three exemplary frequencies in accordance with three measurement limits, as well as to issue a limit code, a collective circuit 14, combining // guide key outputs, 12 and 1.3, through which exemplary frequency postu0 Payuta input of the counter 2.

The device works as follows. The voltage specifying the measured time interval is fed to the input of the imaging device 1 and further to the control unit 6. By

5, a start command, a general reset of the device is performed, and after a delay time set by the delay device 7, the control device is prepared for operation. At the output of the control unit, a signal appears, a range, which opens the valve 4 for the pulses of the exemplary frequency fo from the generator 3 of the exemplary frequency. Thus, the pulses of the exemplary frequency from the generator 3 begin to arrive at the input of frequency dividers 5, which serve to obtain the necessary exemplary frequencies according to the number of measurement limits. The reference frequencies are connected via the keys //, 12, and 13, the collecting circuit 14 to the input of counter 2 using the limit counter on the 9 and 0 triggers. Depending on the state of this counter, one or another key // - 13 is open. In the initial state of the limit counter 00, the key 11 is opened, which corresponds to 1 limit. Limit numbers are calculated from the expression P I X max ilollvM where ui is the limit of the r-th limit; Txmaxi is the max-value of the time interval at the / -th limit; foj is the sample purity of the rth limit. If the ratio, where the minimum value of the time interval on the i-th limit, remains the constant value for all limits l-tal-g d dd TO TH, the limiting number is P; for all limits will have the same value corresponding to the maximum value of the time interval at each limit Nmax: P P Nmax. If the measured interval is at 1 limit, i .e. the number dialed in the counter 2, N p, the signal will not arrive at the limit counter during the measured interval T. from the comparing device, and it will remain in the initial state 00 until the end of the measurement, which corresponds to 1 limit. If the measured interval lies in 2 or 3 limits, the number of pulses recorded by the counter 2, N will exceed n and a signal appears at the output of the comparison device 5, which determines N p. On the one hand, this signal goes to the limit counter, which connects the reference frequency of the next limit, and on the other hand, resets counter 2 so that it contains a number proportional to the already measured part of the interval, but now at 2 limits. If the range of measurable intervals is divided into limits such that. but. then the intermittent reset of counter 2 must be made in the state of - - - 2 - dg -sbr - - - mini where is the number set in the counter 2 after the intermediate reset; min is the number in the counter corresponding to the interval G. Intermediate reset is equivalent to dividing the number of 2 pulses jV ha registered by the counter by the overlap factor a. The measurement at the 2 limit will take place until either the measured interval ends, or the counter 2 again dials the limit number n, after which, just as above, it will switch to the 3 limit. Increasing the number of limits will increase the number of outputs of frequency dividers with keys on them. In accordance with the number of keys, the volume of the limit counter must be selected. Subject of the Invention A digital device for measuring time intervals, comprising an input driver, outputting rectangular pulses, an impulse counter, a fixed reference frequency generator, frequency dividers with an inlet valve, a valve control device, a delay device specifying the device reset time before the measurement, differing from that, in order to automate the measurement process, the device is equipped with a device for selecting measurement limits, consisting of a comparison unit, whose input is connected It is connected to one of the outputs of the pulse counter, and the output to the input of the limit counter, which controls the keys at the outputs of the frequency dividers and the collective circuit, which unites the outputs of the specified keys and passes the reference frequencies to the input of the pulse counter.

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