SU1100605A2 - Repeating time interval meter - Google Patents

Abstract

MEASURING REPEATING INTERVALS OF TIME by author. St. No. 970307, characterized in that, in order to improve the accuracy of measuring and expanding the range of measured time intervals, an additional D-trigger, the signal input of which is connected to the auxiliary output of the imager, is inserted into it, the synchronization input of the additional D-trigger, is connected to the output of the gating pulse generator and the output of the additional D trigger is connected to the auxiliary input of the match element. in C1 / 8 Oh cl

Description

G 7 JITL The invention relates to a pulse technique and can be used to construct digital meters for repeating time intervals. According to the main author. St. No. 970307, a repeater time meter is known, which contains a driver, the output of which is connected to the signal input of the D-trigger, a gate shift generator, the input of which is connected to one of the input of the driver, and the output is connected to the strobe pulse generator, the output of the generator the strobe pulses are connected to the synchronization input of an O-trigger, the output of which is connected to one of the inputs of the coincidence element, the second input of which is connected to the output of the counting pulse generator, the output of the coincidence element Linked to counter l. In such a meter, the measurement accuracy and the minimum measured interval depend on the speed of the former, the output of which receives a rectangular pulse with a duration equal to the interval to be measured. Typically, the response time of the former to the start and end signals of the interval differ. As a result, the front and rear edges of the pulse at the output are formed with different delay, and this in turn leads to the fact that the effective pulse duration (determined by the trigger level D of the trigger) differs from the duration of the measured interval. The final speed of the formatter determines the minimum possible pulse duration that this driver can form, and, therefore, the minimum measured time interval. The purpose of the invention is to increase measurement accuracy and extend the range of measured time intervals. The goal is achieved by the fact that in the meter of repetitive time intervals, containing a driver, the output of which is connected to the signal input of the D-trigger, a generator of propulsion pulses, the input of which is connected to the input of the driver, and the output through the gate pulse generator is connected to the input synchronization of the D-trigger, the output of which is connected to the input of the counter through the coincidence element. the second input of the coincidence element is connected to the output of the generator of counting pulses, an additional D-trigger is introduced, the signal input of which is connected to the additional output of the driver, the synchronization input of the additional D-trigger, is connected to the output of the strobe generator, and the output of the additional D-trigger is connected to an additional element entry matches. FIG. 1 shows a structural diagram of the meter; in fig. 2 and 3 are time diagrams for his work. The meter contains a driver 1 (Fig. 1), one output of which is connected to the signal input D of the trigger 2, and the other output with the signal input of the additional B trigger 3, the strobe pulse generator 4, (strobe pulses) associated with 5 strobe pulse generator. The input of the generator 4 shift strobe pulses connected to one of the inputs of the imaging unit. The output of the strobe pulse generator 5 is connected to the synchronization inputs of D-triggers 2 and 3. The output of t) -rigger 2 is connected to one of the inputs of coincidence element 6, the second input of which is connected to the output of D-trigger 3, and the third input of coincidence element 6 is connected with the output of the generator 7 counting pulses. The output of the coincidence element 6 is connected to the input of the counter 8. The device operates as follows. The signals of the beginning and end of the measured interval (Fig. 2a, b) are fed to the corresponding inputs of the imaging unit 1, which is a two-channel pulse expander (these can be, for example, two Kipp relays). At the outputs of shaper 1, extended pulses are received (Fig. 2c, d), the leading edges of which correspond to the beginning and end of the measured interval. The pulse duration at the output of the imaging device must not be less than the minimum duration necessary for the D-triggers 2 and 3 to operate. The start signal of the measured interval is also fed to the input of the 4-gate generator of the strobe pulses, which generates a signal that is automatically 3110 shifted in time relatively periodically input signal per read step. The signal from the output of the strobe pulse shift generator 4 triggers a generator of 5 btrob pulses, which forms a steep pulse with a steep edge (Fig. 28), whose temporal position is determined by the signal from the strobe pulse shift generator 4. The extended pulses from the outputs of the imaging unit 1 are fed to the signal inputs of the D-triggers 2 and 3, and an extended pulse corresponding to the end of the measured interval is applied to the input of the additional D-trigger 3. The synchronization inputs of the D-triggers 2 and 3 receive strobe pulses (Fig. 2 S) from the output of the strobe pulse generator 5. The signal levels at the outputs of the D triggers take on the values of the signal levels at their signal inputs at the time of the passage of the front gate. Thus, while the signal level of the D-trigger is kept at one signal level, it will remain at the output of the D-trigger, and before the next strobe pulse arrives, the signal level at the signal input of the 13-trigger will change from, as the strobe pulse front passes, the signal level will also change at the output of the D trigger. As a result of the sequential shift of the strobe pulse (Fig. 25) with respect to periodically repeated extended pulses (Fig. 2b, 2), at the outputs of D-triggers 2 and 3 rectangular pulses are formed (Fig. 2; 2), equivalent in duration to the pulses from the outputs of the imaging unit 1 (Fig. 2b, 1), but in a new time scale. The time scale conversion factor is defined as where T is the repetition period of the pulses; bt is the read step. Because the synchronization of the O-triggers is performed from one impulses between output By the signals of D-triggers, the rigid time connection corresponding to the temporal connection of signals at their inputs is preserved. As a result, the interval between the leading edges of the pulses at the outputs of the D triggers (Fig. 2v,) corresponds to the interval between the leading fronts pulses at the outputs of the imager, which is determined by the measured interval. The signals from the outputs of the D triggers 2 and 3 (Fig. 26, :) are received respectively at the first and second inputs of the coincidence element 6, which in this case can be made in the form of a key that is opened by the leading edge of the signal at its first input and closed by the leading edge of the signal at its second input (this could be, for example, a trigger with dividing 4 inputs, the signal from the output of which controls the operation of the AND circuit). The coincidence element 6 transmits to the counter 8 a signal (Fig. 2) from the output of the generator 7 of counting pulses, which arrives at the third input of the coincidence element 6. The number of counting pulses that have passed through the coincidence element 6 (Fig. 2n) is counted by counter 8, which, in order to reduce the measurement error, can average the measurement interval over a certain constant measurement time. Based on the number of counted pulses, the value of the measured interval is determined. When the measurement time can be doubled or the maximum measured. The interval does not exceed half of its repetition period, the coincidence element can be performed more simply - in the form of a three-input circuit I. In the first case, driver 1 can be made in the form of two counting triggers, in the second case in the form of two KIPP-relays, the pulse duration at the outputs of which is not less than the maximum measured interval and not more than half the repetition period of the measured interval. The operation of the device in these cases is basically similar and proceeds as follows. As described above, the signals of the beginning and end of the measured interval (Fig. 3 0, S) go to the corresponding inputs of the former 1, which are executed, for example, in the form of two Kipp-relays. On the outputs of the former 1, extended pulses are received (Fig. 3b, ), the duration of which is longer than the measured interval, but less than half the period of its repetition.

As a result of a sequential shift of the strobe pulse (FI1, 35) with respect to periodically repeated expanded pulses (Fig. 3 d), at the outputs of the 10-triggers 2 and 3 rectangular pulses are formed (Fig. 26), equivalent in duration to the pulses from the outputs shaper 1 in the new time scale, the interval between the leading fronts of which corresponds to the measured one.

The output signal from D-trigger 2 (Fig. Ze) and inverse run D of trigger 3 (Fig. 3-) are fed respectively to the first and second inputs of the coincidence element 6, which in this case is made in the form of a trikhddovoy scheme I.

The coincidence element 6 transmits to the counter 8 a signal (Fig. 3c) from the output of the generator 7 counting pulses, arriving at the third time of the coincidence element 6, when level 1 is present at its two first inputs, which corresponds to the measured interval at a new time scale.

The value of the measured interval is determined from the number of counting pulses that have passed through the coincidence element and are counted by counter 8.

The introduction of an additional trigger allows one to increase the accuracy of the measurement of time intervals and to extend the lower limit of the range of measured time intervals in comparison with the prototype. This is due to the fact that the error is significantly reduced, determined by the final speed of the former.

So, in the case of using the K155TV1 type trigger switch as a trigger generator, out of the widespread 155 series, the switch-off time delay is approximately 37 NS, and the turn-on delay time is approximately T5 HC. As a result, when the output of the driver wants to receive a pulse equal to the measured interval, the duration of the pulse at the output of the driver differs from the true interval by an average of 22 Ns.

In addition, the maximum guaranteed trigger switching frequency is 10 MHz and, because of this, the minimum interval between on and off pulses cannot be greater than 50-100.

In the proposed meter, the measured interval is converted into the interval between the same pulses fronts at the outputs of the two-channel driver. With identical channels, the edge delay is the same and the interval between the edges is equal to the measured one. The minimum possible measured time interval is significantly reduced, since pulses of duration longer than the minimum measured interval are formed. I I I I I I

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Claims (1)

REPEATING INTERVAL TIME METER by ed. St. No. 970307, characterized in that, in order to increase the accuracy of measurement and expand the range of measured time intervals, an additional D-trigger is introduced into it, the signal input of which is connected to an additional output of the driver, the synchronization input of an additional D-trigger is connected to the output of the strobe generator, and the output of the additional D-trigger is connected to the additional input of the match element. 1 1100605 1