SU1034011A1 - Time interval meter - Google Patents

Description

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w. The invention relates to a pulse technique and can be used in the construction of high-precision measuring instruments and devices. A device of a vernier time interval measurement containing a main and a vernier generator, a discriminator, a transmission circuit, and a logic circuit 11 is known. A disadvantage of the known device is a low measurement accuracy. A measure of the duration of time intervals containing interpolation conversion blocks, each of which contains the formers, the main and the vernier generators, the first and second comparison circuits, the keys i enepaTop gating pulses , and counters of the senior and younger bits of p2. In a known device, increasing precision leads to a corresponding increase in conversion time and to compaction of the device. The purpose of the invention is to improve the measurement accuracy without increasing hardware costs. The goal is achieved by the 1gm, that the time interval meter containing a key, two counters, a pulse generator and a sawtooth generator, the output of which is connected to the first input of the reference element, additionally has a digital-analog converter, and the output of the switch is connected to the control input of the sawtooth voltage and with the input of the first counter, the first output of which is connected to the second input of the reference element through a digital-to-analogue converter, the output of which is through a pulse generator a connected to the input of the second counter and the second output of the first counter is connected to the input key. FIG. 1 shows a block diagram of the proposed device; in fig. 2 - diagrams of the 1st of his work. The time interval meter contains a key 1 (FIG. 1), a counter 2, a pulse generator 3, a counter 4, a sawtooth voltage generator 5, reference element b, a digital-to-analog converter 7, a reset bus 8, a signal 9, an output bus 10 result. The device works as follows. When the reset signal comes to the initial state via bus 8, key 1 (the T-flip-flop performs the role of key here), counter 2 and counter 4 come to the zero state. From the output of counter 2 to the control input of Llyuch 1, an enabling signal is received. With the arrival of the first impulse of the measured interval (Fig. 2q), a positive differential (Fig. 2b) is formed on an electromyplug of fig. 1, through which the sawtooth voltage generator 5 is started (Fig. 22) and as soon as the output voltage intersects the voltage level supplied from the digital-to-analog converter 7 (Fig 2S), the comparison element 6 (collar, Fig 2d) starts the generator of 3 pulses, the pulses of which are fed to the summing input of the counter 4 (Fig 2e). The second pulse of the measured interval brings the key 1 to the initial state. In this case, 1 generator 5 is brought back to the original with; stop. Comparison element 6 is zag; the generator 3 is working, and the content of its counter 2 is increased by one. This leads to a change in the voltage level at the output of the digital-to-step converter (Fig.2- &). The change of this voltage leads to the fact that with the arrival of the pulses of the next time interval, the start of generator 3 will be delayed by a time interval equal to (where CJ, is the voltage corresponding to the lower bit of the D / A converter 7, and V is the rate of change of the output voltage generator 5. A measurement result is removed from the output bus 10. In the proposed device, the measurement accuracy depends on the angle of inclination of the generator voltage 5. With the increase in speed Y of the output voltage of the generator 5, h This corresponds to a decrease in the quantization step, the measurement accuracy increases accordingly. For example, if at a threshold voltage level of a logic element equal to 1B, the rate of change V of the output voltage of generator 5 is, say, 10 not / V, then at 10-level digital-to-analog converter 7, the resolution is estimated to be K-1 HC. If the speed V is the change in the output voltage of the first generator. 5 is 2 non / V, then with a 10-level conversion of the digital-analog converter 7, the resolution of the device will be a value of 0.2 non. At the same time, by increasing the size of the digital-to-digital converter, the resolution of the proposed device can be significantly increased by making it a high-precision device in measuring time intervals, when

This measurement accuracy may be higher than that of known time interval meters.

The proposed device is mainly made on discrete elements, which makes it possible to speak about the effectiveness of such devices both in production and in control and adjustment operations.

Thus, with all the simplicity of the proposed converter, it allows measuring the time interval of the nanosecond range.

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Claims (1)

TB7) TIME INTERMETER, pulse generator and sawtooth generator, the output of which is connected to the first input of the comparison element, characterized in that, in order to improve the measurement accuracy, a digital-to-analog converter is introduced into it, and the output of the key is connected to the control input a sawtooth voltage generator and with an input of a first counter, the first output of which is connected via a digital-to-analog converter to the second input of a comparison element, the output of which is connected to an input through a pulse generator m of the second counter and the second output of the first counter,