SU868695A1 - Two-scale time interval meter - Google Patents

Description

(54) TWO-SCALE TIME-INTERVAL METER

The invention relates to information and measurement technology and can be used in radar, laser technology, automation, experimental physics for measuring time integrals with high accuracy. Two-scale time interval meters are known with interpolation of uncertainty zones between start () signals and reference frequency pulses using the time-amplitude code 1 method. A disadvantage of known devices is their relative complexity. The closest to the proposed rto technical entity is a meter that contains a reference frequency generator, two two-stage schemes for the selection of exact intervals, a coarse code selector, two time-amplitude converters, a multiplexer, a memory unit, an amplitude converter one exact coding counter, a rough coding counter, a scale docking system consisting of a trigger, AND, OR L2 schemes. The disadvantage of the known time interval meter is its comparative complexity, which consists of two time-amplitude converters, a memory unit and multiplexer. The purpose of the invention is to increase the reliability of the device by simplifying it. This goal is achieved in that a dual-scale time interval meter containing a reference frequency generator connected to the inputs of the start and stop channel reference selection blocks, a coarse code selector, whose three inputs are respectively connected to the output of the reference frequency generator and the outputs of the reference selection blocks start- and stop-channel pulses, and the output is connected to the input of a coarse coding counter, time-amplitude converter, counter of the counter meter, time-amplitude docking unit, jpeg). The zamplitude-code zoodette, the output of which is connected to the input of a precise coding counter., the scale docking unit, the first input of which is connected to the output of the coarse coding counter, a delay line, two OR elements and a code correction unit, the first input of the first OR element is connected to the second block input

the selection of the reference start-channel pulses, the second input of this element is connected to the output of the stop-channel reference pulse selection unit, and the output is connected to the start-input of the time-amplitude converter, the first input of the second OR element is connected to the second input of the stop-channel reference pulse selection unit through the delay line, the second input of this element is connected to the output of the selection unit (reference pulses of the start-channel, and the output is connected to the stop input of the time-amplitude converter, while the inputs of the code correction locator are connected to the outputs internal and coarse counters encoding, and is its output is connected to the second input of the docking scales.

The drawing shows the block diagram of the proposed two-scale time interval meter.

The device contains sources 1 and 2 start-and stop-signals, blocks 3 and 4 of selection of start-up reference impulses of stop-channels, reference frequency generator 5, elements OR b and 7, delay line 8, coarse code selector 9, time converter 10 The amplitude, the amplitude code converter 11, the exact coding counter 12, the rough coding counter 13, the code correction block 14 and the scale docking block 15.

The device works as follows.

The start signal, which sets the beginning of the measured interval, from the input of source 1 enters the input of the block 3 of selection of reference pulses, the start-channel and, through the OR 6 element, starts the converter 10, the time-amplitude. Unit 3 extracts the second pulse from the reference sequence, which turns on the coarse code selector 9, and uses the OR element 7 to stop the converter 10. On the storage capacitor of the converter 10, the time-amplitude is fixed by a voltage proportional to the time interval applied to the fero input. The stop signal specifying the end of the measured interval, from the input of the source 2, starts the block 4 selection of the reference impulses of the stop channel, which selects the second pulse of the reference sequence after the stop signal. With this impulse the coarse code selector 9 is turned off and is started; Converter 10 time-amplitude. Delayed by line 8 of the delay at a time equal to two periods of the generator 5 of the reference frequency, the stop signal arrives at the stop input of the converter 10 and stops it.

Thus, using the block 4 of the selection of the reference pulses and the delay line 8 at the input of the converter 10, a time interval is formed equal to the interval between the stop-signal

and the previous pulse of the reference frequency generator. A voltage proportional to this time interval is summed at the storage capacitor of the converter 10 k with the previously obtained voltage corresponding to the first interpolation zone. With the help of the converter 11, the amplitude-code and the exact coding counter 12, the amplitude of the sum-time converter formed by the output of the total signal is transformed into a corresponding digital equivalent representing the measurement result on the exact scale of the device. Result

5 coarse measurement is fixed at

this in a coarse counter 13.

The full digital equivalent of the measured time interval is formed from the results of accurate and rough measurements using the docking unit 15 of the scales. At the same time, the result of an accurate measurement before summing up with a gross correction in accordance with the value of the gross code of the correction block 14

5 codes. The need for this operation is associated with the leakage of the storage capacitor of the converter time-amplitude during the measurement interval.

n Thus, in the proposed time interval meter, the introduced delay lines, the OR elements, and the digital code correction block are simple elements compared to

 used blocks in known devices, which leads to increased reliability.

Claims (2)

1. USSR author's certificate 368583, cl. G 04 F 10/04, 1973. 2. Authors certificate of the USSR 619895, cl. G 04 F 10/04, 1979 0 (prototype).