SU944103A1 - Time moment-to-code converter - Google Patents

Description

(5) TIME MOTOR CONVERTER TO CODE

one

The invention relates to a measurement technique and can be used in measuring time-frequency parameters of signals, in particular in measuring time intervals and synchronous meters.

There is a known time converter into a code based on reading the instantaneous values of periodic signals, which contains a sectioned delay line, which forms a pulse generator of the reference signal p.

However, the discreteness of generator states limits the accuracy of the conversion.

The closest to the invention in its technical nature is a point-to-point converter that contains a reference signal generator, the output of which is connected to the first inputs of two mixers, a shock excitation generator, the output of which is directly connected to the second inputs of the mixers, the outputs of the mixers through detectors and analog-digital The converters are connected to the data processing unit C2; i.

The disadvantage of this converter is comparatively low accuracy, since the mismatch and random deviations of the frequency of the jjj generator of the shock excitation relative to the frequency of the reference signal cause the fluctuations of the detected signals and reduce the accuracy of the conversion. 4 similar effect

t5 also leads to instability of the amplitudes of the generators, since the selection of the detected signal requires a relatively longer time, and to ensure the stability of all

20 signals is complicated.

The purpose of the invention is to improve accuracy.

The delivered target is achieved by the fact that neither the code containing the reference frequency generator, the delay line, and the two-analog-digital converter, whose outputs are connected to the inputs of the processing unit whose output is the converter output, are inserted into the time converter; coal impulses and two integrators, where the output of the reference frequency generator is connected via a delay line to the first input of the first integrator and directly to the first input of the second integrator, the second inputs are integrated trench are connected to the output of the rectangular pulse, which is input vyvhod device outputs the first and second yn integrator connected to the inputs of the first and vtorogr analog-digital converters. The drawing shows a structural diagram of the proposed Converter. The converter contains a driver of 1 rectangular pulses, integrators 2 and 3, a generator C of the reference frequency, a delay line 5, analog-digital converters 6 and 7, a data processing unit 8. The device works as follows. In the initial state, the integrators 2 and 3 are blocked by a signal from the output of the imaging device 1 and there is an initial (for example, zero) level at their outputs. Analog-to-digital converters 6, 7 and data processing unit 8 are prepared for the start of the conversion. The oscillator generates a reference signal of a sinusoidal form of stable amplitude and frequency, the delay time of line 5 is chosen equal to a quarter of the period of the reference signal. When an external signal is applied, the former 1 generates a straight-angle constant-current pulse, the onset of which is determined by the external signal. The pulse duration is chosen equal to half the period of the signal (other lengths are possible, but the above is optimal). During the pulse, the reference signal is integrated with some initial phase. After the termination of actions B of the pulse, at the outputs of the integrators the signals are formed: and, sin osCu; t cue, о T -, U2 (u; to-oo), where and, and are the signals at the outputs of integrators 2 and 3, respectively; U is the angular frequency of the reference signal; A is the amplitude of the reference sig; Nala; C is the duration of a rectangular pulse (integration time); & - the duration of the delay line 5; t is the moment of the external signal (the beginning of the integration). The signals from the integrator outputs are digitized by the converters 6 and 7 and fed to the data processing unit 8. As a processing unit 8, for example, a micro-computer can be used. Processing is performed according to the formula, QY4rfcg (cosujg-U LtU) / SiMu; g, - O) L - qs-tr (The formula is derived when solving the system of equations for the signals at the outputs of the integrators 2 and 3) Thus, unlike the well-known the converter is less critical for instability of the parameters of the circuit elements and the effects of noise, which improves the accuracy of the conversion. The converter, using relatively simple technical means, ensures the stability of the duration of a single pulse, much greater than the frequency stability of the generator of shock excitation in a known device, and the instability of the amplitude of the pulse does not have a fundamental effect on accuracy as opposed to instability. amplitudes of the shock excitation generator; during the integration process, high-frequency noise is suppressed; the conversion takes place in a short time, during

the stability of the reference signal is better maintained.

Claims (1)

1. USSR author's certificate in accordance with the application If 2803307 / 18-21, cl. H 03 K-13/20, 07.25.79. 2, Electronic methods of nuclear physics. Ed. L. A. Catalina. I., Atomizdat, 1973, p. 266.