SU819951A1 - Analogue-digital time-to-code converter - Google Patents

Description

I

The invention relates to automation and computer technology and can be used in the construction of high precision digital period meters, phase shifts, single time intervals, null indicators, as well as in research processes in experimental physics.

A known interpolation time meter, consisting of a generator of the reference sequence of two-stage schemes for selecting exact time intervals, delay lines, time-amplitude transducers and amplitude code of the coarse code selector and digital recording and processing unit 1.

This meter has a low speed, because it takes extra time to convert the deadband.

A single time interval meter is also known that contains an exemplary pulse generator, two coincidence elements, two pulse counters, two key elements and two dynamic memory blocks of the beginning and end of the measured interval, with the output of each Of. the key elements are connected to the input of the corresponding counter, and the output of the reference generator is connected to the first inputs of both matching elements and to the signal input of the first key element 2.,;

A disadvantage of the known meter is the low measurement accuracy due to the neglect of the deadband.

The aim of the invention is to improve the accuracy of the analog-digital time-code converter.

This is achieved by the fact that in an analog-to-digital converter a time code containing two binary pulse counters, the outputs of which are connected to boxes, and the inputs are respectively connected to the outputs of the first and second key elements, and an exemplary pulse generator whose output is connected to the first input the first key element, introduced two threshold elements, the inputs of which are connected to the input bus and the third input

Claims (2)

the first key element, the output of the pulse generator is connected to the first input of the second key element, the second inputs of both key elements are connected to the output of the second threshold element. and the third input of the second key element is connected to the output of the first threshold element. This combination of elements allows one to predict (extrapolate) the behavior of the input signal in the dead zone by the extrapolation tact. Most often, digital and pulse automatic control systems use first-order extrapolators that reproduce the input signal with a linear function. To build a straight extrapolating line, you need to know the two previous values of the input signal. The drawing shows a structural electrical converter circuit. The converter contains an exemplary pulse generator 1, which is connected to the first inputs of the And 2 and 3 elements, the key elements 4, 5. The converter input is connected to the threshold elements 7, 8 and the S input of the RS flip-flop 9, and the output of the first threshold element is connected to the S-input of the RS-flip-flop 10, the output of the second threshold element to the R-inputs of the specified triggers, the forward outputs of which are connected to the second inputs of the corresponding elements I. The outputs of the key elements 4 and 5 are co-ordinated with the inputs of the corresponding binary pulse counters 11, and 12, out s which are the outputs 13 and 14 of the transducer. The converter works as follows. The input alternating signal from input 6 is fed to both threshold elements 7, 8 and to the S input of the trigger 9, which goes into one state (in the initial state, the RS flip-flops 9 and 10 are in the zero state). As a result, the counting pulses from the output of the generator 1 through the element AND 2 of the first key element 4 arrive at the first pulse counter 11. When the input signal reaches the voltage response of the UNZ of the first threshold element 7, a pulse appears at its output that flips a trigger 10 into a single state, as a result of which the counting pulses of the generator 1 through the element AND 3 of the second key element 5 arrive at the second pulse counter 12. The instant of the pulse at the output of the threshold element 7 is the first ex rapoliruyuschey point. When the input signal reaches the trigger voltage Una g of the second threshold element 8, a pulse also appears at its output, which converts both flip-flops to the zero state, as a result of which the counts by both counters cease. The output pulse of the threshold element 8 is the second extrapolation point. The AT time between the output pulses of the threshold elements 7 and 8 will be called the extrapolation period. It is at this time that the forward form of the input signal in the dead-band, which starts from the moment of appearance of the pulse at the output of the second threshold element 8, reproduces by forward line. ; (T + AT, where T is the time from the origin to the deadband; -time correction, is equal to the extrapolation period. And, l f where f is the frequency of the counting pulses; Ktijtiz. Number of pulses received on the first and The counters, respectively, and fixed at the outputs 13 and 14. To obtain higher accuracy, the following conditions must be met: Unat 0; ipe1 2upeg. Thus, the device provides high accuracy of the conversion without complicating the circuit solution. containing two binary counters, pulses, the outputs of which are connected to the output buses, and the inputs are respectively connected to the outputs of the first and second key elements, and an exemplary pulse generator, the output to It is costly connected to the first input of the first key element, characterized in that, in order to increase the conversion accuracy, two threshold elements are introduced in it, the inputs of which are connected to the input bus and the third input of the first key element, the output of the pulse generator connected to the first input of the second the key element, the second inputs of both key elements are connected to the output of the second threshold element, and the third input of the second key element is connected to the output of the first threshold element. Sources of information taken into account during the examination 1. USSR author's certificate No. 601656, cl. G 04 F 10/04, 1976. 2. USSR author's certificate number 603946, cl. G 04 F 10/04, 1976 (prototype).