SU1688108A1 - Analog-digital indicator - Google Patents

Abstract

The invention relates to instrumentation, in particular, to electrical measuring instruments, and can be used in systems for displaying information about the state of control objects. In order to increase reliability and speed, the device contains an analog-to-digital converter 1 associated with its outputs from one group of inputs of the comparison element 2 . The second group of inputs of the comparison element 2 is connected to the outputs of the driver 3 pulses of the encoder 4 position, the latter is installed on the shaft of the stepping motor 5, controlled by switch b, the inputs of which are connected to the outputs of the comparison element 2 through the keys 7, 8 2 comparisons are connected to the control inputs of the constant setting unit 9, the outputs of which are connected to the control inputs of the time interval forming unit 10, the clock input of which is connected to the generator 11 mpulsov, and output - with the second key input 7, 8 and 9 counting input unit specifying constants yl 3.

Description

The invention relates to instrumentation, in particular to indicator electric measuring instruments, and can be used in systems for displaying information on the state of control objects.

The purpose of the invention is to increase the reliability and speed of the device.

FIG. 1 shows the functional diagram of the proposed discrete analog switch device; Fig. 2 is a block diagram of the task of constants; Fig. 3 is a block diagram of the formation of time intervals.

The proposed device (Fig. 1) contains an analog-to-digital converter 1 connected by its outputs with one group of inputs of the comparison element 2. The second group of inputs of the comparison element 2 is connected to the outputs of the imaging unit 3 pulses of the position encoder 4. The latter is mounted on the shaft of the stepper motor 5, controlled by the switch b, the inputs of which are connected to the outputs of the comparison element 2 via keys 7 and 8. The output comparison busses of the comparison element 2 are connected to the control inputs of the block 19 for setting constants. The outputs of the block 9 task constants are connected to the control

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the input inputs of the time interval forming unit 10, the input of the clock pulses of which are connected to the generator i il. a output - with the second inputs of keys 7 and 8 and the counting input of the block 9 of the task of constants. The device also includes a scale 12 with an arrow 13 connected to the shaft of the stepping motor 5.

Unit 9 for specifying constants contains the elements OR 14, a counter 15 with a preset operating in the subtraction mode, and also a storage unit 16 whose address inputs are connected to the outputs of the counter 15. When applying control signals to the control inputs of block 9 to assign signals from the output buses of the same Comparison of Comparison Element 2 At the outputs of the OR 14 elements, a code is formed of a number equal to the difference between the Comparison Element 2 comparison element, i. mismatch signal code. When this code is entered into the counter 15, it is also set at its outputs and thereby determines the address of the constant corresponding to the given error signal. When a counter of 15 counting pulses is fed to a counting input, its content decreases by one with the arrival of each successive counting pulse. This will change the addresses and. accordingly, the constants at the outputs of the storage unit 16 until the counter has been zeroed 15.

The time interval shaping unit 10 comprises a counter 17 with a preset operating in the subtraction mode and a logic block 18 generating a signal of a logical unit if there is a zero level voltage on all the outputs of the counter 17. The time interval unit is controllable and generates time intervals in accordance with the binary number on its control inputs as follows. In counter 17, a binary number is entered through the control inputs. If the number is not zero, then the output of logic block 18 will be a logical zero, which is fed to the input of the Account Resolution, and the counter 17 begins to work for subtraction. At times Tt Nt, where Twee is the duration of the time interval: Tt is the period of clock pulses, and N is the decimal number corresponding to the given binary number, the counter 17 is zeroed, and the logical unit voltage appears at the output of the logic device 18, stopping counter 17 When a new binary number (constant) is entered into counter 17, the output of logical block 18 again causes a voltage of logical zero, which changes to a logical one with time determined by the new constant.

Discrete analog switch device works as follows.

The comparison element 2 receives codes of two numbers: code A from analog-to-digital converter 1 and code B from the driver of 3 pulses from the encoder 4 of the position.

0Item 2 Comparing Results

Comparison produces either an AB signal — a conditional forward movement, or an AB — conditional backward movement, as well as bitwise comparison signals of these numbers,

5 formed on tires ai, .. an 1. an, hi

Bp 1, bp

P (.and the receipt of signals of discharge on the control inputs of the block 9 ..; d no constants at the output of the latter A binary number is formed (KOMI tapta)

cic, ii CD depends on the magnitude of the difference (pat matching) of compared elements 2 comparing the numbers A and B. The specified binary number is then fed to the control 5 inputs of the time interval shaping unit 10 and the input pulses from this block continuously Oscillator 11 At the output of the time interval formation block 10, corresponding constants are formed; time intervals ending in short pulses with the level of a logical unit (except for the last constant

5 after which the voltage of the logical unit is set at the output of the time interval shaping unit 10) The above short pulses, which determine the long cycle, and therefore, the frequency or speed of the phase switching, arrive at the counting input of the constant setting unit 9 causing constants for it output, as well as through one of the keys 7. 8 and further through switch 6 on

5 stepping motor 5 After testing the last constant at the output of the time interval formation unit 10, a constant voltage is established with the level of a logical unit, which is equivalent to the Stop signal (no impulses are received to the commutator)

A discrete analog switch indicating device has a number of advantages over the known ones, which consist in the fact that with a decrease in the value of the corresponding assignment of constants, it is possible to form a deceleration section at which the phase switching frequency decreases not discretely, but smoothly, which provides a more flexible

conditions for error-free operation of the position encoder with the pulse shaper when errors are eliminated due to possible escapes or other reasons related to the transient processes of the step motor in the dynamic mode of its operation (the effect of this effect is a further increase in the accuracy of operation of the device), and also increase the service life and reliability of the device as a whole.

Claims (1)

Invention Formula A discrete analog switch device containing a scale reading device with a pointer pointer, a stepping motor whose shaft is connected to a pointer pointer and a position encoder, a pulse driver, an analog-to-digital converter, a comparison element with one of the same comparison tires, the first and second the groups of inputs of which are connected to the outputs of the pulse former and the analog-digital converter, respectively, the switch of the phases of the stepper motor, the inputs of which are connected respectively but with the outputs of the comparison element via two keys, as well as the generator, which is characterized by the fact that, in order to improve reliability and speed, it is equipped with a constant reference unit and a block for forming time intervals, while the outputs of the comparison element are connected to the corresponding control Clicking the block to set the constants connected by its outputs to the control inputs of the block of time interval formation, the clock input of which is connected to the generator output, and the output to the second key inputs and counting input Setting constant ka. R Btod and -1UL00 FIG. five Counting & to3 FIG. 2 yul J