SU756630A1 - Analogue-digital dc voltage deviation converter - Google Patents

Description

The invention relates to measuring-integrating analog-to-digital converters DC voltage deviation and can be used in devices for digital measurement and direct digital control. ^five

Known analog-to-digital sensor deviations of DC voltage, which contains an integrator, to the input of which the reference and measured voltages are alternately connected via keys, and the output is connected to a null organ, specifying: and measuring counters that are connected to the generator of the reference frequency through keys, two ₁₅ delay lines, three valve groups, output register, coincidence circuits [Ϊ].

Depending on the sign of the deviation of the measured voltage from the reference, the code of the deviation in the measuring counter is either direct or reverse.

In the latter case, this requires the conversion of the reverse code into a direct one with the help of a group of gates;

2

delay lines and the output register, which reduces the reliability of the device.

The aim of the invention is to improve the reliability of the device and simplify the algorithm of its work by eliminating the conversion from the return code to the direct while maintaining the functionality.

The goal is achieved by the fact that a DC voltage deviation analog converter that contains an integrator whose output is connected to a null organ, keys, two key management triggers, an exemplary frequency generator, a group of gates, a counter, a delay line, a comparator and a switch are introduced, the switch is connected to the inputs of the keys, the control input of the switch is connected to the input of the comparator, and the inputs of the comparator and the switch are connected to the bus, the input voltage and the reference voltage bus.

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FIG. 1 shows a block diagram of the converter; figure 2-image time, diagrams of his work.

The DC voltage deviation converter contains a comparator 1, the inputs of which are _{supplied with} reference + 11 _Э1 and measured + 11 _Вх voltage ', switch 2, which is controlled from the comparator output, inverting repeater 3, keys 4 and 5, integrator 6, zero-authority 7 , generator of exemplary frequency 8, prohibition scheme 9, η-digit counter 10, triggers 11 and 12, delay line 13 and group of gates 14 of the code entry.

The Converter operates as follows.

The trigger pulse allows writing to counter 10 through a group of valves 14 of the reference code. By the same pulse through the delay line 13, the trigger 12 is set to one state and allows the supply from the output of the switch 2 through the inverting repeater 3 and the key 5 to the voltage of the input of the integrator 6 - the integration 'up' begins. The switch is controlled from the output of comparator 1 in such a way that the input voltage of the repeater 3 is always higher (and _Bh or at the floor). Simultaneously, from the output of the comparator, the sign of the deviation of K _Βχ relative to ϋ _e t is given in the form of a positive or negative voltage. At the time of the beginning of integration, the state of the zero-organ 7 ai is increased by increasing the voltage at the output of the integrator 6, and the passage of counting pulses from the generator of the exemplary frequency 8 through the inhibitor circuit 9 to the counting input of counter 10 is allowed.

Let υ _Βχ > υ _3γ , then the + sign acts at the output of the comparator, the switch is in the state shown in FIG. 1, the voltage at the integrator output reaches

1 * 1

Ό ~ ΟΓ..1 “ ^βΧ νν_сс ^and 0 ^х '1 ·'

35

45

(one)

where - A /

Tobr

- integration time is 'up', where N ₃ is the code value of the task recorded in the counter before integration,

1 - the frequency of the gene ^x OP

Rator 8.

After time T, at the output of the latter.

ten

15

the discharge of the counter 10, a unit appears, which sets the counter 10 and the trigger 12 to zero, and the trigger 11 begins to integrate into the unit; downward voltage B _at the integration, and the integration time T ^ can be determined from the formula

^υ ° ⁼ Ρ0 ' ^υ 3τ ^Τ 2 (2)

From equations (1) and (2), after transformations

^ Βχ ^ Ι '^ ET ^T 2 (3)' eslii _VC = _{fl +} and di _{(i (fl} and li) .T _r and t _{2 et,}

from where

20

di

and ^-

at

(four)

From equality (4) it is seen that the relative voltage deviation D K is equal to the relative time deviation

25

After time T =

happens

thirty

40

50

55

° ^B R

resetting the counter 10 to the zero state, and the number of pulses counted by the counter from that moment until the zero-body response, will be the voltage deviation code.

The resolution of the transducer is determined by the formula

'<oo

The voltage deviation code can be read from the output of the counter 10 in any case in the direct code. Indeed, if B _{in x} <and _et , then at the output of comparator 1 a sign -., Switch 2 connects voltage to Repeater 3 _{at Et} and when applying 113, the integration starts up 'II _e t> ^and then the integration occurs'down'

υ _Βχ . In the rest of the operation, the converter works in the same way, and at the output of the counter, a direct code of deviation _bx from and _{fl is} obtained.

The device provides a direct code for the voltage deviation directly and the output of the measuring counter, regardless of the sign of the deviation. It can also be used to convert negative voltages, if you invert the operation of the switch and change the connection points of the trigger output, 11 and 12 in FIG. one.

Thus, the dignity of the device ¹ VA consists in simplifying the scheme and algo-

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rhythm of work while maintaining functionality, which significantly increases its reliability.

Claims (1)

Claim Analog-to-digital converter (deviations, constant voltage, which contains an integrator, the output of which is connected to a null body, keys, two key management triggers, a generator of exemplary frequency, a group of gates, a counter, a delay line, I distinguish "0 In order to increase reliability, a comparator and a switch are inserted into it, the switch outputs are connected to the key inputs, the switch control input is connected to the comparator input, and the comparator and switch inputs are connected to the input voltage bus and the reference bus voltage.