SU1365045A1 - Comparing device - Google Patents

Abstract

The invention may be used in angle-code converters, code-angle converters. The purpose of the invention is to simplify and improve the accuracy of the comparator. The comparison device contains three switches 6-8 that are controlled by the clock pulse generator 3, the adder to the input of which the sinus and cosine components of the first compared value tp are fed through the switch 6, the digital-to-analog converter 2, to the control inputs of which the second comparable code is fed scaling amplifier 4 with a transfer coefficient of 0.357, and a low-pass filter 5, the output of which through a period of reference voltage produces an unbalance voltage between the angle about and Odom angle Wed. If the output voltage is zero, the angle oi. is equal to the cf angle code with an error not exceeding 2 arcs. min 1 il. G € cl

Description

with

ABOUT)

ate

The invention relates to the field of automation and computer technology and can be used in angle to code converters, code to angle, and digital following systems.

The aim of the invention is to simplify the device and improve its accuracy.

The drawing shows a block diagram of a comparison device.

The device contains an adder I, a digital-to-analog converter 2, a shaper of 3 clock pulses, a scaling amplifier 4, a low-pass filter 5 and, the first, second and third switches 6-8.

The digital-to-analog converter 2 is a digital controlled resistor consisting of resistors and controllable switches. Normally closed outputs of keys are combined and form a normally closed output of converter 2. Normally open outputs of keys are combined and form a normally open output of converter 2. Comparative device works

in the following way.

The input buses are supplied with appropriate voltages.

Us Uc -U cosst,

where and is the amplitude value of the voltage of the first compared quantity;

o is the current value of the angle of the first compared quantity. The digital code N of the angle cf of the second compared quantity is fed to the control input of the digital-to-analog converter 2, and

.

(one)

the input of the scaling amplifier 4 with the transfer coefficient K.,.

The output of the scaling amplifier 4 is connected to the second input of the adder I, forming a negative feedback with a transmission coefficient equal to 1.

Taking into account the feedback in the first half cycle of the reference voltage, the overall transfer coefficient is

TO,

Ko (l-n)

T-kP-n)

(2)

Consequently, the voltage at the output of the scaling amplifier 4 in the first half period of the reference voltage is equal to

and

 with

and bOrN)

5 H-K (l-n)

(3)

In the second half-period of the reference voltage, the voltage through the normally open contact of the switch 6 is fed to the first input of the adder 1 and the normally open output of the converter 2 is connected to the input of the scaling amplifier 4,

Considering the feedback in the second half-period of the reference voltage, the total transmission coefficient is

K - iti.

 - H-KN

(four)

Consequently, the voltage at the output of the scaling amplifier 4 in the second half-period of the reference voltage is equal to

and

and,

Cd5

ewxc with l + kn

(five)

The voltage at the output of the low-pass filter is proportional to the total value of the DC components

45 voltages U. and U.

The converter 2 is switched on according to the circuit with current summation and has one input and two outputs. The transfer coefficient of converter 2 on a normally closed output is 1-N, the transfer coefficient on a normally open output is equal to N.

In the first half cycle of the reference voltage, the voltage Ug is fed through the normally closed contact of the switch 6 to the first input of the adder 1 and the normally closed output of the converter 2 is connected to

0

and

it's "

-and.

Ko (l-n)

and 1-t-KN

(6)

5 1 + K (1-n)

With the balance (U,)) after the transformation (6), taking into account (1), (4) and (5), and entering the designation, we get ti-. (7)

55

Dependence (7) at, 357 is an approximation of the tangential function within the O-T / 2 angle with an approximation error not exceeding 2, while providing a balance of the circuit for the angle code corresponding to the angle about.

For comparison, the O – 21G angles are supplemented by a quad switch.

Claims (1)

Invention Formula A comparison device containing input wiring sine and cosine components of the first compared quantity, an adder, a digital-analogue converter, the control inputs of which are connected to the code bus of the second comparable quantity, characterized in that, in order to simplify and improve the accuracy, a clock pulse generator is introduced , a scale-stabilizing amplifier, a low-pass filter, and three switches, the control inputs of which are connected to the output of the clock pulse former, which is normally closed and mally ra The closed inputs of the first switch are connected to the input busses of the connection, respectively, sine and cosine components of the first compared value, and the output of the first switch is connected to the first input of the adder, the output of which is connected to the input of the digital-to-analog converter, normally closed and normally open outputs of which are connected to the inputs of the second and three respectively, the normally open output of the second switch and the normally closed output of the third switch are connected A zero-potential bus, and a normally closed output of the second switch and a normally open output of the third switch are connected to the input of a scaling amplifier, the output of which is connected to the second input of the adder and to the input of a low-pass filter, the output of which is a comparison device.