SU1601745A1 - D.c. amplifier - Google Patents

Abstract

This invention relates to a measurement technique. The purpose of the invention is to increase accuracy and speed. The DC amplifier contains a differential amplifier (RC) 1, a cumulative element 2, made on series-connected N capacitors, a switching unit 3 made on two demultiplexers, each of which is made on key elements, and a control unit 4, made on series-connected g -re clock pulses and pulse distributor. Accuracy increase is achieved due to a decrease in N times the error of the DC amplifier from the bias voltage of the remote control 1. Since The DC amplifier does not use fixing and memory circuits, this increases its speed. 1 il.

Description

UNION OF SOVIET

SOCIALIST

REPUBLIC (19)

(51) 5

3/38

STATE COMMITTEE

BY INVENTIONS AND DISCOVERIES

AT SCST USSR

DESCRIPTION OF THE INVENTION

PATENT TECHNZHShg

LIBRARY )

TO AUTHOR'S CERTIFICATE

(21) 4610877 / 24-09 (22) 11.28.88 (46) 10.23.90. Bull. No. 39 (71) All-Union Research and Design Institute of Electrothermal Equipment (72) I.A. Babanov and V.P. Kurochkin (53) 621.375.026 (088.8) (56) Copyright certificate of the USSR No. 666631, class . H 03 F 3 / 3β.

(54) DC Amplifier (57) The invention relates to measuring equipment. The purpose of the invention is improving accuracy and speed. The DC amplifier contains a differential amplifier (DU) 1, a storage element 2, made on series-connected N capacitors, a switching unit 3, made on two demultiplexers, each of which is made on key elements, and a control unit 4, made on series-connected g- clock pulses and a pulse distributor. An increase in accuracy is achieved due to a decrease in N times the error of the DC amplifier from the bias voltage of the remote control 1. Since the DC amplifier does not use fixation and memory circuits, this increases its speed. 1 ill.

o »o cl

The invention relates to measuring technique and can be used in various electronic devices.

The purpose of the invention is improving accuracy and speed. 5

The drawing shows a structural electrical circuit of a DC amplifier.

The DC amplifier contains a differential amplifier (DU) 1, a storage element 2, made on series-connected N capacitors C1 ... CN, a switching unit 3, made on the first and second demultiplexers, each of which 15 is made on the key elements respectively K1a ... KNa and K1b ... KN6, a control unit 4 made on a series-connected clock generator and a pulse distributor. 20

The amplifier operates as follows.

The input signal from an isolated voltage source (thermocouple - shunt and others) is fed through the input terminals 25 to the input of the switching unit 3, in which the key pairs (K1a, K1 b: ... KNa, последовательноδ) are sequentially opened by pulses from the control unit 4 . This causes a short-term connection 30 of the input signal source to each capacitor (C1 ... CN) of the storage element 2. As a result, the voltage at the second pole of the storage element 2 is equal to the sum of the voltages at each capacitor relative to the common bus in accordance with the expression U _c = Ubx 'N. where N is the number of capacitors in the storage element 2. The input of the remote control 1 is connected to the second pole of the storage element 2, which performs the function of a precision voltage follower, at the output of which the output voltage is R xKt; the value is Uswx = U _S x · N ± Ucm, where Ucm is the bias voltage of DN 1. 45

The error of the proposed DC amplifier from the bias voltage DU 1 is N times less than in the known device.

In addition, the installation time of the DC amplifier in the proposed circuit is determined by the expression r _us t = Gt · N, where ΐ _τ is the time of one cycle, while the device does not use locking circuits and 10 memorization, which increases the speed of the device ..

Claims (1)

Claim A direct current amplifier comprising a differential amplifier, the output of which is the output of a direct current amplifier, a storage element made on N capacitors connected in series, a switching unit, the N first outputs of which are connected to the first terminals of the respective capacitors, and N second outputs are connected to the second terminals of the corresponding capacitors , as well as a control unit, which means that, in order to increase accuracy and speed, the storage element is connected between a common bus and not the inverting input of the differential amplifier, the output of which is connected to its inverting input, the switching unit is made on the first and second demultiplexers, the inputs of which are the corresponding inputs of the DC amplifier, N outputs of the first demultiplexer are N first outputs, N outputs of the second demultiplexer are N second outputs of the switching unit . and their control inputs are control inputs of the switching unit, while the control unit is made in the form of series-connected clock pulses and a pulse distributor. the outputs of which are the outputs of the control unit and are connected to the control inputs of the switching unit.