SU1409993A1 - D.c. standard - Google Patents

Abstract

The invention relates to electrical engineering, in particular to precision direct current sources. The purpose of the invention is to increase the accuracy of the playback of direct current. The device contains a supply circuit consisting of a regulator 5 and a magnetic induction coil 4. The control loop, which provides compensatory testing of current instability, includes a reference oscillator 1, a quantum magnetic induction converter 3 into a frequency located in the working volume of coil 4, and a frequency comparing node 2. To eliminate the influence of temperature changes of the coil 4, the source 6 of the reference voltage and the differential amplifier 7 of direct current are introduced into the device. The latter compares the reference voltage at the output of source 6 with the voltage at the top of coil 4 and, with temperature changes in its winding resistance, affects the reference generator 1 accordingly, correcting its frequency. 1 il. o (l

Description

; about; about with

The invention relates to electrical engineering and is intended to insulate when measuring electrical circuit parameters.

The aim of the invention is to improve the accuracy of the reproduction of direct current.

The drawing shows a functional diagram of a DC measure.

The DC measure contains an adjustable reference oscillator 1, a frequency comparing node 2, a magnetic induction quantum converter 3 to frequency magnetic induction coil 4, regulator organ 5 (of the series type), reference voltage source 6 and differential amplifier 7 dc.

The diagram also shows the load 8 and pins 9 and 10 for connecting the primary DC power source.

The input of the regulator 5 is connected to the terminals 9 and 10, and the output circuit through the magnetic induction coil 4 is connected to the load 8, the Quantum transducer 3 magnetic induction into the frequency is placed in the working volume of the magnetic induction coil 4. The inputs of the frequency comparison node 2 are connected to the outputs of the reference generator 1 and the quantum converter of magnetic induction into frequency, and the output to the control input of the regulator body 5. One of the inputs of the DC differential amplifier 7 is connected to the output of the reference voltage source 6, the other input - with coil 4 magicians

induction, and the output is from the control input of the reference generator 1,

The device works as follows.

A constant current flowing through a circuit with series-connected regulator 5, a load 8 and a magnetic induction coil 4 creates a permanent magnetic field in the latter. The quantum converter 3 converts with a high degree of accuracy the magnetic induction of this field into an electrical signal, the frequency of which is compared with the frequency of the reference oscillator 1 in the frequency comparison node 2. As a result, at the output of the frequency comparison node 2, an error signal appears, which is proportional to the changes in the reproduced current. This signal

enters the control input of the regulator 5 and maintains its output current

ID

TO

ten

s

20

25 to 5

0

five

0

five

where (, is the frequency of the reference oscillator

one;

Wo is the conversion coefficient of the quantum converter 3;

KQ is the current-to-g conversion factor of inductive induction. The values of fo and UD with a high degree of accuracy can be considered constant, and the value of Ko depends on the temperature of the coil of the magnetic induction determined by the ambient temperature and the amount of heat radiated by the quantum converter 3 and the coil winding 4 .

A change in the temperature of the core of the magnetic induction coil 4 leads to both a change in the constant K and a change in the ohmic resistance of the winding of the coil 4. In this case, the voltage drop across it due to the flow of the reproducible current Dj also changes. This voltage is compared by a DC differential amplifier 7 with a reference voltage from source 6. At the same time, the voltage difference containing information about the temperature change of the coil 4 frame is amplified and fed to the control input of the reference generator 1, changing its frequency in according to the magnitude and sign of the change in temperature of the coil 4 frame, the gain of the differential amplifier 7 of direct current is chosen so that changes in the frequency of the reference generator 1 adequately tvetstvovali temperature variations in the coil bobbin 4.

Eliminating the effect of temperature variations on the magnetic induction coil 4 can significantly improve the accuracy of DC current reproduction.

Claims (1)

Invention Formula A measure of direct current, containing a regulating 1st organ, the input of which is connected to the leads for connecting a primary power source constant, 1409993 current circuit, and the output circuit through ka-what, in order to increase the accuracy, the exaltation of magnetic induction - with the conclusions of the production of direct current, into it to connect the load, the quantum voltage source is introduced a magnetic induction converter - and a differential amplifier constant frequency, placed in the working volume of the current, and the reference generator in the magnetic induction coil is adjustable, one of the frequency comparison, the inputs of which of the differential amplifier Switched to the outputs of the reference generation current is connected to the output The rand and quantum converter of the Q-source of the reference voltage, Dranit induction into frequency, and the output of the nd input, with the coil leads of the magnetic control input of the regulating induction, and the output from the control unit of the reference oscillator.