SU815692A1 - Digital meter of magnetic field induction - Google Patents

Description

(54) DIGITAL INDUCTION MAGNETIC MEASURER

FIELD

bus device, and the control inputs of the first key are connected to the first outputs of the control unit and comparator, the control input of the second key is connected to the second output of the control unit connected to the converter time interval - digit

The drawing shows a block diagram of a digital magnetic induction meter.

It contains a field magnetotransistor 1 connected to a direct current source 2, an amplifier 3, a comparator 4, the first input of which is connected to the field, the second electrode of the magnetotransistor 1, the second input connected to the source 5 of the reference voltage, and the output the interval is a digit that is additionally connected to the control unit 7 and the digital recording device 8. Amplifier input, l 3 is connected to the connection point of power supply current source 2 and magnetotransistor 1, and the output of amplifier 3 is connected to input The second amplifier 9 and the inductive element 10 connected to the common bus device,. Starter of the second amplifier 9 is connected to the Mugshtotransisyur's pope electrode, 1, which is additionally connected; through the key 11 with the output of the second constant DC source 12 and through the key 13 from the common screw device. The control inputs of the switch 11 are connected to the first output of the control unit 7 and the control output of the comparator 4. The control input of the switch 13 is connected to the second output of the control unit 7,

Measuredbear works in a speduid way.

In the dynamic mode of operation, the connection of the magnetotransistor 1 and amplifiers 3 and 9 is implemented by an impedance inverter, the input of which is a pale-yellow electrode of magnetotransference of mountain 1, and the output of the amplifier 9 input. Such an inverter is characterized by the following parameter matrix

oQ3

(L

-K-B.-Gg. about

where RJ is the direct transmission conductivity

3J amplifier

K is a constant coefficient, 1 / T, B is the magnitude of the measured magnetic induction;

GIJ — Direct Conductivity Transmission Amplifier Z 9.

From the expression (1) we have / that the impedance value, plug-in between the input of the comparator 4 and the common bus of the device is expressed

-one

ABOUT)

2

VaVi, ioJb gKujG B

where l, g elements of the matrix LY inverter impedance; jyjLfO is the complex impedance of the inductive element 10. Thus, in the proposed device g. Between the input of the comparator 4 and the common bus of the device, there is a bipolar element, the impedance of which is determined by the magnitude of the measured magnetic induction.

According to (2) the capacity of this bipolar element is determined by the expression C (B) and, oXeC9B, i.e. depends linearly on the measured induction B, and the sign of the capacitance is determined by the direction of induction B.

5. In the initial state of the device, the potential on the capacitance C (B) is zero, and the keys 11 and 13 are open. The measurement process starts at time t when a start pulse from the control unit 7 arrives at the start input of the time converter - digit 6 , and, simultaneously, on the keys 11. In this case, the key 11 closes and the charge of the capacitance C (B) from

from the current source 13, and the voltage U (t) at the input of the comparator 4 increases linearly. When reaching at time tj the level UQ of the operation of the comparator 4, i.e. When U (t2) U (}, the comparator 4 is activated and a pulse-stop is received from the output of the converter 6, a digital value N is formed at the output of the converter 6, which is proportional to the time interval tj-t-j, i.e.

.t,.) iiEl Mo iJfii i 9 .. to (5 |

where 3) 3 is the current of the source 12.

From expression (3), we find that the proposed device provides a direct linear transformation of magnetic induction - time interval.

Simultaneously with the stop of the converter 6, the pulse coming from the control output of the comparator 4, the key 11 opens. After that, the pulse 13 closes with a pulse from the second output of the control unit 7 and the potential on the capacitance C (B) drops to zero. During the transient discharge of capacitance C (B), the digital value N is written to the digital registers.

of the registering instrument 8. After the processes of recording the digit N and the discharge of capacitance C (B) by pulses from the outputs of control block 7 are completed, the converter is transferred to the beginning state of the account, and the key 13 is opened.

Upon receipt of the next start pulse from control unit 7, the process is repeated.

Thus, the proposed device provides the conversion of the measured induction into digital conduct

Claims (1)

Claim A digital magnetic field induction meter containing a field magnetotransistor, an amplifier connected to it, a reference voltage source connected in series, a comparator, a time interval-digit converter, and a digital recording device, as well as keys and a control unit, characterized in that, in order to increase accuracy measurement, a second amplifier, an inductive element and a direct current source are introduced into it, and the input of the second amplifier is connected to the output of the first amplifier and the inductive element, is connected connected to the device common bus, the output of the second amplifier is connected to the field electrode of the magnetotransistor, which is additionally connected to the first input of the comparator, and also connected through the first key to the output of the DC source and through the second key to the common bus of the device, the control inputs of the first key being connected with the first outputs of the control unit and the comparator, the control input of the second key is connected to the second output of the control unit connected to the time converter. interval is a digit.