JPH0649996U - Simple AC / DC magnetometer - Google Patents

Abstract

(57) [Summary] [Objective] The strength of the AC magnetic field generated by the AC current can be easily known. For example, know the ability of parts feeder, strength of various types of degaussers, and the direction of magnetic field. [Structure] Hall elements and light-emitting diodes have a fast response time, and can of course sufficiently cope with changes in the AC magnetic field. The minute voltage change of the Hall element is amplified and the amplified output is compared with the reference voltage group of another circuit. As a result, the blinking of the light emitting diode is decided and the strength of the magnetic field is known from the number of lighting. If the NS display lights up at the same time, the AC magnetic field is emitted, and only N or S lights up the DC magnetic field.

Description

[Detailed description of the device]       Recently, the use of magnetic effects has been particularly expanded. On the other hand, the residual magnetism is a problem. It is also true that it is the subject. Therefore, of course, a degausser (also called a demagnetizer) Is required.       However, I do not know its ability, and I cannot measure easily.       What can not be measured is the display method of the instrument. Indicator and digital display However, it cannot follow the rapidly changing NS magnetic field and AC magnetic field.       So, I thought that there was no way to read it, It blinks rapidly, but it is visible to the eye even though it is blinking.       In order to utilize this phenomenon, a large number of light emitting diodes are arranged in two rows It is a method to know the Gaussian value by number.       Figure 1 is the connection diagram. Magnetic force is detected by the Hall element of H, and its output Input to the AMP differential amplifier through each resistor and COS changeover switch. . The amplification factor is determined by COS, and the output is between (a) and (-). (To this output If you connect the A meter as shown in Fig. 2, it will be a magnetometer with only DC magnetic field. Input the output to the comparator group (CP1 to 20) that has each reference voltage. Na The output of each CP group is connected to the light emitting diodes of the PL group (PL1 to PL20). Re     Amplified output voltage> Reference voltage   Then, with the S pole side that lights up     Amplified output voltage <reference voltage   So, it is the N pole side that lights up.   Therefore, the number of lights in the PL group is determined by each judgment of the CP group, and the Gaussian value can be known. I will.   For example, suppose COS is set to x100 and H is applied to an object. That If 5 lights on the S side are lit at that time, it means that there is 500 to 600 gauss of the S pole. This is read as S pole 500 gauss of DC magnetic field.   To explain the voltage relationship in the order of adjustment, place the Hall element of H in the O Gauss field. You At this time, the voltage between the AMP outputs (a) to (-) is     Voltage between (a) and (-) = Voltage between (b) and (-)   Adjust the Kansai department so that (However, the voltage between (b) and (-) is the power supply voltage. Decide in half place.) Next, go to H. Unit gauss value of each range (1 ga at x1 place) Usus, 10 Gauss for × 10, 100 Gauss for × 100), (a) Readjust the gating part so that the amount of voltage change between (-) and (-) is the same.   Dividing resistor r group which makes the amount of voltage change in unit Gaussian value the reference voltage VR5, VR so that a voltage corresponding to the amount of voltage change is applied to each of (r1 to r20) Adjust the potential meter of 6 to finish. If COS is set to XI00 and the H sensor is applied to the degausser, both NS light emission The same number of Iodos will light up. AC magnetic field measurement. Do each part of the degausser in each direction? If you apply H, etc., you can see the strength.       With this, both magnetic fields of AC and DC can be measured.     ・ Degaussing condition       You can know in advance (Gauss value of degausser> Gauss value of magnetized material).       How to deal with the magnetizing situation of equipment and tunnel type degausser etc. You can also investigate, and why do you magnetize the work from a press machine etc. For research and preparation of materials for countermeasures, use a battery as a power source and use a simple AC / DC that is small and lightweight and portable. I think a magnetometer will help.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified AC / DC dual-use fluxmeter connection diagram, in which H is a Hall element, Tr is a transistor, and R0 to R14 and r1 to r1.
20 and rp1 to rp2 are fixed resistors, DZ is a zener diode, VR1 is a variable resistor, V.I. R2 to VR7 are potential meters, COS is rotary switch, AM
P is a differential amplifier, CP1 to CP20 are comparators, PL1 to
PL2 is a light emitting diode. Figure 2 is a reference diagram of the DC magnetometer. AMP is a differential amplifier, A is an ammeter, VR8 is a potential meter, R9, R10, R15, R16,
R17 is a fixed resistor. Figure 3 is a diagram of a simple AC / DC dual-purpose magnetometer, where H is the Hall element sensor, COS is the rotary switch, and PL is the light emitting diode group.

Claims (1)

[Claims for utility model registration] There are various measuring instruments and methods for magnetic measurement, but there is no measuring instrument that can easily measure AC magnetic field or DC magnetic field. Therefore, we devised a simple AC / DC dual-purpose magnetometer.
A Hall element is used for the sensor, and its output is amplified by a differential amplifier. The amplified output is input to the comparator group that has the reference voltage corresponding to each Gaussian value. In addition, each light emitting diode is connected to the output of the comparator group, and it is divided into a block that lights up at input voltage> reference voltage and input voltage <reference voltage. 1. A simple AC / DC dual-purpose magnetometer that knows the Gaussian values of the N and S magnetic fields sensed by the sensor from the number of lit LEDs.