JP2009198301A - Rod-shaped magnetometric sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and easily-portable rod-shaped magnetometric sensor. <P>SOLUTION: This rod-shaped magnetometric sensor is formed by installing a Hall element, its electronic circuit and a voltage detector inside a rod-shaped body having a sensor probe on one end and an output connection part on the other end. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bar-shaped magnetic sensor intended to detect the strength of magnetism and the north and south poles.

Conventionally known magnetic sensors are diverse and have been added with technical characteristics so as to exhibit characteristics depending on the application, but for general purposes, the magnetic strength or the polarity of the N pole and S pole is distinguished. There are no known magnetic sensors that can be used in relatively small locations.
JP 2007-121256 A JP 2002-31116 A JP 2002-31115 A

  Conventionally, as a small magnetic sensor, a technique for capturing the amount of movement of a member incorporated in a camera by magnetic change has been proposed (Cited document 1).

  In addition, a magnetic sensor has been proposed in which a magnetic change is detected using a coil and a linear or rod-like magnetic body having conductivity (Cited document 2).

  Further, there is a proposal of a magnetic sensor that can be miniaturized by using one coil of a double coil as a negative feedback magnetic field generating coil and the other coil as a bias magnetic field generating coil (Cited Document 3).

  Although the technique of the cited document 1 is effective as a sensor that can detect the amount of movement of a member, there is a problem that it cannot be used to simply measure the magnetic strength. The technique of the cited document 2 is a technique for detecting an external magnetic field as an electric signal by using an external magnetic field by a magnetic field generated in the circumferential direction of the magnetic body by a pulse current or an alternating current.

  Further, in the cited document 3, a double coil is an indispensable requirement. One of the double coils is used as a negative feedback magnetic field generating coil, and the other coil is preferably used as a bias magnetic field generating coil. A magnetic impedance effect element with a magnetic field generating coil and a bias magnetic field generating coil is miniaturized.

  As described above, the conventionally known small magnetic sensors are adapted to their respective uses and achieve their respective purposes, but there is a problem that they are small and cannot be used as general-purpose magnetic sensors. The polarity of the N pole or S pole of the magnetic pole to be measured has a problem that it cannot be detected.

  The present invention provides a sensor probe on one side of a rod-shaped main body, an output connection part on the other end, a Hall element, its electronic circuit and a voltage detector inside, a magnetic display part, and a power source The rod-shaped magnetic sensor of the present invention is accommodated to obtain a magnetic sensor capable of accurately detecting magnetism even in a narrow place, thereby solving the conventional problems.

  That is, the present invention is characterized in that a Hall element, its electronic circuit and a voltage detector are installed in a rod-shaped cylinder having a sensor probe projecting at one end, a battery is housed, and a magnetic display unit is provided. This is a rod-shaped magnetic sensor, which has a sensor probe at one end and an output connection at the other end. A hall element, its electronic circuit and voltage detector are installed inside the battery, and the battery is built in. A bar-shaped magnetic sensor characterized in that a portion is provided. In another aspect of the invention, a polarity display part of N pole and S pole is provided, and the voltage detector detects the strength of magnetism based on a change in voltage.

  Further, the magnetic display unit is a green LED and a red LED that are turned on or numerically displayed on the display window.

  Since the present invention can detect and display the polarities of the N pole and the S pole as described above, it can cope with the magnetic pole surface accurately.

  Since the present invention has a built-in battery, there is an advantage that magnetic measurement can be performed even in a place where there is no power transmission line. The magnetic sensor of the present invention is, for example, a pencil type having a length of 10 cm to 15 cm and a diameter of 1 cm to 1.5 cm, and is easy to carry and extremely easy to use.

  The magnetic strength of the present invention includes a case where a numerical value is displayed by providing a display window, and a case where a green LED and a red LED are turned on to indicate a general strength.

  For example, a green LED is lit at 0.0005 Tesla (5 gauss) or less, and a red LED is lit at 0.0010 Tesla (10 gauss) or more. Accordingly, when neither the green LED nor the red LED is lit, the case is over 0.0005 Tesla and less than 0.0010 Tesla.

  In order to provide other capabilities (connecting the output to the interface, degaussing operation, etc.), the output of the sensor according to the present invention can be used as an input of a processing device.

  The present invention is a simple magnetic sensor, and can measure the magnetic strength independently without being shared with others. Therefore, in addition to the above characteristics, there is an advantage that it can be carried as required and can be stored in a pocket or the like when not in use, which is extremely simple and can be used immediately when necessary.

  Since the present invention is a magnetic sensor having a power source, it can be used alone even in a place without delivery power, and since it is relatively small, there are various effects such as convenient and easy carrying and holding.

  Further, since the polarities of the N pole and the S pole can be detected, there is an effect that the correspondence can be accurately performed.

  Further, since the output of the sensor of the present invention can be used as an input of another electronic device, there is an effect that automatic control and other control devices can be easily automated by the strength of magnetism.

  In this invention, a sensor probe is fixed to one end of an elongated cylindrical body, an output connection portion is provided at the other end, a Hall element and its electronic circuit, and a voltage detector are installed in the cylinder, Configured the sensor.

  In the above description, if the cord of the output connecting portion is connected as an input of an intended electronic device, the demagnetization operation of an automatic machine (for example, an electromagnetic crane) can be controlled via this electronic device.

  In the present invention, since the whole is a rod-like (long and narrow) cylindrical body, magnetic detection (measurement) in a narrow place can be easily performed.

  An embodiment of the present invention will be described with reference to FIGS. 1 and 2. A sensor probe 2 is protruded from one end of an elongated cylinder 1, and green g and red r LEDs are placed on the wall of the cylinder 1. Install. Further, one end of the output cord 3 is connected to a circuit in the other end of the cylindrical body 1, and a plug 4 is connected to the other end of the cord 3.

  A circuit 6 of the Hall element 5, a voltage detector 7 and a power source 8 are housed in the cylindrical body 1 to constitute a magnetic sensor 10 of the present invention. In the figure, 9 is an outlet of the control unit 16 connected to the plug 4, 11 is a latching piece of the magnetic sensor 10, 12 is a switch, and 18 is a temperature detector.

  In order to use the magnetic sensor 10, after the switch 12 is turned on, when the sensor probe 2 is brought into contact with the steel plate 13 and the attracting portion 14a of the electromagnet 14, the magnetic strength of the magnetic pole of the electromagnet 14 is 5 gauss to 10 gauss. The LEDs for green g and red r are lit up to Gauss, and if they are on the N pole side, the LEDs for green g and red r are turned on and flickered. If the magnetic strength is 10 gauss or more, the red r is lit, the red LED is lit if it is the north pole side, and the red LED is flickering if it is the south pole side. . Therefore, the polarity of magnetism can be immediately known by the lighting state of the green g and red r LEDs. The detection of the presence / absence of magnetism has been described in the case where the magnetic strength is relatively small. However, when a sensor that numerically knows the magnetic strength is required, a display window 15 is provided on one side of the cylinder 1. The numerical value of magnetism can be displayed on the display window 15.

  Next, an example of use of the magnetic sensor 10 will be described. The plug 4 of the magnetic sensor 10 is connected to the outlet 9 of the electromagnet control unit 16 and the switch 12 is turned on so that the sensor probe 2 end of the magnetic sensor 10 is turned on. Is brought into contact with the electromagnet 14 and predetermined demagnetization is started, the demagnetization operation is repeated according to a predetermined pattern. Therefore, if the switch 17 of the control unit 16 is pressed when the remanence becomes 5 gauss or less, the demagnetization recording becomes a parameter as it is and is automatically set. Therefore, after deactivation, it is automatically demagnetized according to the recording of the parameters. The above shows an example of use of the sensor 10.

The present invention is a magnetic sensor using a Hall element. Accordingly, a magnetic field measurement method using a Hall element will be described. This is a magnetic sensor using the Hall effect of a semiconductor, and can directly convert the strength of magnetism into electricity. That is, when the magnetic field B applied from the direction perpendicular to the semiconductor element a current flows I _C, the voltage V _H generated. This voltage V _H is the Hall voltage and is given by the following equation.

V _H = K _H × I _C × B | v |
K _H : Constant determined by the material and dimensions of the Hall element
I _C : Control current
B: Magnetic flux density
V _H : Hall voltage

In the above, I _C and V _H can be measured, and K _H is also determined, so that B (magnetic strength) can be known. That is, if the detection control is performed, the numerical value of the magnetic strength of the magnet can be expressed.

  In the embodiment of the present invention, since the numerical value is displayed on the display window 15 in FIG. 1, the intensity can be immediately recognized as a numerical value.

  Further, since the direction of the magnetic flux is N → S, by determining the direction of the magnetic flux, the LED (g or r) is turned on by the polarity with which the sensor probe 2 is contacted. The polarity can be immediately known according to the state.

  Next, the magnetic field measurement by the magnetic sensor 10 of the present invention will be described with reference to FIG. When a current flows through the semiconductor element, the Hall element 5 applies a magnetic field in a direction perpendicular to the direction of the current to generate a voltage. Since this voltage is proportional to the strength of the magnetic force, the strength of the magnetic force can be determined by measuring the voltage.

  Therefore, in the magnetic force measurement circuit, as shown in FIG. 3A, the output side of the Hall element drive circuit 24 is connected to the input side of the Hall element 5, and the output side of the Hall element 5 is connected to the Hall voltage detection circuit 19. For example, since a voltage proportional to the magnetic force applied to the Hall element 5 is generated, if this voltage is detected, the magnetic force applied to the Hall element 5 can be detected from the voltage.

  The current given to the Hall element 5 is sent stably by, for example, the circuit shown in FIG. In the circuit, 20 corresponds to the drive circuit 24 of the Hall element 5, 22 is a voltage amplification circuit, and 21 is an input and output circuit of the Hall element 5. Since the output voltage of the Hall element 5 is proportional to the magnetic force applied to the Hall element 5, if the voltage is converted into the strength of the magnetic force, the magnetic force value can be immediately known.

(A) The conceptual diagram of the parameter automatic setting in the case of using the magnetic sensor of this invention for a demagnetization, (b) The front view of the Example of a magnetic sensor similarly. The block diagram which similarly shows the structure of a magnetic sensor. (A) Hall element magnetic field measurement circuit configuration diagram, (b) Hall element drive circuit diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tube 2 Sensor probe 3 Cord 4 Plug 5 Hall element 6 Circuit 7 Voltage detector 8 Power supply 9 Outlet 10 Magnetic sensor 11 Latching piece 12 Switch 13 Steel plate 14 Electromagnet 15 Display window 16 Magnet control unit

Claims (5)

  A bar-shaped magnetic sensor characterized in that a Hall element, its electronic circuit, and a voltage detector are installed in a rod-shaped cylinder having a sensor probe projecting at one end, a battery is housed, and a magnetic display unit is provided.   Inside the rod-shaped cylinder having a sensor probe at one end and an output connection at the other end, the Hall element, its electronic circuit and voltage detector were installed, the battery was built, and the magnetic display was provided. Features a bar-shaped magnetic sensor.   3. A bar-shaped magnetic sensor according to claim 1, further comprising a polarity display section for N and S poles.   3. The bar-shaped magnetic sensor according to claim 1, wherein the voltage detector detects a magnetic strength by a change in voltage.   3. The bar-shaped magnetic sensor according to claim 1 or 2, wherein the magnetic display unit is a green LED and a red LED that are turned on or numerically displayed on a display window.

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