Magnetic field generation control device and magnetic field generation system with controllable magnetic flux

Abstract

The present invention discloses a magnetic field generation control device, which includes an input module, a control module, a constant current source module, and a display module. The input module, the constant current source module, and the display module are connected to the control module. The constant current source module is used to be connected to a coil. The input module is used to receive input operations to obtain the distance value between the coil and the target object, as well as the magnitude and direction of the desired magnetic field. The control module obtains the current value required for the coil based on the desired magnetic field and the distance value, and outputs a corresponding voltage signal to the constant current source module. The constant current source module outputs a corresponding current to the coil according to the voltage signal. The present invention can provide a precise magnetic field with controllable magnitude and direction, without additional manual calculation and debugging, improving work efficiency and simplifying the operation difficulty. Moreover, by displaying the required current value and distance value through the display module, the control interface is intuitive and simple, with good human-computer interaction performance. Additionally, the present invention also discloses a magnetic field generation system with controllable magnetic flux.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic technology, and in particular to a magnetic field generation control device and a magnetic field generation system with controllable magnetic flux. Background Art

[0002] In the test pipeline of magnetic sensor chips, due to production and debugging requirements, it is often necessary to apply a magnetic field with a certain magnitude and direction on the die of the wafer. The generation of the magnetic field is mainly achieved through coils. However, the magnetic field generation coil cannot automatically generate a magnetic field with the required magnitude and direction according to the test requirements. When it is necessary to change the magnetic field magnitude, at present, it is often achieved by manually changing the distance between the coil and the chip and calculating the magnitude of the current required to be applied to the coil, and then applying a corresponding current to the coil through ATE (Automatic Test Equipment). This method is cumbersome and inefficient, and it is also easy to generate errors when manually adjusting the distance between the coil and the chip and calculating the required current magnitude, which affects the accuracy of the test results.

[0003] Therefore, there is an urgent need to provide a magnetic field generation control device that can automatically control the coil to generate a magnetic field with the desired magnitude and direction to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a magnetic field generation control device that can automatically control the coil to generate a magnetic field with the desired magnitude and direction.

[0005] Another purpose of the present invention is to provide a magnetic field generation system that can automatically generate a magnetic field with the desired magnitude and direction.

[0006] To achieve the above purpose, the present invention provides a magnetic field generation control device for controlling the coil to generate a magnetic field with the desired magnitude and direction. The magnetic field generation control device includes an input module, a control module, a constant current source module, a display module, and a power supply module. The input module, the constant current source module, and the display module are respectively connected to the control module. The output end of the constant current source module is used to connect to the coil. The input module is used to receive input operations to obtain the distance value between the coil and the target object, and the magnitude and direction of the desired magnetic field. The control module obtains the current value required for the coil based on the desired magnetic field and the distance value, and outputs a corresponding voltage signal to the constant current source module. The constant current source module outputs a corresponding current to the coil according to the voltage signal. The display module is used to display the required current value and the distance value.

[0007] Preferably, a sampling resistor and an AD conversion unit are included in the constant current source module. The sampling resistor is connected to the AD conversion unit, and the AD conversion unit is connected to the control module. The AD conversion unit performs analog-to-digital conversion on the actual voltage signal on the sampling resistor and feeds it back to the control module.

[0008] More preferably, the control module compares the voltage signal it outputs with the actual voltage signal and adjusts the voltage signal it outputs according to the voltage difference.

[0009] Preferably, the control module converts the actual voltage signal into an actual current value according to the resistance value of the sampling resistor, and the display module displays the actual current value.

[0010] Preferably, the constant current source module includes a first triode, a voltage dividing circuit, a first amplifying circuit, a Darlington tube, a load resistor, and the sampling resistor. The base of the first triode is connected to the control module, the voltage dividing circuit is connected to the collector of the first triode, the first amplifying circuit is connected to the voltage dividing circuit, the Darlington tube is connected to the output end of the first amplifying circuit, the load resistor is connected between the Darlington tube and the first amplifying circuit, and the sampling resistor is connected between the Darlington tube and the ground.

[0011] In one embodiment, the control module includes a single-chip microcomputer and a DA conversion unit. The DA conversion unit is connected to the single-chip microcomputer and the constant current source module. The single-chip microcomputer is connected to the input module and the display module. The single-chip microcomputer obtains the required current value according to the desired magnetic field and the distance value and outputs a corresponding voltage signal. The DA conversion unit converts the voltage signal into an analog quantity and transmits it to the constant current source module.

[0012] Preferably, the DA conversion unit includes a D / A conversion circuit, a voltage amplifying circuit, and an adjustable voltage stabilizing circuit. The D / A conversion circuit is connected to the single-chip microcomputer, the voltage amplifying circuit is connected to the output end of the D / A conversion circuit, the adjustable voltage stabilizing circuit is connected to the output end of the voltage amplifying circuit, the output end of the adjustable voltage stabilizing circuit is connected to the constant current source module. The voltage amplifying circuit amplifies the voltage analog quantity output by the D / A conversion circuit and outputs it to the adjustable voltage stabilizing circuit, and then outputs it to the constant current source module through the adjustable voltage stabilizing circuit.

[0013] In one embodiment, the control module outputs a corresponding PWM signal to the constant current source module according to the required current value so that the constant current source module outputs a corresponding current to the coil.

[0014] Preferably, the input module is a matrix keyboard, and the display module is an LCD display screen.

[0015] To achieve the above object, the present invention also provides a magnetic field generation system with controllable magnetic flux, including a coil and a magnetic field generation control device. Among them, the magnetic field generation control device includes an input module, a control module, a constant current source module, a display module and a power supply module. The input module, the constant current source module and the display module are respectively connected to the control module. The output end of the constant current source module is connected to the coil. The input module is used to receive input operations to obtain the distance value between the coil and the target object, and the magnitude and direction of the desired magnetic field. The control module obtains the current value required for the coil based on the desired magnetic field and the distance value and outputs a corresponding voltage signal to the constant current source module. The constant current source module outputs a corresponding current to the coil according to the voltage signal. The display module is used to display the required current value and the distance value.

[0016] Compared with the prior art, the present invention provides a corresponding current to the coil through the cooperation of the input module, the control module and the constant current source module, so as to be able to provide an accurate magnetic field with controllable magnitude and direction, without additional manual calculation and debugging, improving work efficiency and simplifying the operation difficulty, and can meet the large-scale production requirements. Moreover, by displaying the required current value and the distance value through the display module, the control interface is intuitive and simple, has good human-computer interaction performance, and is easy to operate, which can save operation time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a block diagram of the composition structure of the magnetic field generation system with controllable magnetic flux according to an embodiment of the present invention.

[0018] Figure 2 It is a block diagram of the composition structure of the magnetic field generation system with controllable magnetic flux according to another embodiment of the present invention.

[0019] Figure 3 It is a partial circuit diagram of the constant current source module.

[0020] Figure 4 It is a circuit schematic diagram of the AD conversion unit.

[0021] Figure 5 It is a circuit schematic diagram of the single-chip microcomputer and its peripheral circuits.

[0022] Figure 6 It is a circuit schematic diagram of the DA conversion unit.

[0023] Figure 7 It is a circuit schematic diagram of the input module.

[0024] Figure 8 It is a circuit schematic diagram of the display module.

[0025] Figure 9 It is a circuit schematic diagram of the power supply module.

[0026] Figure 10 It is a schematic diagram of the geometric relationship of each point on the coil. Specific embodiments

[0027] In order to elaborate on the technical content and structural features of the present invention in detail, the following further explanations are provided in conjunction with the embodiments and accompanied by the drawings.

[0028] Please refer to Figures 1 to 9 , the present invention provides a magnetic field generation system 100 with controllable magnetic flux, which can generate a magnetic field with a desired magnitude and direction to meet the test requirements of a target object (such as a magnetic sensor chip, etc.). The magnetic field generation system 100 with controllable magnetic flux includes a coil 60 and a magnetic field generation control device for controlling the coil 60 to generate a magnetic field with a desired magnitude and direction. Specifically, the magnetic field generation control device includes an input module 10, a control module 20, a constant current source module 30, a display module 40, and a power supply module 50. The input module 10, the constant current source module 30, and the display module 40 are respectively connected to the control module 20. The output end of the constant current source module 30 is used to connect to the coil 60. The input module 10 is used to receive input operations to obtain the distance value between the coil 60 and the target object, as well as the magnitude and direction of the desired magnetic field. The control module 20 obtains the current value required for the coil 60 based on the desired magnetic field and the distance value and outputs a corresponding voltage signal to the constant current source module 30. The constant current source module 30 outputs a corresponding current to the coil 60 according to the voltage signal. The display module 40 is used to display the required current value and the distance value.

[0029] Next, taking the target object as a magnetic sensor chip as an example, the calculation principle of the magnitude of the current required for the coil 60 is described:

[0030] During the actual test process, the center of the magnetic sensor chip is always located on the central axis L1 of the coil 60, and the magnetic induction intensity at any point P on the central axis L1 of the coil 60 due to the circular current is:

[0031]

[0032] Since the current I flowing through the coil 60 = Rctgβ, so Also, due to the existence of a triangular relationship: Substituting the triangular relationship into the formula one for integration, the magnetic induction intensity at any point P on the central axis L1 of the coil 60 can be obtained:

[0033]

[0034] And the relationship between the magnetic induction intensity B and the magnetic field intensity H is: The relationship between the magnetic field intensity H at any point P on the central axis L1 of the coil 60 and the current can be obtained as:

[0035] Among them, in each of the above formulas, μ represents the magnetic permeability, n represents the number of turns of the coil 60, R represents the radius of the coil 60, l represents the distance from a point P on the central axis L1 of the coil 60 to the center O of the coil 60 (that is, the sum of the distance value between the coil 60 and the magnetic sensor chip and half of the length of the coil 60), β1 represents the angle between the line connecting a point P on the central axis L1 of the coil 60 to the upper edge of the coil 60 and the central axis L1 of the coil 60, and β2 represents the angle between the line connecting a point P on the central axis L1 of the coil 60 to the lower edge of the coil 60 and the central axis L1 of the coil 60 (as Figure 10 shown). When the number of turns n, diameter, and length of the coil 60 are fixed, the control module 20 can calculate the magnitude of the required current I according to the magnitude of the expected magnetic field input and the distance value between the magnetic sensor chip and the coil 60.

[0036] Incidentally, when it is necessary to change the direction of the magnetic field, it can be achieved by changing the direction of the current output by the constant current source module 30.

[0037] Next, Figures 1 - 9 the magnetic flux controllable magnetic field generation system 100 of the present invention will be described in detail with reference to the accompanying

[0038] Please refer to Figure 3, Specifically, the constant current source module 30 includes a resistor R8, a first triode Q1, a voltage dividing circuit 31, a first amplifying circuit 32, a Darlington tube 33, a load resistor RL, a sampling resistor RS, and an AD conversion unit 34. One end of the resistor R8 is connected to the control module 20, and the other end is connected to the base of the first triode Q1. The voltage dividing circuit 31 includes a resistor R1, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, and a capacitor C2. The first ends of the resistor R1 and the resistor R4 are connected to the collector of the first triode Q1. The second end of the resistor R1 is connected to a 12V voltage. The first end of the capacitor C1 is connected to the second end of the resistor R4, and the second end is connected to the second end of the resistor R1. The first end of the resistor R5 is connected to the second end of the resistor R4. The first end of the capacitor C2 is connected to the second end of the resistor R5, and the second end is connected to the second end of the capacitor C1. The first end of the resistor R3 is connected to the first end of the capacitor C2, and the second end is connected to the second end of the capacitor C2. The first amplifying circuit 32 includes an operational amplifier U1, a balancing resistor R6, and a resistor R2. The first end of the balancing resistor R6 is connected to the first end of the resistor R3. The inverting input terminal of the operational amplifier U1 is connected to the second end of the balancing resistor R6, and the non-inverting input terminal is connected to the resistor R2. In this embodiment, the operational amplifier U1 uses LM324. The resistance value of the balancing resistor R6 is 1kΩ, and the resistance value of the resistor R2 is 22kΩ, but it should not be limited thereto. The Darlington tube 33 includes a triode Q2 and a triode Q3. A resistor R7 is connected between the emitter of the triode Q2 and the output terminal of the operational amplifier U1. The base of the triode Q3 is connected to the emitter of the triode Q2. The first end of the load resistor RL is connected to the emitter of the triode Q3, and the second end is connected to the operational amplifier U1. The collector of the triode Q3 is connected to the collector of the triode Q2. The collector of the triode Q2 is connected to the first end of the sampling resistor RS. The second end of the sampling resistor RS is grounded. The resistance value of the sampling resistor RS is 1kΩ. A capacitor C3 is also connected to the collector of the triode Q2, and one end of the capacitor C3 is grounded. The AD conversion unit 34 (as Figure 4 shown) is connected to the sampling resistor RS and the control module 20. The AD conversion unit 34 performs analog-to-digital conversion on the actual voltage signal on the sampling resistor RS and then feeds it back to the control module 20.

[0039] Further, the control module 20 compares the voltage signal it outputs with the actual voltage signal, and adjusts the voltage signal it outputs according to the voltage difference, so as to improve the accuracy of the output current of the constant current source module 30, and further ensure that the coil 60 can generate a magnetic field of the desired magnitude. In addition, the control module 20 also converts the actual voltage signal into an actual current value according to the resistance value of the sampling resistor RS, and the display module 40 displays the actual current value to intuitively display the gap between the actual current value and the required current value.

[0040] In one embodiment, the control module 20 outputs a corresponding PWM signal to the constant current source module 30 according to the required current value, and through the PWM signal, the constant current source module 30 outputs a corresponding current to the coil 60. In another embodiment, the control module 20 converts the digital quantity output by it into an analog quantity through the DA conversion unit 22 and outputs it to the constant current source module 30. In this embodiment, the control module 20 includes a single-chip microcomputer 21 and a DA conversion unit 22. The DA conversion unit 22 is connected to the single-chip microcomputer 21 and the constant current source module 30. The single-chip microcomputer 21 is connected to the input module 10 and the display module 40. The single-chip microcomputer 21 obtains the required current value according to the desired magnetic field and distance value and outputs a corresponding voltage signal. The DA conversion unit 22 converts the voltage signal into an analog quantity and transmits it to the constant current source module 30 (as Figure 2 shown).

[0041] Please refer to Figure 6 , further, the DA conversion unit 22 includes a D / A conversion circuit 221, a voltage amplification circuit 222 and an adjustable voltage stabilizing circuit 223. The D / A conversion circuit 221 is connected to the single-chip microcomputer 21. The voltage amplification circuit 222 is connected to the output end of the D / A conversion circuit 221. The adjustable voltage stabilizing circuit 223 is connected to the output end of the voltage amplification circuit 222. The output end of the adjustable voltage stabilizing circuit 223 is connected to the constant current source module 30. The voltage amplification circuit 222 amplifies the voltage analog quantity output by the D / A conversion circuit 221 and outputs it to the adjustable voltage stabilizing circuit 223, and outputs it to the constant current source module 30 through the adjustable voltage stabilizing circuit 223.

[0042] In this embodiment, the D / A conversion circuit 221 uses a DAC0808. The D / A conversion circuit 221 converts the 8-bit binary number output by the single-chip microcomputer 21 into a voltage of 0 to -5V, and then reversely amplifies it by two times through the voltage amplification circuit 222 to obtain a voltage of 0 to 10V. The adjustable voltage stabilizing circuit 223 uses an LM317. The voltage adjustment pin ADJ of the LM317 is connected to the output end of the voltage amplification circuit 222. The voltage input pin Vin of the LM317 is connected to a +15V voltage. The voltage output pin Vout of the LM317 is connected to the constant current source module 30.

[0043] In one embodiment, the input module 10 is a 4×4 matrix keyboard (as Figure 7 shown), which can save the I / O port resources of the single-chip microcomputer 21. The display module 40 is an LCD display screen (schematic diagram as Figure 8 shown). Preferably, the display module 40 uses a 12864 Chinese character graphic dot matrix liquid crystal display to simultaneously display the required current value, the actual current value and the distance value. The single-chip microcomputer 21 uses an STC89C52, but it should not be limited thereto.

[0044] Figure 9The schematic diagram of the power supply module 50 is shown. It uses three-terminal voltage regulators 7805, 78H15, and 79H15 to form a regulated power supply, which is used to output corresponding supply voltages to the control module 20, the constant current source module 30, etc. For example, it outputs ±12V supply voltages to the operational amplifier U1, and outputs +5V supply voltages to the single-chip microcomputer 21, the AD conversion unit 34, etc., which will not be elaborated here.

[0045] When using the magnetic field generation system 100 of this embodiment to test the magnetic sensor chip, first, fix the coil 60 directly above the test probe card (not shown in the figure), and fix the magnetic sensor chip (not shown in the figure) at a preset distance directly above the coil 60; then, turn on the switch of the power supply module 50. At this time, the LCD display screen 40 is initialized. Then, according to the prompts on the LCD display screen 40, input the vertical distance value between the magnetic sensor chip and the coil 60 and the expected magnetic field magnitude respectively through the 4×4 matrix keyboard 10. Then, click the clear key to clear the input data and clear the display data on the LCD display screen 40; then confirm to start, so that the single-chip microcomputer 21 calculates the required current value according to the algorithm in the program, and outputs the corresponding voltage signal to make the constant current source module 30 output the corresponding current to the coil 60. At the same time, the single-chip microcomputer 21 obtains the actual voltage signal on the sampling resistor RS through the AD conversion unit 34 to obtain the actual current value, and adjusts the output voltage signal to finally make the coil 60 generate the expected magnetic field. During this process, the required current value, the actual current value, and the distance value are displayed on the LCD display screen 40.

[0046] Compared with the prior art, the present invention provides the corresponding current to the coil 60 through the cooperation of the input module 10, the control module 20, and the constant current source module 30, so as to be able to provide an accurate magnetic field with controllable magnitude and direction, without additional manual calculation and debugging, improving the work efficiency and simplifying the operation difficulty, and can meet the large-scale production requirements. Moreover, by displaying the required current value, the actual current value, and the distance value through the display module 40, the control interface is intuitive and simple, with good human-computer interaction performance and simple operation, which can save operation time.

[0047] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited by this. Therefore, the equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A magnetic field generation control device for controlling a coil to generate a magnetic field of a desired magnitude and direction, characterized in that, The magnetic field generation control device includes an input module, a control module, a constant current source module, a display module, and a power supply module. The input module, the constant current source module, and the display module are respectively connected to the control module. The output end of the constant current source module is used to connect to a coil. The input module is used to receive input operations to obtain the distance value between the coil and the target object, as well as the magnitude and direction of the desired magnetic field. The control module obtains the required current value for the coil based on the desired magnetic field and the distance value and outputs a corresponding voltage signal to the constant current source module. The constant current source module outputs a corresponding current to the coil according to the voltage signal. The display module is used to display the required current value and the distance value.

2. The magnetic field generation control device according to claim 1, wherein The constant current source module includes a sampling resistor and an AD conversion unit. The sampling resistor is connected to the AD conversion unit, and the AD conversion unit is connected to the control module. The AD conversion unit performs analog-to-digital conversion on the actual voltage signal on the sampling resistor and then feeds it back to the control module.

3. The magnetic field generation control device according to claim 2, characterized in that, The control module compares the voltage signal it outputs with the actual voltage signal and adjusts the output voltage signal according to the voltage difference.

4. The magnetic field generation control device according to claim 2, wherein The control module converts the actual voltage signal into an actual current value according to the resistance value of the sampling resistor, and the display module displays the actual current value.

5. The magnetic field generation control device according to claim 2, wherein, The constant current source module includes a first triode, a voltage dividing circuit, a first amplifier circuit, a Darlington tube, a load resistor, and the sampling resistor. The base of the first triode is connected to the control module, the voltage dividing circuit is connected to the collector of the first triode, the first amplifier circuit is connected to the voltage dividing circuit, the Darlington tube is connected to the output end of the first amplifier circuit, the load resistor is connected between the Darlington tube and the first amplifier circuit, and the sampling resistor is connected between the Darlington tube and the ground.

6. The magnetic field generation control device according to claim 1, characterized in that, The control module includes a single-chip microcomputer and a DA conversion unit. The DA conversion unit is connected to the single-chip microcomputer and the constant current source module. The single-chip microcomputer is connected to the input module and the display module. The single-chip microcomputer obtains the required current value based on the desired magnetic field and the distance value and outputs a corresponding voltage signal. The DA conversion unit converts the voltage signal into an analog quantity and transmits it to the constant current source module.

7. The magnetic field generation control device according to claim 6, characterized in that, The DA conversion unit includes a D / A conversion circuit, a voltage amplification circuit, and an adjustable voltage stabilizing circuit. The D / A conversion circuit is connected to the single-chip microcomputer, the voltage amplification circuit is connected to the output end of the D / A conversion circuit, the adjustable voltage stabilizing circuit is connected to the output end of the voltage amplification circuit, the output end of the adjustable voltage stabilizing circuit is connected to the constant current source module. The voltage amplification circuit amplifies the voltage analog quantity output by the D / A conversion circuit and then outputs it to the adjustable voltage stabilizing circuit, and outputs it to the constant current source module through the adjustable voltage stabilizing circuit.

8. The magnetic field generation control device according to claim 1, wherein The control module outputs a corresponding PWM signal to the constant current source module according to the required current value so that the constant current source module outputs a corresponding current to the coil.

9. The magnetic field generation control device according to claim 1, characterized in that, The input module is a matrix keyboard, and the display module is an LCD display screen.

10. A magnetic field generation system with controllable magnetic flux, characterized in that, It includes a coil and a magnetic field generation control device. The magnetic field generation control device includes an input module, a control module, a constant current source module, a display module and a power supply module. The input module, the constant current source module and the display module are respectively connected to the control module. The output end of the constant current source module is connected to the coil. The input module is used to receive input operations to obtain the distance value between the coil and the target object, as well as the magnitude and direction of the desired magnetic field. The control module obtains the current value required for the coil based on the desired magnetic field and the distance value and outputs a corresponding voltage signal to the constant current source module. The constant current source module outputs a corresponding current to the coil according to the voltage signal. The display module is used to display the required current value and the distance value.

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