CN111564276A - Magnetic field generation control device and magnetic field generation system with controllable magnetic flux - Google Patents

Abstract

The invention discloses a magnetic field generation control device, which comprises an input module, a control module, a constant current source module and a display module, wherein the input module, the constant current source module and the display module are connected with the control module, the constant current source module is connected to a coil and used for receiving input operation to obtain a distance value between the coil and a target object and the size and the direction of an expected magnetic field, the control module obtains a current value required by the coil according to the expected magnetic field and the distance value and outputs a corresponding voltage signal to the constant current source module, and the constant current source module outputs a corresponding current to the coil according to the voltage signal. The invention can provide a magnetic field with accurate and controllable size and direction, does not need additional manual calculation and debugging, improves the working efficiency and simplifies the operation difficulty. Moreover, the required current value and the distance value are displayed through the display module, a control interface is visual and concise, and the human-computer interaction performance is good. In addition, the invention also discloses a magnetic field generating system with controllable magnetic flux.

Description

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

technical field

The invention relates to the field of electromagnetic technology, in particular to a magnetic field generation control device and a magnetic flux controllable magnetic field generation system.

Background technique

In the test pipeline of the magnetic sensor chip, due to the production and debugging requirements, it is often necessary to apply a magnetic field of a certain size and a certain direction on the die (wafer) of the wafer (wafer), and the generation of the magnetic field is mainly realized by coils. However, the magnetic field generating coil cannot automatically generate a magnetic field of the required size and direction according to the test requirements. When the size of the magnetic field needs to be changed, at this stage, the distance from the coil to the chip is often artificially changed and the current size required to be applied to the coil is calculated. Then, a corresponding magnitude of current is applied to the coil through ATE (Automatic Test Equipment, testing machine). This method is cumbersome and inefficient, and is prone to errors when adjusting the distance from the coil to the chip and calculating the required current, which affects the accuracy of the test results.

Therefore, there is an urgent need to provide a magnetic field generation control device capable of automatically controlling a coil to generate a magnetic field of a desired size and direction to solve the above problems.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a magnetic field generation control device capable of automatically controlling a coil to generate a magnetic field of a desired magnitude and direction.

Another object of the present invention is to provide a magnetic field generating system capable of automatically generating a magnetic field of a desired magnitude and direction.

In order to achieve the above object, the present invention provides a magnetic field generation control device for controlling a coil to generate a magnetic field of a desired size 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 The 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, and the input module is used to accept the input operation to obtain the coil and the coil. The distance value between the target objects and the size and direction of the desired magnetic field, the control module obtains the current value required by the coil according to the desired magnetic field and the distance value, and outputs the corresponding voltage signal to the constant current source module, the constant current source module. The current source module outputs the corresponding current to the coil according to the voltage signal, and the display module is used for displaying the required current value and the distance value.

Preferably, the constant current source module includes a sampling resistor and an AD conversion unit, the sampling resistor is connected to the AD conversion unit, the AD conversion unit is connected to the control module, and the AD conversion unit converts The actual voltage signal on the sampling resistor is fed back to the control module after analog-to-digital conversion.

Preferably, the control module compares the output voltage signal with the actual voltage signal, and adjusts the output voltage signal according to the voltage difference.

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.

Preferably, the constant current source module includes a first transistor, a voltage divider circuit, a first amplifier circuit, a Darlington tube, a load resistor and the sampling resistor, and the base of the first transistor is connected to To the control module, the voltage divider circuit is connected to the collector of the first transistor, the first amplifier circuit is connected to the voltage divider circuit, and the Darlington tube is connected to the first amplifier circuit. At the output end, 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.

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, and 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 expected magnetic field and the distance value and outputs a corresponding voltage signal, and the DA conversion unit converts the voltage signal into an analog quantity and transmits it to the constant current source module.

Preferably, the DA conversion unit includes a D/A conversion circuit, a voltage amplifier circuit and an adjustable voltage regulator circuit, the D/A conversion circuit is connected to the single-chip microcomputer, and the voltage amplifier circuit is connected to the D/A conversion circuit. The output end of the circuit, the adjustable voltage stabilizer circuit is connected to the output end of the voltage amplifier circuit, the output end of the adjustable voltage stabilizer circuit is connected to the constant current source module, and the voltage amplifier circuit converts the D/ The voltage analog output from the A conversion circuit is amplified and output to the adjustable voltage regulator circuit, and then output to the constant current source module through the adjustable voltage regulator circuit.

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.

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

In order 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, wherein the magnetic field generation control device includes an input module, a control module, a constant current source module, and 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 terminal of the constant current source module is connected to the coil, and the input module is used for accepting input operations to obtain all the The distance value between the coil and the target object and the size and direction of the desired magnetic field, the control module obtains the current value required by the coil according to 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 the corresponding current to the coil according to the voltage signal, and the display module is used for displaying the required current value and the distance value.

Compared with the prior art, the present invention provides the corresponding current to the coil through the cooperation of the input module, the control module and the constant current source module, so as to provide a precise and controllable size and direction of the magnetic field, without the need for additional artificial calculation and control. Debugging improves work efficiency and simplifies the difficulty of operation, which can meet the needs of large-scale production. Moreover, the required current value and distance value are displayed through the display module, the control interface is intuitive and concise, has good human-computer interaction performance, and is easy to operate, which can save operation time.

Description of drawings

FIG. 1 is a structural block diagram of a magnetic field generating system with controllable magnetic flux according to an embodiment of the present invention.

FIG. 2 is a structural block diagram of a magnetic field generating system with controllable magnetic flux according to another embodiment of the present invention.

FIG. 3 is a partial circuit diagram of the constant current source module.

FIG. 4 is a circuit schematic diagram of an AD conversion unit.

Figure 5 is a schematic diagram of the microcontroller and its peripheral circuits.

FIG. 6 is a circuit schematic diagram of a DA conversion unit.

FIG. 7 is a circuit schematic diagram of the input module.

FIG. 8 is a circuit schematic diagram of the display module.

FIG. 9 is a circuit schematic diagram of a power module.

FIG. 10 is a schematic diagram of the geometric relationship of each point on the coil.

Detailed ways

In order to describe the technical content and structural features of the present invention in detail, further description will be given below with reference to the embodiments and the accompanying drawings.

Referring to FIGS. 1 to 9 , the present invention provides a magnetic field generating system 100 with a controllable magnetic flux, which can generate a magnetic field of a desired size and direction to meet the testing requirements of a target object (eg, a magnetic sensor chip, etc.). The magnetic flux controllable magnetic field generation system 100 includes a coil 60 and a magnetic field generation control device for controlling the coil 60 to generate a magnetic field of 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, and the input module 10 is used to accept the input operation to obtain the distance value between the coil 60 and the target object and the size and direction of the desired magnetic field. The control module 20 is based on the desired magnetic field and The distance value obtains the required current value of the coil 60 and outputs the corresponding voltage signal to the constant current source module 30. The constant current source module 30 outputs the corresponding current to the coil 60 according to the voltage signal, and the display module 40 is used to display the required current value and distance. value.

Below, the calculation principle of the current required by the coil 60 will be described by taking the target object as the magnetic sensor chip as an example:

In 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 of the circular current at any point P on the central axis L1 of the coil 60 is:

又由于存在三角关系：

将三角关系代入公式一中求积分可以得到线圈60的中心轴线L1上任一点P的磁感应强度：Since the current I=Rctgβ flowing through the coil 60, so

And because of the triangular relationship:

Substituting the triangular relationship into formula 1 for integration can obtain the magnetic induction intensity of any point P on the central axis L1 of the coil 60:

可以得到线圈60的中心轴线L1上任一点P的磁场强度H与电流的关系为：

The relationship between the magnetic induction intensity B and the magnetic field intensity H is:

The relationship between the magnetic field strength H and the current at any point P on the central axis L1 of the coil 60 can be obtained as:

Among them, in the above formulae, μ represents the magnetic permeability, n represents the number of turns of the coil 60, R represents the radius of the coil 60, and 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 coil 60 and the magnetic sensor chip and half of the length of the coil 60), β1 represents the connection between a point P on the central axis L1 of the coil 60 and the upper edge of the coil 60 and the central axis L1 of the coil 60. β2 represents the included angle between a line connecting a point P on the central axis L1 of the coil 60 to the lower end edge of the coil 60 and the central axis L1 of the coil 60 (as shown in FIG. 10 ). When the number of turns n, diameter and length of the coil 60 are all fixed, the control module 20 can calculate the required current I according to the input expected magnetic field and the distance between the magnetic sensor chip and the coil 60 .

Incidentally, when the direction of the magnetic field needs to be changed, the direction of the current output by the constant current source module 30 can be changed.

Hereinafter, the magnetic flux controllable magnetic field generating system 100 of the present invention will be described in detail with reference to the accompanying drawings 1-9:

Please refer to FIG. 3. Specifically, the constant current source module 30 includes a resistor R8, a first transistor Q1, a voltage divider circuit 31, a first amplifier circuit 32, a Darlington transistor 33, a load resistor RL, and a sampling resistor RS. And the 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 transistor Q1. The voltage divider circuit 31 includes a resistor R1, a resistor R3, a resistor R4, a resistor R5, a capacitor C1 and a capacitor C2. The first terminals of the resistor R1 and the resistor R4 are connected to the collector of the first transistor Q1, and the second terminal of the resistor R1 is connected to the collector of the first transistor Q1. Connected to 12V voltage, the first end of capacitor C1 is connected to the second end of resistor R4, the second end is connected to the second end of resistor R1, the first end of resistor R5 is connected to the second end of resistor R4, and the first end of capacitor C2 is connected to The second end of the resistor R5 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 balanced resistor R6 and a resistor R2, the first terminal of the balanced 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 balanced resistor R6, and the positive Phase input termination resistor R2. In this embodiment, the operational amplifier U1 adopts LM324, the resistance value of the balance resistor R6 is 1kΩ, and the resistance value of the resistor R2 is 22kΩ, but it should not be limited by this. The Darlington tube 33 includes a transistor Q2 and a transistor Q3, a resistor R7 is connected between the emitter of the transistor Q2 and the output end of the operational amplifier U1, the base of the transistor Q3 is connected to the emitter of the transistor Q2, and the first end of the load resistor RL is connected to The emitter of the transistor Q3, the second terminal is connected to the operational amplifier U1, the collector of the transistor Q3 is connected to the collector of the transistor Q2, the collector of the transistor Q2 is connected to the first terminal of the sampling resistor RS, and the second terminal of the sampling resistor RS Ground, the resistance value of sampling resistor RS is 1kΩ. The collector of the transistor Q2 is also connected with a capacitor C3, and one end of the capacitor C3 is grounded. The AD conversion unit 34 (as shown in FIG. 4 ) 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 feeds back to the control module 20 .

Further, the control module 20 compares the output voltage signal with the actual voltage signal, and adjusts the output voltage signal according to the voltage difference, thereby improving the accuracy of the output current of the constant current source module 30, thereby ensuring that the coil 60 can generate the desired size. the magnetic field. 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 visually display the difference between the actual current value and the required current value.

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 the constant current source module 30 outputs a corresponding current to the coil 60 through the PWM signal. In another embodiment, the control module 20 converts the digital quantity outputted by the control module 20 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, and the single-chip microcomputer 21 is connected to the input module 10 and the display module 40. The magnetic field and the distance value obtain the required current value and output the 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 shown in FIG. 2 ).

Please refer to FIG. 6 , further, the DA conversion unit 22 includes a D/A conversion circuit 221 , a voltage amplification circuit 222 and an adjustable voltage regulator circuit 223 , the D/A conversion circuit 221 is connected to the microcontroller 21 , and the voltage amplification circuit 222 is connected to the D/A The output end of the conversion circuit 221, the adjustable voltage stabilizer circuit 223 is connected to the output end of the voltage amplifier circuit 222, the output end of the adjustable voltage stabilizer circuit 223 is connected to the constant current source module 30, and the voltage amplifier circuit 222 outputs the D/A conversion circuit 221 After being amplified, the analog voltage is output to the adjustable voltage regulator circuit 223 , and then output to the constant current source module 30 via the adjustable voltage regulator circuit 223 .

In this embodiment, the D/A conversion circuit 221 adopts a DAC0808, and the D/A conversion circuit 221 converts the 8-bit binary number output by the single-chip microcomputer 21 into a voltage of 0-5V, and then reversely amplifies the voltage twice by the voltage amplification circuit 222 A voltage of 0 to 10V is obtained. The adjustable voltage regulator circuit 223 adopts LM317. The voltage adjustment pin ADJ of LM317 is connected to the output end of the voltage amplifier circuit 222 , the voltage input pin Vin of LM317 is connected to +15V voltage, and the voltage output pin Vout of LM317 is connected to the constant current source module 30 .

In one embodiment, the input module 10 is a 4×4 matrix keyboard (as shown in FIG. 7 ), which can save the I/O port resources of the microcontroller 21 . The display module 40 is an LCD display screen (the schematic diagram is shown in FIG. 8 ). Preferably, the display module 40 adopts 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 microcontroller 21 adopts STC89C52, but it should not be limited by this.

FIG. 9 shows the schematic diagram of the power supply module 50, which uses three-terminal voltage regulators 7805, 78H15, and 79H15 to form a regulated power supply to output the corresponding power supply voltage to the control module 20, the constant current source module 30, etc., For example, the ±12V power supply voltage is output to the operational amplifier U1, and the +5V power supply voltage is output to the microcontroller 21 and the AD conversion unit 34, etc., which will not be repeated here.

When using the magnetic field generation system 100 of this embodiment to test the magnetic sensor chip, first, the coil 60 is fixed directly above the test probe card (not shown), and the magnetic sensor chip (not shown) is fixed on the coil 60. Just above the preset distance; then, turn on the switch of the power supply module 50, at this time, the LCD display screen 40 is initialized. Next, according to the prompts on the LCD display screen 40 , the value of the vertical distance between the magnetic sensor chip and the coil 60 and the expected magnitude of the magnetic field are respectively input 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 the start so that the microcontroller 21 calculates the required current value according to the algorithm in the program, and outputs the corresponding voltage signal to make the constant The current source module 30 outputs 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 desired 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 .

Compared with the prior art, the present invention provides a 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 provide an accurate and controllable size and direction of the magnetic field without additional The artificial calculation and debugging improves the work efficiency and simplifies the operation difficulty, which can meet the needs of large-scale production. Moreover, the display module 40 displays the required current value, the actual current value and the distance value, the control interface is intuitive and concise, has good human-computer interaction performance, is easy to operate, and can save operation time.

The above disclosures are only preferred embodiments of the present invention, and of course, the scope of the rights of the present invention cannot be limited by this. Therefore, equivalent changes made according to the claims of the present invention still belong to the scope covered by the present invention.

Claims (10)

1. a magnetic field generation control device for controlling a coil to generate a magnetic field of desired size and direction, characterized in that the magnetic field generation control device comprises 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, and the input module is used to accept input operations to obtain the relationship between the coil and the target object. The distance value and the size and direction of the expected magnetic field, the control module obtains the required current value of the coil according to the expected magnetic field and the distance value and outputs the corresponding voltage signal to the constant current source module, the constant current source module According to the voltage signal, the corresponding current is output to the coil, and the display module is used for displaying the required current value and the distance value. 2. The magnetic field generation control device according to claim 1, wherein a sampling resistor and an AD conversion unit are included in the constant current source module, the sampling resistor is connected with the AD conversion unit, and the AD conversion unit is connected to the AD conversion unit. The unit is connected to the control module, and 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. 3 . The magnetic field generation control device of claim 2 , wherein the control module compares the output voltage signal with the actual voltage signal, and adjusts the output voltage signal according to the voltage difference. 4 . 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 actual current value. 5. The magnetic field generation control device according to claim 2, wherein the constant current source module comprises a first transistor, a voltage divider circuit, a first amplifier circuit, a Darlington tube, a load resistor and the a sampling resistor, the base of the first triode is connected to the control module, the voltage divider circuit is connected to the collector of the first triode, the first amplifier circuit is connected to the voltage divider 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 to the Darlington between the tube and the ground. 6. The magnetic field generation control device according to claim 1, wherein the control module comprises a single chip microcomputer and a DA conversion unit, the DA conversion unit is connected with the single chip microcomputer and the constant current source module, and the single chip microcomputer is connected to the constant current source module. Connected with the input module and the display module, the single-chip microcomputer obtains the required current value according to the expected magnetic field and the distance value and outputs the corresponding voltage signal, and the DA conversion unit converts the voltage signal into an analog quantity for transmission to the constant current source module. 7. The magnetic field generation control device according to claim 6, wherein the DA conversion unit comprises a D/A conversion circuit, a voltage amplifier circuit and an adjustable voltage regulator circuit, and the D/A conversion circuit is connected to the Single chip microcomputer, the voltage amplifier circuit is connected to the output end of the D/A conversion circuit, the adjustable voltage stabilizer circuit is connected to the output end of the voltage amplifier circuit, and the output end of the adjustable voltage stabilizer circuit is connected to the constant voltage A current source module, wherein the voltage amplifying circuit amplifies the voltage analog output from the D/A conversion circuit and outputs it to the adjustable voltage regulator circuit, and outputs to the constant current source via the adjustable voltage regulator circuit module. 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 the output. 9 . corresponding current to the coil. 9 . The magnetic field generation control device according to claim 1 , wherein the input module is a matrix keyboard, and the display module is an LCD display screen. 10 . 10. A magnetic flux controllable magnetic field generation system, characterized in that it comprises a coil and a magnetic field generation control device, and 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, so The input module, the constant current source module and the display module are respectively connected to the control module, the output terminal of the constant current source module is connected to the coil, and the input module is used for accepting input operations to obtain the relationship between the coil and the target object. The distance value and the size and direction of the expected magnetic field, the control module obtains the required current value of the coil according to the expected magnetic field and the distance value and outputs the corresponding voltage signal to the constant current source module, the constant current The source module outputs the corresponding current to the coil according to the voltage signal, and the display module is used for displaying the required current value and the distance value.

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