Method and sensor for reducing power consumption of magnetically balanced Hall current sensor

Abstract

The present invention application provides a method and sensor for reducing the power consumption of a magnetic balance Hall current sensor, wherein the Hall current sensor comprises: a Hall element, a magnetic circuit, a feedback current coil wound on the magnetic circuit, a post-amplifier and a switch control signal module; the method comprises: the Hall element is placed in the magnetic circuit to detect the magnetic induction intensity of the environment; the electrical signal detected by the Hall element is amplified to form a feedback control signal; the feedback control signal is input into the switch control signal module for discretization processing to form a switch control signal, drive the feedback current coil, and realize magnetic balance control of the magnetic circuit. This method regards the magnetic circuit and the feedback current coil as an inductor, and drives it with the discrete switch control signal, which can effectively reduce the power consumption of the sensor.

Description

Technical Field

[0001] The present invention relates to the field of electronic circuits, and in particular to a method for reducing the power consumption of a magnetic balance Hall current sensor and a sensor. Background Art

[0002] The classical Hall effect is a magnetoelectric effect discovered by American physicist EH Hall in 1879 and named after it. In modern industry, semiconductor components made using the Hall effect (called Hall elements) are widely used in automation technology, detection technology, and information processing.

[0003] The Hall effect can be used to detect the magnetic induction intensity of the environment in which the Hall element is located. The typical application is the field of current measurement, and the related product is the Hall current sensor. Hall sensors are divided into two types: linear Hall sensors and switch Hall sensors. Linear Hall sensors include open-loop current sensors and closed-loop current sensors. Hall closed-loop current sensors are also called magnetic balance current sensors. Among them, linear Hall sensors have a wide magnetic field working range and are almost unaffected by environmental factors such as vibration, moisture, dust, oil film or ambient lighting. They are widely used, especially magnetic balance current sensors.

[0004] In order to better illustrate the characteristics and advantages of the present invention, a brief description is first given of the characteristics of "linear transformation" and "switch transformation" in electronics.

[0005] Assume there is a voltage (or current) converter whose input voltage (usually the power supply voltage) is , the output voltage is , the output current is .

[0006] 1. If the converter adopts the "linear conversion" scheme, then ideally, the power consumed by the power supply ( P ) is at least:

[0007] (1)

[0008] The conversion efficiency at this time (denoted as η ) is at most:

[0009] (2)

[0010] 2. If the converter adopts the "switching conversion" scheme, then under ideal conditions, the conversion efficiency is at most 100%, and the power consumed by the power supply ( P ) is at least:

[0011] (3)

[0012] The characteristics of the above two conversion schemes are well known in the field of electronic technology and will not be discussed in detail here. The characteristics of the two conversion schemes have many applications and comparative examples in the field of electronic technology: for example, in audio power amplifiers, class A, class B and class AB amplifiers are equivalent to "linear conversion", so their efficiency is far less than that of class D amplifiers, which are equivalent to "switch conversion".

[0013] Another point that needs to be emphasized is that in electronics, all "switching conversions" require at least one "conversion inductor"; the efficient energy conversion of all "switching conversion" schemes is essentially based on the energy storage characteristics of the "conversion inductor".

[0014] Figure 1 It is a schematic diagram of the structure and principle of a traditional magnetic balance Hall current sensor, as shown in the figure, comprising: a magnetic circuit 11, a Hall element 12, a post-amplifier 13 and a feedback current coil 14 wound around the magnetic circuit 11.

[0015] The magnetic circuit 11 is made of magnetic material, and the current to be measured Generally, a single turn passes through the core in the magnetic circuit 11; the Hall element 12 is placed in the magnetic circuit 11, and the output signal of the Hall element 12 is detected and amplified by the post-amplifier 13, and then drives the feedback current coil 14, and generates a feedback current in the feedback current coil 14. .

[0016] At this time, the magnetic induction intensity in the magnetic circuit 11 is the current to be measured The generated magnetic induction intensity and the feedback current Through negative feedback control, the magnetic induction intensity in the magnetic circuit 11 is always zero (or a constant value), and the current in the feedback current coil can be used to generate the superposition of the magnetic induction intensity. To characterize the current to be measured This current detection method is generally called "zero flux (or constant flux)" control.

[0017] Using the above control method, the current in the feedback current coil Proportional to the current to be measured , the number of turns of the feedback current coil is recorded as N , then:

[0018] (4)

[0019] It must be emphasized here that in the above conventional control method, the feedback current in the feedback current coil 14 The generation of the feedback current is achieved by the so-called "linear transformation" method in electronics. , the power consumed by the power supply is:

[0020] (5)

[0021] in, is the power supply voltage; P is the power consumed by the power supply.

[0022] It can be seen that the power consumption of the power supply at this time is related to the current to be measured. , number of turns of feedback current coil N and the supply voltage Especially when measuring high current, it will cause large power consumption. Summary of the invention

[0023] In view of this, based on the traditional control method, the present invention provides a method for reducing the power consumption of the magnetic balance Hall current sensor. The basic idea is to use the "switch conversion" method to generate the current in the feedback current coil. ; Since "switching conversion" has a high conversion efficiency that is incomparable to "linear conversion", it can effectively reduce circuit power consumption.

[0024] In a possible implementation, the current sensor includes a Hall element, a magnetic circuit, a feedback current coil wound on the magnetic circuit, a post-amplifier, and a switch control signal module; the method for reducing the power consumption of the magnetic balance Hall current sensor includes:

[0025] The Hall element is placed in the magnetic circuit to detect the magnetic induction intensity of the environment;

[0026] The electrical signal detected by the Hall element is amplified by the post-amplifier to form a feedback control signal;

[0027] The feedback control signal is input into the switch control signal module for discretization processing to form a switch control signal;

[0028] The switch control signal drives the feedback current coil to achieve magnetic balance control in the magnetic circuit.

[0029] In the method proposed in the present invention, compared with the traditional method described above, a switch control signal module is added; the function of the switch control signal module is to discretize the feedback control signal output by the post-stage amplifier to form a switch control signal; then the switch control signal is used to drive the feedback current coil, and the required feedback current is generated in the feedback current coil, thereby realizing magnetic balance control in the magnetic circuit.

[0030] Here, the magnetic circuit and the feedback current coil can be collectively regarded as one inductor, which is directly equivalent to the "conversion inductor" required in the "switch conversion". Therefore, there is no need to actually add additional "conversion inductor" to the circuit, and therefore there is no need to increase excessive hardware costs.

[0031] According to the above characteristics, the present invention adopts a "switch conversion" method to generate the current in the feedback current coil, which can effectively reduce the power consumption of the circuit.

[0032] In addition, the following points are added:

[0033] 1. The method for reducing the power consumption of the magnetic balance Hall current sensor proposed in the present invention comprises at least one Hall chip for detecting the magnetic induction intensity of the environment in which it is placed. In the traditional technical solution, multiple Hall chips can be placed in a magnetic circuit, and the offset voltage of the Hall chip can be eliminated (or reduced) through a specific connection method to stabilize the measurement. This solution is also applicable to the method proposed in the present invention.

[0034] 2. The method for reducing the power consumption of the magnetically balanced Hall current sensor proposed in the present invention comprises at least one magnetic circuit, on which at least one set of feedback current coils is wound. In the traditional technical scheme, for example, in the application scenario of a single power supply, multiple sets of feedback current coils can be wound on the magnetic circuit, and the direction of the magnetic motive force generated by the feedback current can be controlled by adjusting the winding direction of the multiple sets of feedback current coils. This scheme is also applicable to the method proposed in the present invention.

[0035] 3. The six basic structures of switching converters (Buck, Boost, Buck-Boost, Cuk, Sepic and Zeta) and their derivative structures are all applicable to the present invention. If an electronic switch group structure with a boost function (Boost, Buck-Boost, Cuk, Sepic and Zeta and their derivative structures) is used, the method proposed in the present invention will be equivalent to making the output of the sensor have a larger dynamic voltage output range; compared with the traditional control method, when the same feedback current needs to be generated In this case, the sensor can operate at a lower power supply voltage.

[0036] In a possible implementation, the magnetic balance Hall current sensor includes a Hall element, a magnetic circuit, a feedback current coil wound on the magnetic circuit, a post-stage amplifier, and a switch control signal module;

[0037] The current to be measured passes through the core in the magnetic circuit;

[0038] The Hall element is placed in the magnetic circuit to detect the magnetic induction intensity of the environment.

[0039] The post-stage amplifier is used to amplify the electrical signal detected by the Hall element to form a feedback control signal;

[0040] The switch control signal module is used to discretize the feedback control signal to form a switch control signal;

[0041] The feedback current coil is used to realize magnetic balance control in the magnetic circuit based on the drive of the switch control signal; the current in the feedback coil represents the current value to be measured.

[0042] The magnetic circuit and the feedback current coil are collectively regarded as an inductor and driven by the switch control signal, which is equivalent to using "switch conversion" to generate the required feedback current in the feedback current coil, thereby reducing the power consumption of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0044] Figure 1 It is a schematic diagram of the structure and principle of a traditional magnetic balance current sensor;

[0045] Figure 2 A schematic diagram of the structure of a magnetic balance current sensor provided by an embodiment of the present invention;

[0046] Figure 3 It is a schematic diagram of the structure and working principle of a switch control signal module provided by an embodiment of the present invention;

[0047] Figure 4 is a flow chart of a method for reducing power consumption of a magnetic balance current sensor provided by an embodiment of the present invention;

[0048] Reference numerals:

[0049] 11. Magnetic circuit;

[0050] 12. Hall element;

[0051] 13. Post-amplifier;

[0052] 14. Feedback current coil;

[0053] 21. Magnetic circuit;

[0054] 22. Hall element;

[0055] 23. Post-amplifier;

[0056] 24. Switch control signal module;

[0057] 25. Feedback current coil;

[0058] 241. Comparator;

[0059] 242. Electronic switch group. DETAILED DESCRIPTION

[0060] In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0061] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0062] The present invention aims to reduce power consumption by improving the magnetic balance current sensor.

[0063] The following is a detailed description of the implementation of the present invention in conjunction with the specific drawings:

[0064] Figure 2 This is a schematic diagram of the structure of a magnetic balance current sensor provided in an embodiment of the present invention. The magnetic balance current sensor includes: a magnetic circuit 21, a Hall element 22, a post-amplifier 23, a switch control signal module 24 and a feedback current coil 25.

[0065] The Hall element 22 is placed in the magnetic circuit 21 , and the Hall element 22 , the post-stage amplifier 23 , the switch control signal module 24 and the feedback current coil 25 are connected in sequence.

[0066] The feedback current coil 25 is wound around the magnetic circuit 21 , and the current to be measured flows through the core of the magnetic circuit 21 .

[0067] The Hall element 22 is used to detect the magnetic induction intensity of the environment and output a detection signal, wherein the detection signal is an electrical signal.

[0068] The post-stage amplifier 23 is used to amplify the detection signal to generate a feedback control signal.

[0069] The switch control signal module 24 is used to perform discrete processing on the feedback control signal to generate a switch control signal. Figure 1 Compared with the traditional magnetic balance current sensor, the output signal of the post-stage amplifier 23 is not directly used to control the feedback current coil 25, but is input into the switch control signal module 24 as a modulation signal. The switch control signal module 24 discretizes the output signal of the post-stage amplifier 23 to form a switch control signal, which further controls and drives the feedback current coil 25.

[0070] The feedback current coil 25 is used to generate feedback current and realize magnetic balance control. The feedback current in the feedback current coil 25 is controlled by negative feedback so that the magnetic induction intensity in the magnetic circuit 11 is always zero (or a constant value), and the current to be measured can be represented by the current in the feedback current coil.

[0071] The magnetic circuit 21 and the feedback current coil 25 are collectively regarded as an inductor, and driven by the switch control signal, which is equivalent to using "switch conversion" to generate the required feedback current in the feedback current coil 25, thereby reducing the power consumption of the circuit.

[0072] like Figure 3 , which is a schematic diagram of the structure and working principle of a switch control signal module provided in an embodiment of the present invention, wherein the switch control signal module 24 includes a comparator 241 .

[0073] The input terminals of the comparator 241 are connected to the post-stage amplifier 23 and the alternating signal respectively.

[0074] The comparator 241 is used to generate a discrete switch control signal by comparing the amplified electrical signal with the alternating signal.

[0075] The output terminal of the comparator 241 is used to output a switch control signal.

[0076] In some embodiments, the alternating signal is a triangular wave or a sawtooth wave. Figure 3 The alternating signal shown is a triangle wave.

[0077] In some embodiments, the switch control signal module 24 further includes an electronic switch group 242 (in Figure 3 The electronic switch group 242 is connected to the output terminal of the comparator 241 to enhance the driving capability of the switch control signal.

[0078] In some embodiments, the number of the switch control signal modules is one or more, and is used to perform discrete processing or multi-level discrete processing on the feedback control signal.

[0079] Figure 3The discretization processing method shown adopts the common pulse width modulation technology to discretize the output signal of the post-stage amplifier 23 to form a switch control signal.

[0080] In other embodiments, discrete modulation may be performed based on techniques such as frequency modulation or on-time control.

[0081] Figure 4 FIG. 1 is a flow chart showing a method for reducing power consumption of a magnetic balance current sensor provided by an embodiment of the present invention. Figure 4 As shown, the following steps are included:

[0082] S401, the Hall element is placed in the magnetic circuit to detect the magnetic induction intensity of the environment.

[0083] S402, the electrical signal detected by the Hall element is amplified by a post-stage amplifier to form a feedback control signal.

[0084] S403, the feedback control signal is input into a switch control signal module for discretization processing to form a switch control signal.

[0085] S404, the switch control signal drives the feedback current coil to achieve magnetic balance control in the magnetic circuit.

[0086] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0087] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for reducing power consumption of a magnetically balanced Hall current sensor, characterized in that: The current sensor includes a Hall element, a magnetic circuit, a feedback current coil wound on the magnetic circuit, a post-amplifier and a switch control signal module; the method includes: The Hall element is placed in the magnetic circuit to detect the magnetic induction intensity of the environment; The electrical signal detected by the Hall element is amplified by the post-amplifier to form a feedback control signal; The feedback control signal is input into the switch control signal module for discretization processing to form a switch control signal; The switch control signal drives the feedback current coil to achieve magnetic balance control in the magnetic circuit; Among them, the switch control signal module includes a comparator; the input end of the comparator is respectively connected to the post-stage amplifier and the alternating signal, and is used to generate a discrete switch control signal based on the comparison of the amplified electrical signal and the alternating signal; the output end of the comparator is used to output the switch control signal.

2. The method according to claim 1, characterized in that Contains at least one Hall chip for detecting the magnetic induction intensity of the surrounding environment.

3. The method according to claim 1, characterized in that: It comprises at least one magnetic circuit, on which at least one set of feedback current coils is wound.

4. The method according to claim 1, characterized in that: It comprises at least one post-stage amplifier for amplifying the electrical signal detected by the Hall element.

5. The method according to claim 1, characterized in that It comprises at least one switch control signal module, which is used for discretizing the output signal of the post-stage amplifier to form a switch control signal for driving the feedback current coil.

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