Hall element constant current source circuit

Abstract

The utility model discloses a Hall element constant current source circuit which comprises a constant current control module, a reference voltage adjusting module, a Hall element H and a processing module, and the constant current control module is electrically connected with the reference voltage adjusting module, the Hall element H and the processing module respectively. The Hall element constant current source circuit is convenient to use, through the cooperative arrangement of the Hall element, the processing circuit, the operational amplifier, the triode, the resistor and the capacitor, stable current output is provided, the working current of the Hall element is kept constant, and the influence of temperature change and other factors is reduced. Therefore, the measurement precision and stability of the Hall element can be ensured, and the performance of the whole Hall sensor system is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of current sensors, in particular to a constant current source circuit of a Hall element. Background Art

[0002] The Hall current sensor is a detection device based on the Hall effect. Its main working principle is to use the Hall effect principle. When current passes through a conductor material in a magnetic field, the magnetic field will produce a force perpendicular to the direction of electron movement on the electrons in the conductor, thereby generating a potential difference in two directions perpendicular to the conductor and the magnetic flux lines. The Hall current sensor has the advantages of high sensitivity, high accuracy, good linearity, wide bandwidth, fast response, and strong overload capacity. The application of Hall current sensors is very extensive.

[0003] When designing a Hall current sensor, factors such as stability, accuracy, temperature compensation, noise, and interference need to be considered. Among them, the constant current source circuit is crucial. Its main function is to provide a stable current output, so that the operating current of the Hall element remains constant and the influence of temperature changes and other factors is reduced. This ensures the measurement accuracy and stability of the Hall element, thereby improving the performance of the entire Hall sensor system.

[0004] Based on the above situation, the utility model proposes a Hall element constant current source circuit, which can effectively solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a constant current source circuit of a Hall element. The Hall element constant current source circuit of the utility model is easy to use, and provides a stable current output through the coordination of the Hall element, processing circuit, operational amplifier, triode, resistor and capacitor, so that the working current of the Hall element remains constant and the influence of temperature change and other factors is reduced. In this way, the measurement accuracy and stability of the Hall element can be ensured, thereby improving the performance of the entire Hall sensor system.

[0006] The utility model is realized by the following technical solutions:

[0007] A Hall element constant current source circuit comprises a constant current control module, a reference voltage adjustment module, a Hall element H and a processing module, wherein the constant current control module is electrically connected to the reference voltage adjustment module, the Hall element H and the processing module respectively.

[0008] The purpose of the utility model is to provide a constant current source circuit of a Hall element. The Hall element constant current source circuit of the utility model is easy to use, and provides a stable current output through the coordination of the Hall element, processing circuit, operational amplifier, triode, resistor and capacitor, so that the working current of the Hall element remains constant and the influence of temperature change and other factors is reduced. In this way, the measurement accuracy and stability of the Hall element can be ensured, thereby improving the performance of the entire Hall sensor system.

[0009] Preferably, the constant current control module includes a first operational amplifier U1, a second operational amplifier U2, a first PNP transistor Q1, a second PNP transistor Q3, a third PNP transistor Q4, an NPN transistor Q2, a transistor D1, a capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a ninth resistor R9;

[0010] Pin 6 of the first operational amplifier U1 is electrically connected to one end of the second resistor R2 and the emitter of the second PNP transistor Q3, respectively; the other end of the second resistor R2 is electrically connected to one end of the first resistor R1, and the other end of the first resistor R1 is electrically connected to pin 5 of the first operational amplifier U1, one end of the third resistor R3, one end of the fourth resistor R4, and one end of the capacitor C1, respectively; the other end of the third resistor R3 is electrically connected to the emitter of the first PNP transistor Q1, and the base of the first PNP transistor Q1 is electrically connected to the other end of the fourth resistor R4 and the collector of the NPN transistor Q2, and the collector of the first PNP transistor Q1 is electrically connected to pin 3 of the transistor D1, the base of the NPN transistor Q2, and the other end of the capacitor C1, respectively; and pin 1 of the transistor D1 is electrically connected to the NPN transistor Q2. The emitter of the transistor Q2 is electrically connected to one end of the fifth resistor R5, and pin 2 of the transistor D1 is electrically connected to the other end of the fifth resistor R5 and one end of the ninth resistor R9 respectively. Pin 7 of the first operational amplifier U1 is electrically connected to the base of the second PNP transistor Q3, and the collector of the second PNP transistor Q3 is electrically connected to pin 4 of the Hall element H. Pin 2 of the Hall element H is electrically connected to the emitter of the third PNP transistor Q4, and the base of the third PNP transistor Q4 is electrically connected to pin 7 of the second operational amplifier U2. The collector of the third PNP transistor Q4 is electrically connected to the other end of the ninth resistor R9, and pin 6 of the second operational amplifier U2 is electrically connected to pin 3 of the Hall element H. Pin 5 of the second operational amplifier U2 is electrically connected to the other end of the seventh resistor R7.

[0011] Preferably, the reference voltage adjustment module includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a potentiometer RP1, the collector of the second PNP transistor Q3 is electrically connected to one end of the sixth resistor R6, the other end of the sixth resistor R6 is electrically connected to pin 1 of the potentiometer RP1, pin 3 of the potentiometer RP1 is electrically connected to one end of the seventh resistor R7, pin 2 of the potentiometer RP1 is electrically connected to one end of the eighth resistor R8, and the other end of the eighth resistor R8 is respectively electrically connected to pin 2 of the Hall element H and the emitter of the third PNP transistor Q4.

[0012] Preferably, the processing module is a processing circuit A1, and the processing circuit A1 includes an IN1 interface, an IN2 interface, an IN3 interface, and an OUT interface electrically connected, pin 2 of the transistor D1 is electrically connected to the IN3 interface of the processing circuit A1, pin 5 of the second operational amplifier U2 is electrically connected to the IN2 interface of the processing circuit A1, and pin 1 of the Hall element H is electrically connected to the IN1 interface of the processing circuit A1.

[0013] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0014] The Hall element constant current source circuit of the utility model is easy to use. Through the coordination of the Hall element, processing circuit, operational amplifier, triode, resistor and capacitor, a stable current output is provided to keep the working current of the Hall element constant and reduce the influence of temperature change and other factors. In this way, the measurement accuracy and stability of the Hall element can be ensured, thereby improving the performance of the entire Hall sensor system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the technical solution of the utility model, the preferred implementation scheme of the utility model is described below in conjunction with specific embodiments. However, it should be understood that the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationship described in the drawings is only used for illustrative purposes and cannot be understood as a limitation on this patent.

[0017] Embodiment 1:

[0018] like Figure 1As shown, the utility model provides a Hall element constant current source circuit, including a constant current control module, a reference voltage adjustment module, a Hall element H and a processing module, wherein the constant current control module is electrically connected to the reference voltage adjustment module, the Hall element H and the processing module respectively.

[0019] The Hall element H can detect and measure the magnetic field. Through the Hall effect, the change of the magnetic field is converted into a measurable electrical signal. When the current passed through the Hall element H changes, the output voltage will change when detecting the same magnetic field, so the temperature drift performance of the constant current source is very important. Connecting the Hall element H to a low-temperature drift constant current source can ensure that the Hall element H obtains a stable current supply at different temperatures, thereby reducing the impact of temperature on the measurement results and improving the measurement accuracy.

[0020] Embodiment 2:

[0021] like Figure 1 As shown, the utility model provides a Hall element constant current source circuit, including a constant current control module, a reference voltage adjustment module, a Hall element H and a processing module, wherein the constant current control module is electrically connected to the reference voltage adjustment module, the Hall element H and the processing module respectively.

[0022] The constant current control module includes a first operational amplifier U1, a second operational amplifier U2, a first PNP transistor Q1, a second PNP transistor Q3, a third PNP transistor Q4, an NPN transistor Q2, a transistor D1, a capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a ninth resistor R9;

[0023] Pin 6 of the first operational amplifier U1 is electrically connected to one end of the second resistor R2 and the emitter of the second PNP transistor Q3, respectively; the other end of the second resistor R2 is electrically connected to one end of the first resistor R1, and the other end of the first resistor R1 is electrically connected to pin 5 of the first operational amplifier U1, one end of the third resistor R3, one end of the fourth resistor R4, and one end of the capacitor C1, respectively; the other end of the third resistor R3 is electrically connected to the emitter of the first PNP transistor Q1, and the base of the first PNP transistor Q1 is electrically connected to the other end of the fourth resistor R4 and the collector of the NPN transistor Q2, and the collector of the first PNP transistor Q1 is electrically connected to pin 3 of the transistor D1, the base of the NPN transistor Q2, and the other end of the capacitor C1, respectively; and pin 1 of the transistor D1 is electrically connected to the NPN transistor Q2. The emitter of the transistor Q2 is electrically connected to one end of the fifth resistor R5, and pin 2 of the transistor D1 is electrically connected to the other end of the fifth resistor R5 and one end of the ninth resistor R9 respectively. Pin 7 of the first operational amplifier U1 is electrically connected to the base of the second PNP transistor Q3, and the collector of the second PNP transistor Q3 is electrically connected to pin 4 of the Hall element H. Pin 2 of the Hall element H is electrically connected to the emitter of the third PNP transistor Q4, and the base of the third PNP transistor Q4 is electrically connected to pin 7 of the second operational amplifier U2. The collector of the third PNP transistor Q4 is electrically connected to the other end of the ninth resistor R9, and pin 6 of the second operational amplifier U2 is electrically connected to pin 3 of the Hall element H. Pin 5 of the second operational amplifier U2 is electrically connected to the other end of the seventh resistor R7.

[0024] The third resistor R3, the fifth resistor R5 and the ninth resistor R9 are used for current limiting: by connecting the third resistor R3, the fifth resistor R5 and the ninth resistor R9 in series to the circuit and selecting appropriate resistance values ​​to limit the current, a constant current can be obtained when the voltage is constant.

[0025] The fourth resistor R4 stabilizes the voltage: by utilizing the voltage-dividing characteristics of the resistor, when the current passed is constant, the voltage can be kept constant.

[0026] R1=R2 ensures constant current output: Equal resistance can ensure constant current output. The principle is to introduce equal resistance into the circuit to obtain nearly the same voltage division value, so that the circuit generates a constant current when it is working. When used in conjunction with the first operational amplifier U1, it can ensure that the constant current source is not affected by the auxiliary power supply or the load.

[0027] The first PNP transistor Q1 and the second PNP transistor Q3 are selected from the same series of transistors. When the temperature changes, the temperature drift changes are opposite and almost equal, which compensate each other and reduce the influence of temperature on the constant current source. The use of transistor pairs is relatively simple, easy to understand and design. This helps to reduce the complexity of the constant current source circuit and speed up the design and development process.

[0028] The first operational amplifier U1, the second operational amplifier U2, the second PNP transistor Q3, and the third PNP transistor Q4 provide stable DC bias and voltage amplification factor: the constant current source circuit of the operational amplifier can provide a more stable current output, reducing the influence of factors such as voltage bias and temperature drift on the current. It can drive a larger load resistance and maintain a constant current output.

[0029] Transistor D1 uses a high-performance power reference chip. First, this design can provide a very accurate reference voltage, which helps to improve the accuracy and stability of the system. Secondly, it is less affected by temperature changes and can still maintain stable output under different temperature environments. It is usually manufactured using advanced processes and technologies, has high reliability and durability, and has low output voltage noise, which helps to improve the signal-to-noise ratio of the system.

[0030] By adding capacitor C1 to the constant current source, when the alternating current containing pulsating components passes through the capacitor, the capacitor will be charged in the voltage rising stage to store electric energy; and discharged in the voltage falling stage to supplement the current. This can smooth out voltage fluctuations, filter out the alternating current component, and make the output voltage more stable, thus achieving a filtering effect.

[0031] Further, in another embodiment, the reference voltage adjustment module includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a potentiometer RP1, the collector of the second PNP transistor Q3 is electrically connected to one end of the sixth resistor R6, the other end of the sixth resistor R6 is electrically connected to pin 1 of the potentiometer RP1, pin 3 of the potentiometer RP1 is electrically connected to one end of the seventh resistor R7, pin 2 of the potentiometer RP1 is electrically connected to one end of the eighth resistor R8, and the other end of the eighth resistor R8 is electrically connected to pin 2 of the Hall element H and the emitter of the third PNP transistor Q4, respectively.

[0032] Select the potentiometer RP1 with appropriate resistance and accuracy to adjust the voltage range as needed.

[0033] Resistors R6 and R7 are connected in series to obtain voltage outputs of different proportions through the distribution of voltage by resistors. In practical applications, appropriate adjustments and optimizations need to be made according to specific circuits and requirements.

[0034] Furthermore, in another embodiment, the processing module is a processing circuit A1, and the processing circuit A1 includes an IN1 interface, an IN2 interface, an IN3 interface, and an OUT interface electrically connected, pin 2 of the transistor D1 is electrically connected to the IN3 interface of the processing circuit A1, pin 5 of the second operational amplifier U2 is electrically connected to the IN2 interface of the processing circuit A1, and pin 1 of the Hall element H is electrically connected to the IN1 interface of the processing circuit A1.

[0035] The processing circuit A1 includes three input signals and one output signal, where the input signal is the Hall output voltage difference, the signal ground and a stable reference voltage. The signal processing mainly relies on the operation circuit composed of various levels of operational amplifiers to calculate and output the actual required signal output.

[0036] According to the description and drawings of the present invention, those skilled in the art can easily manufacture or use the Hall element constant current source circuit of the present invention, and can produce the positive effects recorded in the present invention.

[0037] Unless otherwise specified, in the present invention, the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicating orientation or positional relationships are based on the orientation or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the orientation or positional relationship in the present invention are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood in conjunction with the drawings and according to specific circumstances.

[0038] Unless otherwise specified and limited, in the present invention, the terms "disposed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A Hall element constant current source circuit, characterized in that: It includes a constant current control module, a reference voltage adjustment module, a Hall element H and a processing module. The constant current control module is electrically connected to the reference voltage adjustment module, the Hall element H and the processing module respectively.

2. The Hall element constant current source circuit according to claim 1, characterized in that: The constant current control module includes a first operational amplifier U1, a second operational amplifier U2, a first PNP transistor Q1, a second PNP transistor Q3, a third PNP transistor Q4, an NPN transistor Q2, a transistor D1, a capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a ninth resistor R9; Pin 6 of the first operational amplifier U1 is electrically connected to one end of the second resistor R2 and the emitter of the second PNP transistor Q3, respectively; the other end of the second resistor R2 is electrically connected to one end of the first resistor R1, and the other end of the first resistor R1 is electrically connected to pin 5 of the first operational amplifier U1, one end of the third resistor R3, one end of the fourth resistor R4, and one end of the capacitor C1, respectively; the other end of the third resistor R3 is electrically connected to the emitter of the first PNP transistor Q1, and the base of the first PNP transistor Q1 is electrically connected to the other end of the fourth resistor R4 and the collector of the NPN transistor Q2, and the collector of the first PNP transistor Q1 is electrically connected to pin 3 of the transistor D1, the base of the NPN transistor Q2, and the other end of the capacitor C1, respectively; and pin 1 of the transistor D1 is electrically connected to the NPN transistor Q2. The emitter of the transistor Q2 is electrically connected to one end of the fifth resistor R5, and pin 2 of the transistor D1 is electrically connected to the other end of the fifth resistor R5 and one end of the ninth resistor R9 respectively. Pin 7 of the first operational amplifier U1 is electrically connected to the base of the second PNP transistor Q3, and the collector of the second PNP transistor Q3 is electrically connected to pin 4 of the Hall element H. Pin 2 of the Hall element H is electrically connected to the emitter of the third PNP transistor Q4, and the base of the third PNP transistor Q4 is electrically connected to pin 7 of the second operational amplifier U2. The collector of the third PNP transistor Q4 is electrically connected to the other end of the ninth resistor R9, and pin 6 of the second operational amplifier U2 is electrically connected to pin 3 of the Hall element H. Pin 5 of the second operational amplifier U2 is electrically connected to the other end of the seventh resistor R7.

3. The Hall element constant current source circuit according to claim 2, characterized in that: The reference voltage adjustment module includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a potentiometer RP1. The collector of the second PNP transistor Q3 is electrically connected to one end of the sixth resistor R6, the other end of the sixth resistor R6 is electrically connected to pin 1 of the potentiometer RP1, pin 3 of the potentiometer RP1 is electrically connected to one end of the seventh resistor R7, pin 2 of the potentiometer RP1 is electrically connected to one end of the eighth resistor R8, and the other end of the eighth resistor R8 is electrically connected to pin 2 of the Hall element H and the emitter of the third PNP transistor Q4, respectively.

4. The Hall element constant current source circuit according to claim 3, characterized in that: The processing module is a processing circuit A1, and the processing circuit A1 includes an IN1 interface, an IN2 interface, an IN3 interface, and an OUT interface that are electrically connected. Pin 2 of the transistor D1 is electrically connected to the IN3 interface of the processing circuit A1, pin 5 of the second operational amplifier U2 is electrically connected to the IN2 interface of the processing circuit A1, and pin 1 of the Hall element H is electrically connected to the IN1 interface of the processing circuit A1.

Images