Magnetoelectric encoder circuit with protection function

Abstract

The utility model discloses a magnetoelectric encoder circuit with a protection function, which comprises a power supply and protection module, a signal acquisition and encoding module and a signal conditioning and protection module, and is characterized in that the power supply and protection module is electrically connected with an external direct-current power supply and is used for performing input protection and voltage reduction processing on voltage from the external direct-current power supply; the signal acquisition and coding module is electrically connected with an external permanent magnet, acquires a magnetic field signal of the permanent magnet, codes the magnetic field signal to acquire a coded electric signal, and transmits the coded electric signal to the signal conditioning and protecting module to supply power to the signal conditioning and protecting module; and the encoded electric signal is transmitted to the signal conditioning and protecting module, and the signal conditioning and protecting module carries out differential processing and anti-static processing on the encoded electric signal in sequence. According to the utility model, the technical problem that the existing encoder is too large in size and is difficult to be applied to humanoid robot application scenes can be solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to encoder technical field, more specifically, it relates to a kind of magnetoelectric encoder circuit with protection function. BACKGROUND

[0002] With the rapid development of artificial intelligence and robot technology, the encoder has been increasingly widely used.

[0003] However, the existing encoder has some defects that cannot be ignored:

[0004] First, the existing encoder is mostly large in size (usually greater than 30mm in diameter) ;

[0005] Second, the existing encoder is mostly photoelectric encoder, which has high requirements for humidity, dust, etc., making it difficult to apply to humanoid robot application scenarios;

[0006] Third, the existing encoder cannot simultaneously realize input overvoltage protection, surge protection, anti-reverse connection protection and anti-static protection, and has poor reliability;

[0007] Fourth, the existing encoder is prone to differential mode signal and common mode signal interference under the condition of high signal transmission rate due to power fluctuations, ground noise and other factors. INVENTION CONTENTS

[0008] In view of the above defects or improvement needs of the prior art, the utility model provides a magnetoelectric encoder circuit with protection function, which aims to solve the technical problems of the existing encoder, such as large size, difficulty in application to humanoid robot application scenarios, inability to simultaneously realize input overvoltage protection, surge protection, anti-reverse connection protection and anti-static protection, low reliability, and easy to cause differential mode signal and common mode signal interference under the action of power fluctuations, ground noise and other factors.

[0009] To achieve the above purpose, according to one aspect of the utility model, a magnetoelectric encoder circuit with protection function is provided, which includes a power supply and protection module, a signal acquisition and encoding module, and a signal conditioning and protection module. The power supply and protection module is electrically connected with an external DC power supply, performs input protection and voltage reduction processing on the voltage from the external DC power supply, obtains the processed voltage, and transmits the processed voltage to the signal acquisition and encoding module and the signal conditioning and protection module to supply power to the two modules.

[0010] The signal acquisition and encoding module is electrically connected with an external permanent magnet, acquires the magnetic field signal of the permanent magnet, encodes the magnetic field signal, obtains the encoded electrical signal, and transmits the encoded electrical signal to the signal conditioning and protection module.

[0011] The signal conditioning and protection module performs differential processing and anti-static processing on the encoded electrical signal from the signal acquisition and encoding module in sequence to obtain a processed electrical signal.

[0012] Preferably, the power supply and protection module comprises a surge protection circuit, an anti-reverse connection protection circuit, and a low dropout regulator (LDO) voltage reduction circuit.

[0013] The surge protection circuit and the anti-reverse connection protection circuit are connected in parallel, and the anti-reverse connection protection circuit is connected in parallel with the LDO voltage reduction circuit.

[0014] The PVCC end and the GND end of the power supply and protection module are respectively electrically connected with the positive and negative poles of an external DC power supply.

[0015] The surge protection circuit is connected between the PVCC end and the GND end, and performs surge absorption processing on the input voltage of the external DC power supply.

[0016] Preferably, the surge protection circuit comprises a transient voltage suppression (TVS) diode and a first capacitor connected in parallel.

[0017] The model of the TVS diode is SMAJ26A.

[0018] The model of the first capacitor C1 is CGA0805X5R106K350MT.

[0019] Preferably, the anti-reverse connection protection circuit comprises a first metal oxide semiconductor (MOS) transistor, the source of which is connected with the PVCC end of the power supply and protection module, the gate of which is connected with the GND end of the power supply and protection module, and the drain of which is connected with the LDO voltage reduction circuit.

[0020] The first MOS transistor is a PMOS transistor, and the specific model thereof is CJ3401.

[0021] Preferably, the LDO voltage reduction circuit comprises an LDO chip, a second capacitor, and a third capacitor.

[0022] The first pin of the LDO chip is electrically connected with the drain of the first MOS transistor as an input end, and is connected with the GND end of the power supply and protection module through the second capacitor.

[0023] The second pin of the LDO chip is connected with the GND end of the power supply and protection module.

[0024] The third pin of the LDO chip outputs a voltage less than or equal to 5V as an output end, and is connected with the GND end of the power supply and protection module through the second capacitor.

[0025] Preferably, the model of the LDO chip is DIO7709, the input voltage range thereof is +2.5V~+30V, and the output voltage thereof is 3.3V.

[0026] The second and third capacitors are both model number CC0603KRX7R9BB104.

[0027] Preferably, the signal acquisition and encoding module adopts an encoding integrated circuit IC, whose voltage input pin is connected to the 3.3V voltage output by the LDO chip, and whose signal output pin is electrically connected to the signal conditioning and protection module;

[0028] The encoding IC uses a high-precision magnetic angle encoding IC, which detects the magnetic field change of the external permanent magnet through a non-contact detection method to obtain the rotation angle signal or linear displacement signal of the external permanent magnet, and encodes the rotation angle signal or linear displacement signal to obtain the encoded electrical signal.

[0029] Preferably, the encoding IC is MT6701 or KTH7801, which supports both incremental ABZ and absolute SPI signal output.

[0030] Preferably, the signal conditioning and protection module includes a differential IC and an ESD discharge IC connected in series.

[0031] The differential IC model is MS2583;

[0032] The model number of the ESD IC is ESD8004-ES.

[0033] Preferably, the differential IC converts the encoded electrical signal output by the encoding IC into a differential signal, and transmits the differential signal to the ESD IC using a twisted pair cable;

[0034] The ESD IC performs electrostatic discharge (ESD) protection on the differential signal.

[0035] In summary, compared with the prior art, the above-described technical solution conceived by this utility model can achieve the following beneficial effects:

[0036] 1. Because the magnetic encoder circuit of this utility model uses few components, and all components are standard packaged components, it is not only low in cost, but also compact in structure.

[0037] 2. The coding IC of this utility model detects the magnetic field changes of the external permanent magnet through a non-contact detection method, and has strong resistance to pollutants such as dust, oil, and water vapor, and has good environmental adaptability;

[0038] 3. Because the magneto-electric encoder circuit of this utility model adopts input overvoltage protection, surge protection, reverse connection protection and electrostatic protection, it has a wide input voltage range, high fault tolerance during use, and high reliability.

[0039] 4. Because the signal conditioning and protection module of this utility model uses twisted pair cable for signal transmission to eliminate differential mode interference, the signal anti-interference capability is further enhanced. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the circuit structure of the magnetoelectric encoder with protection function of this utility model;

[0041] Figure 2 This is a circuit diagram of the magnetoelectric encoder circuit with protection function of this utility model. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0043] It should be understood that, as used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or other sets.

[0044] Similarly, the terms "upper," "lower," "front," "back," "left," "right," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0045] As used in this article, the terms “installation,” “electrical connection,” and “connection” should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct electrical connections or indirect electrical connections through an intermediate medium.

[0046] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0047] The present invention will now be described in more detail with reference to specific embodiments thereof.

[0048] This invention provides a magnetoelectric encoder circuit with protective functions, which has fewer components and a smaller size compared to a photoelectric encoder; it also has wide voltage range input, surge protection, reverse connection protection and electrostatic discharge protection functions, and has higher reliability than a photoelectric encoder.

[0049] like Figure 1 As shown, this utility model provides a magnetoelectric encoder circuit with protection function, including a power supply and protection module 1, a signal acquisition and encoding module 2, and a signal conditioning and protection module 3.

[0050] The power supply and protection module 1 is electrically connected to an external DC power supply and performs input protection and voltage reduction processing on the voltage from the external DC power supply to obtain a processed voltage (which is +3.3V). The processed voltage is then transmitted to the signal acquisition and encoding module 2 and the signal conditioning and protection module 3 to power them.

[0051] The signal acquisition and encoding module 2 is electrically connected to an external permanent magnet (not shown), acquires the magnetic field signal of the permanent magnet, encodes the magnetic field signal to obtain an encoded electrical signal, and transmits the encoded electrical signal to the signal conditioning and protection module.

[0052] The signal conditioning and protection module 3 performs differential processing and anti-static processing on the encoded electrical signal from the signal acquisition and encoding module 2 to obtain the processed electrical signal.

[0053] like Figure 2 As shown, the power supply and protection module 1 includes a surge protection circuit 101, a reverse connection protection circuit 102, and a low-dropout regulator (LDO) step-down circuit 103. The surge protection circuit 101 and the reverse connection protection circuit 102 are connected in parallel, and the reverse connection protection circuit 102 is connected in parallel with the LDO step-down circuit 103. The PVCC terminal and GND terminal of the power supply and protection module 1 are electrically connected to the positive and negative terminals of the external DC power supply, respectively.

[0054] Surge protection circuit 101 is connected between the PVCC terminal and the GND terminal to absorb surges in the input voltage of the external DC power supply. Surge protection circuit 101 includes a transient voltage suppression diode (TVS) D1 and a first capacitor C1 connected in parallel, wherein the first capacitor C1 serves as a voltage regulator.

[0055] The TVS diode D1 is model SMAJ26A, with a reverse cutoff voltage of +26V. When the input voltage is below 26V, the TVS diode D1 is in a high-impedance state (cutoff state), not affecting the normal operation of the subsequent circuit. When the input voltage is above 26V and reaches the reverse cutoff voltage of the TVS diode D1, the TVS diode D1 will quickly break down, discharging the abnormal overvoltage (such as surge voltage) to ground, and clamping the abnormal overvoltage to a voltage range below 40V, thereby protecting the subsequent circuit from damage by abnormal overvoltage. The first capacitor C1 is model CGA0805X5R106K350MT.

[0056] The reverse connection protection circuit 102 includes a first metal-oxide-semiconductor (MOS) transistor Q1, whose source is connected to the PVCC terminal of the power supply and protection module 1, its gate is connected to the GND terminal of the power supply and protection module 1, and its drain is connected to the LDO step-down circuit 103.

[0057] In one embodiment, the first MOSFET Q1 is a PMOS transistor, specifically model CJ3401. When the positive terminal of the external DC power supply is connected to the PVCC terminal of the power supply and protection module 1 and the negative terminal is connected to the GND terminal of the power supply and protection module 1, if the potential difference between the source and gate of the first MOSFET Q1 exceeds the threshold voltage (in this embodiment, it is equal to 0.6V), the first MOSFET Q1 is turned on, and the subsequent LDO step-down circuit 103 starts to connect the voltage of the PVCC terminal of the power supply and protection module 1. Conversely, when the positive terminal of the power supply is connected to the GND terminal of the power supply and protection module 1 and the negative terminal is connected to the PVCC terminal of the power supply and protection module 1 (i.e., reverse connection), the first MOSFET Q1 is turned off, and the subsequent circuit of the first MOSFET Q1 is in an open circuit state, thereby protecting the overall circuit safety of the magneto-electric encoder circuit of this utility model.

[0058] The LDO step-down circuit 103 includes an LDO chip, a second capacitor C2, and a third capacitor C3. The first pin of the LDO chip is the input terminal, which is electrically connected to the drain of the first MOSFET Q1 and connected to the GND terminal of the power supply and protection module 1 through the second capacitor C2; the second pin of the LDO chip is connected to the GND terminal of the power supply and protection module 1; the third pin of the LDO chip is the output terminal, which outputs a voltage not exceeding 5V and is connected to the GND terminal of the power supply and protection module 1 through the second capacitor C3.

[0059] Specifically, the LDO chip is model DIO7709, with an input voltage range of +2.5V to +30V and an output voltage of 3.3V. The second capacitor C2 and the third capacitor C3 are both model CC0603KRX7R9BB104.

[0060] The signal acquisition and encoding module 2 uses an integrated circuit (IC) for encoding. Its voltage input pin is connected to the 3.3V voltage output by the LDO chip, and its signal output pin is electrically connected to the signal conditioning and protection module 3.

[0061] In this invention, the encoding IC employs a high-precision magnetic angle encoding IC and detects the magnetic field change of the external permanent magnet using a non-contact detection method to obtain the rotation angle signal or linear displacement signal of the external permanent magnet. This rotation angle signal or linear displacement signal is then encoded to obtain the encoded electrical signal. The technical principles include, but are not limited to, the Hall effect, the Anisotropy of Magnetoresistance (AMR) effect, and the Tunnel Magnetoresistance (TMR) effect. The mounting structure includes, but is not limited to, on-axis and off-axis mounting.

[0062] The encoding IC supports either incremental or absolute signal output, or both simultaneously. Incremental signals include, but are not limited to, two-channel AB signals and three-channel ABZ signals. Absolute signals include, but are not limited to, SSI (Synchronous Serial Interface) signals and SPI (Serial Peripheral Interface) signals. In one embodiment, the encoding IC is model MT6701, which can simultaneously support incremental ABZ and absolute SPI signal output; in another embodiment, the encoding IC is model MA732, which can simultaneously support incremental ABZ and absolute SSI signal output.

[0063] The signal conditioning and protection module 3 includes a differential IC 301 and an electrostatic discharge (ESD) IC 302 connected in series, which respectively perform signal differential processing and electrostatic discharge protection.

[0064] The differential IC 301 is model MS2583, and the ESD IC is model ESD8004-ES. The differential IC converts the encoded electrical signal output from the encoding IC into a differential signal and transmits the differential signal to the ESD IC via twisted pair cable (to eliminate differential-mode interference and enhance the anti-interference performance of the differential signal). The ESD IC performs electrostatic discharge (ESD) protection on the differential signal. The ESD IC includes, but is not limited to, low-clamp multiplex unidirectional ESD protection devices and high-speed switching diodes. Regardless of whether low-clamp multiplex unidirectional ESD protection devices or high-speed switching diodes are used, their junction capacitance is very small (less than 10pF), and their impact on the differential signal is minimal.

[0065] In this novel magneto-electric encoder circuit, the rated operating voltage of the encoding IC, differential IC, and ESDIC is typically 3.3V, with a maximum withstand voltage of 6V. However, in practical engineering, situations inevitably arise where the external DC power supply voltage is set too high (e.g., 12V, 24V) or a voltage exceeding 6V is mistakenly connected to the PVCC, potentially burning out the aforementioned three chips and other components. Therefore, without input voltage protection, the input range is only 3.3V to 5.5V, resulting in extremely low fault tolerance. Adding an LDO chip can increase the encoder input voltage to over 24V, significantly improving fault tolerance. The second capacitor C2 and the third capacitor C3 serve to filter and reduce noise, maintain stable output voltage, and improve the transient response of the LDO chip to changes in load current.

[0066] The working principle of this utility model is as follows:

[0067] First, the positive and negative terminals of the external DC power supply are connected to the PVCC and GND terminals of the power supply and protection module 1, respectively, with an input voltage of +3.3V to +26V. This voltage first passes through the surge protection circuit 101, which consists of the first capacitor C1 and the first transient suppression diode connected in parallel. If a surge voltage is present, the surge protection is activated, clamping the input voltage to a stable range (below +40V). Otherwise, the input voltage is input to the source of the first MOSFET Q1. When the voltage difference between the source and gate potentials of the first MOSFET Q1 exceeds the threshold voltage (usually 0.6V), the first MOSFET Q1 is turned on, and the input voltage is connected to the LDO chip. If the positive terminal of the external DC power supply is connected to the GND terminal of the power supply and protection module 1, and the negative terminal is connected to the PVCC terminal of the power supply and protection module 1 (i.e., reverse connection), the first MOSFET Q1 is turned off, and the subsequent circuit of the first MOSFET Q1 is disconnected, thus providing reverse connection protection. When the positive and negative terminals of the external DC power supply are normally connected to the PVCC and GND terminals of the protection module 1, respectively, the input voltage is input to the LDO chip through the first MOSFET Q1. The LDO chip outputs a +3.3V voltage to power the subsequent chips and circuits. At the same time, the second capacitor C2 and the third capacitor C3 play the roles of filtering and noise reduction, maintaining output voltage stability, and improving the transient response of the LDO to changes in load current. That is, the power supply and protection module 1 play the roles of surge protection, reverse connection protection and overvoltage protection.

[0068] When the signal acquisition and encoding module 2 and the signal conditioning and protection module 3 are powered normally (+3.3V), the encoding IC 201 of the signal acquisition and encoding module 2 obtains the rotation angle signal or linear displacement signal of the external permanent magnet by detecting the change of the magnetic field, encodes the rotation angle signal or linear displacement signal, and outputs the encoded electrical signal to the signal conditioning and protection module 3. After differential processing by the signal differential IC 301 and anti-static processing by the ESD IC 302, the anti-static protection of the electrical signal is completed, and the robustness of the electrical signal output is ensured.

[0069] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A magnetoelectric encoder circuit with protection function, comprising a power supply and protection module, a signal acquisition and encoding module, and a signal conditioning and protection module, characterized in that, The power supply and protection module is electrically connected to an external DC power supply. It performs input protection and voltage reduction processing on the voltage from the external DC power supply to obtain the processed voltage, and then transmits the processed voltage to the signal acquisition and encoding module and the signal conditioning and protection module to power them. The signal acquisition and encoding module is electrically connected to an external permanent magnet, acquires the magnetic field signal of the permanent magnet, encodes the magnetic field signal to obtain an encoded electrical signal, and transmits the encoded electrical signal to the signal conditioning and protection module. The signal conditioning and protection module performs differential processing and electrostatic discharge (ESD) processing on the encoded electrical signal from the signal acquisition and encoding module to obtain the processed electrical signal.

2. The magnetoelectric encoder circuit with protection function according to claim 1, characterized in that, The power supply and protection module includes surge protection circuit, reverse connection protection circuit, and low dropout regulator (LDO) step-down circuit. The surge protection circuit and the reverse connection protection circuit are connected in parallel, and the reverse connection protection circuit is connected in parallel with the LDO step-down circuit; The PVCC and GND terminals of the power supply and protection module are electrically connected to the positive and negative terminals of the external DC power supply, respectively. The surge protection circuit is connected between the PVCC terminal and the GND terminal to absorb surges in the input voltage of the external DC power supply.

3. The magnetoelectric encoder circuit with protection function according to claim 2, characterized in that, The surge protection circuit includes a transient suppression TVS diode and a first capacitor connected in parallel; The TVS diode model is SMAJ26A; The first capacitor C1 is model CGA0805X5R106K350MT.

4. The magnetoelectric encoder circuit with protection function according to claim 3, characterized in that, The reverse connection protection circuit includes a first metal-oxide-semiconductor MOSFET, whose source is connected to the PVCC terminal of the power supply and protection module, its gate is connected to the GND terminal of the power supply and protection module, and its drain is connected to the LDO step-down circuit. The first MOSFET is a PMOS transistor, specifically model CJ3401.

5. The magnetoelectric encoder circuit with protection function according to claim 4, characterized in that, The LDO step-down circuit includes an LDO chip, a second capacitor, and a third capacitor; The first pin of the LDO chip is connected to the drain of the first MOSFET as an input terminal, and is connected to the power supply and the GND terminal of the protection module through the second capacitor. The second pin of the LDO chip is connected to the GND terminal of the power supply and protection module; The third pin of the LDO chip is used as the output terminal to output a voltage of less than or equal to 5V, which is then connected to the GND terminal of the power supply and protection module through the second capacitor.

6. The magnetoelectric encoder circuit with protection function according to claim 5, characterized in that, The LDO chip is model DIO7709, with an input voltage range of +2.5V to +30V and an output voltage of 3.3V. The second and third capacitors are both model number CC0603KRX7R9BB104.

7. The magnetoelectric encoder circuit with protection function according to claim 6, characterized in that, The signal acquisition and encoding module uses an encoding integrated circuit (IC). Its voltage input pin is connected to the 3.3V voltage output by the LDO chip, and its signal output pin is electrically connected to the signal conditioning and protection module. The encoding IC uses a high-precision magnetic angle encoding IC, which detects the magnetic field change of the external permanent magnet through a non-contact detection method to obtain the rotation angle signal or linear displacement signal of the external permanent magnet, and encodes the rotation angle signal or linear displacement signal to obtain the encoded electrical signal.

8. The magnetoelectric encoder circuit with protection function according to claim 7, characterized in that, The encoding IC is either MT6701 or KTH7801, which supports both incremental ABZ and absolute SPI signal output.

9. The magnetoelectric encoder circuit with protection function according to claim 8, characterized in that, The signal conditioning and protection module includes differential ICs and electrostatic discharge (ESDIC) components connected in series. The differential IC model is MS2583; The ESDIC model number is ESD8004-ES.

10. The magnetoelectric encoder circuit with protection function according to claim 9, characterized in that, The differential IC converts the encoded electrical signal output by the encoding IC into a differential signal, and transmits the differential signal to the ESD IC using a twisted pair cable. The ESD IC performs electrostatic discharge (ESD) protection on the differential signal.

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