Sampling conditioning and protecting circuit, sensing device and gearbox

Abstract

The utility model relates to a sampling conditioning and protecting circuit, a sensing device and a gearbox. A signal input end of the sampling conditioning and protection circuit is used for receiving a current signal of a to-be-tested device, and the sampling conditioning and protection circuit comprises a conversion circuit which is connected with the signal input end so as to convert the current signal into a voltage signal; the conditioning circuit is connected with the conversion circuit and is used for conditioning the voltage signal into a square wave level signal which can be identified by an external controller and outputting the square wave level signal to the external controller; the protection circuit is connected with the conversion circuit, and the protection circuit is switched on when the signal input end has a power supply short-circuit fault so as to control the voltage at the two ends of the conversion circuit to be within a safe voltage range; according to the embodiment of the invention, the load resistor is protected when the signal input end has a power supply short-circuit fault, so that the load resistor can be prevented from selecting a relatively large package, and the model selection cost of the load resistor is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of gearboxes, and in particular to a sampling conditioning and protection circuit, a sensor device and a gearbox. Background Art

[0002] In the current automotive market, Hall effect speed sensors are mostly used to sense the gear speed and steering of the gearbox shaft. The Hall effect speed sensor can output current square waves of different frequencies and pulse widths to characterize the gear speed and steering of the gearbox shaft. Usually, in the process of the microcontroller acquiring the current square wave, a load resistor and a sampling and conditioning circuit need to be added to convert the current square wave into a square wave level signal that the microcontroller can recognize; at the same time, due to the internal chip junction temperature limit of the Hall effect speed sensor, the power supply voltage of the Hall effect speed sensor is generally provided by a low-voltage power supply. In related technologies, in order to avoid the input of the sampling and conditioning circuit being short-circuited to the low-voltage power supply and damaging the load resistor, the load resistor needs to select a relatively large package, which increases the cost of load resistor selection. Utility Model Content

[0003] Based on this, it is necessary to provide a sampling conditioning and protection circuit, a sensor device and a gearbox.

[0004] In a first aspect, an embodiment of the present application provides a sampling conditioning and protection circuit, wherein a signal input terminal of the sampling conditioning and protection circuit is used to receive a current signal of a device under test, and the sampling conditioning and protection circuit comprises:

[0005] A conversion circuit, connected to the signal input terminal, to convert the current signal into a voltage signal;

[0006] A conditioning circuit connected to the conversion circuit, wherein the protection circuit conditions the voltage signal into a square wave level signal recognizable by an external controller, and outputs the square wave level signal to the external controller to instruct the external controller to read information carried by the current signal according to the square wave level signal;

[0007] The protection circuit is connected to the conversion circuit to be turned on when a short circuit fault occurs to the power supply at the signal input end, so as to control the voltage at both ends of the conversion circuit to be within a safe voltage range.

[0008] In one embodiment, the protection circuit comprises:

[0009] A first sampling circuit, connected to the conversion circuit, to divide the voltage signal to obtain a first sampling signal;

[0010] A first switch circuit is connected to the first sampling circuit and is controlled to be on and off based on the strength of the first divided voltage signal and the first sampling signal received;

[0011] A second sampling circuit is connected to the power supply signal and is connected to the first switch circuit to divide the power supply signal to obtain a second sampling signal;

[0012] The second switch circuit is connected to the conversion circuit and the second sampling circuit respectively, and is turned on or off as the first switch circuit is turned on based on the received second sampling signal, so as to control the voltage across the conversion circuit within a safe voltage range.

[0013] In one embodiment, the first sampling circuit includes a first resistor and a second resistor, the second sampling circuit includes a third resistor and a fourth resistor, the first switch circuit includes a first transistor, and the second switch circuit includes a second transistor;

[0014] A first end of the first resistor is connected to the conversion circuit, a second end of the first resistor is connected to a first end of the second resistor, and a second end of the second resistor is grounded;

[0015] The first end of the third resistor is connected to the power signal, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is grounded;

[0016] The control end of the first transistor is connected to the second end of the first resistor, the first end of the first transistor is connected to the second end of the third resistor, and the second end of the first transistor is grounded;

[0017] The control end of the second transistor is connected to the second end of the third resistor, the first end of the second transistor is connected to the conversion circuit, and the second end of the second transistor is grounded;

[0018] When a short circuit fault to the power supply occurs at the signal input terminal, the first transistor is turned on and the second transistor is turned off, so as to control the voltage at both ends of the conversion circuit to be within a safe voltage range.

[0019] In one embodiment, the sampling conditioning and protection circuit further includes:

[0020] The diagnostic circuit is connected to the conversion circuit and the protection circuit respectively to convert the voltage signal into an analog voltage signal, and output the analog voltage signal to the external controller to instruct the external controller to diagnose whether a short circuit to ground or a short circuit to power occurs at the signal input terminal according to the analog voltage signal.

[0021] In one embodiment, the diagnostic circuit includes a fifth resistor, a sixth resistor and a first capacitor;

[0022] The first end of the fifth resistor is connected to the conversion circuit and the protection circuit respectively, and the second end of the fifth resistor is used to connect to the external controller;

[0023] The first end of the sixth resistor is connected to the first end of the fifth resistor, and the second end of the sixth resistor is grounded;

[0024] The first end of the first capacitor is connected to the second end of the fifth resistor, and the second end of the first capacitor is connected to the second end of the sixth resistor.

[0025] In one embodiment, the sampling conditioning and protection circuit further includes:

[0026] A reset circuit is connected to the protection circuit to receive a reset signal sent by the external controller when the external controller diagnoses that a short circuit fault to the power supply occurs at the signal input terminal, and controls the protection circuit to shut down according to the reset signal so that the protection circuit stops controlling the voltage at both ends of the conversion circuit, so that the external controller can diagnose again whether a short circuit fault to the power supply occurs at the signal input terminal.

[0027] In one embodiment, the reset circuit includes a seventh resistor and a third transistor;

[0028] The first end of the third transistor is connected to the protection circuit, the second end of the third transistor is grounded, and the control end of the third transistor is used to connect to the external controller;

[0029] A first end of the seventh resistor is connected to the control end of the third transistor, and a second end of the seventh resistor is grounded.

[0030] In one embodiment, the conditioning circuit includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor and a first comparator;

[0031] A first end of the eighth resistor is connected to the conversion circuit, and a second end of the eighth resistor is connected to the first input end of the first comparator;

[0032] The first end of the ninth resistor is connected to the power signal, the second end of the ninth resistor is connected to the first end of the tenth resistor, and the second end of the tenth resistor is grounded;

[0033] The second input terminal of the first comparator is connected to the second terminal of the ninth resistor, the output terminal of the first comparator is connected to the first terminal of the eleventh resistor, and the second terminal of the eleventh resistor is used to connect to the external controller;

[0034] A first end of the twelfth resistor is connected to the output end of the first comparator, and a second end of the twelfth resistor is connected to the power signal.

[0035] In a second aspect, an embodiment of the present application provides a sensor device, which includes a Hall speed sensor and a sampling conditioning and protection circuit as provided in any of the above embodiments, wherein the signal input end of the sampling conditioning and protection circuit is connected to the Hall speed sensor, and the Hall speed sensor is used to sample the current signal of the device under test and output the sampled current signal to the signal input end.

[0036] In a third aspect, an embodiment of the present application provides a gearbox, which includes an external controller and a sensor device as provided in the above embodiment; the external controller is connected to the sampling conditioning and protection circuit.

[0037] In one embodiment, the sampling conditioning and protection circuit includes a reset circuit, and the reset circuit is connected to the protection circuit;

[0038] Wherein, when the external controller diagnoses that a short circuit fault to the power supply occurs at the signal input terminal, it sends a reset signal, so that the reset circuit controls the protection circuit to shut down according to the reset signal, so that the protection circuit stops controlling the voltage at both ends of the conversion circuit, and then the external controller diagnoses again whether a short circuit fault to the power supply occurs at the signal input terminal; wherein, when the external controller sends the reset signal twice and the corresponding two diagnosis results are both that a short circuit fault to the power supply occurs at the signal input terminal, the external controller determines that a short circuit fault to the power supply occurs at the signal input terminal and reports the fault.

[0039] The above-mentioned sampling conditioning and protection circuit, sensor device and gearbox, wherein the signal input end of the sampling conditioning and protection circuit is used to receive the sampling current signal of the device to be tested, the device to be tested is, for example, a gearbox shaft gear, the sampling conditioning and protection circuit includes a conversion circuit, a conditioning circuit and a protection circuit; the conversion circuit is connected to the signal input end, the conversion circuit converts the current signal into a voltage signal, the conversion circuit is, for example, a load resistor, that is, the current signal is converted into a voltage signal through the load resistor.

[0040] The conditioning circuit is connected to the conversion circuit. The conditioning circuit conditions the voltage signal into a square wave level signal that can be recognized by an external controller, and outputs the square wave level signal to the external controller. The external controller is, for example, a single-chip microcomputer. The embodiment of the present application thereby realizes the conversion from the voltage signal to the square wave level signal that can be recognized by the single-chip microcomputer, ensuring that the single-chip microcomputer can identify the speed and direction of the gearbox shaft gear according to the square wave level signal. At the same time, the protection circuit is connected to the conversion circuit. The protection circuit is turned on when a short circuit fault occurs to the power supply at the signal input end, so as to control the voltage at both ends of the conversion circuit to a safe voltage range, for example, to control the voltage at both ends of the conversion circuit to about 0V. The embodiment of the present application thereby realizes the protection of the load resistor when a short circuit fault occurs to the power supply at the signal input end. While avoiding damage to the load resistor, it can also avoid selecting a relatively large package for the load resistor, thereby reducing the selection cost of the load resistor; and the sampling conditioning and protection circuit provided in the embodiment of the present application has a simple structure, low cost, easy implementation, and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 One of the circuit diagrams of a sampling conditioning and protection circuit in one embodiment;

[0043] Figure 2 The second circuit diagram of the sampling conditioning and protection circuit in one embodiment;

[0044] Figure 3 The third circuit diagram of a sampling conditioning and protection circuit in one embodiment;

[0045] Figure 4 is a circuit diagram of a sensor device in one embodiment;

[0046] Figure 5 FIG. 4 is a circuit diagram of a gearbox in one embodiment.

[0047] Explanation of the accompanying drawings: A-signal input terminal, R13-load resistor, 110-conversion circuit, 120-conditioning circuit, 130-protection circuit, 140-diagnostic circuit, 150-reset circuit, 131-first sampling circuit, 132-first switching circuit, 133-second sampling circuit, 134-second switching circuit, R1-first resistor, R2-second resistor, R3-third resistor, R4-fourth resistor, R5-fifth resistor, R6-sixth resistor, R7-seventh resistor, R8-eighth resistor, R9-ninth resistor, R10-tenth resistor, R11-eleventh resistor, R12-twelfth resistor, C1-first capacitor, U1-first comparator, Q1-first transistor, Q2-second transistor, Q3-third transistor. DETAILED DESCRIPTION

[0048] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0050] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor R1 may be referred to as a second resistor R2, and similarly, a second resistor R2 may be referred to as a first resistor R1. Both the first resistor R1 and the second resistor R2 are resistors, but they are not the same resistor.

[0051] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0052] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least a portion of an element” means a part or all of an element.

[0053] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0054] The sampling conditioning and protection circuit provided in the embodiments of the present application can be applied to sensors, such as Hall effect speed sensors, which can be used to sense the gear speed and steering of automobile transmission shafts.

[0055] In one embodiment, Figure 1 As shown, the signal input terminal A of the sampling conditioning and protection circuit is used to receive the current signal of the device under test. The device under test is, for example, a shaft gear of an automobile transmission. The signal input terminal A can be connected to a Hall effect speed sensor, and the Hall effect speed sensor outputs the sampled current square wave of the shaft gear of the automobile transmission to the signal input terminal A.

[0056] Continue to refer Figure 1 The sampling conditioning and protection circuit includes a conversion circuit 110 , a conditioning circuit 120 and a protection circuit 130 .

[0057] The conversion circuit 110 is connected to the signal input terminal A to convert the current signal into a voltage signal VIN.

[0058] The conversion circuit 110 may be a load resistor R13. The current signal is converted into a voltage signal VIN through the load resistor R13.

[0059] The conditioning circuit 120 is connected to the conversion circuit 110 to be connected to an external controller, and conditions the voltage signal VIN into a square wave level signal SIG that can be recognized by the external controller, and outputs the square wave level signal SIG to the external controller.

[0060] The external controller may be a single-chip microcomputer, which is a control chip of a gearbox or a main control chip of other controllers. Exemplarily, the conditioning circuit 120 may condition the voltage signal VIN into a square wave level signal SIG that can be recognized by the single-chip microcomputer, and the conditioning circuit 120 outputs the square wave level signal SIG to a GPIO port of the single-chip microcomputer, ensuring that the single-chip microcomputer can recognize the speed and direction of the gearbox shaft gear according to the square wave level signal SIG, and the single-chip microcomputer can determine the speed and direction of the gearbox shaft gear according to the frequency and pulse width time of the square wave level signal SIG.

[0061] The protection circuit 130 is connected to the conversion circuit 110 . When a short circuit fault occurs to the power supply at the signal input terminal A, the protection circuit 130 is turned on to control the voltage at both ends of the conversion circuit 110 to be within a safe voltage range.

[0062] Among them, the protection circuit 130 includes two states: on and off. The on state of the protection circuit 130 can also be understood as the protection circuit 130 working, and the off state of the protection circuit 130 can also be understood as the protection circuit not working. When the protection circuit 130 is in the on state, the protection circuit 130 can control the voltage at both ends of the conversion circuit 110 to within a safe voltage range, for example, to about 0V, so as to achieve the purpose of protecting the conversion circuit 110. When the protection circuit 130 is off, the protection circuit 130 stops controlling the voltage at both ends of the conversion circuit 110, that is, the protection circuit 130 does not control the voltage at both ends of the conversion circuit 110. It can be understood that when a short circuit fault occurs to the power supply at the signal input terminal A, the excessive voltage signal VIN turns on the protection circuit 130, and the protection circuit 130 controls the voltage at both ends of the conversion circuit 110 to about 0V, so as to achieve the purpose of protecting the conversion circuit 110. When there is no short circuit fault to the power supply at the signal input terminal A, the smaller voltage signal VIN is insufficient to turn on the protection circuit 130, and the protection circuit 130 is in the off state. The protection circuit 130 does not control the voltage at both ends of the conversion circuit 110, and the conversion circuit 110 performs normal conversion from the current signal to the voltage signal VIN.

[0063] The sampling conditioning and protection circuit provided in the embodiment of the present application, the conversion circuit 110 converts the current signal output by the Hall effect speed sensor into a voltage signal VIN; the conditioning circuit 120 conditions the voltage signal VIN into a square wave level signal SIG that can be recognized by the single-chip microcomputer, ensuring that the single-chip microcomputer can identify the speed and direction of the gearbox shaft gear according to the square wave level signal SIG, and the protection circuit 130 controls the voltage across the conversion circuit 110 to a safe voltage range when a short circuit fault occurs to the power supply at the signal input terminal A, thereby achieving the purpose of protecting the conversion circuit 110, thereby avoiding damage to the load resistor R13 and avoiding the load resistor R13 from selecting a relatively large package, thereby reducing the selection cost of the load resistor R13; and the sampling conditioning and protection circuit provided in the embodiment of the present application has a simple structure, low cost, easy implementation, and strong practicality.

[0064] In one embodiment, continue to refer to Figure 1 The protection circuit 130 includes a first sampling circuit 131 , a first switch circuit 132 , a second sampling circuit 133 and a second switch circuit 134 .

[0065] The first sampling circuit 131 is connected to the conversion circuit 110 to divide the voltage signal VIN to obtain a first sampling signal. The first switch circuit 132 is connected to the first sampling circuit 131, and is controlled to be on and off based on the strength of the received first sampling signal. Among them, when there is no short circuit fault to the power supply at the signal input terminal A, the smaller first sampling signal is not enough to turn on the first switch circuit 132, and the first switch circuit 132 is in the off state, which can be understood as the protection circuit 130 is in the off state. When a short circuit fault to the power supply occurs at the signal input terminal A, the excessive first sampling signal causes the first switch circuit 132 to be turned on, which can be understood as the protection circuit 130 being turned on.

[0066] The second sampling circuit 133 receives the power signal and is connected to the first switch circuit 132 to divide the power signal to obtain a second sampling signal. The second switch circuit 134 is connected to the conversion circuit 110 and the second sampling circuit 133 respectively, and is turned on or off when the first switch circuit 132 is turned on based on the received second sampling signal to control the voltage across the conversion circuit 110 to a safe voltage range.

[0067] The voltage of the power signal may be 5V. When the signal input terminal A does not have a short circuit fault to the power supply, the second switch circuit 134 is in a conducting state based on the second sampling signal as the first switch circuit 132 is turned off, ensuring that the conversion circuit 110 performs normal conversion of the current signal to the voltage signal VIN, that is, the current signal is converted into the voltage signal VIN through the load resistor R13. When a short circuit fault to the power supply occurs at the signal input terminal A, the second switch circuit 134 is turned off based on the second sampling signal as the first switch circuit 132 is turned on, so that the voltage across the conversion circuit 110 is about 0V, thereby achieving the purpose of protecting the conversion circuit 110.

[0068] In one embodiment, continue to refer to Figure 1 The first sampling circuit 131 includes a first resistor R1 and a second resistor R2, the second sampling circuit 133 includes a third resistor R3 and a fourth resistor R4, the first switch circuit 132 includes a first transistor Q1, and the second switch circuit 134 includes a second transistor Q2.

[0069] A first end of the first resistor R1 is connected to the conversion circuit 110, a second end of the first resistor R1 is connected to a first end of the second resistor R2, and a second end of the second resistor R2 is grounded GND; a first end of the third resistor R3 is connected to a first end of the fourth resistor R4, and a second end of the fourth resistor R4 is grounded GND; a control end of the first transistor Q1 is connected to a second end of the first resistor R1, a first end of the first transistor Q1 is connected to a second end of the third resistor R3, and a second end of the first transistor Q1 is grounded GND; a control end of the second transistor Q2 is connected to a second end of the third resistor R3, a first end of the second transistor Q2 is connected to the conversion circuit 110, and a second end of the second transistor Q2 is grounded GND.

[0070] The second resistor R2 constitutes a GS pull-down circuit of the first transistor Q1, and the voltage signal VIN is divided by the first resistor R1 and the second resistor R2 to obtain a first sampling signal, and the first sampling signal constitutes the gate drive voltage VGS1 of the first transistor Q1. The fourth resistor R4 constitutes a GS pull-down circuit of the second transistor Q2, and the power signal is divided by the third resistor R3 and the fourth resistor R4 to obtain a second sampling signal, and the second sampling signal constitutes the gate drive voltage VGS2 of the second transistor Q2.

[0071] When there is no short circuit fault to the power supply at the signal input terminal A, the voltage signal VIN is less than the turn-on threshold voltage of the first transistor Q1, so the gate drive voltage VGS1 of the first transistor Q1 is less than the turn-on threshold voltage of the first transistor Q1, and the first transistor Q1 is turned off. At the same time, the gate drive voltage VGS2 of the second transistor Q2 is greater than the turn-on threshold voltage of the second transistor Q2, and the second transistor Q2 is turned on. In this case, it can be considered that the protection circuit 130 is turned off, that is, the protection circuit 130 does not control the voltage across the conversion circuit 110, ensuring that the conversion circuit 110 performs normal conversion from the current signal to the voltage signal VIN.

[0072] When a short circuit fault occurs to the power supply at the signal input terminal A, the voltage VGS1 of the voltage division between the first resistor R1 and the second resistor R2 is greater than the turn-on threshold voltage of the first transistor Q1, and the first transistor Q1 is turned on, which lowers the gate drive voltage VGS2 of the second transistor Q2, and the second transistor Q2 is turned off, that is, the protection circuit 130 is turned on, so that the voltage across the conversion circuit 110 is about 0V, thereby achieving the purpose of protecting the conversion circuit 110.

[0073] In one embodiment, Figure 2 As shown, the sampling conditioning and protection circuit also includes a diagnostic circuit 140 .

[0074] The diagnostic circuit 140 is connected to the conversion circuit 110 and the protection circuit 130 respectively to convert the voltage signal into an analog voltage signal V_DIAG, and output the analog voltage signal V_DIAG to an external controller to instruct the external controller to diagnose whether a short circuit fault to ground or a short circuit fault to power occurs at the signal input terminal A according to the analog voltage signal V_DIAG.

[0075] Among them, the external controller may store a short-circuit to ground threshold and a short-circuit to power supply threshold, and the external controller may be configured to: determine whether a short-circuit to ground fault occurs at the signal input terminal A according to the analog voltage signal V_DIAG and the short-circuit to ground threshold, for example, if the analog voltage signal V_DIAG is less than the short-circuit to ground threshold, it is determined that a short-circuit to ground fault occurs at the signal input terminal A; determine whether a short-circuit to power supply fault occurs at the signal input terminal A according to the analog voltage signal V_DIAG and the short-circuit to power supply threshold, for example, if the analog voltage signal V_DIAG is greater than or equal to the short-circuit to power supply threshold, it is determined that a short-circuit to power supply fault occurs at the signal input terminal A. When the external controller diagnoses that a short-circuit to ground fault or a short-circuit to power supply fault occurs at the signal input terminal A, the external controller may report the fault to the administrator so that the administrator can solve the fault in time or upload the fault to be stored in a log.

[0076] In one embodiment, continue to refer to Figure 2 , the diagnosis circuit 140 includes a fifth resistor R5, a sixth resistor R6 and a first capacitor C1.

[0077] The first end of the fifth resistor R5 is connected to the conversion circuit 110 and the protection circuit 130 respectively, and the second end of the fifth resistor R5 is used to connect to the external controller; the first end of the sixth resistor R6 is connected to the first end of the fifth resistor R5, and the second end of the sixth resistor R6 is grounded GND; the first end of the first capacitor C1 is connected to the second end of the fifth resistor R5, and the second end of the first capacitor C1 is connected to the second end of the sixth resistor R6.

[0078] The voltage signal VIN is first divided by the fifth resistor R5 and the sixth resistor R6, and then passes through a first-order RC filter circuit composed of the fifth resistor R5 and the first capacitor C1 to be converted into an analog voltage signal V_DIAG and output to an ADC port of the microcontroller.

[0079] In one embodiment, Figure 3 As shown, the sampling conditioning and protection circuit further includes a reset circuit 150 .

[0080] The reset circuit 150 is connected to the protection circuit 130. The reset circuit 150 is used to connect to an external controller and to receive a reset signal RESET sent by the external controller when the external controller diagnoses that a short circuit fault occurs at the signal input terminal A to the power supply, and to control the protection circuit 130 to shut down according to the reset signal RESET, so that the protection circuit 130 stops controlling the voltage at both ends of the conversion circuit 110, so that the external controller can diagnose again whether a short circuit fault occurs at the signal input terminal A to the power supply.

[0081] Among them, the reset signal RESET can be output by another GPIO port of the external controller. In order to avoid the interference signal causing the misdiagnosis of the short circuit fault of the signal input terminal A to the power supply, the reset circuit 150 is set. When the external controller diagnoses that the signal input terminal A has a short circuit fault to the power supply, in order to avoid the misdiagnosis caused by the interference signal, the external controller sends a reset signal RESET to the reset circuit 150, and the reset circuit 150 controls the protection circuit 130 to turn off according to the reset signal RESET, and the protection circuit 130 does not control the voltage at both ends of the conversion circuit 110, and the conversion circuit 110 performs the normal current signal to voltage signal VIN conversion work, so that the external controller again diagnoses whether the signal input terminal A has a short circuit fault to the power supply according to the analog voltage signal V_DIAG and the short circuit to the power supply threshold.

[0082] Each time the external controller sends a reset signal RESET, the corresponding external controller diagnoses once more whether a short circuit fault to the power supply occurs at the signal input terminal A. When the external controller sends the reset signal RESET once or twice, and the corresponding first or second diagnosis result is that the signal input terminal A does not have a short circuit fault to the power supply, it means that the analog voltage signal V_DIAG recovers to the normal voltage range during the reset process, the signal input terminal A is disturbed by the signal, and the signal input terminal A does not actually have a short circuit fault to the power supply, and the external controller does not report or upload the fault. When the external controller sends the reset signal RESET twice, and the corresponding two diagnosis results are that the signal input terminal A has a short circuit fault to the power supply, the external controller determines that the signal input terminal A has a short circuit fault to the power supply and reports or uploads the fault.

[0083] In one embodiment, continue to refer to Figure 3 , the reset circuit 150 includes a seventh resistor R7 and a third transistor Q3.

[0084] The first end of the third transistor Q3 is connected to the protection circuit 130, the second end of the third transistor Q3 is grounded GND, and the control end of the third transistor Q3 is used to connect to an external controller; the first end of the seventh resistor R7 is connected to the control end of the third transistor Q3, and the second end of the seventh resistor R7 is grounded GND.

[0085] Among them, the seventh resistor R7 constitutes a pull-down circuit between GS of the third transistor Q3, and the driving voltage of the third transistor Q3 is the reset signal RESET. When the external controller does not diagnose that the signal input terminal A has a short circuit fault to the power supply, the reset signal RESET is at a low level, and the third transistor Q3 is turned off. When the external controller diagnoses that the signal input terminal A has a short circuit fault to the power supply, in order to avoid misdiagnosis caused by interference signals, the external controller sends a reset signal RESET to the reset circuit 150, with a pulse length of 1ms, and the first transistor Q1 is turned on to pull down VGS1, so that the voltage of VGS2 is restored, and the second transistor Q2 is turned on, and the conversion circuit 110 performs normal conversion work from the current signal to the voltage signal VIN, so that the external controller can diagnose again whether the signal input terminal A has a short circuit fault to the power supply.

[0086] In one embodiment, continue to refer to Figure 3 The conditioning circuit 120 includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12 and a first comparator U1.

[0087] A first end of the eighth resistor R8 is connected to the conversion circuit 110, and a second end of the eighth resistor R8 is connected to a first input end of the first comparator U1; a first end of the ninth resistor R9 is connected to a power signal, a second end of the ninth resistor R9 is connected to a first end of a tenth resistor R10, and a second end of the tenth resistor R10 is grounded GND; a second input end of the first comparator U1 is connected to a second end of the ninth resistor R9, an output end of the first comparator U1 is connected to a first end of an eleventh resistor R11, and a second end of the eleventh resistor R11 is used to connect to an external controller; a first end of the twelfth resistor R12 is connected to an output end of the first comparator U1, and a second end of the twelfth resistor R12 is connected to a power signal.

[0088] Among them, the first input terminal of the first comparator U1 can be the positive input terminal of the first comparator U1, and the second input terminal of the first comparator U1 can be the negative input terminal of the first comparator U1. The eighth resistor R8 constitutes the current limiting resistor of the first input terminal of the first comparator U1, the ninth resistor R9 and the tenth resistor R10 divide the voltage to provide the threshold voltage VREF of the second input terminal of the first comparator U1, the eleventh resistor R11 constitutes the output current limiting resistor of the first comparator U1, and the twelfth resistor R12 constitutes the output pull-up resistor of the first comparator U1, and the pull-up level is 5V. When the voltage signal VIN is greater than the threshold voltage VREF, the square wave level signal SIG is a 5V high level, and when the voltage signal VIN is less than the threshold voltage VREF, the square wave level signal SIG is a 0V low level, so that the square wave level signal SIG is a signal that can be recognized by the single-chip microcomputer.

[0089] The following continues to refer to Figure 3, the working principle of the sampling conditioning and protection circuit provided in the embodiment of the present application is explained again:

[0090] The signal input terminal A receives the current signal output by the Hall effect speed sensor.

[0091] The load resistor R13 converts the current signal into a voltage signal VIN.

[0092] The eighth resistor R8 constitutes a current limiting resistor of the positive input terminal + of the first comparator U1, the ninth resistor R9 and the tenth resistor R10 divide the voltage to provide a threshold voltage VREF of the negative input terminal - of the first comparator U1, the eleventh resistor R11 constitutes an output current limiting resistor of the first comparator U1, and the twelfth resistor R12 constitutes an output pull-up resistor of the first comparator U1, and the pull-up level is 5V. When the voltage signal VIN is greater than the threshold voltage VREF, the square wave level signal SIG is a high level of 5V, and when the voltage signal VIN is less than the threshold voltage VREF, the square wave level signal SIG is a low level of 0V, so that the square wave level signal SIG is a signal recognizable by the single-chip microcomputer, and the square wave level signal SIG can be output to a GPIO port of the single-chip microcomputer, and the single-chip microcomputer can determine the speed and direction of the gear of the gearbox shaft according to the frequency and pulse width time of the square wave level signal SIG.

[0093] The second resistor R2 forms a GS pull-down circuit of the first transistor Q1, and the voltage signal VIN is divided by the first resistor R1 and the second resistor R2 to obtain a first sampling signal, and the first sampling signal constitutes the gate drive voltage VGS1 of the first transistor Q1. The fourth resistor R4 forms a GS pull-down circuit of the second transistor Q2, and the power signal is divided by the third resistor R3 and the fourth resistor R4 to obtain a second sampling signal, and the second sampling signal constitutes the gate drive voltage VGS2 of the second transistor Q2.

[0094] When there is no short circuit fault to the power supply at the signal input terminal A, the voltage signal VIN is less than the turn-on threshold voltage of the first transistor Q1, so the gate drive voltage VGS1 of the first transistor Q1 is less than the turn-on threshold voltage of the first transistor Q1, and the first transistor Q1 is turned off. At the same time, the gate drive voltage VGS2 of the second transistor Q2 is greater than the turn-on threshold voltage of the second transistor Q2, and the second transistor Q2 is turned on. The load resistor R13 performs normal conversion from the current signal to the voltage signal VIN.

[0095] When a short circuit fault occurs to the power supply at the signal input terminal A, the voltage VGS1 divided by the first resistor R1 and the second resistor R2 is greater than the turn-on threshold voltage of the first transistor Q1, and the first transistor Q1 is turned on, pulling down the gate drive voltage VGS2 of the second transistor Q2, and the second transistor Q2 is turned off, so that the voltage across the load resistor R13 is about 0V, thereby achieving the purpose of protecting the load resistor R13.

[0096] In addition, the voltage signal VIN is first divided by the fifth resistor R5 and the sixth resistor R6, and then passes through a first-order RC filter circuit formed by the fifth resistor R5 and the first capacitor C1 to be converted into an analog voltage signal V_DIAG and output to an ADC port of the microcontroller.

[0097] The external controller may store a short-circuit to ground threshold and a short-circuit to power supply threshold. The external controller may determine whether a short-circuit to ground fault occurs at the signal input terminal A based on the analog voltage signal V_DIAG and the short-circuit to ground threshold. For example, if the analog voltage signal V_DIAG is less than the short-circuit to ground threshold, it is determined that a short-circuit to ground fault occurs at the signal input terminal A. The external controller may also determine whether a short-circuit to power supply fault occurs at the signal input terminal A based on the analog voltage signal V_DIAG and the short-circuit to power supply threshold. For example, if the analog voltage signal V_DIAG is greater than or equal to the short-circuit to power supply threshold, it is determined that a short-circuit to power supply fault occurs at the signal input terminal A. When the external controller diagnoses that a short-circuit to ground fault or a short-circuit to power supply fault occurs at the signal input terminal A, the external controller may report the fault to the administrator so that the administrator can solve the fault in time or upload the fault to be stored in a log.

[0098] The seventh resistor R7 constitutes a pull-down circuit between GS of the third transistor Q3, and the driving voltage of the third transistor Q3 is the reset signal RESET. When the external controller does not diagnose that the signal input terminal A has a short circuit fault to the power supply, the reset signal RESET is at a low level, and the third transistor Q3 is turned off. When the external controller diagnoses that the signal input terminal A has a short circuit fault to the power supply, in order to avoid misdiagnosis caused by interference signals, another GPIO port of the external controller sends a reset signal RESET with a pulse length of 1ms, so that the first transistor Q1 is turned on to pull down VGS1, so that the voltage of VGS2 is restored, the second transistor Q2 is turned on, and the load resistor R13 performs a normal conversion work from the current signal to the voltage signal VIN, so that the external controller can diagnose again whether the signal input terminal A has a short circuit fault to the power supply.

[0099] Each time the external controller sends a reset signal RESET, the corresponding external controller diagnoses once more whether a short circuit fault to the power supply occurs at the signal input terminal A. When the external controller sends the reset signal RESET once or twice, and the corresponding first or second diagnosis result is that the signal input terminal A does not have a short circuit fault to the power supply, it means that the analog voltage signal V_DIAG recovers to the normal voltage range during the reset process, the signal input terminal A is disturbed by the signal, and the signal input terminal A does not actually have a short circuit fault to the power supply, and the external controller does not report or upload the fault. When the external controller sends the reset signal RESET twice, and the corresponding two diagnosis results are that the signal input terminal A has a short circuit fault to the power supply, the external controller determines that the signal input terminal A has a short circuit fault to the power supply and reports or uploads the fault.

[0100] When a short circuit occurs to the ground at the signal input terminal A, the voltage signal VIN level is close to 0V, the microcontroller diagnoses that the analog voltage signal V_DIAG voltage is lower than the short circuit threshold, the reset signal RESET maintains a low level, and the third transistor Q3, the first transistor Q1 and the second transistor Q2 maintain a normal working mode.

[0101] In one embodiment, the resistance of the load resistor R13 is approximately 100Ω, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10 and the twelfth resistor R12 are all in the kΩ level, the resistance of the eleventh resistor R11 is approximately several Ω, and the first capacitor C1 is in the μF level.

[0102] In one embodiment, Figure 4 As shown, a sensing device is provided, which includes a Hall speed sensor 400 and a sampling conditioning and protection circuit as provided in any of the above embodiments, wherein the signal input terminal A of the sampling conditioning and protection circuit is connected to the Hall speed sensor 400, and the Hall speed sensor 400 is used to sample the current signal of the device to be tested and output the sampled current signal to the signal input terminal A.

[0103] The sensing device and sampling conditioning and protection circuit provided in the embodiments of the present application belong to the same utility model concept and can achieve the same technical effect, and the repeated contents will not be repeated here.

[0104] In one embodiment, Figure 5 As shown, a gearbox is provided, which includes an external controller and a sensor device as provided in any of the above embodiments; the external controller 500 is connected to the sampling conditioning and protection circuit.

[0105] In one embodiment, the sampling conditioning and protection circuit includes a reset circuit 150, which is connected to the protection circuit 130; wherein the external controller 500 is used to send a reset signal RESET when diagnosing that the signal input terminal A has a short circuit to the power supply, so that the reset circuit 150 controls the protection circuit 130 to shut down according to the reset signal RESET, so that the protection circuit 130 stops controlling the voltage across the conversion circuit 110, and then the external controller 500 diagnoses again whether the signal input terminal A has a short circuit to the power supply; wherein, when the external controller 500 sends the reset signal RESET twice and the corresponding two diagnosis results are both that the signal input terminal A has a short circuit to the power supply, the external controller 500 determines that the signal input terminal A has a short circuit to the power supply and reports the fault.

[0106] The gearbox and sampling conditioning and protection circuit provided in the embodiments of the present application belong to the same utility model concept and can achieve the same technical effect, and the repeated contents will not be repeated here.

[0107] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0108] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0109] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A sampling conditioning and protection circuit, characterized in that: The signal input end of the sampling conditioning and protection circuit is used to receive the current signal of the device under test, and the sampling conditioning and protection circuit includes: A conversion circuit, connected to the signal input terminal, to convert the current signal into a voltage signal; A conditioning circuit connected to the conversion circuit to condition the voltage signal into a square wave level signal recognizable by an external controller, and output the square wave level signal to the external controller; A protection circuit connected to the conversion circuit, the protection circuit is turned on when a short circuit occurs to the power supply at the signal input end, so as to control the voltage at both ends of the conversion circuit to a safe voltage range; Among them, the protection circuit includes a first sampling circuit, a first switching circuit, a second sampling circuit and a second switching circuit; the first sampling circuit is connected to the conversion circuit to divide the voltage signal to obtain a first sampling signal; the first switching circuit is connected to the first sampling circuit, and controls the on and off based on the strength of the received first sampling signal; the second sampling circuit is connected to the power supply signal and connected to the first switching circuit to divide the power supply signal to obtain a second sampling signal; the second switching circuit is respectively connected to the conversion circuit and the second sampling circuit, and based on the received second sampling signal, it is turned on when the first switching circuit is turned off or turned off when the first switching circuit is turned on, so as to control the voltage at both ends of the conversion circuit to within a safe voltage range.

2. The sampling conditioning and protection circuit according to claim 1, characterized in that: The first sampling circuit includes a first resistor and a second resistor, the second sampling circuit includes a third resistor and a fourth resistor, the first switch circuit includes a first transistor, and the second switch circuit includes a second transistor; A first end of the first resistor is connected to the conversion circuit, a second end of the first resistor is connected to a first end of the second resistor, and a second end of the second resistor is grounded; The first end of the third resistor is connected to the power signal, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is grounded; The control end of the first transistor is connected to the second end of the first resistor, the first end of the first transistor is connected to the second end of the third resistor, and the second end of the first transistor is grounded; The control end of the second transistor is connected to the second end of the third resistor, the first end of the second transistor is connected to the conversion circuit, and the second end of the second transistor is grounded; When a short circuit fault to the power supply occurs at the signal input terminal, the first transistor is turned on and the second transistor is turned off, so as to control the voltage at both ends of the conversion circuit to be within a safe voltage range.

3. The sampling conditioning and protection circuit according to claim 1, characterized in that: The sampling conditioning and protection circuit also includes: The diagnostic circuit is connected to the conversion circuit and the protection circuit respectively to convert the voltage signal into an analog voltage signal, and output the analog voltage signal to the external controller to instruct the external controller to diagnose whether a short circuit to ground or a short circuit to power occurs at the signal input terminal according to the analog voltage signal.

4. The sampling conditioning and protection circuit according to claim 3, characterized in that: The diagnostic circuit includes a fifth resistor, a sixth resistor and a first capacitor; The first end of the fifth resistor is connected to the conversion circuit and the protection circuit respectively, and the second end of the fifth resistor is used to connect to the external controller; The first end of the sixth resistor is connected to the first end of the fifth resistor, and the second end of the sixth resistor is grounded; The first end of the first capacitor is connected to the second end of the fifth resistor, and the second end of the first capacitor is connected to the second end of the sixth resistor.

5. The sampling conditioning and protection circuit according to claim 3, characterized in that: The sampling conditioning and protection circuit also includes: A reset circuit is connected to the protection circuit to receive a reset signal sent by the external controller when the external controller diagnoses that a short circuit fault to the power supply occurs at the signal input terminal, and controls the protection circuit to shut down according to the reset signal so that the protection circuit stops controlling the voltage at both ends of the conversion circuit, so that the external controller can diagnose again whether a short circuit fault to the power supply occurs at the signal input terminal.

6. The sampling conditioning and protection circuit according to claim 5, characterized in that: The reset circuit includes a seventh resistor and a third transistor; The first end of the third transistor is connected to the protection circuit, the second end of the third transistor is grounded, and the control end of the third transistor is used to connect to the external controller; A first end of the seventh resistor is connected to the control end of the third transistor, and a second end of the seventh resistor is grounded.

7. The sampling conditioning and protection circuit according to claim 1, characterized in that: The conditioning circuit includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor and a first comparator; A first end of the eighth resistor is connected to the conversion circuit, and a second end of the eighth resistor is connected to the first input end of the first comparator; The first end of the ninth resistor is connected to the power signal, the second end of the ninth resistor is connected to the first end of the tenth resistor, and the second end of the tenth resistor is grounded; The second input terminal of the first comparator is connected to the second terminal of the ninth resistor, the output terminal of the first comparator is connected to the first terminal of the eleventh resistor, and the second terminal of the eleventh resistor is used to connect to the external controller; A first end of the twelfth resistor is connected to the output end of the first comparator, and a second end of the twelfth resistor is connected to the power signal.

8. A sensing device, characterized in that: The sensing device includes a Hall speed sensor and a sampling conditioning and protection circuit as described in any one of claims 1 to 7, wherein the signal input end of the sampling conditioning and protection circuit is connected to the Hall speed sensor, and the Hall speed sensor is used to sample the current signal of the device under test and output the sampled current signal to the signal input end.

9. A gearbox, characterized in that: The gearbox comprises an external controller and a sensing device as claimed in claim 8; the external controller is connected to the sampling conditioning and protection circuit.

10. The gearbox according to claim 9, characterized in that: The sampling conditioning and protection circuit includes a reset circuit, and the reset circuit is connected to the protection circuit; Wherein, the external controller is used to send a reset signal when diagnosing that the signal input terminal has a short circuit fault to the power supply, so that the reset circuit controls the protection circuit to shut down according to the reset signal, so that the protection circuit stops controlling the voltage at both ends of the conversion circuit, and then the external controller diagnoses again whether the signal input terminal has a short circuit fault to the power supply; wherein, when the external controller sends the reset signal twice and the corresponding two diagnosis results are both that the signal input terminal has a short circuit fault to the power supply, the external controller determines that the signal input terminal has a short circuit fault to the power supply and reports the fault.

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