Switching value sensor input self-checking circuit

Abstract

The utility model belongs to the technical field of sensor input detection, and particularly discloses a switching value sensor input self-checking circuit, which comprises a switching value acquisition circuit and a switching value sensor self-checking circuit. According to the utility model, the switching value sensor self-checking circuit is added on the basis of the switching value acquisition circuit, so that whether the switching value sensor is in a fault state, including a short circuit state and an open circuit state, can be detected, a self-checking function is realized, wrong judgment and processing are avoided, and a fault problem point of equipment can be positioned more quickly; the maintenance efficiency is improved, and the maintenance cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of sensor input detection technology, and in particular to a self-test circuit for input of a switch quantity sensor. Background Technology

[0002] Switching signal sensors have wide applications in power electronics, electrical testing, and other fields. In current switching signal sensor circuit design, a common method is to use optocoupler modules or chips for signal isolation, and then input the signal to a control chip to obtain the logic level. Generally, the positive and negative terminals of the output signal lines of the external switching signal sensor are connected to the input terminals of the optocoupler module or chip. The other end of the optocoupler module or chip outputs a logic level signal, which is then connected to an embedded processor for acquisition, thereby obtaining a digital logic signal.

[0003] In some applications, external sensors may malfunction or fail, such as structural damage, internal disconnection, overcurrent or overvoltage breakdown, short circuits, or broken connection cables. Simple input circuits that only detect digital signals cannot accurately diagnose these faults, leading to incorrect assessments and system malfunctions. Furthermore, some operating environments may be unsuitable for on-site maintenance, making it difficult to locate the sensor and pinpoint the fault. These challenges further complicate system control and maintenance. Utility Model Content

[0004] The purpose of this invention is to solve the technical problems existing in the background art. To this end, a self-test circuit for input of a switch quantity sensor is provided.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A self-test circuit for input of a switch quantity sensor includes a switch quantity acquisition circuit and a switch quantity sensor self-test circuit;

[0007] The switching quantity acquisition circuit includes an optocoupler isolation chip U1A, wherein the anode of the optocoupler isolation chip U1A is electrically connected to the sensor output terminal IN+, the cathode of the optocoupler isolation chip U1A is electrically connected to the sensor output terminal IN-, the emitter of the optocoupler isolation chip U1A is grounded, and the collector of the optocoupler isolation chip U1A is electrically connected to the output terminal OUT1.

[0008] The self-test circuit of the switching sensor includes an optocoupler isolation chip U2A, a comparator amplifier U3A, and an optocoupler isolation chip U4A. The anode of the optocoupler isolation chip U2A is connected to a high level VCC2, the cathode of the optocoupler isolation chip U2A is electrically connected to the CIN signal terminal, the collector of the optocoupler isolation chip U2A is connected to a high level VCC_BIT, the emitter of the optocoupler isolation chip U2A is electrically connected to the sensor output terminal IN+, the positive terminal of the comparator amplifier U3A is electrically connected to the sensor output terminal IN+, the negative terminal of the comparator amplifier U3A is connected to a high level VCC_BIT through resistor R8 and grounded through resistor R9, the output terminal of the comparator amplifier U3A is electrically connected to the anode of the optocoupler isolation chip U4A, the cathode of the optocoupler isolation chip U4A is grounded, the emitter of the optocoupler isolation chip U4A is grounded, and the collector of the optocoupler isolation chip U4A is electrically connected to the output terminal OUT2.

[0009] The following is a further technical solution of this utility model: a Zener diode Dz1 and a resistor R2 are connected in series on the line between the anode of the optocoupler isolation chip U1A and the sensor output terminal IN+.

[0010] The following is a further defined technical solution of this utility model: the cathode of the optocoupler isolation chip U1A is grounded through a Zener diode Dz2.

[0011] The following is a further defined technical solution of this utility model: the collector of the optocoupler isolation chip U1A is connected to the high level VCC2 through resistor R1.

[0012] The following is a further defined technical solution of this utility model: the anode of the optocoupler isolation chip U2A is connected to the high level VCC2 through resistor R4.

[0013] The following is a further defined technical solution of this utility model: the collector of the optocoupler isolation chip U2A is connected to the high level VCC_BIT through resistor R3.

[0014] The following is a further defined technical solution of this utility model: the positive terminal of the comparator amplifier U3A is electrically connected to the sensor output terminal IN+ through resistor R6.

[0015] The following is a further defined technical solution of this utility model: the output terminal of the comparator amplifier U3A is electrically connected to the anode of the optocoupler isolation chip U4A through resistor R7.

[0016] The following is a further defined technical solution of this utility model: the collector of the optocoupler isolation chip U4A is connected to the high level VCC2 through resistor R5.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] This invention adds a self-test circuit for the switch quantity sensor to the switch quantity acquisition circuit, which can detect whether the switch quantity sensor is in a fault state, including short circuit and open circuit states. It realizes the self-test function, avoids incorrect judgment and processing, and can more quickly locate the fault point of the equipment, improve maintenance efficiency and reduce maintenance costs.

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a circuit connection diagram of this utility model. Detailed Implementation

[0022] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0023] like Figure 1 As shown, this embodiment provides a switch quantity sensor input self-test circuit, including a switch quantity acquisition circuit and a switch quantity sensor self-test circuit.

[0024] The optocoupler isolation chips U1A, U2A, and U4A have the same structure, and their pin functions are as follows: 1. Cathode: the cathode of the LED; 2. Anode: the anode of the LED; 3. Emitter: the emitter of the phototransistor; 4. Collector: the collector of the phototransistor.

[0025] The digital input acquisition circuit consists of an optocoupler isolation chip U1A, Zener diodes Dz1 and Dz2, and resistors R1 and R2. Specifically, Zener diode Dz1 and resistor R2 are connected in series between the anode of optocoupler isolation chip U1A and the sensor output terminal IN+. The cathode of optocoupler isolation chip U1A is electrically connected to the sensor output terminal IN-, and the cathode of optocoupler isolation chip U1A is grounded through Zener diode Dz2. The emitter of optocoupler isolation chip U1A is grounded, and the collector of optocoupler isolation chip U1A is connected to the high-level voltage VCC2 through resistor R1. The collector of optocoupler isolation chip U1A is electrically connected to the output terminal OUT1.

[0026] The self-test circuit of the switch sensor consists of an optocoupler isolation chip U2A, a comparator amplifier U3A, an optocoupler isolation chip U4A, and resistors R3, R4, R5, R6, R7, R8, and R9. Specifically, the anode of the optocoupler isolation chip U2A is connected to the high-level VCC2 through resistor R4, the cathode of the optocoupler isolation chip U2A is electrically connected to the CIN signal terminal, the collector of the optocoupler isolation chip U2A is connected to the high-level VCC_BIT through resistor R3, and the emitter of the optocoupler isolation chip U2A is electrically connected to the sensor output terminal IN+. The positive terminal of comparator amplifier U3A is electrically connected to the sensor output terminal IN+ through resistor R6. The negative terminal of comparator amplifier U3A is connected to the high level VCC_BIT through resistor R8 and grounded through resistor R9. The output terminal of comparator amplifier U3A is electrically connected to the anode of optocoupler isolation chip U4A through resistor R7. The cathode of optocoupler isolation chip U4A is grounded, the emitter of optocoupler isolation chip U4A is grounded, the collector of optocoupler isolation chip U4A is connected to the high level VCC2 through resistor R5, and the collector of optocoupler isolation chip U4A is electrically connected to the output terminal OUT2.

[0027] The working process of this embodiment will be further described below:

[0028] The overall circuit input of this embodiment is the output signal IN+ and IN- of a switch sensor. The switch acquisition circuit is responsible for converting the output signal IN+ and IN- of the switch sensor into a 0-3.3V logic level signal that can be received by the microprocessor, and uses an optocoupler isolation chip U1A to isolate internal and external signals.

[0029] The self-test circuit for the digital input sensor is responsible for detecting external digital input sensors. When the self-test is initiated, the microprocessor outputs a low-level CIN signal, which turns on the optocoupler isolation chip U2A, applying a voltage VCC_BIT to the sensor's output terminal IN+. The voltage VCC_BIT is applied to the input terminal of the digital input sensor to detect its impedance.

[0030] When the external switching sensor is in a short-circuit fault state, IN+ remains low after voltage is applied, the optocoupler isolation chip U1A will not conduct, and OUT1 will be high. When the positive terminal of the comparator amplifier U3A is lower than the negative terminal and outputs a low level, the optocoupler isolation chip U4A will also not conduct, and OUT2 will be high.

[0031] When the external switch sensor is in an open-circuit fault state, IN+ becomes high after voltage is applied, the optocoupler isolation chip U1A conducts, and OUT1 becomes low. The positive terminal of the comparator amplifier U3A is greater than the negative terminal and outputs a high level, the optocoupler isolation chip U4A conducts, and OUT2 becomes low.

[0032] When the external switching sensor is in normal impedance state, IN+ is high after voltage is applied, the optocoupler isolation chip U1A is turned on, and OUT1 is low. The comparator amplifier U3A is configured according to the resistance values ​​of R8 and R9, its positive terminal will be smaller than its negative terminal and it will output a low level, the optocoupler isolation chip U4A will not be turned on, and OUT2 will be high.

[0033] Thus, the microprocessor can determine whether the external digital sensor is working properly or in what fault state it is through the logic levels of OUT1 and OUT2, thereby realizing the self-test function of the digital sensor status.

[0034] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any way. Any person skilled in the art can make many possible variations and modifications to the technical solution of this utility model using the disclosed methods and techniques, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of this utility model. Therefore, all equivalent changes made based on the shape, structure, and principle of this utility model without departing from its technical solution should be covered within the protection scope of this utility model.

Claims

1. A self-test circuit for input of a switch quantity sensor, characterized in that, Includes a switch quantity acquisition circuit and a switch quantity sensor self-test circuit; The switching quantity acquisition circuit includes an optocoupler isolation chip U1A, wherein the anode of the optocoupler isolation chip U1A is electrically connected to the sensor output terminal IN+, the cathode of the optocoupler isolation chip U1A is electrically connected to the sensor output terminal IN-, the emitter of the optocoupler isolation chip U1A is grounded, and the collector of the optocoupler isolation chip U1A is electrically connected to the output terminal OUT1. The self-test circuit of the switching sensor includes an optocoupler isolation chip U2A, a comparator amplifier U3A, and an optocoupler isolation chip U4A. The anode of the optocoupler isolation chip U2A is connected to a high level VCC2, the cathode of the optocoupler isolation chip U2A is electrically connected to the CIN signal terminal, the collector of the optocoupler isolation chip U2A is connected to a high level VCC_BIT, the emitter of the optocoupler isolation chip U2A is electrically connected to the sensor output terminal IN+, the positive terminal of the comparator amplifier U3A is electrically connected to the sensor output terminal IN+, the negative terminal of the comparator amplifier U3A is connected to a high level VCC_BIT through resistor R8 and grounded through resistor R9, the output terminal of the comparator amplifier U3A is electrically connected to the anode of the optocoupler isolation chip U4A, the cathode of the optocoupler isolation chip U4A is grounded, the emitter of the optocoupler isolation chip U4A is grounded, and the collector of the optocoupler isolation chip U4A is electrically connected to the output terminal OUT2.

2. The self-test circuit for input of a switch quantity sensor as described in claim 1, characterized in that, A Zener diode Dz1 and a resistor R2 are connected in series on the line between the anode of the optocoupler isolation chip U1A and the sensor output terminal IN+.

3. The self-test circuit for input of a switch quantity sensor as described in claim 1, characterized in that, The cathode of the optocoupler isolation chip U1A is grounded through a Zener diode Dz2.

4. The self-test circuit for input of a switch quantity sensor as described in claim 1, characterized in that, The collector of the optocoupler isolation chip U1A is connected to the high level VCC2 through resistor R1.

5. The self-test circuit for input of a switch quantity sensor as described in claim 1, characterized in that, The anode of the optocoupler isolation chip U2A is connected to the high level VCC2 through resistor R4.

6. The self-test circuit for input of a switch quantity sensor as described in claim 1, characterized in that, The collector of the optocoupler isolation chip U2A is connected to the high level VCC_BIT through resistor R3.

7. The self-test circuit for input of a switch quantity sensor as described in claim 1, characterized in that, The positive terminal of the comparator amplifier U3A is electrically connected to the sensor output terminal IN+ through resistor R6.

8. The self-test circuit for input of a switch quantity sensor as described in claim 1, characterized in that, The output terminal of the comparator amplifier U3A is electrically connected to the anode of the optocoupler isolation chip U4A through resistor R7.

9. The self-test circuit for input of a switch quantity sensor as described in claim 1, characterized in that, The collector of the optocoupler isolation chip U4A is connected to the high level VCC2 through resistor R5.

Images