Switch protection circuit, control method and equipment

Abstract

The invention relates to a switch protection circuit, a control method and equipment. The voltage detection module is used for acquiring a first voltage and a second voltage at the two ends of the switch; the input end of the voltage comparison module is connected with the output end of the voltage detection module, and the voltage comparison module compares the first voltage with the second voltage and outputs a corresponding comparison result; and the input end of the protection output module is connected with the output end of the voltage comparison module, and the protection output module is used for outputting a corresponding on-off signal according to the comparison result of the first voltage and the second voltage. The technical problem to be solved by the invention is that water enters a switch of a motor vehicle in rainy days or during vehicle washing, so that micro short circuit of the switch occurs, and misoperation occurs. One purpose of the invention is to determine whether the switch is fully closed by detecting the change condition of the input voltage, thereby improving the waterproof protection effect of the switch.

Description

Technical Field

[0001] The present invention relates to the technical field of switch protection, and more specifically, to a switch protection circuit, a control method and a device. Background Art

[0002] Motor vehicle switches usually refer to switchgear used to control the electrical system of motor vehicles. They can turn the current on or off, thereby controlling the operation of electrical equipment such as engines, lights, and audio.

[0003] Motor vehicle switches protect the electrical system through waterproof measures to ensure that the switch works normally in bad weather or humid environments and prevent failures or short circuits. Specifically, it uses sealed design and rubber gaskets or sealing rings to prevent moisture and dust from entering the inside of the switch; choose switches with specific waterproof levels (such as IP protection level). IP67 level means that the switch can be immersed in water for a short time without damage; some switches have drainage holes or tilted designs to ensure that moisture can be discharged in time without accumulating inside the switch.

[0004] Since all switches of motor vehicles are exposed outdoors, some switches cannot be completely waterproof due to mechanical problems. This causes water to enter the switches on rainy days or when washing the car, resulting in a micro-short circuit of the switches, causing some components to receive wrong signals and malfunction. Summary of the invention

[0005] One purpose of the present invention is to provide a switch protection circuit, control method and device to solve the problem that all switches of a motor vehicle are exposed outdoors, and some switches cannot be completely waterproof due to structural problems. This causes water to enter the switches on rainy days or when washing the car, resulting in a micro-short circuit of the switches, causing some components to receive wrong signals and malfunction.

[0006] According to one aspect of the present invention, there is provided a switch protection circuit, comprising: a voltage detection module, the voltage detection module being used to obtain a first voltage and a second voltage at both ends of the switch; A voltage comparison module, wherein an input end of the voltage comparison module is connected to an output end of the voltage detection module, and the voltage comparison module compares the first voltage and the second voltage and outputs a corresponding comparison result; A protection output module, wherein the input end of the protection output module is connected to the output end of the voltage comparison module, and the protection output module is used to output a corresponding on-off signal according to a comparison result of the first voltage and the second voltage.

[0007] Preferably, the voltage detection module includes: A first resistor, one end of the first resistor is connected to the input voltage, the other end of the first resistor is connected to a second resistor, and one end of the second resistor away from the first resistor is grounded; A third resistor, one end of the third resistor is connected to the input voltage, the other end of the third resistor is connected to a fourth resistor, and one end of the fourth resistor away from the third resistor is grounded.

[0008] Preferably, the voltage comparison module includes: A voltage comparator, wherein a first pin of the voltage comparator is connected to a connection between a first resistor and a second resistor, a third pin of the voltage comparator is connected to a connection between a third resistor and a fourth resistor, and an output end of the voltage comparator is connected to a connection between the first resistor and the third resistor through a fifth resistor.

[0009] Preferably, the protection output module comprises: An output transistor, wherein a first pin of the output transistor is connected to an output end of the voltage comparator, a second pin of the output transistor is grounded, and a third pin of the output transistor is used to output an on-off signal.

[0010] Preferably, the protection output module further includes: A protection subunit, wherein the input end of the protection subunit is connected to the output end of the voltage comparison module, the output end of the protection subunit is connected to the input end of the protection output module, and the protection subunit is used for voltage division to protect the circuit.

[0011] Preferably, the protection subunit further includes: a sixth resistor, one end of the sixth resistor being connected to the fourth pin of the voltage comparator, and the other end of the sixth resistor being connected to the first pin of the output transistor; A seventh resistor, one end of the seventh resistor is connected to the connection between the sixth resistor and the output transistor, and the other end of the seventh resistor is grounded.

[0012] In a second aspect, the present application also provides a control method for a switch protection circuit, comprising: Acquire a first voltage signal and corresponding time information; If the time information corresponding to the first voltage signal is greater than the preset time range, the output transistor is controlled to perform on-off operation according to the corresponding comparison result; If the time information corresponding to the first voltage signal is not greater than a preset time range, the output transistor is controlled to be turned off.

[0013] Preferably, when the time information corresponding to the first voltage signal is not greater than a preset time range, it includes: Get historical voltage signals; comparing the historical voltage signal with the first voltage signal; If the historical voltage signal matches the first voltage signal, the output transistor is controlled to be turned off.

[0014] In a third aspect, the present application also provides a switch protection circuit device, which can be applied to the switch protection circuit as described in the first aspect.

[0015] One technical effect of the present invention is that the above-mentioned switch protection circuit compares the voltages at both ends of the voltage comparator input, and determines whether the switch is fully closed by detecting the change in the input voltage, thereby reducing the possibility of rainwater seeping into the switch when the switch is not closed, causing the switch to be in a micro-open state, and then causing the possibility of malfunction of components, thereby improving the waterproof protection effect of the switch.

[0016] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0018] Figure 1 It is a schematic diagram of the prior art.

[0019] Figure 2 It is a schematic diagram of the overall structure in the embodiment of the present application.

[0020] Figure 3 It is a specific circuit diagram in the embodiment of the present application. DETAILED DESCRIPTION

[0021] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0022] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0023] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0024] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0025] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0026] The term "components" is mainly used in manufacturing industries such as automobiles and machinery, and refers to the various parts or components that make up a whole. In the automotive industry, parts usually refer to various components, such as engines, transmissions, brake systems, suspension systems, etc., which together make up a complete car.

[0027] like Figure 1 As shown, in the prior art, the switch wiring of a motor vehicle is generally a grounding switch, that is, one end of the switch is grounded, and the other end (output) is connected to the component. When the switch is closed, the output ground is given to the component, and the component is powered on. If water enters the switch at this time, since there are impurities in general water, it cannot be completely insulated, and the switch is in a slightly conductive state, which will cause the component to be slightly powered, causing the component to malfunction.

[0028] like Figure 2 and Figure 3 As shown, a switch protection circuit of an embodiment includes a voltage detection module, a voltage comparison module and a protection output module, wherein: A voltage detection module, wherein the voltage detection module is used to obtain a first voltage and a second voltage across the switch; A voltage comparison module, wherein an input end of the voltage comparison module is connected to an output end of the voltage detection module, and the voltage comparison module compares the first voltage and the second voltage and outputs a corresponding comparison result; A protection output module, wherein the input end of the protection output module is connected to the output end of the voltage comparison module, and the protection output module is used to output a corresponding on-off signal according to a comparison result of the first voltage and the second voltage.

[0029] The above switch protection circuit compares the voltages at both ends of the voltage comparator input and determines whether the switch is fully closed by detecting the change in the input voltage, thereby reducing the possibility of rainwater seeping into the switch when the switch is not closed, causing the switch to be in a micro-open state, and then causing the possibility of malfunction of components, thereby improving the waterproof protection effect of the switch.

[0030] like Figure 3 As shown, the voltage detection module specifically includes: A first resistor, one end of the first resistor is connected to the input voltage, the other end of the first resistor is connected to a second resistor, and one end of the second resistor away from the first resistor is grounded; A third resistor, one end of the third resistor is connected to the input voltage, the other end of the third resistor is connected to a fourth resistor, and one end of the fourth resistor away from the third resistor is grounded.

[0031] like Figure 3 As shown, the voltage comparison module includes: A voltage comparator, wherein a first pin of the voltage comparator is connected to a connection between a first resistor and a second resistor, a third pin of the voltage comparator is connected to a connection between a third resistor and a fourth resistor, and an output end of the voltage comparator is connected to a connection between the first resistor and the third resistor through a fifth resistor.

[0032] It is worth mentioning that the comparator circuit has the function of comparing the voltages of the positive input terminal Vin(+) and the negative input terminal Vin(-). In a specific example, the voltage of the negative input terminal Vin(-) is the reference voltage. When the voltage of the positive input terminal Vin(+) is greater than the voltage of the negative input terminal Vin(-), the output terminal Vout outputs a high level. When the voltage of the negative input terminal Vin(-) is greater than the voltage of the positive input terminal Vin(+), the output terminal Vout outputs a low level.

[0033] like Figure 3 As shown, the protection output module includes: An output transistor, wherein a first pin of the output transistor is connected to an output end of the voltage comparator, a second pin of the output transistor is grounded, and a third pin of the output transistor is used to output an on-off signal.

[0034] It is worth mentioning that the protection output module also includes a protection subunit, the input end of the protection subunit is connected to the output end of the voltage comparison module, the output end of the protection subunit is connected to the input end of the protection output module, and the protection subunit is used to divide the voltage to protect the circuit.

[0035] The protection subunit also includes: a sixth resistor, one end of the sixth resistor being connected to the fourth pin of the voltage comparator, and the other end of the sixth resistor being connected to the first pin of the output transistor; A seventh resistor, one end of the seventh resistor is connected to the connection between the sixth resistor and the output transistor, and the other end of the seventh resistor is grounded.

[0036] Among them, the seventh resistor is a pull-down resistor. A pull-down resistor is a resistor element commonly used in electronic circuits. Its main function is to pull an uncertain signal port to a low level (usually ground, i.e. 0 volts) to ensure that the voltage of the signal port always remains at a low level when there is no external signal input.

[0037] It can be understood that the above-mentioned voltage detection module, voltage comparison module and protection output module can also adopt other forms, and are not limited to the forms mentioned in the above embodiments. The voltage detection module can be used as long as it can achieve the function of detecting the voltage change after the switch has water ingress; the voltage comparison module can be used as long as it can achieve the function of outputting different results for the voltage change after water ingress, and the protection output module can be used as long as it can achieve the function of controlling the output of the component.

[0038] Reference Figure 3 It is worth mentioning that the specific implementation process of this application may include: If the switch is in the open state, SW-1 is not grounded. According to calculation, the voltage of U1's pin 3 is 0.92V, the voltage of U1's pin 1 is 9.3V, the output of U1's pin 4 is low, Q1 is turned off, and OUT has no output; if the switch is in the closed state, SW-1 is grounded. According to calculation, the voltage of U1's pin 3 is 0.92V, the voltage of U1's pin 1 is 0V, the output of U1's pin 4 is high, Q1 is turned on, and OUT output is GND; if water is in the water-in state, there will be water impedance between SW-1 and SW-2, which is equivalent to connecting a resistor between SW-1 and SW-2. Taking the water impedance of 500Ω as an example, the voltage of U1's pin 3 is 0.92V, the voltage of U1's pin 1 is 3.255V, the output of U1's pin 4 is low, Q1 is turned off, and OUT has no output.

[0039] In some embodiments, the voltage signal may be caused by dust or other factors, so the voltage fluctuation needs to be checked. The specific checking process may be performed as follows: Acquire a first voltage signal and corresponding time information; If the time information corresponding to the first voltage signal is greater than the preset time range, the output transistor is controlled to perform on-off operation according to the corresponding comparison result; If the time information corresponding to the first voltage signal is not greater than a preset time range, the output transistor is controlled to be turned off.

[0040] Through the above embodiments, it can be determined that the change of the voltage signal is not a fluctuating signal, but a stable signal, thereby improving the stability of the voltage signal.

[0041] In some embodiments, considering that the circuit may fluctuate regularly under certain circumstances due to historical voltage, it is also necessary to display this situation in a timely manner when such anomaly does not affect the use. The specific display includes: Get historical voltage signals; comparing the historical voltage signal with the first voltage signal; If the historical voltage signal matches the first voltage signal, the output transistor is controlled to be turned off; If the historical voltage signal does not match the first voltage signal, the output transistor is controlled to normally output the corresponding on / off signal.

[0042] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A switch protection circuit, characterized in that: include: A voltage detection module, wherein the voltage detection module is used to obtain a first voltage and a second voltage across the switch; A voltage comparison module, wherein an input end of the voltage comparison module is connected to an output end of the voltage detection module, and the voltage comparison module compares the first voltage and the second voltage and outputs a corresponding comparison result; A protection output module, wherein the input end of the protection output module is connected to the output end of the voltage comparison module, and the protection output module is used to output a corresponding on-off signal according to a comparison result of the first voltage and the second voltage.

2. The switch protection circuit according to claim 1, characterized in that: The voltage detection module comprises: A first resistor, one end of the first resistor is connected to the input voltage, the other end of the first resistor is connected to a second resistor, and one end of the second resistor away from the first resistor is grounded; A third resistor, one end of the third resistor is connected to the input voltage, the other end of the third resistor is connected to a fourth resistor, and one end of the fourth resistor away from the third resistor is grounded.

3. The switch protection circuit according to claim 2, characterized in that: The voltage comparison module comprises: A voltage comparator, wherein a first pin of the voltage comparator is connected to a connection between a first resistor and a second resistor, a third pin of the voltage comparator is connected to a connection between a third resistor and a fourth resistor, and an output end of the voltage comparator is connected to a connection between the first resistor and the third resistor through a fifth resistor.

4. The switch protection circuit according to claim 3, characterized in that: The protection output module comprises: An output transistor, wherein a first pin of the output transistor is connected to an output end of the voltage comparator, a second pin of the output transistor is grounded, and a third pin of the output transistor is used to output an on-off signal.

5. The switch protection circuit according to claim 1, characterized in that: The protection output module also includes: A protection subunit, wherein the input end of the protection subunit is connected to the output end of the voltage comparison module, the output end of the protection subunit is connected to the input end of the protection output module, and the protection subunit is used for voltage division to protect the circuit.

6. The switch protection circuit according to claim 5, characterized in that: The protection subunit also includes: a sixth resistor, one end of the sixth resistor being connected to the fourth pin of the voltage comparator, and the other end of the sixth resistor being connected to the first pin of the output transistor; A seventh resistor, one end of the seventh resistor is connected to the connection between the sixth resistor and the output transistor, and the other end of the seventh resistor is grounded.

7. A control method for a switch protection circuit, the method being applied to the switch protection circuit according to any one of claims 1 to 6, characterized in that: The method further comprises: Acquire a first voltage signal and corresponding time information; If the time information corresponding to the first voltage signal is greater than the preset time range, the output transistor is controlled to perform on-off operation according to the corresponding comparison result; If the time information corresponding to the first voltage signal is not greater than a preset time range, the output transistor is controlled to be turned off.

8. The control method of the switch protection circuit according to claim 7, characterized in that: When the time information corresponding to the first voltage signal is not greater than a preset time range, it includes: Get historical voltage signals; comparing the historical voltage signal with the first voltage signal; If the historical voltage signal matches the first voltage signal, the output transistor is controlled to be turned off.

9. A switch protection circuit device, characterized in that: The invention comprises a switch protection circuit according to any one of claims 1 to 6.

10. A switch protection circuit device, characterized in that: The invention comprises a switch protection circuit according to any one of claims 1 to 6.

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