CN211429285U

CN211429285U - Switch self-checking circuit, device and equipment

Info

Publication number: CN211429285U
Application number: CN202020162065.7U
Authority: CN
Inventors: 武庚生; 邹载文; 温煦
Original assignee: Guangzhou Yameizhi Technology Co ltd
Current assignee: Guangzhou Yameizhi Technology Co ltd
Priority date: 2020-02-11
Filing date: 2020-02-11
Publication date: 2020-09-04
Anticipated expiration: 2030-02-11

Abstract

The application relates to a switch self-checking circuit, a device and equipment. In the switch self-checking circuit, a first end of a first divider resistor is grounded through a functional switch, and a second end of the first divider resistor is grounded through a switch unit; an ADC pin of the processing unit is connected with a VCC power supply through a second voltage-dividing resistor and is connected with a first end of a first voltage-dividing resistor through an ADC port; meanwhile, the enabling pin of the processing unit is connected with the control pole of the switch unit through the control port. Based on the structure, the ADC pin of the processing unit is matched with the VCC power supply, the ADC port, the function switch, the first divider resistor and the second divider resistor, and the function switch can trigger the level change of the ADC pin, so that the processing unit can realize corresponding functions; meanwhile, the processing unit can control the switch unit to be switched on or switched off through the enabling pin, and the ADC pin of the processing unit can judge whether the connection between the switch module and the ADC port of the mainboard is normal or not based on the voltage division values of the first voltage division resistor and the second voltage division resistor, so that the self-checking of the switch is completed.

Description

Switch self-checking circuit, device and equipment

Technical Field

The application relates to the technical field of circuits, in particular to a switch self-checking circuit, a device and equipment.

Background

A switch is an electronic component that can open a circuit, interrupt a current, or cause it to flow to other circuits. The most common switch may comprise one or several electrical contacts. The "closing" of a contact means that the electronic contact is conductive, allowing current to flow; an "open" of the switch indicates that the electrical contact is non-conductive, creating an open circuit, not allowing current to flow. In the fields of SOS emergency switches, alarm switches, and the like, the functions of the switches are relatively outstanding, and therefore, good connection between the switches and a main board is guaranteed by the application of the switches.

The connection state of switch and mainboard does not have the monitoring, then can't realize switch function when the switch drops or not hard up, and then causes switch function inefficacy and product defect, consequently, need monitor switch and mainboard connection good. In the implementation process, the inventor finds that at least the following problems exist in the conventional technology: the traditional switch monitoring circuit is complex in design.

SUMMERY OF THE UTILITY MODEL

In view of this, it is necessary to provide a switch self-checking circuit, device and apparatus for solving the problem of complicated design of the conventional switch monitoring circuit.

In order to achieve the above object, in one aspect, an embodiment of the present application provides a switch self-test circuit, including:

the switch module comprises a function switch, a switch unit and a first divider resistor; the first end of the function switch is grounded, and the second end of the function switch is connected with the first end of the first divider resistor; the first pole of the switch unit is connected with the second end of the first voltage-dividing resistor, and the second pole of the switch unit is grounded.

The mainboard module comprises an ADC port, a control port, a processing unit and a second divider resistor; the first end of the second voltage-dividing resistor is used for connecting a VCC power supply, and the second end of the second voltage-dividing resistor is respectively connected with an ADC port and an ADC pin of the processing unit; the ADC port is connected with the first end of the first voltage-dividing resistor; the control port is respectively connected with the control electrode of the switch unit and the enabling pin of the processing unit.

In one embodiment, the motherboard module further includes a first current limiting resistor.

The second end of the second voltage-dividing resistor is connected with an ADC pin of the processing unit through the first current-limiting resistor.

In one embodiment, the second terminal of the second divider resistor is further connected to an INT pin of the processing unit.

In one embodiment, the motherboard module further includes a second current limiting resistor.

And the second end of the second voltage-dividing resistor is connected with an INT pin of the processing unit through a second current-limiting resistor.

In one embodiment, the switching unit includes an NPN transistor.

The collector of the NPN type triode is connected with the first pole of the switch unit, the emitter of the NPN type triode is connected with the second pole of the switch unit, and the base of the NPN type triode is connected with the control pole of the switch unit.

In one embodiment, the motherboard module further comprises a ground port.

The ground port is respectively connected with the first end of the functional switch and the second pole of the switch unit.

In one embodiment, the switch module further comprises a third voltage dividing resistor.

The second end of the function switch is connected with the first end of the first voltage-dividing resistor through a third voltage-dividing resistor.

In one embodiment, the function switch is a key switch.

The processing unit is an MCU.

On the other hand, the embodiment of the application also provides a device, which comprises a substrate.

The switch self-checking circuit is arranged on the substrate.

In one embodiment, a device is provided that includes the switch self-test circuit as described above.

One of the above technical solutions has the following advantages and beneficial effects:

the switch module is provided with a functional switch, a switch unit and a first divider resistor; the mainboard module is provided with an ADC port, a control port, a processing unit and a second divider resistor. The first end of the first divider resistor is grounded through the functional switch, and the second end of the first divider resistor is grounded through the switch unit; an ADC pin of the processing unit is connected with a VCC power supply through a second voltage-dividing resistor and is connected with a first end of a first voltage-dividing resistor through an ADC port; meanwhile, the enabling pin of the processing unit is connected with the control pole of the switch unit through the control port. Based on the structure, the ADC pin of the processing unit is matched with the VCC power supply, the ADC port, the function switch, the first divider resistor and the second divider resistor, and the function switch can trigger the level change of the ADC pin, so that the processing unit can realize corresponding functions; meanwhile, the processing unit can control the switch unit to be switched on or switched off through the enabling pin, and the ADC pin of the processing unit can judge whether the connection between the switch module and the ADC port of the mainboard is normal or not based on the voltage division values of the first voltage division resistor and the second voltage division resistor. Based on this, can multiplexing the ADC pin and the enable pin of processing unit on the mainboard module, accomplish the self-checking of switch, in time detect whether the switch module is connected unusually with the mainboard module, and then can in time remind the user, avoid influencing the application function of product.

Drawings

The foregoing and other objects, features and advantages of the application will be apparent from the following more particular description of preferred embodiments of the application, as illustrated in the accompanying drawings. Like reference numerals refer to like parts throughout the drawings, and the drawings are not intended to be drawn to scale in actual dimensions, emphasis instead being placed upon illustrating the subject matter of the present application.

FIG. 1 is a first schematic block diagram of a switch self-test circuit in one embodiment;

FIG. 2 is a second schematic block diagram of a switch self-test circuit in one embodiment;

FIG. 3 is a third schematic block diagram of a switch self-test circuit in one embodiment;

FIG. 4 is a fourth schematic block diagram of a switch self-test circuit in one embodiment;

FIG. 5 is a fifth schematic block diagram of a switch self-test circuit in one embodiment;

FIG. 6 is a sixth schematic block diagram of a switch self-test circuit in one embodiment.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are shown in the drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element and be integral therewith, or intervening elements may also be present. The terms "first end," "second end," "control end," and the like are used herein for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In some applications, the connection state between the switch and the main board is not monitored. In the conventional technology, when the safety switch is closed, the pulse self-checking signal can be continuously sent, whether the complete pulse self-checking signal is received or not is judged in real time, and when the complete pulse self-checking signal is not received, the fault of the safety switch is self-checked. However, the pulse signal output circuit is complex in design, and the pulse signal is easily interfered by the external environment, so that signal distortion is caused, and the detection result is influenced.

Therefore, the embodiment of the application provides a switch self-checking circuit, which has the advantages of simple circuit design, few peripheral components and low cost, and simple detection method, and realizes self-checking by multiplexing the ADC pin and the enable pin of the processing unit of the main board. Specifically, the embodiment of the present application can be applied to application scenarios where the function of the switch key is important, such as: self-checking a vehicle-mounted SOS emergency call key; digital doorbell button self-checking; self-checking the emergency call key of the medical sickbed; self-checking an emergency brake key of the escalator; the self-checking method for the emergency call button of the subway carriage comprises the following fields.

In one embodiment, there is provided a switch self-test circuit, as shown in fig. 1, comprising:

a switch module including a function switch, a switch unit and a first voltage dividing resistor R1; the first end of the function switch is grounded, and the second end of the function switch is connected with the first end of the first divider resistor R1; the first pole of the switch unit is connected with the second end of the first voltage dividing resistor R1, and the second pole of the switch unit is grounded.

The mainboard module comprises an ADC (analog-to-digital conversion) port, a control port, a processing unit and a second voltage-dividing resistor R2; a first end of the second voltage-dividing resistor R2 is used for connecting a VCC (voltage supply) power supply, and a second end of the second voltage-dividing resistor R2 is respectively connected to an ADC port and an ADC pin of the processing unit; the ADC port is connected with a first end of a first voltage dividing resistor R1; the control port is respectively connected with the control electrode of the switch unit and the enabling pin of the processing unit.

Specifically, the switch self-checking circuit comprises a switch module and a mainboard module; the switch module can be used for acquiring an external switch trigger signal and further transmitting the external switch trigger signal to the mainboard module so as to execute the function of the switch self-checking circuit; the processing unit in the motherboard module may set the signal processing process and the connection relationship between the signal processing process and the peripheral circuit according to the actual application scenario, which is not limited herein.

Specifically, the switch module includes a function switch for acquiring an external switch trigger signal, and a switch unit and a first voltage dividing resistor R1; the mainboard module comprises an ADC port, a control port, a processing unit and a second voltage-dividing resistor R2. The ADC pin of the processing unit is connected with a VCC power supply through a second voltage-dividing resistor R2, connected with the second end of the functional switch through an ADC port, and connected with the first pole of the switch unit through the ADC port and a first voltage-dividing resistor R1 in sequence; that is, the ADC port may be grounded through the functional switch and the switching unit, respectively.

Based on the structure, when the functional switch and the switch unit are not conducted, the ADC pin of the processing unit can keep a high-level state; when the function switch is turned on, the high level of the ADC pin is changed into the low level, and the processing unit can confirm that the function switch is triggered to be turned on, so that corresponding signal processing is executed. Furthermore, an enabling pin of the processing unit is connected with a control electrode of the switch unit through a control port; based on this, the processing unit can control the switch-on or switch-off of the switch unit through the enabling pin, and then can realize the self-checking of the connection state of the ADC port by matching with the ADC pin of the processing unit.

Illustratively, the processing unit outputs a high-level signal through the enable pin to trigger the switch unit to be turned on, and at this time, the voltage of the ADC pin is a divided value of the VCC power supply at the first voltage dividing resistor R1 and the second voltage dividing resistor R2, so that the processing unit can determine whether the connection between the ADC port and the switch module is good or not through the voltage change of the ADC pin.

It should be noted that the switch module and the motherboard module may be disposed on a substrate, or disposed on different substrates, so as to meet the actual application requirements of the circuit. When the function switch is conducted, the ADC port is grounded; according to the actual application requirement, the function switch may be a button switch, a micro switch or a toggle switch, and the like, and is not limited specifically here.

The switch unit may be a switch tube circuit, such as a triode switch circuit, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOS fet) switch circuit, etc., and the specific structure thereof may be implemented by selecting corresponding devices and setting corresponding connection relationships according to actual requirements, which is not limited herein.

The Processing unit may be a single chip, a DSP (Digital Signal Processing), an FPGA (Field Programmable Gate Array), or the like, and is not limited specifically here. The enable pin of the processing unit may control the switching on or off of the switching unit by transmitting a high level signal or a low level signal. Furthermore, the resistances and types of the first divider resistor R1 and the second divider resistor R2 can be selected according to the actual application requirements of the circuit; the ADC pin of the processing unit can acquire the voltage division value of the VCC power supply on the first voltage division resistor R1 and the second voltage division resistor R2, and the processing unit can confirm whether the voltage division value falls into a normal range or not, and further confirm whether the connection state of the ADC port and the switch module is normal or not.

The ADC port may be a junction of the second ends of the second divider resistors R2; the control port may be a connection of an enable pin of the processing unit.

The embodiment of the application can multiplex the ADC pin and the enabling pin of the processing unit on the mainboard module, complete the self-checking of the switch, and detect whether the switch module is abnormal in connection with the mainboard module or not in time, namely whether the circuit of the mainboard module and the switch module is closed loop or not, so that a user can be reminded in time, and the application function of a product is prevented from being influenced.

In one embodiment, as shown in fig. 2, the motherboard module further includes a first current limiting resistor R3.

The second end of the second voltage-dividing resistor R2 is connected to the ADC pin of the processing unit through a first current-limiting resistor R3.

Specifically, the main board module may further include a first current limiting resistor R3 connected between the second terminal of the second voltage dividing resistor R2 and the ADC pin of the processing unit. Based on this, the first current limiting resistor R3 can be used to limit the current of the ADC pin branch, so as to prevent the processing unit from being burned out due to excessive current, thereby improving reliability. In addition, the first current limiting resistor R3 can also perform a voltage division function. It should be noted that the type and the resistance of the first current limiting resistor R3 can be selected according to the application requirement of the actual circuit, and is not limited herein.

In one embodiment, the second terminal of the second divider resistor R2 is also connected to the INT pin (interrupt pin) of the processing unit.

Specifically, the second ends of the second voltage-dividing resistors R2 are connected to the ADC port, and the ADC pin and INT pin of the processing unit, respectively. The INT pin can be used for detecting whether the functional switch is conducted or not; specifically, when the functional switch is turned on, the INT pin is pulled low, i.e., an external interrupt is triggered. Illustratively, when the functional switch is not pressed, the ADC port is kept high at all times, i.e., the INT pin is high; when the functional switch is turned on, the ADC port is changed from high level to low level, namely the high level of the INT pin is changed to low level, the processing unit triggers an interrupt mechanism of the processing unit, and the functional switch is judged to be turned on. Based on this, the embodiment of the application can realize the trigger function of the functional switch based on the cooperation of the functional switch, the ADC pin, the INT pin and the like.

In one embodiment, as shown in fig. 3, the motherboard module further includes a second current limiting resistor R4.

The second terminal of the second divider resistor R2 is connected to the INT pin of the processing unit through a second current limiting resistor R4.

Specifically, the main board module may further include a second current limiting resistor R4 connected between a second terminal of the second voltage dividing resistor R2 and the INT pin of the processing unit. Based on this, the second current limiting resistor R4 can be used to limit the current of the INT pin branch, so as to prevent the processing unit from being burned out due to excessive current and improve reliability. In addition, the second current limiting resistor R4 can also play a role in voltage division. It should be noted that the type and the resistance of the second current limiting resistor R4 can be selected according to the application requirements of the actual circuit, and are not limited herein.

In one embodiment, as shown in fig. 4, the switching unit includes an NPN transistor Q1.

The collector of the NPN type triode Q1 is connected to the first pole of the switching unit, the emitter of the NPN type triode Q1 is connected to the second pole of the switching unit, and the base of the NPN type triode Q1 is connected to the control pole of the switching unit.

Specifically, the switching unit may be mainly constituted by an NPN type transistor Q1; the collector of the NPN transistor Q1 may be connected to the second terminal of the first voltage divider resistor R1 through the first pole of the switching unit, the emitter of the NPN transistor Q1 may be grounded through the second pole of the switching unit, and the base of the NPN transistor Q1 may be connected to the control port of the motherboard module through the control pole of the switching unit. Based on the above structure, the control port of the main board module can send a high level signal to the NPN transistor Q1, so as to turn on the NPN transistor Q1; based on this, the processing unit can detect the level change of the ADC port, and then judge whether the connection state of the ADC port and the switch module is normal. The embodiment of the application realizes switch self-checking by multiplexing the pins of the processing unit and matching the pins with the resistor and the triode, and has simple circuit design and low cost.

In one embodiment, as shown in FIG. 5, the motherboard module further includes a ground port.

In particular, the motherboard module may also be provided with a ground port, which is connected with a ground structure in the switch module. Based on this, the stability of the embodiments of the present application can be improved.

In one embodiment, as shown in fig. 5, the switch module further includes a third voltage dividing resistor R5.

The second terminal of the function switch is connected to the first terminal of the first voltage dividing resistor R1 through a third voltage dividing resistor R5.

Specifically, the main board module may further include a third voltage dividing resistor R5 connected between the second terminal of the function switch and the first terminal of the first voltage dividing resistor R1. The third voltage dividing resistor R5 may function to divide the voltage when the function switch is turned on. It should be noted that the type and the resistance of the third voltage dividing resistor R5 can be selected according to the application requirements of the actual circuit, and is not limited herein.

In one embodiment, as shown in FIG. 6, the function switches are push-button switches.

Specifically, the function switch may be a key switch, which facilitates external triggering of the motherboard module to perform a corresponding function.

In one embodiment, as shown in FIG. 6, the processing unit is an MCU.

Specifically, the switch self-test circuit may include a two-part switch module and a motherboard module.

The switch module mainly comprises a J1 key switch, a first voltage-dividing resistor R1, a third voltage-dividing resistor R5 and an NPN type triode Q1.

The main board module may mainly include a second voltage-dividing resistor R2, a first current-limiting resistor R3, a second current-limiting resistor R4, and a main board MCU.

In normal operation, the switch J1 is pressed, and the MCU _ ADC (i.e., ADC pin) changes from high to low. R4 is a current limiting resistor. MCU _ INT (INT pin) triggers MCU interruption, and MCU can receive the signal of switch pressing.

During the switch self-test, the MCU enable pin MCU _ TESTSELF signal controls the transistor BTN _ CTRL (i.e., the control port) to be at a high level, so that the transistor Q1 is turned on, and the voltage of the transistor BTN _ ADC (i.e., the ADC port) is the divided voltage of the R1 resistor and the R2 resistor. The R3 resistor is a current limiting resistor. The MCU detects that the voltage of the MCU _ ADC changes, and the specific voltage value can be calculated according to the divider resistance. If the voltage value falls into the preset voltage range, the BTN _ ADC signal circuit can be judged to be normal, and the switch module is well connected with the mainboard module.

In one embodiment, the first voltage divider resistor may be selected to be on the order of kilo-ohms.

In one embodiment, the second voltage-dividing resistor may be a kilo-ohm resistor.

For example, the resistance of the second voltage-dividing resistor may be the same as or similar to the resistance of the first voltage-dividing resistor.

In one embodiment, the first current limiting resistor may be a hundred ohm resistor.

In one embodiment, the second current limiting resistor may be a hundred ohm resistor.

For example, the resistance of the second current limiting resistor may be the same as or similar to the resistance of the first current limiting resistor.

In one embodiment, the third voltage dividing resistor may be a hundred ohm resistor.

In one embodiment, the first voltage-dividing resistor and the second voltage-dividing resistor have the same resistance.

During the switch self-checking, the MCU controls the enable pin MCU _ TESSELF to output a high level signal, and at the moment, the triode Q1 is conducted. The voltage of the ADC port BTN _ ADC is a divided value of VCC over the first voltage dividing resistor and the second voltage dividing resistor. When the switch module is normally connected with the mainboard module, the voltage division value is 1/2 of VCC; i.e., 1/2 where the voltage at ADC pin MCU _ ADC is VCC. Therefore, when the MCU reads 1/2 that the voltage value of the ADC pin deviates from VCC, the MCU can judge that the key switch is not well connected with the mainboard module, and remind a user to check whether the key is loose or the connecting wire falls off.

In one embodiment, an apparatus is provided, which comprises a substrate, and the switch self-test circuit is arranged on the substrate.

Specifically, the device may be a switch core board, a switch integrated module, or the like.

For specific limitations of the device, reference may be made to the above limitations of the self-test circuit for the switch, and details are not repeated here.

In one embodiment, there is provided a device comprising a switch self-test circuit as described above.

Specifically, the switch self-checking circuit can be arranged on equipment such as an SOS (save our souls) SOS (emergency services system) SOS (emergency service system) alarm and a fire alarm.

For specific limitations of the device, reference may be made to the above limitations of the switch self-test circuit, which are not described herein again.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A switch self-test circuit, comprising:

the switch module comprises a function switch, a switch unit and a first divider resistor; the first end of the function switch is grounded, and the second end of the function switch is connected with the first end of the first divider resistor; the first pole of the switch unit is connected with the second end of the first divider resistor, and the second pole of the switch unit is grounded;

the mainboard module comprises an ADC port, a control port, a processing unit and a second divider resistor; a first end of the second voltage-dividing resistor is used for connecting a VCC power supply, and a second end of the second voltage-dividing resistor is respectively connected with the ADC port and the ADC pin of the processing unit; the ADC port is connected with a first end of the first voltage dividing resistor; the control port is respectively connected with the control electrode of the switch unit and the enabling pin of the processing unit.

2. The switch self-test circuit of claim 1, wherein the motherboard module further comprises a first current limiting resistor;

and the second end of the second voltage-dividing resistor is connected with an ADC pin of the processing unit through the first current-limiting resistor.

3. The switch self-test circuit according to claim 2, wherein the second terminal of the second voltage-dividing resistor is further connected to an INT pin of the processing unit.

4. The switch self-test circuit of claim 2, wherein the motherboard module further comprises a second current limiting resistor;

and the second end of the second voltage-dividing resistor is connected with an INT pin of the processing unit through the second current-limiting resistor.

5. The switched self-test circuit according to claim 1, wherein the switching unit comprises an NPN transistor;

6. The switch self-test circuit of claim 1, wherein the motherboard module further comprises a ground port;

7. The switching self-test circuit according to any one of claims 1 to 6, wherein the switching module further comprises a third voltage dividing resistor;

the second end of the function switch is connected with the first end of the first voltage dividing resistor through the third voltage dividing resistor.

8. The switch self-test circuit according to any one of claims 1 to 6, wherein the function switch is a key switch; the processing unit is an MCU.

9. An apparatus, comprising a substrate; the substrate is provided with a switch self-test circuit according to any one of claims 1 to 8.

10. An apparatus comprising a switch self-test circuit as claimed in any one of claims 1 to 8.