CN211318699U

CN211318699U - Control circuit for self-detecting power failure

Info

Publication number: CN211318699U
Application number: CN201921313265.1U
Authority: CN
Inventors: 刘国涛
Original assignee: Shenzhen H & T Home Online Network Technology Co ltd
Current assignee: Shenzhen Shuliantianxia Intelligent Technology Co Ltd
Priority date: 2019-08-13
Filing date: 2019-08-13
Publication date: 2020-08-21
Anticipated expiration: 2029-08-13

Abstract

The application provides a control circuit for self-detecting power supply faults. The control circuit comprises a switching power supply circuit, a controller, a communication device, an abnormality control circuit, a standby power supply circuit and a first detection circuit. The switching power supply circuit is electrically connected with the power supply, the abnormality control circuit, the first detection circuit and the voltage switching circuit. The voltage switching circuit is electrically connected with the standby power supply circuit and the controller. The controller is electrically connected with the first detection circuit and the abnormality control circuit. The communication device is electrically connected with the switching power supply circuit and the standby power supply circuit. The controller is in communication connection with the user terminal through the communication device. The abnormality control circuit is electrically connected with the power supply and the standby power supply circuit. The first detection circuit is used for detecting the voltage of the first output end of the switching power supply circuit and outputting a first voltage. The controller determines the working state of the switching power supply circuit according to the first voltage and outputs high level or low level. The abnormality control circuit controls on and off of the backup power supply circuit based on the first voltage and the high level or the low level.

Description

Control circuit for self-detecting power failure

Technical Field

The application relates to the technical field of household appliances, in particular to a control circuit for self-detecting power supply faults.

Background

In the household electrical appliance industry, along with the progress of times, the intelligent control of household electrical appliances is more and more popular among people. The intelligent control of household appliances is realized by an internal controller. The controller in the household appliance is powered by its own switching power supply.

At present, a switching power supply of a controller of a traditional household appliance product has no fault detection, once the switching power supply of the controller has a fault, the controller cannot work normally, and even clear indication of the state of the controller cannot be given. The user can only contact with the after-sale repair and only repair according to experience after-sale, so that the maintenance efficiency is low.

SUMMERY OF THE UTILITY MODEL

In view of this, it is necessary to provide a control circuit for self-detecting a power failure, in order to solve the problem that the conventional controller does not have a self-detection function for a failure of its own switching power supply.

A control circuit for self-detecting a power failure in electrical connection with a power source, the control circuit comprising: the device comprises a switching power supply circuit, a controller, a communication device, an abnormality control circuit, a standby power supply circuit and a first detection circuit;

the input end of the switching power supply circuit is electrically connected with the power supply, and the first output end of the switching power supply circuit is respectively electrically connected with the first input end of the abnormality control circuit and the input end of the first detection circuit;

a first input end of the controller is electrically connected with a second output end of the switching power supply circuit and an output end of the standby power supply circuit respectively, a second input end of the controller is electrically connected with an output end of the first detection circuit, and a first output end of the controller is electrically connected with a second input end of the abnormality control circuit;

a third input end of the abnormality control circuit is electrically connected with the power supply, and an output end of the abnormality control circuit is electrically connected with an input end of the standby power supply circuit;

the input end of the communication device is respectively and electrically connected with the second output end of the switching power supply circuit and the output end of the standby power supply circuit, and the controller is in communication connection with the user terminal through the communication device;

the first detection circuit is used for detecting the voltage of a first output end of the switching power supply circuit and outputting the first voltage to the controller, the controller determines the current working state of the switching power supply circuit according to the second voltage and outputs a high level or a low level to the abnormal control circuit, the abnormal control circuit controls the on and off of the standby power supply circuit based on the first voltage and the high level or the low level, and the controller is further used for outputting the current working state of the switching power supply circuit to the user terminal through the communication device.

Compared with the prior art, the control circuit for self-detecting the power supply fault detects the voltage of the first output end of the switching power supply circuit through the first detection circuit and outputs the first voltage to the controller. And enabling the controller to determine the current working state of the switching power supply circuit according to the first voltage and output a high level or a low level to the abnormal control circuit. The abnormality control circuit controls the standby power supply circuit to be turned on and off based on the high level or the low level and the first voltage, thereby controlling whether the standby power supply circuit supplies power to the controller. And when the switching power supply circuit fails, the standby power supply circuit supplies power to the controller, so that the controller can work normally, and the current working state of the switching power supply circuit can be detected automatically. And the fault reason of the switching power supply circuit is given, so that after-sale maintenance is facilitated, and the maintenance efficiency is improved.

Drawings

FIG. 1 is a schematic block circuit diagram of a control circuit for self-detecting a power failure according to an embodiment of the present application;

fig. 2 is a circuit diagram of a control circuit for self-detecting a power failure according to an embodiment of the present application.

10 control circuit for self-detecting power failure

11 power supply

100 rectification filter circuit

200 switching power supply circuit

210 DC/DC circuit

220 first capacitor

230 step-down circuit

240 second capacitance

300 voltage switching circuit

310 second diode

320 third diode

330 third capacitance

340 fourth capacitance

400 controller

410 display device

420 communication device

500 abnormal control circuit

510 Relay

520 first diode

530 triode

540 first resistance

550 second resistor

600 standby power supply circuit

610 first voltage reduction circuit

620 sixth capacitance

700 first detection circuit

710 third resistor

720 fourth resistor

730 fifth resistor

740 fourth diode

750 fifth diode

760 fifth capacitance

800 second detection circuit

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the embodiments disclosed below.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

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.

Referring to fig. 1 and 2, an embodiment of the present application provides a control circuit 10 for self-detecting a power failure, which is electrically connected to a power source 11. The control circuit includes: the switching power supply circuit 200, the controller 400, the communication device 420, the abnormality control circuit 500, the standby power supply circuit 600, and the first detection circuit 700. The input terminal of the switching power supply circuit 200 is electrically connected to the power supply 11. A first output terminal of the switching power supply circuit 200 is electrically connected to a first input terminal of the abnormality control circuit 500 and an input terminal of the first detection circuit 700, respectively. A first input terminal of the controller 400 is electrically connected to a second output terminal of the switching power supply circuit 200 and an output terminal of the standby power supply circuit 600, respectively. A second input terminal of the controller 400 is electrically connected to an output terminal of the first detection circuit 700. A first output of the controller 400 is electrically connected to a second input of the anomaly control circuit 500.

A third input terminal of the abnormality control circuit 500 is electrically connected to the power supply 11. The output terminal of the abnormality control circuit 500 is electrically connected to the input terminal of the standby power supply circuit 600. The input terminal of the communication device 420 is electrically connected to the second output terminal of the switching power supply circuit 200 and the output terminal of the standby power supply circuit 600, respectively. The controller 400 is communicatively connected to the user terminal through the communication device 420. The first detection circuit 700 is configured to detect a voltage at a first output terminal of the switching power supply circuit 200 and output a first voltage to the controller 400. The controller 400 determines the current operating state of the switching power supply circuit 200 according to the first voltage, and outputs a high level or a low level to the abnormality control circuit 500. The abnormality control circuit 500 controls the turn-on and turn-off of the standby power supply circuit 600 based on the first voltage and the high level or the low level.

The controller 400 is further configured to output the current operating state of the switching power supply circuit 200 to the user terminal through the communication device 420. If the first voltage received by the controller 400 is equal to zero within a first preset time, it is determined that the current working state of the switching power supply circuit 200 is an output short circuit, and the controller 400 outputs a low level to the abnormal control circuit 500. The abnormality control circuit 500 controls the standby power supply circuit 600 to be turned on based on the first voltage and the low level, so that the standby power supply circuit 600 supplies power to the controller 400.

In one embodiment, the power source 11 may be a dc power source, and the power supply voltage provided by the dc power source is directly output to the circuit. In one embodiment, the power source 11 may also be an ac power source. In one embodiment, if the power source 11 is an ac power source, the control circuit 10 for self-detecting power failure further includes a rectifying and filtering circuit 100. Specifically, the input terminal of the rectifying and filtering circuit 100 is electrically connected to the power supply 11. The output end of the rectifying and filtering circuit 100 is electrically connected to the input end of the switching power supply circuit 200 and the third input end of the abnormality control circuit 500, respectively, and is configured to output a second voltage.

It is understood that the specific circuit structure of the rectifying and filtering circuit 100 is not particularly limited as long as the rectifying and filtering circuit has a rectifying and filtering function. In one embodiment, the rectifying and filtering circuit 100 may be composed of a rectifier bridge and a filter. In one embodiment, the rectifying and filtering circuit 100 may also be composed of a rectifying bridge and a capacitor C1. In one embodiment, the rectifier bridge may be constructed of four diodes (D1, D2, D3, D4). In one embodiment, the rectifier bridge may employ full-bridge or half-bridge rectification. After the power supply voltage provided by the power supply 11 is processed by the rectifying and filtering circuit 100, the output of the second voltage is more stable.

It is understood that the specific circuit structure of the switching power supply circuit 200 is not limited as long as the switching power supply circuit has a function of processing the second voltage (i.e., DC-P in fig. 2) and outputting a weak voltage. The specific circuit structure of the switching power supply circuit 200 can be selected according to actual requirements. In one embodiment, the switching power supply circuit 200 may be formed of a conventional step-down circuit and a DC/DC converter. In one embodiment, the switching power supply circuit 200 may also be constructed by a conventional DC/DC converter, a DC/DC converter and a capacitor.

After the second voltage is processed by the switching power supply circuit 200, a first voltage (i.e., V1 in fig. 2) can be output, and the first voltage is output to the abnormality control circuit 500 and the first detection circuit 700, respectively. Meanwhile, the first voltage may be further stepped down to output a third voltage (i.e., V2 in fig. 2, and output to the controller 400 to provide power for the controller 400. in one embodiment, the first voltage is a direct output voltage of the switching power supply circuit 200, and may be a detection voltage object of the first detection circuit 700.

It is understood that the specific structure of the controller 400 is not limited as long as it has a function of determining the current operating state of the switching power supply circuit 200 according to the first voltage and outputting a high level or a low level. In one embodiment, the controller 400 may be an MCU (micro control unit). In one embodiment, the controller 400 may also be an FPGA (Field-Programmable Gate Array) chip. The controller 400 determines the current working state of the switching power supply circuit 200 according to the first voltage, that is, performs self-detection on the current working state of the switching power supply circuit 200, so as to facilitate after-sales maintenance and improve maintenance efficiency. Meanwhile, the controller 400 outputs a high level or a low level to the abnormality control circuit 500 according to the detection result, so that the abnormality control circuit 500 controls the standby power circuit 600 to be turned on and off based on the first voltage and the high level or the low level. Thereby enabling the controller 400 to operate normally at all times.

In an embodiment, the communication device 420 may adopt a wireless communication mode such as WIFI, bluetooth, GPRS, etc., or a wired communication mode. In one embodiment, the user terminal may be a PC, a mobile phone, a tablet computer, or the like. The controller 400 may upload the real-time status information of the switching power supply circuit 200 to the user terminal through the communication device 420, and when a fault occurs, the after-sales service may be provided to the user according to the fault status information, thereby improving the maintenance efficiency.

It is to be understood that the specific circuit configuration of the abnormality control circuit 500 is not limited as long as it has a function of controlling the on and off of the standby power supply circuit 600 based on the first voltage and the high level or the low level. The specific circuit structure of the abnormality control circuit 500 can be selected according to actual requirements. In one embodiment, the abnormality control circuit 500 may be composed of a single-throw relay, a transistor, and a resistor. In one embodiment, the abnormality control circuit 500 may be composed of a double-throw relay, a MOS transistor and a resistor. The abnormal control circuit 500 switches the standby power supply circuit 600 to be turned on or off, so as to provide standby power for the controller 400, so that the controller 400 can always work, and the self-detection of the switching power supply circuit 200 is facilitated.

It is understood that the specific circuit structure of the standby power supply circuit 600 is not limited, as long as the standby power supply circuit has a function of supplying power to the controller 400 when the output of the switching power supply circuit 200 fails, for example, when the first voltage V1 output by the switching power supply circuit 200 fails due to short circuit, under voltage, over voltage, or open circuit. In one embodiment, the standby power circuit 600 may be formed by the first voltage dropping circuit 610 and the capacitor C4. In one embodiment, the first voltage dropping circuit 610 may be a DC/DC circuit. After the second voltage is converted by the standby power circuit 600, a fourth voltage (i.e. V3 in fig. 2) is output to the voltage switching circuit 300, so as to supply power to the controller 400.

In one embodiment, the specific circuit structure of the first detection circuit 700 is not limited, as long as the first detection circuit has the function of detecting the voltage (i.e., V1) at the first output terminal of the switching power supply circuit 200 and outputting the first voltage to the controller 400. In one embodiment, the first detection circuit 700 may be constructed by resistors (R3, R4, R5), diodes (D6, D7) and a capacitor C5 (as shown in fig. 2). The resistor R3 is a third resistor 710, the resistor R4 is a fourth resistor 720, the resistor R5 is a fifth resistor 730, the diode D6 is a fourth diode 740, the diode D7 is a fifth diode 750, and the capacitor C5 is a fifth capacitor 760. The resistors R3 and R4 can divide the voltage of V1. The resistor R5 and the capacitor C5 form a low-pass filter for filtering the sampled voltage (i.e. V1). V4 is the output of the voltage switching circuit 300 and is also the clamping voltage of the first detection circuit 700. The diode D6 and the diode D7 can protect the controller 400.

In one embodiment, the first detection circuit 700 may also be formed by a voltage detection sensor. Through first detection circuitry 700 detects the first voltage of switching power supply circuit 200 output to with the testing result send to controller 400, thereby pass through controller 400 confirms switching power supply circuit 200's current operating condition, and then accomplish right switching power supply circuit 200's self-checking is convenient for maintain when breaking down.

In one embodiment, the controller 400 may determine the operating state of the switching power supply circuit 200 according to the first voltage after receiving the first voltage. Specifically, if the first voltage is equal to zero within a first preset time, it may be determined that the current working state of the switching power supply circuit 200 is an output short circuit, and the controller 400 outputs a low level to the abnormal control circuit 500. At this time, the abnormality control circuit 500 may control the standby power supply circuit 600 to be turned on based on the first voltage and the low level, thereby controlling the standby power supply circuit 600 to supply power to the controller 400. And then the controller 400 can perform self-detection on the current working state of the switching power supply circuit 200 according to the voltage, thereby facilitating after-sales maintenance and improving maintenance efficiency.

In one embodiment, the specific time of the first preset time may be set according to actual requirements, such as 10 ms. The first voltage is equal to zero in a first preset time period, which means that: during a consecutive plurality of said first preset times (for example 40ms), said first voltage is equal to zero.

In one embodiment, if the first voltage is a periodic voltage which is continuously present for a second preset time equal to zero and a third preset time greater than zero, it may be determined that the current operating state of the switching power supply circuit 200 is an output open circuit, and the controller 400 outputs a low level to the abnormality control circuit 500. At this time, the abnormality control circuit 500 may control the standby power supply circuit 600 to be turned on based on the first voltage and the low level, thereby controlling the standby power supply circuit 600 to supply power to the controller 400. And then the controller 400 can perform self-detection on the current working state of the switching power supply circuit 200 according to the voltage, thereby facilitating after-sales maintenance and improving maintenance efficiency.

In one embodiment, the specific time of the second preset time may be set according to actual requirements, such as 5 ms. The third preset time may be different from the second preset time, such as 8 ms. In one embodiment, the first voltage is a periodic voltage which is equal to zero at a second preset time and is greater than zero at a third preset time which continuously occurs, and the first voltage is: a time period may include a second predetermined time and a third predetermined time, and the voltage of the first voltage varies during the consecutive time periods as follows: and when the second preset time is equal to zero, the third preset time is greater than zero.

In one embodiment, if the first voltage is greater than zero and less than or equal to the first threshold voltage for a fourth predetermined time, it may be determined that the current operating state of the switching power supply circuit 200 is an output under-voltage, and the controller 400 outputs a low level to the abnormal control circuit 500. In an embodiment, the specific time of the fourth preset time may be set according to an actual requirement, such as 20 ms. In one embodiment, the first threshold voltage may be eighty percent of V1 at rated output.

In one embodiment, if the first voltage is greater than the first threshold voltage and less than or equal to the second threshold voltage for a fifth preset time, it may be determined that the current operating state of the switching power supply circuit 200 is normal, and the controller 400 outputs a high level to the abnormal control circuit 500. So that the abnormality control circuit 500 controls the standby power circuit 600 to be turned off based on the first voltage and the high level, at which time the standby power circuit 600 stops supplying power to the controller 400. In an embodiment, the specific time of the fifth preset time may be set according to an actual requirement, such as 15 ms. In one embodiment, the second threshold voltage may be one hundred percent of V1 at rated output.

In one embodiment, if the first voltage is greater than the second threshold voltage for a sixth preset time, it may be determined that the current operating state of the switching power supply circuit 200 is an output overvoltage, and the controller 400 outputs a low level to the abnormality control circuit 500. In an embodiment, the specific time of the sixth preset time may be set according to an actual requirement, for example, 15 ms. In one embodiment, the first preset time, the fourth preset time, the fifth preset time and the sixth preset time may be set to be the same time or different times.

In this embodiment, the first detection circuit 700 detects a voltage at a first output terminal of the switching power supply circuit 200 and outputs a first voltage to the controller 400. So that the controller 400 determines the current operating state of the switching power supply circuit 200 according to the first voltage and outputs a high level or a low level to the abnormality control circuit 500. The abnormality control circuit 500 controls the standby power supply circuit 600 to be turned on and off based on the high level or the low level and the first voltage, thereby controlling whether the standby power supply circuit 600 supplies power to the controller 400. Further, when the switching power supply circuit 200 fails, the standby power supply circuit 600 supplies power to the controller 400, so that the controller 400 can still work normally, and the current working state of the switching power supply circuit 200 can be self-detected. And further, the fault reason of the switching power supply circuit 200 is given, so that after-sale maintenance is facilitated, and the maintenance efficiency is improved.

Referring to fig. 2, in an embodiment, the control circuit 10 for self-detecting power failure further includes: a second detection circuit 800. The input end of the second detection circuit 800 is electrically connected to the output end of the rectifying and filtering circuit 100. An output terminal of the second detection circuit 800 is electrically connected to a third input terminal of the controller 400. The second detection circuit 800 is configured to detect the second voltage and output a detection result to the controller 400. The controller 400 determines whether the power supply 11 is powered off based on the detection result.

Specifically, the controller 400 may compare the detection result with a third threshold voltage to obtain a difference comparison result. If the difference comparison result is less than or equal to zero, determining that the power supply 11 is powered off; and if the difference comparison result is greater than zero, determining that the power supply 11 is not powered off. In one embodiment, the third threshold voltage may be eighty percent of the supply voltage provided by the power supply 11.

It is to be understood that the specific circuit structure of the second detection circuit 800 is not limited as long as it has the function of detecting the second voltage and outputting the detection result to the controller 400. In one embodiment, the second detection circuit 800 may be constituted by a voltage detection sensor. In one embodiment, the second detection circuit 800 may also be constructed by resistors (R6, R7, R8, R9), diodes (D10, D11), and a capacitor C9 (as shown in fig. 2). The resistor R6, the resistor R7, and the resistor R8 may divide the first voltage (i.e., DC-P). The resistor R9 and the capacitor C9 form a low-pass filter to filter the sampled voltage (i.e., the first voltage). The diode D10 and the diode D11 can protect the controller 400.

In one embodiment, the second voltage output by the rectifying and smoothing circuit 100 and the first voltage output by the switching power supply circuit 200 are ground (i.e., not isolated), and can be detected by the second detection circuit 800 shown in fig. 2. In one embodiment, the second voltage output by the rectifying-filtering circuit 100 and the first voltage output by the switching power supply circuit 200 are not supplied to ground (i.e., isolated), and a conventional detection circuit may be used for voltage detection.

The second detection circuit 800 detects the second voltage output by the rectifying and smoothing circuit 100 and outputs the detection result to the controller 400. The condition of the mains input voltage, i.e. the supply voltage provided by the power supply 11, is determined by the controller 400, i.e. it is determined whether the power supply 11 is powered down. Thereby assisting the controller 400 in determining the current operating state of the switching power supply circuit 200.

In one embodiment, the second voltage may be compared with the third threshold voltage by the controller 400 to obtain a difference comparison result; if the difference comparison result is less than or equal to zero, it may be determined that the power supply 11 is powered off; if the difference comparison result is greater than zero, it may be determined that the power supply 11 is not powered off.

Specifically, if it is determined that the power supply 11 is not powered off, the second voltage may be compared with a third threshold voltage (e.g., a difference comparison) by the controller 400. If the second voltage is less than or equal to the third threshold voltage, it may be determined that the power supply 11 is in a powered-down state. If the second voltage is greater than the third threshold voltage, it is determined that the power supply 11 is in an unpowered state. In one embodiment, the power source 11 being in an unpowered state may include: an under-voltage condition, a normal condition, an over-voltage condition, etc. In one embodiment, the third threshold voltage may be eighty percent of the supply voltage provided by the power supply 11.

In one embodiment, if the second voltage is greater than the third threshold voltage and less than or equal to a fourth threshold voltage, it may be determined that the supply voltage provided by the power supply 11 is in an under-voltage state. Wherein the fourth threshold voltage may be ninety percent of the supply voltage provided by the power supply 11. In one embodiment, if the second voltage is greater than the fourth threshold voltage and less than or equal to a fifth threshold voltage, it may be determined that the power supply voltage provided by the power supply 11 is in a normal state. Wherein the fifth threshold voltage may be one hundred percent of the supply voltage provided by the power supply 11. In one embodiment, if the second voltage is greater than the fifth threshold voltage, it may be determined that the power supply voltage provided by the power supply 11 is in an overvoltage state.

In one embodiment, the switching power supply circuit 200 includes: a dc/dc circuit 210, a first capacitor 220, a voltage dropping circuit 230, and a second capacitor 240. The input terminal of the dc/dc circuit 210 is electrically connected to the output terminal of the rectifying and filtering circuit 100, and is configured to receive the second voltage. The output terminal of the dc/dc circuit 210 is electrically connected to the first terminal of the first capacitor 220, the input terminal of the voltage-reducing circuit 230, the first input terminal of the abnormality control circuit 500, and the input terminal of the first detection circuit 700, respectively. An output terminal of the voltage dropping circuit 230 is electrically connected to a first terminal of the second capacitor 240 and a first input terminal of the controller 400, respectively. The second terminal of the first capacitor 220 and the second terminal of the second capacitor 240 are both grounded.

In one embodiment, the second voltage is processed by the dc/dc circuit 210 to output a first voltage (i.e., V1). The first voltage is a direct output voltage of the switching power supply circuit 200, and can be a detection voltage object of the first detection circuit 700. The first voltage is reduced by the voltage reducing circuit 230, and then a third voltage (i.e., V2) is output. In one embodiment, the voltage dropping circuit 230 may be a conventional DC/DC circuit. The voltage dropping circuit 230 outputs the third voltage to the controller 400 to supply power to the controller 400.

In one embodiment, the abnormality control circuit 500 includes a relay 510, a first diode 520, a transistor 530, a first resistor 540, and a second resistor 550. The moving contact of the relay 510 is electrically connected with the output end of the rectifying and filtering circuit 100, and the normally closed stationary contact of the relay 510 is electrically connected with the input end of the standby power supply circuit 600. A first end of the coil of the relay 510 is electrically connected to a first output terminal of the switching power supply circuit 200 and a cathode of the first diode 520, respectively.

A second terminal of the coil of the relay 510 is electrically connected to an anode of the first diode 520 and a collector of the transistor 530, respectively. A first terminal of the first resistor 540 is electrically connected to a base of the transistor 530 and a first terminal of the second resistor 550, respectively. A second terminal of the first resistor 540 is electrically connected to a first output terminal of the controller 400. The second terminal of the second resistor 550 and the emitter of the transistor 530 are both grounded. The transistor 530 is turned on and off based on a high level or a low level output from the controller 400, so that the relay 510 controls the standby power circuit 600 to be turned on and off based on the first voltage.

In one embodiment, the control circuit 10 for self-detecting a power failure further comprises: a voltage switching circuit 300. A first input terminal of the voltage switching circuit 300 is electrically connected to a second output terminal of the switching power supply circuit 200. A second input terminal of the voltage switching circuit 300 is electrically connected to an output terminal of the standby power supply circuit 600. An output terminal of the voltage switching circuit 300 is electrically connected to a first input terminal of the controller 400 and an input terminal of the communication device 420, respectively. The voltage switching circuit 300 is configured to transmit the voltage output by the second output terminal of the switching power supply circuit 200 or the voltage output by the standby power supply circuit 600 to the controller 400 and the communication device 420.

It is understood that the specific circuit structure of the voltage switching circuit 300 is not limited as long as it has a function of transmitting the third voltage or the voltage output by the standby power supply circuit 600 to the controller 400. In one embodiment, the voltage switching circuit 300 may be constructed by two unidirectional conducting diodes and a capacitor. In one embodiment, the voltage switching circuit 300 may also be composed of two diodes conducting in one direction and resistors. The third voltage or the voltage output from the standby power circuit 600 is transmitted to the controller 400 through the voltage switching circuit 300, thereby supplying power to the controller 400. When the switching power supply circuit 200 has a short-circuit fault, the controller 400 can still work normally and perform self-detection on the fault.

In one embodiment, the voltage switching circuit 300 may include: a second diode 310, a third diode 320, a third capacitor 330 and a fourth capacitor 340. The anode of the second diode 310 is electrically connected to the second output terminal of the switching power supply circuit 200. The cathode of the second diode 310 is electrically connected to the cathode of the third diode 320, the first terminal of the third capacitor 330, the first terminal of the fourth capacitor 340, and the first input terminal of the controller 400, respectively. The anode of the third diode 320 is electrically connected to the output terminal of the standby power supply circuit 600. The second terminal of the third capacitor 330 and the second terminal of the fourth capacitor 340 are both grounded. The second diode 310 and the third diode 320 each function as an isolation. The third capacitor 330 and the fourth capacitor 340 mainly function as energy storage and filtering.

In one embodiment, the control circuit 10 for self-detecting a power failure further comprises: a device 410 is displayed. The display device 410 is electrically connected to an output terminal of the voltage switching circuit 300. The display device 410 is communicatively connected to the controller 400 and is used to display the current operating status of the switching power supply circuit 200. In one embodiment, the display device 410 may be a dual eight-digit tube or a light emitting diode. In one embodiment, the control circuit 10 for self-detecting power failure may further include an alarm device (not shown), such as a buzzer alarm. An alarm device may be electrically connected to the controller 400.

The working principle of the application is as follows:

first, when the control circuit 10 for self-detecting a power failure is powered on, the coil of the relay 510 (the relay 510 is a normally closed relay) in the abnormality control circuit 500 is not energized. The movable contact of the relay 510 is connected to a normally closed contact, which energizes the backup power circuit 600 and outputs a fourth voltage (i.e., V3). The controller 400, the display device 410, and the communication device 420 are powered by a fourth voltage through the third diode 320 in the voltage switching circuit 300.

Next, after the controller 400 is reset and initialized, the first output terminal of the controller 400 outputs a low level, so that the movable contact of the relay 510 is connected to the normally closed stationary contact. At this time, the standby power circuit 600 is in a power-on state, and the fourth voltage output by the standby power circuit 600 supplies power to the controller 400, the display device 410, and the communication device 420 through the voltage switching circuit 300.

Then, the controller 400 detects the grid voltage (i.e., the power source 11) through the first detection circuit 800, and determines whether the grid voltage is powered off. If the power is off, the controller 400 does not determine the operating state of the switching power supply circuit 200; meanwhile, the controller 400 maintains the output terminal of the abnormality control circuit 500 (i.e., the first output terminal of the controller 400) at the original output level.

If not, the controller 400 detects V1 of the switching power supply circuit 200 through the first detection circuit 700, and determines the current working state of the switching power supply circuit 200. In one embodiment, if the current operating state is normal output (i.e., the output of V1 is normal), the controller 400 outputs a high level to the output terminal controlling the abnormality control circuit 500. The transistor 530 in the abnormal control circuit 500 is turned on, and the moving contact of the relay 510 is connected to the normally open stationary contact (i.e., at this time, the coil of the relay 510 is powered on, and the switch of the relay 510 is controlled to be turned off), so that the standby power circuit 600 is in a power-off state. At this time, the controller 400 operates normally, and the control circuit 10 that self-detects the power failure operates normally.

In one embodiment, if the current operating state is a short-circuit fault (i.e., the output of V1 is equal to zero), or the current operating state is an open-circuit fault (i.e., the output of V1 is abnormal), or the current operating state is an under-voltage fault (i.e., the output of V1 is under-voltage), or the current operating state is an over-voltage fault (i.e., the output of V1 is over-voltage), the controller 400 outputs a low level to the output terminal controlling the abnormal control circuit 500. The transistor 530 in the abnormal control circuit 500 is turned off, and the moving contact of the relay 510 is connected to the normally closed stationary contact (i.e., when the coil of the relay 510 is de-energized and the switch of the relay 510 is closed), so that the standby power circuit 600 is energized and outputs a fourth voltage (V3) to power the controller 400, the display device 410 and the communication device 420. Meanwhile, the controller 400 reports the fault information through the display device 410 and the communication device 420.

In one embodiment, if the controller 400 determines that the operating state of the switching power supply circuit 200 is an output short circuit, the display device 410 may display a fault code E1, and upload fault information to a user terminal through the communication device 420. Meanwhile, the alarm can be given through a buzzer (such as alarm for 30 s).

In one embodiment, if the controller 400 determines that the current operating state of the switching power supply circuit 200 is output under-voltage, the display device 410 may display a fault code E2, and upload the fault information to the user terminal through the communication device 420. Meanwhile, the alarm can be given for 5s through a buzzer. In one embodiment, if the controller 400 determines that the current operating state of the switching power supply circuit 200 is output overvoltage, the display device 410 may display a fault code E3, and upload the fault information to the user terminal through the communication device 420. Meanwhile, the alarm can be given for 10s through a buzzer.

In one embodiment, if the controller 400 determines that the current operating state of the switching power supply circuit 200 is output open circuit, the display device 410 may display a fault code E4, and upload fault information to the user terminal through the communication device 420. Meanwhile, the alarm can be given for 20s through a buzzer.

In summary, the present application detects the voltage at the second output terminal of the switching power supply circuit 200 through the first detection circuit 700, and outputs the first voltage to the controller 400. So that the controller 400 determines the current operating state of the switching power supply circuit 200 according to the second voltage and outputs a high level or a low level to the abnormality control circuit 500. The abnormality control circuit 500 controls the standby power supply circuit 600 to be turned on and off based on the high level or the low level and the first voltage, thereby controlling whether the standby power supply circuit 600 supplies power to the controller 400. Further, when the switching power supply circuit 200 fails, the standby power supply circuit 600 supplies power to the controller 400, so that the controller 400 can still work normally, and the current working state of the switching power supply circuit 200 can be self-detected. And further, the fault reason of the switching power supply circuit 200 is given, so that after-sale maintenance is facilitated, and the maintenance efficiency is improved.

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 utility model. 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 patent shall be subject to the appended claims.

Claims

1. A control circuit for self-detecting a power failure, electrically connected to a power source (11), the control circuit comprising: the device comprises a switching power supply circuit (200), a controller (400), a communication device (420), an abnormality control circuit (500), a standby power supply circuit (600) and a first detection circuit (700);

the input end of the switching power supply circuit (200) is electrically connected with the power supply (11), and the first output end of the switching power supply circuit (200) is respectively electrically connected with the first input end of the abnormality control circuit (500) and the input end of the first detection circuit (700);

a first input end of the controller (400) is electrically connected with a second output end of the switching power supply circuit (200) and an output end of the standby power supply circuit (600), a second input end of the controller (400) is electrically connected with an output end of the first detection circuit (700), and a first output end of the controller (400) is electrically connected with a second input end of the abnormality control circuit (500);

a third input end of the abnormity control circuit (500) is electrically connected with the power supply (11), and an output end of the abnormity control circuit (500) is electrically connected with an input end of the standby power supply circuit (600);

the input end of the communication device (420) is electrically connected with the second output end of the switching power supply circuit (200) and the output end of the standby power supply circuit (600) respectively, and the controller (400) is in communication connection with a user terminal through the communication device (420);

the first detection circuit (700) is configured to detect a voltage at a first output terminal of the switching power supply circuit (200) and output a first voltage to the controller (400), the controller (400) determines a working state of the switching power supply circuit (200) according to the first voltage and outputs a high level or a low level to the abnormal control circuit (500), the abnormal control circuit (500) controls on and off of the standby power supply circuit (600) based on the first voltage and the high level or the low level, and the controller (400) is further configured to output the working state of the switching power supply circuit (200) to the user terminal through the communication device (420).

2. The control circuit for self-detecting a power failure of claim 1, further comprising: a rectifying-filtering circuit (100);

the input end of the rectification filter circuit (100) is electrically connected with the power supply (11), and the output end of the rectification filter circuit (100) is respectively electrically connected with the input end of the switching power supply circuit (200) and the third input end of the abnormity control circuit (500) and used for outputting a second voltage.

3. The control circuit for self-detecting a power failure of claim 2, further comprising: a second detection circuit (800);

the input end of the second detection circuit (800) is electrically connected with the output end of the rectification filter circuit (100), the output end of the second detection circuit (800) is electrically connected with the third input end of the controller (400), the second detection circuit (800) is used for detecting the second voltage and outputting a detection result to the controller (400), and the controller (400) determines whether the power supply (11) is powered off or not based on the detection result.

4. The control circuit for self-detecting a power supply fault according to claim 2, characterized in that the switching power supply circuit (200) comprises: a DC/DC circuit (210), a first capacitor (220), a voltage reduction circuit (230), and a second capacitor (240);

the input end of the direct current/direct current circuit (210) is electrically connected with the output end of the rectification filter circuit (100) and is used for receiving the second voltage, and the output end of the direct current/direct current circuit (210) is electrically connected with the first end of the first capacitor (220), the input end of the voltage reduction circuit (230), the first input end of the abnormality control circuit (500) and the input end of the first detection circuit (700) respectively;

the output end of the voltage reduction circuit (230) is electrically connected with the first end of the second capacitor (240) and the first input end of the controller (400) respectively, and the second end of the first capacitor (220) and the second end of the second capacitor (240) are both grounded.

5. The control circuit for self-detecting a power failure of claim 2, wherein the abnormality control circuit (500) includes a relay (510), a first diode (520), a transistor (530), a first resistor (540), and a second resistor (550);

the movable contact of the relay (510) is electrically connected with the output end of the rectification filter circuit (100), the normally closed stationary contact of the relay (510) is electrically connected with the input end of the standby power supply circuit (600), the first end of the coil of the relay (510) is respectively electrically connected with the first output end of the switching power supply circuit (200) and the cathode of the first diode (520), and the second end of the coil of the relay (510) is respectively electrically connected with the anode of the first diode (520) and the collector of the triode (530);

a first end of the first resistor (540) is electrically connected with a base of the triode (530) and a first end of the second resistor (550) respectively, a second end of the first resistor (540) is electrically connected with a first output end of the controller (400), and a second end of the second resistor (550) and an emitter of the triode (530) are both grounded;

the transistor (530) is turned on and off based on a high level or a low level output from the controller (400) so that the relay (510) controls the standby power circuit (600) to be turned on and off.

6. The control circuit for self-detecting a power failure according to claim 1, wherein the first detection circuit (700) comprises: a third resistor (710), a fourth resistor (720), a fifth resistor (730), a fourth diode (740), a fifth diode (750), and a fifth capacitor (760);

a first end of the third resistor (710) is electrically connected with a first output end of the switching power supply circuit (200), and a second end of the third resistor (710) is respectively electrically connected with a first end of the fourth resistor (720), a first end of the fifth resistor (730), a positive electrode of the fourth diode (740), and a negative electrode of the fifth diode (750);

a second end of the fifth resistor (730) is electrically connected with a first end of the fifth capacitor (760) and a second input end of the controller (400), respectively;

the cathode of the fourth diode (740) is electrically connected to the first input terminal of the controller (400), and the second terminal of the fourth resistor (720), the anode of the fifth diode (750), and the second terminal of the fifth capacitor (760) are all grounded.

7. The control circuit for self-detecting a power failure of claim 1, further comprising: a voltage switching circuit (300);

the first input end of the voltage switching circuit (300) is electrically connected with the second output end of the switching power supply circuit (200), the second input end of the voltage switching circuit (300) is electrically connected with the output end of the standby power supply circuit (600), the output end of the voltage switching circuit (300) is electrically connected with the first input end of the controller (400) and the input end of the communication device (420) respectively, and the voltage switching circuit (300) is used for transmitting the voltage output by the second output end of the switching power supply circuit (200) or the voltage output by the standby power supply circuit (600) to the controller (400) and the communication device (420).

8. The control circuit for self-detecting a power failure according to claim 7, wherein the voltage switching circuit (300) comprises: a second diode (310), a third diode (320), a third capacitor (330), and a fourth capacitor (340);

the anode of the second diode (310) is electrically connected with the second output end of the switching power supply circuit (200), and the cathode of the second diode (310) is respectively electrically connected with the cathode of the third diode (320), the first end of the third capacitor (330), the first end of the fourth capacitor (340) and the first input end of the controller (400);

the anode of the third diode (320) is electrically connected with the output end of the standby power supply circuit (600), and the second end of the third capacitor (330) and the second end of the fourth capacitor (340) are both grounded.

9. The control circuit for self-detecting a power failure of claim 8, further comprising: a display device (410);

the display device (410) is electrically connected with the output end of the voltage switching circuit (300), and the display device (410) is in communication connection with the controller (400) and is used for displaying the current working state of the switching power supply circuit (200).

10. The control circuit for self-detecting a power failure of claim 1, wherein the backup power circuit (600) comprises: a first voltage-reducing circuit (610) and a sixth capacitor (620);

the input end of the first voltage reduction circuit (610) is electrically connected with the output end of the abnormity control circuit (500), the output end of the first voltage reduction circuit (610) is respectively electrically connected with the first end of the sixth capacitor (620) and the first input end of the controller (400), and the second end of the sixth capacitor (620) is grounded.