Fault detection circuit and fault detection device of circuit board

Abstract

The embodiment of the invention belongs to the technical field of circuits, and provides a fault detection circuit and a fault detection device of a circuit board, the fault detection circuit comprises a first power supply and a switch control circuit, the first power supply is connected with a second power supply of a to-be-detected circuit board through the switch control circuit, and the first power supply is configured to supply power to the fault detection circuit. The switch control circuit is configured to cut off an access between the first power supply and the second power supply when the circuit board to be detected is short-circuited, so that the fault detection circuit is protected, and the risk that the fault detection circuit is damaged is reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of circuit technology, and more specifically, to a fault detection circuit and a fault detection device for a circuit board. Background Art

[0002] Short circuits can occur on circuit boards due to defective components or problems in the manufacturing process. Failure to detect short circuits and powering up a circuit board can damage it. Therefore, short circuit testing is essential to ensure safe, stable, and efficient operation of circuit boards.

[0003] Typically, a detection device can be used to perform fault detection on a circuit board to be tested. The power lines and signal lines of the detection device are interconnected with the power lines and signal lines of the circuit board to be tested, and then the circuit board to be tested is tested.

[0004] However, since it is unknown whether the power supply of the circuit board to be tested is faulty, if there is a short circuit fault in the power supply, a large current will appear in the path between the power supply and GND (ground terminal of the wire), which may easily cause the fault range to expand further, and the current will damage the detection device. Summary of the Invention

[0005] The embodiments of the present application provide a circuit board fault detection circuit and a fault detection device, which can be used to solve the problem that when a short circuit fault occurs in the circuit board to be tested, the fault is likely to further expand and damage the detection device.

[0006] In a first aspect, an embodiment of the present application provides a circuit board fault detection circuit, comprising:

[0007] a first power supply connected to a second power supply of the circuit board to be tested via a switch control circuit, the first power supply being configured to supply power to the fault detection circuit;

[0008] The switch control circuit is configured as follows:

[0009] When a short circuit occurs on the circuit board to be tested, the path between the first power supply and the second power supply is cut off.

[0010] In this embodiment, the fault detection circuit includes a first power supply and a switch control circuit. The first power supply is connected to a second power supply of the circuit board under test via the switch control circuit. The first power supply is configured to power the fault detection circuit. If a short circuit occurs in the circuit board under test, the switch control circuit is configured to cut off the path between the first power supply and the second power supply, thereby protecting the fault detection circuit and reducing the risk of damage.

[0011] In some embodiments of the present application, the fault detection circuit further includes an alarm unit, and the alarm unit is connected to the first power supply through the switch control circuit;

[0012] When a short circuit occurs on the circuit board to be tested, the switch control circuit switches on a path between the first power supply and the alarm unit, so that the alarm unit prompts that a fault occurs on the circuit board to be tested.

[0013] In this embodiment, an alarm unit may be added to indicate whether the circuit board to be tested has a fault, so that a tester can quickly determine whether the circuit board to be tested has a fault.

[0014] In some embodiments of the present application, the warning unit includes at least one LED.

[0015] In this embodiment, the LED can be used to indicate whether the circuit board to be tested has a fault, so that the tester can quickly determine whether the circuit board to be tested has a fault according to the on and off status of the LED.

[0016] In some embodiments of the present application, the switch control circuit includes a third power supply, a first switch, a first resistor, a second resistor, and a third power supply, and the supply voltage of the third power supply is lower than the supply voltage of the first power supply;

[0017] The third power supply is connected to the first end of the first resistor via a first connecting line, and the second end of the first resistor is connected to the second power supply of the circuit board to be tested via a second connecting line; the common contact of the first switch is connected to the first power supply, the first contact of the first switch is connected to the second connecting line, and the second contact of the first switch is connected to the first end of the second resistor; and the second end of the second resistor is connected to the alarm unit;

[0018] The positive electrode of the first switch is connected to the first connection line, and the negative electrode of the first switch is connected to the second connection line, so that the first switch is connected in parallel with the first resistor.

[0019] In this embodiment, a current limiting resistor and an analog switch are combined to cut off the path between the circuit board under test and the fault detection circuit when the circuit board under test is short-circuited, thereby protecting the circuit board under test.

[0020] In some embodiments of the present application, when the circuit board to be tested does not have a short circuit, the first switch connects the first contact to turn off the at least one LED;

[0021] When a short circuit occurs on the circuit board to be tested, the first switch alternately connects the second contact and the first contact to make the at least one LED alternately light up and go out, indicating that a fault occurs on the circuit board to be tested.

[0022] In this embodiment, a combination of a current-limiting resistor and an analog switch is used to control the LED to be off when the circuit board to be tested is not short-circuited, and to control the LED to light up and turn off alternately when the circuit board to be tested is short-circuited, so as to indicate that the circuit board to be tested has a fault, thereby protecting the circuit board to be tested.

[0023] In some embodiments of the present application, the switch control circuit includes an optocoupler element, a first switch, a first resistor, a second resistor, a third resistor, and a third power supply, and the supply voltage of the third power supply is lower than the supply voltage of the first power supply;

[0024] In which, the third power supply is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the optocoupler element through a third connecting line, the second end of the optocoupler element is connected to the third connecting line, the third and fourth ends of the optocoupler element are grounded, and the fifth end of the optocoupler element is connected to the first end of the second resistor; the second end of the second resistor is connected to the fourth connecting line; the common contact of the first switch is connected to the first power supply, the first contact of the first switch is connected to the second power supply of the circuit board to be tested through the fourth connecting line, the second contact of the first switch is connected to the first end of the third resistor, and the second end of the third resistor is connected to the alarm unit.

[0025] In this embodiment, an optocoupler element is used to cut off the path between the circuit board under test and the fault detection circuit when the circuit board under test is short-circuited, thereby protecting the circuit board under test.

[0026] In some embodiments of the present application, the positive electrode of the first switch is connected to the third connection line, and the negative electrode of the first switch is grounded;

[0027] When the circuit board to be tested does not have a short circuit, the first switch connects the first contact to connect the path between the first power supply and the second power supply, and turns off the at least one LED;

[0028] When a short circuit occurs on the circuit board to be tested, the first switch connects to the second contact to disconnect the path between the first power supply and the second power supply, and causes the at least one LED to light up alternately to indicate that a fault occurs on the circuit board to be tested.

[0029] In this embodiment, the conduction condition of the optocoupler element is utilized to cut off the path between the circuit board to be tested and the fault detection circuit when the circuit board to be tested is short-circuited, thereby protecting the circuit board to be tested.

[0030] In some embodiments of the present application, the fault detection circuit further includes a control component, wherein a first interface of the control component is connected to the positive electrode of the first switch, and a negative electrode of the first switch is grounded; and a second interface of the control component is connected to the third connection line;

[0031] The control component is configured to:

[0032] Respectively detecting level signals of the first interface and the second interface;

[0033] If the level signal of the first interface is at a low level and the level signal of the second interface is at a low level, controlling the first switch to connect the first contact to connect the path between the first power supply and the second power supply, and turning off the at least one LED;

[0034] If the level signal of the first interface is at a high level and the level signal of the second interface is at a high level, the first switch is controlled to connect the second contact to disconnect the path between the first power supply and the second power supply, and the at least one LED is alternately lit to indicate that the circuit board to be tested has a fault.

[0035] In this embodiment, the level signal at the output side of the optocoupler element is detected by the control component to control the state of the first switch according to the level signal.

[0036] In some embodiments of the present application, the fault detection circuit further includes a first connector configured to connect the first power supply and the switch control circuit;

[0037] The circuit board under test includes a second connector configured to connect the second power supply and the switch control circuit.

[0038] In this embodiment, the fault detection circuit and the circuit board to be tested are connected via a connector, which can improve test efficiency.

[0039] In a second aspect, the present application provides a fault detection device, comprising the fault detection circuit described in any one of the first aspects.

[0040] The fault detection device provided in the embodiment of the present application includes the fault detection circuit as described in any one of the above items, so the fault detection device has the technical effects of the fault detection circuit as described in any one of the above items, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the implementation methods in the embodiments of the present application or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technology descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0042] Figure 1 A schematic structural diagram of a circuit board fault detection circuit provided in an embodiment of the present application;

[0043] Figure 2 A schematic structural diagram of another circuit board fault detection circuit provided in an embodiment of the present application;

[0044] Figure 3 A schematic structural diagram of a fault detection circuit of another circuit board provided in an embodiment of the present application;

[0045] Figure 4 A schematic structural diagram of a switch control circuit 102 provided in an embodiment of the present application;

[0046] Figure 5 A schematic diagram of a first switch S1 disconnecting a path between the first power source 101 and the second power source 201;

[0047] Figure 6 A schematic structural diagram of another switch control circuit 102 provided in an embodiment of the present application;

[0048] Figure 7 A schematic structural diagram of another switch control circuit 102 provided in an embodiment of the present application;

[0049] Figure 8 A schematic diagram of a first switch S1 disconnecting a path between the first power source 101 and the second power source 201;

[0050] Figure 9 A schematic structural diagram of another switch control circuit 102 provided in an embodiment of the present application;

[0051] Figure 10 Schematic diagram of the first switch S1 disconnecting the path between the first power source 101 and the second power source 201.

[0052] Description of reference numerals:

[0053] 10-Fault detection circuit;

[0054] 101- first power supply;

[0055] 102- switch control circuit;

[0056] 103- warning unit;

[0057] 104-first connector;

[0058] 105-control component;

[0059] 20-circuit board to be tested;

[0060] 201- second power supply;

[0061] 202-second connector;

[0062] 21- third power supply;

[0063] 22- Optocoupler;

[0064] S1-first switch;

[0065] R1-first resistor;

[0066] R2-second resistor;

[0067] R3 - the third resistor. DETAILED DESCRIPTION

[0068] In order to make the purpose, implementation mode and advantages of the present application clearer, the exemplary implementation mode of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0069] It should be noted that the brief descriptions of terms in this application are only for the purpose of facilitating the understanding of the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their ordinary and usual meanings.

[0070] In addition, the terms "comprises" and "comprising" and any variations thereof are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to those components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0071] Typically, when performing fault detection on a circuit board under test, the power and signal lines of the detection device can be interconnected with the power and signal lines of the circuit board under test. Since it is unknown whether the power supply of the circuit board under test is faulty, if a power short circuit occurs on the circuit board under test, a large current will flow in the path between the power supply and the ground, which can easily expand the scope of the fault. At the same time, it will also short-circuit the power supply and ground of the detection device, posing a risk of damage to the detection device due to the high current.

[0072] During actual testing, when the tester knows that a short circuit has occurred on the electronic control board, they manually cut off the power. If the tester does not know whether a short circuit has occurred, the power cannot be cut off in time between the time the short circuit fault occurs and the tester confirms the fault, which may cause greater damage to the circuit board under test.

[0073] Therefore, the present application provides a fault detection circuit for a circuit board. By setting a switch control circuit between the power supply of the fault detection circuit and the power supply of the circuit board to be tested, when a short circuit fault occurs in the circuit board to be tested, the path between the first power supply and the second power supply is cut off to protect the fault detection circuit and reduce the risk of damage.

[0074] In an embodiment of the present application, the circuit board to be tested may be a circuit board used in a refrigeration device, such as a refrigerator. The circuit board to be tested may also be a circuit board used in other devices, and the present application does not impose any restrictions on this.

[0075] The technical solution of the present application is described in detail below in conjunction with specific embodiments. The following specific embodiments can be combined with each other or exist independently. For the same or similar concepts or processes, some embodiments may not be described in detail. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0076] Figure 1 A schematic diagram of a circuit board fault detection circuit according to an embodiment of the present application is shown in FIG. Figure 1 As shown, the fault detection circuit 10 includes a first power supply 101 and a switch control circuit 102 .

[0077] The first power supply 101 is connected to the second power supply 201 of the circuit board 20 under test via the switch control circuit 102. The first power supply 101 is configured to supply power to the fault detection circuit 10.

[0078] The switch control circuit 102 is configured to:

[0079] When a short circuit occurs in the circuit board 20 to be tested, the path between the first power source 101 and the second power source 201 is cut off.

[0080] In this embodiment, the fault detection circuit includes a first power supply and a switch control circuit. The first power supply is connected to a second power supply of the circuit board under test via the switch control circuit. The first power supply is configured to power the fault detection circuit. If a short circuit occurs in the circuit board under test, the switch control circuit is configured to cut off the path between the first power supply and the second power supply, thereby protecting the fault detection circuit and reducing the risk of damage.

[0081] In one possible implementation, Figure 2 A schematic diagram of the structure of another circuit board fault detection circuit provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the fault detection circuit 10 further includes an alarm unit 103 , which is connected to the first power supply 101 through the switch control circuit 102 .

[0082] When a short circuit occurs in the circuit board 20 to be tested, the switch control circuit 102 connects the path between the first power supply 101 and the alarm unit 103 , so that the alarm unit 103 prompts that a fault occurs in the circuit board 20 to be tested.

[0083] That is, an alarm unit 103 may be provided in the fault detection circuit 10 to indicate whether a fault occurs in the circuit board 20 to be tested.

[0084] In one possible implementation, the alarm unit 103 may include at least one light-emitting diode (LED). For example, at least one LED may be connected in series to form a light string, or may be connected in series and in parallel to form a light board. This application does not impose any restrictions on this.

[0085] The LED can be used to indicate whether the circuit board 20 to be tested has a fault, so that the tester can quickly determine whether the circuit board 20 to be tested has a fault based on the on / off status of the LED.

[0086] In a possible implementation, the alarm unit 103 may be a buzzer. When a short circuit fault occurs in the circuit board 20 to be tested, the buzzer emits an alarm tone to indicate that the circuit board to be tested has a fault.

[0087] It is understandable that the present application does not limit the specific structure of the alarm unit 103 , and the alarm unit 103 may also be other devices that can indicate that a fault has occurred in the circuit board 20 to be tested.

[0088] In one possible implementation, Figure 3 A schematic diagram of a circuit board fault detection circuit according to another embodiment of the present invention is shown in FIG. Figure 3 As shown, the fault detection circuit 10 further includes a first connector 104 configured to connect the first power supply 101 and the switch control circuit 102 , that is, the first power supply 101 and the switch control circuit 102 can be connected via the first connector 104 .

[0089] The circuit board under test 20 includes a second connector 202 configured to connect the second power supply 201 and the switch control circuit 102 . That is, the second power supply 201 and the switch control circuit 102 can be connected via the second connector 202 .

[0090] The first connector 104 and the second connector 202 may be pin connectors.

[0091] In this embodiment, the fault detection circuit 10 and the circuit board to be tested 20 are connected via the first connector 104 and the second connector 202 , which can improve the test efficiency.

[0092] Next, taking the example of the alarm unit 103 being composed of an LED, how the switch control circuit 102 cuts off the path between the first power supply 101 and the second power supply 201 when a short circuit occurs in the circuit board 20 to be tested is described.

[0093] Figure 4 A schematic diagram of the structure of a switch control circuit 102 provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the switch control circuit 102 includes a third power source 21 , a first switch S1 , a first resistor R1 , and a second resistor R2 .

[0094] The third power supply 21 is connected to the first end of the first resistor R1 via a first connecting line, and the second end of the first resistor R1 is connected to the second power supply 201 of the circuit board under test 20 via a second connecting line. The common contact of the first switch S1 is connected to the first power supply 101, the first contact of the first switch S1 is connected to the second connecting line, the second contact of the first switch S1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected to the alarm unit 103.

[0095] The positive electrode of the first switch S1 is connected to the first connection line, and the negative electrode of the first switch S1 is connected to the second connection line, so that the first switch S1 is connected in parallel with the first resistor R1. It is understood that the first switch S1 can be an analog switch, and power supply for the first switch S1 is required through the positive electrode interface and the negative electrode interface.

[0096] Among them, the supply voltage of the third power supply 21 is lower than the supply voltage of the first power supply 101. Exemplarily, the supply voltage of the third power supply 21 can be 5V (volts), and the supply voltage of the first power supply 101 can be 12V or 25V. The third power supply 21 can be used to power the first switch S1 and other components that require a lower voltage.

[0097] In a possible implementation, the initial state of the first switch S1 may be to connect the first contact. Figure 4 As shown, Figure 4This is a schematic diagram of the first switch S1 connecting to the first contact. After the fault detection circuit 10 is connected to the circuit board 20 under test, if the current flowing through the first resistor R1 is small, it means that there is no short circuit fault in the circuit board 20 under test at this time, and the voltage across the first resistor R1 is insufficient to drive the first switch S1 to work, so that the first switch S1 maintains the initial state, that is, the first contact is connected. The output voltage of the first power supply 101 of the fault detection circuit 10 forms a loop with the circuit board 20 under test through the first contact of the first switch S1. At this time, the alarm unit 103 is not connected, so that at least one LED in the alarm unit 103 is off.

[0098] If a short circuit occurs in the power supply of the circuit board 20 under test, the first switch S1 alternately connects the second contact and the first contact to make at least one LED alternately light up and go out, indicating that the circuit board 20 under test has a fault.

[0099] Specifically, such as Figure 5 As shown, Figure 5 This is a schematic diagram showing how the first switch S1 disconnects the path between the first power source 101 and the second power source 201. After the fault detection circuit 10 is connected to the circuit board 20 under test, if a large current flows through the first resistor R1, it indicates that a short circuit fault has occurred in the circuit board 20 under test. A large voltage is generated across the first resistor R1, causing the first switch S1 to connect to the second contact, i.e., switch from the first contact to the second contact, disconnecting the path between the first power source 101 and the second power source 201. Consequently, the voltage output from the first power source 101 of the fault detection circuit forms a loop with the alarm unit 103 through the second contact of the first switch S1, causing the LED in the alarm unit 103 to illuminate. At this point, the circuit of the circuit board 20 under test is disconnected, and no power is input to the circuit board under test. The current in the first resistor R1 decreases, and the voltage across it decreases, causing the first switch S1 to return to its initial state, i.e., switch to the first contact. The power output of the fault detection circuit 10 forms a loop with the circuit board 20 under test through the first contact of the first switch S1. At this point, the alarm unit 103 is disconnected, causing the LED in the alarm unit 103 to turn off. This process repeats. The LED of the warning unit 103 changes state from on-off-on-off, etc. to indicate that the circuit board to be tested has a fault.

[0100] It can be understood that this embodiment determines that a short circuit fault occurs in the circuit board 20 to be tested by the current flowing through the first resistor R1. When the current is large, the first switch S1 is automatically controlled to disconnect the path between the first power supply 101 of the fault detection circuit 10 and the second power supply 201 of the circuit board 20 to be tested, thereby protecting the circuit board 20 to be tested.

[0101] It should be noted that when the current flowing through the first resistor R1 increases to a certain value, and this current value causes the voltage across the first resistor R1 to be sufficient to drive the first switch S1 to operate, it indicates that a short circuit fault has occurred in the circuit board 20 under test. This application does not limit the magnitude of this current value. Similarly, when the current flowing through the first resistor R1 is insufficient to drive the first switch S1 to operate, that is, when the first switch S1 remains in its initial state, it indicates that the circuit board 20 under test has not experienced a short circuit fault.

[0102] Figure 6 This is a structural diagram of another switch control circuit 102 provided in an embodiment of the present application, as shown in FIG. Figure 6 As shown, the switch control circuit 102 includes an optocoupler element 22 , a first switch S1 , a first resistor R1 , a second resistor R2 , a third resistor R3 and a third power supply 21 . The supply voltage of the third power supply 21 is lower than the supply voltage of the first power supply 101 .

[0103] The third power supply 21 is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the first end of the optocoupler 22 via a third connecting line, the second end of the optocoupler 22 is connected to the third connecting line, the third and fourth ends of the optocoupler 22 are grounded, and the fifth end of the optocoupler 22 is connected to the first end of the second resistor R2. The second end of the second resistor R2 is connected to the fourth connecting line. The common contact of the first switch S1 is connected to the first power supply 101, the first contact of the first switch S1 is connected to the second power supply 201 of the circuit board 20 to be tested via the fourth connecting line, the second contact of the first switch S1 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the alarm unit 103.

[0104] based on Figure 6 The switch control circuit 102 can control the state of the first switch S1, that is, connect the first contact or the second contact, in the following two ways:

[0105] Method 1: Based on the conduction condition of the optical coupler 22 , the path between the circuit board 20 under test and the fault detection circuit 10 is cut off when the circuit board 20 under test is short-circuited.

[0106] Specifically, Figure 7 This is a structural diagram of another switch control circuit 102 provided in an embodiment of the present application, as shown in FIG. Figure 7 As shown, the positive electrode of the first switch S1 is connected to the third connection line, and the negative electrode of the first switch S1 is grounded.

[0107] When there is no short circuit fault in the circuit board 20 to be tested, Figure 7As shown, the voltage at the second end of the second resistor R2 is the power supply voltage, so that the optocoupler element 22 works, and the secondary side of the optocoupler element 22 (i.e., the transistor side of the optocoupler element 22) is turned on. The second end of the first resistor R1 is at a low level, so that the first switch S1 does not work, that is, is in the initial state (the first contact is connected), so that the path between the first power supply 101 and the second power supply 201 is connected. Figure 7 Schematic diagram of the first switch S1 connecting the path between the first power source 101 and the second power source 201.

[0108] When a short circuit fault occurs in the circuit board 20 to be tested, the voltage at the second end of the second resistor R2 is a low voltage, the optocoupler element 22 does not work, so that the secondary side of the optocoupler element 22 is not conductive, and the second end of the first resistor R1 is a high level, so that the first switch S1 works, switches from the initial state to connecting the second contact, cuts off the path between the first power supply 101 and the second power supply 201, and lights up the LED of the alarm unit 103 to indicate that a fault has occurred in the circuit board 20 to be tested. Figure 8 Schematic diagram of the first switch S1 disconnecting the path between the first power source 101 and the second power source 201.

[0109] Mode 2: The control component detects the level signal of the output side (the first interface and the second interface) of the optical coupling element 22 to control the state of the first switch S1 according to the level signal.

[0110] Specifically, Figure 9 This is a structural diagram of another switch control circuit 102 provided in an embodiment of the present application, as shown in FIG. Figure 9 As shown, the fault detection circuit 10 further includes a control component 105, a first interface of the control component 105 is connected to the positive electrode of the first switch S1, the negative electrode of the first switch is grounded, and a second interface of the control component 105 is connected to the third connection line.

[0111] The control component 105 is configured to:

[0112] The level signals of the first interface and the second interface are detected respectively.

[0113] If the level signal of the first interface is low and the level signal of the second interface is low, the first switch S1 is controlled to connect the first contact to connect the path between the first power supply 101 and the second power supply 201, and the LED of the alarm unit 103 is turned off.

[0114] like Figure 9As shown, if the circuit board 20 to be tested does not have a short circuit fault, the voltage at the second end of the second resistor R2 is the power supply voltage, the optocoupler 22 works, so that the secondary side of the optocoupler 22 (that is, the transistor side of the optocoupler 22) is turned on, resulting in the level signal of the second interface being low, the level signal of the first interface being low, and the first switch S1 not working, that is, in the initial state (the first contact is connected), so that the path between the first power supply 101 and the second power supply 201 is connected. Figure 9 Schematic diagram of the first switch S1 connecting the path between the first power source 101 and the second power source 201.

[0115] If the level signal of the first interface is high and the level signal of the second interface is high, the first switch S1 is controlled to connect the second contact to disconnect the path between the first power supply 101 and the second power supply 201, and the LED of the alarm unit 103 is lit to indicate that a fault has occurred in the circuit board 20 to be tested.

[0116] Figure 10 Schematic diagram of the first switch S1 disconnecting the path between the first power source 101 and the second power source 201, as shown in FIG. Figure 10 As shown, if a short circuit fault occurs in the circuit board 20 to be tested, the voltage at the second end of the second resistor R2 is a low voltage, and the optocoupler element 22 does not work, so that the secondary side of the optocoupler element 22 (i.e., the transistor side of the optocoupler element 22) is not turned on, resulting in the level signal of the second interface being a high level, and the level signal of the first interface being a high level. The first switch S1 works, switches from the initial state to connecting the second contact, cuts off the path between the first power supply 101 and the second power supply 201, and lights up the LED of the alarm unit 103 to indicate that a fault has occurred in the circuit board 20 to be tested.

[0117] In a possible implementation, the control component 105 may be a microcontroller unit (MCU). The first interface may be an input / output (IO) interface, and the second interface may be an analog-to-digital (AD) interface.

[0118] An embodiment of the present application provides a fault detection device, which includes any of the above-mentioned fault detection circuits.

[0119] It is understandable that the fault detection device may also include circuits or devices with other functions, which is not limited in this application.

[0120] In the embodiment of the present application, except for the first switch S1, 1 in the circuit diagram represents the first end, 2 represents the second end, 3 represents the third end, 4 represents the fourth end, and 5 represents the fifth end. Taking the first resistor R1 as an example, 1 of the first resistor R1 represents the first end of the first resistor R1, and 2 of the first resistor R1 represents the second end of the first resistor R1. 1 of the optocoupler element 22 represents the first end, 2 of the optocoupler element 22 represents the second end, 3 of the optocoupler element 22 represents the third end, 4 of the optocoupler element 22 represents the fourth end, and 5 of the optocoupler element 22 represents the fifth end. Other similarities will not be repeated here. 1 of the first switch S1 represents the first contact, and 2 of the first switch S1 represents the second contact. GND represents grounding.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0122] For ease of explanation, the above description has been presented in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations are possible. The above embodiments have been selected and described to better explain the principles and practical applications, thereby enabling those skilled in the art to better utilize the embodiments and various variations of the embodiments suitable for specific use considerations.

[0123] In this application, "at least one" means one or more. "Multiple" means two or more. The first, second, etc. descriptions that appear in the embodiments of this application are only for illustration and to distinguish the described objects. There is no order, nor does it represent a special limitation on the number of devices in the embodiments of this application, and cannot constitute any limitation on the embodiments of this application. For example, the first threshold and the second threshold are only for distinguishing different thresholds, and do not indicate the difference in size, priority, or importance of the two thresholds.

[0124] Throughout this application, the terms "exemplary," "in some embodiments," and "in other embodiments" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner.

[0125] In this application, the terms "of," "corresponding," "relevant," "corresponding," and "associated" may sometimes be used interchangeably. It should be noted that, when the distinction is not emphasized, the meanings they convey are consistent. In the embodiments of this application, the terms "communication" and "transmission" may sometimes be used interchangeably. It should be noted that, when the distinction is not emphasized, the meanings they convey are consistent. For example, "transmission" may include "sending" and / or "receiving," and may be either a noun or a verb.

[0126] In this application, "equal to" can be used in conjunction with "less than" or "greater than", but not with both "less than" and "greater than". When "equal to" is used in conjunction with "less than", the technical solution used for "less than" applies. When "equal to" is used in conjunction with "greater than", the technical solution used for "greater than" applies.

Claims

1. A circuit board fault detection circuit, characterized in that: include: a first power supply connected to a second power supply of the circuit board to be tested via a switch control circuit, the first power supply being configured to supply power to the fault detection circuit; The switch control circuit is configured as follows: When a short circuit occurs on the circuit board to be tested, the path between the first power supply and the second power supply is cut off.

2. The fault detection circuit according to claim 1, characterized in that: The fault detection circuit further includes an alarm unit, which is connected to the first power supply through the switch control circuit; When a short circuit occurs on the circuit board to be tested, the switch control circuit switches on a path between the first power supply and the alarm unit, so that the alarm unit prompts that a fault occurs on the circuit board to be tested.

3. The fault detection circuit according to claim 2, characterized in that: The warning unit includes at least one LED.

4. The fault detection circuit according to claim 3, characterized in that: The switch control circuit includes a third power supply, a first switch, a first resistor, a second resistor and a third power supply, wherein the supply voltage of the third power supply is lower than the supply voltage of the first power supply; The third power supply is connected to the first end of the first resistor via a first connecting line, and the second end of the first resistor is connected to the second power supply of the circuit board to be tested via a second connecting line; the common contact of the first switch is connected to the first power supply, the first contact of the first switch is connected to the second connecting line, and the second contact of the first switch is connected to the first end of the second resistor; and the second end of the second resistor is connected to the alarm unit; The positive electrode of the first switch is connected to the first connection line, and the negative electrode of the first switch is connected to the second connection line, so that the first switch is connected in parallel with the first resistor.

5. The fault detection circuit according to claim 4, characterized in that: When the circuit board to be tested does not have a short circuit, the first switch connects the first contact to turn off the at least one LED; When a short circuit occurs on the circuit board to be tested, the first switch alternately connects the second contact and the first contact to make the at least one LED alternately light up and go out, indicating that a fault occurs on the circuit board to be tested.

6. The fault detection circuit according to claim 3, characterized in that: The switch control circuit includes an optocoupler element, a first switch, a first resistor, a second resistor, a third resistor and a third power supply, wherein the supply voltage of the third power supply is lower than the supply voltage of the first power supply; In which, the third power supply is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the optocoupler element through a third connecting line, the second end of the optocoupler element is connected to the third connecting line, the third and fourth ends of the optocoupler element are grounded, and the fifth end of the optocoupler element is connected to the first end of the second resistor; the second end of the second resistor is connected to the fourth connecting line; the common contact of the first switch is connected to the first power supply, the first contact of the first switch is connected to the second power supply of the circuit board to be tested through the fourth connecting line, the second contact of the first switch is connected to the first end of the third resistor, and the second end of the third resistor is connected to the alarm unit.

7. The fault detection circuit according to claim 6, characterized in that: The positive electrode of the first switch is connected to the third connection line, and the negative electrode of the first switch is grounded; When the circuit board to be tested does not have a short circuit, the first switch connects the first contact to connect the path between the first power supply and the second power supply, and turns off the at least one LED; When a short circuit occurs on the circuit board to be tested, the first switch connects the second contact to light up the at least one LED, thereby disconnecting the path between the first power supply and the second power supply and indicating that a fault occurs on the circuit board to be tested.

8. The fault detection circuit according to claim 6, characterized in that: The fault detection circuit further includes a control component, wherein a first interface of the control component is connected to the positive electrode of the first switch, and a negative electrode of the first switch is grounded; and a second interface of the control component is connected to the third connection line; The control component is configured to: Respectively detecting level signals of the first interface and the second interface; If the level signal of the first interface is at a low level and the level signal of the second interface is at a low level, controlling the first switch to connect the first contact to connect the path between the first power supply and the second power supply, and turning off the at least one LED; If the level signal of the first interface is at a high level and the level signal of the second interface is at a high level, the first switch is controlled to connect the second contact to disconnect the path between the first power supply and the second power supply, and the at least one LED is alternately lit to indicate that the circuit board to be tested has a fault.

9. The fault detection circuit according to any one of claims 3 to 7, characterized in that: The fault detection circuit further includes a first connector configured to connect the first power supply and the switch control circuit; The circuit board under test includes a second connector configured to connect the second power supply and the switch control circuit.

10. A fault detection device, characterized in that: include: A fault detection circuit as claimed in any one of claims 1 to 9.

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