AC / DC switching circuit, circuit board, and driving device

Abstract

The application provides an AC-DC switching circuit, a circuit board and a driving device, relates to the technical field of electronic circuits, and solves the problem of poor practicability and reliability of the switching circuit in the prior art. The scheme realizes compatibility of AC and DC loads, can further accelerate the response speed of the switching circuit through driving of the driving module, realizes fast response to the control signal, has large output capacity so that the circuit can drive a large load, and can quickly turn off the switching circuit when a short circuit occurs in the subsequent circuit through the short circuit protection module, thereby effectively ensuring the safety of the equipment and improving the reliability of the circuit.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to an AC / DC output circuit, a circuit board, and a driving device. Background Art

[0002] Devices that need to output two on / off states, such as relays, solenoid valves, lamps, and motors, require a controlled drive output signal. This requires an output circuit to achieve this output. Commonly used output circuits in related technologies typically employ mechanical relay outputs, solid-state relay outputs, and other methods.

[0003] Among them, the mechanical relay output method has a slow response speed and a limited life span of the number of operations, which makes the circuit less practical. While the solid-state relay output method can have a faster response speed and no life span limit on the number of operations, its output capacity is small, making it difficult to apply to high-current control scenarios, which in turn leads to poor circuit practicality. Moreover, the output circuit in the related art does not have a short-circuit protection function. Once a short circuit occurs in the loop, it is very easy to cause damage to the components in the circuit. Therefore, the practicality and reliability of the output circuit in the related art are poor, and it is difficult to be widely used in various scenarios. Summary of the Invention

[0004] The present application provides an AC / DC switching circuit, a circuit board, and a driving device, which solves the problem of poor practicality and reliability of the switching circuit in the related art. This solution is compatible with AC / DC loads, so that the circuit has a faster response speed while also improving the output capacity, and provides short-circuit protection for the circuit, which helps make the circuit more practical and reliable.

[0005] In the first aspect, the present application provides an AC / DC output circuit, which is used to receive a control signal output by a main control device and output a signal corresponding to the switching state to a subsequent circuit, and output a short-circuit signal to the main control device when a short circuit occurs. The AC / DC output circuit includes a signal isolation module, a drive module, a main circuit module and a short-circuit protection module.

[0006] The input end of the signal isolation module is connected to the main control device. The signal isolation module is used to isolate the signal of the main control device and transmit the control signal when receiving the control signal;

[0007] The input end of the driving module is connected to the output end of the signal isolation module. The driving module is used to output the amplified driving current when receiving a control signal, and provide a discharge path for the subsequent circuit when not receiving a control signal.

[0008] The input end of the main circuit module is connected to the output end of the drive module, and the output end of the main circuit module is used to connect to the subsequent circuit;

[0009] The power supply input end of the short-circuit protection module is connected to the output end of the signal isolation module, the drive control end of the short-circuit protection module is connected to the signal providing end of the drive module, the first short-circuit detection end of the short-circuit protection module is connected to the first short-circuit prompt end of the main circuit module, the second short-circuit detection end of the short-circuit protection module is connected to the second short-circuit prompt end of the main circuit module, and the output end of the short-circuit protection module is connected to the main control device. The short-circuit protection module is used to control the drive module to stop driving the main circuit module when a short circuit is detected, and output a short-circuit signal to the main control device.

[0010] In a second aspect, the present application further provides a circuit board, which includes the AC / DC output circuit provided in the first aspect.

[0011] In a third aspect, the present application also provides a driving device, which includes the circuit board provided in the second aspect.

[0012] The AC / DC circuit of the present application achieves compatibility with AC / DC loads. The drive module can further accelerate the response speed of the output circuit and achieve a rapid response to the control signal. The output capacity is large so that the circuit can drive a larger load. Moreover, the short-circuit protection module can quickly shut down the output circuit when a short circuit occurs in the subsequent circuit, thereby effectively ensuring the safety of the equipment and improving the reliability of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A block diagram of the AC / DC output circuit provided in one embodiment of the present application;

[0014] Figure 2 A schematic diagram of the circuit structure of a signal isolation module provided in one embodiment of the present application;

[0015] Figure 3 A schematic diagram of the circuit structure of a driving module provided in one embodiment of the present application;

[0016] Figure 4 A schematic diagram of the circuit structure of a main circuit module provided in one embodiment of the present application;

[0017] Figure 5 A schematic diagram of the circuit structure of a short-circuit shutdown unit provided in one embodiment of the present application;

[0018] Figure 6 A schematic diagram of the circuit structure of a signal feedback unit provided in one embodiment of the present application;

[0019] Figure 7 A schematic diagram of the circuit structure of an AC / DC switching circuit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0020] The embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and examples. It will be understood that the specific embodiments described herein are merely used to explain the embodiments of the present application, rather than to limit the embodiments of the present application. It should also be noted that, for ease of description, only portions related to the embodiments of the present application, rather than all structures, are shown in the accompanying drawings. After reading this specification, those skilled in the art should be able to understand that, as long as the technical features do not contradict each other, any combination of the technical features may constitute an optional embodiment.

[0021] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated before and after are in an "or" relationship. In the description of this application, "multiple" means two or more, and "several" means one or more.

[0022] Devices that need to output two on / off states, such as relays, solenoid valves, lamps, and motors, require a controlled drive output signal. This requires an output circuit to achieve this output. Commonly used output circuits in related technologies typically employ mechanical relay outputs, solid-state relay outputs, and other methods.

[0023] Among them, the mechanical relay output method has a slow response speed, and the mechanical relay has a life span of actuation times, which makes the circuit practicality poor; while the solid-state relay output method can have a faster response speed and no life span limit of actuation times, its output capacity is small, making it difficult to apply to high current control scenarios, which in turn leads to poor practicality of the circuit. Moreover, the output circuit in the related art does not have a short-circuit protection function. Once a short circuit occurs in the loop, it is very easy to cause damage to the components in the circuit. For this reason, the output circuit in the related art has poor practicality and reliability, and is difficult to be widely used in various scenarios. For example, it is difficult to achieve compatibility for AC and DC application scenarios.

[0024] In this regard, the present application provides an AC / DC output circuit, which can be applied to relay protection devices, relay coils, solenoid valves, lamps, motors, etc. as corresponding drive units. Of course, the circuit can also play the role of transmitting switching signals. Figure 1 This is a principle block diagram of an AC / DC output circuit provided in one embodiment of the present application. The circuit is compatible with AC and DC loads. The circuit has a faster response speed while improving output capacity and providing short-circuit protection, which helps make the circuit more practical and reliable.

[0025] It is understood that the AC / DC output circuit is connected to the main control device, such as by connecting to an I / O interface on the main control device to receive control signals output by the main control device or send a short-circuit signal to the main control device. In other words, the AC / DC output circuit is used to receive the control signal output by the main control device and output a signal corresponding to the switch state to the subsequent circuit (such as a load, drive circuit, etc.), and output a short-circuit signal to the main control device in the event of a short circuit. The switch state includes an on state and an off state. Therefore, the AC / DC output circuit can provide the subsequent circuit with a signal corresponding to the on state or the off state according to the control signal output by the main control device.

[0026] like Figure 1 As shown, the AC / DC output circuit includes a signal isolation module 110, a drive module 120, a main circuit module 130, and a short-circuit protection module 140. The input end of the signal isolation module 110 is connected to the main control device, the input end of the drive module 120 is connected to the output end of the signal isolation module 110, the input end of the main circuit module 130 is connected to the output end of the drive module 120, and the output end of the main circuit module 130 is used to connect to the subsequent circuit. The power supply input end of the short-circuit protection module 140 is connected to the output end of the signal isolation module 110, the drive control end of the short-circuit protection module 140 is connected to the signal supply end of the drive module 120, the first short-circuit detection end of the short-circuit protection module 140 is connected to the first short-circuit prompt end of the main circuit module 130, the second short-circuit detection end of the short-circuit protection module 140 is connected to the second short-circuit prompt end of the main circuit module 130, and the output end of the short-circuit protection module 140 is connected to the main control device.

[0027] It is understood that the signal isolation module 110 isolates signals from the main control device and transmits the control signal when it receives it. The driver module 120 outputs an amplified drive current when it receives the control signal to shorten the conduction time of the main circuit module 130. Furthermore, the driver module 120 provides a discharge path for the subsequent circuit when it does not receive the control signal.

[0028] When a short circuit occurs, such as a load short circuit or a drive circuit short circuit in the subsequent circuit, the voltage and current of the main circuit module 130 increase. The short-circuit protection module 140 can shut down the drive module 120 when a short circuit is detected, that is, control the drive module 120 to stop driving the main circuit module 130 and stop providing a large drive voltage, so that the main circuit module 130 no longer provides a conductive loop for the subsequent circuit, achieving shutdown, and outputting a short-circuit signal to the main control device. It can be seen that the AC / DC circuit achieves compatibility with AC / DC loads, and the drive module can further accelerate the response speed of the output circuit through the drive module, achieving a rapid response to the control signal, and the output capacity is large so that the circuit can drive a large load. Moreover, the short-circuit protection module can quickly shut down the output circuit when a short circuit occurs in the subsequent circuit, thereby effectively ensuring the safety of the equipment and improving the reliability of the circuit.

[0029] In some embodiments, the signal isolation module includes a first resistor, a first photoelectric coupler, and a second resistor, wherein the anode end of the first photoelectric coupler is connected to the main control device via the first resistor, the cathode end of the first photoelectric coupler is grounded, the collector end of the first photoelectric coupler is connected to the operating voltage, the emitter end of the first photoelectric coupler is connected to the first end of the second resistor, and the second end of the second resistor is grounded. It can be understood that when the first photoelectric coupler receives a control signal provided by the main control device, such as when the control signal is a high-level signal, the first photoelectric coupler is turned on and the emitter end thereof provides an optical signal to the receiver end, causing the emitter end on the receiver side to output a high-level signal, that is, the potential of the first end of the second resistor serving as a pull-down resistor increases, thereby providing a high-level signal to the driver module. Of course, when the main control device provides a low-level signal, the first photoelectric coupler does not meet the conduction condition, and the signal isolation module no longer provides a high-level signal to the driver module, causing the driver module to stop driving and providing a discharge path for the subsequent circuit. Therefore, through the isolation of the first photoelectric coupler, small signal fluctuations on the main control device will not affect the AC / DC output circuit, thereby making the circuit more practical and reliable.

[0030] In one embodiment, the signal isolation module further includes a power isolation unit, which can isolate the wave points of the external power supply, thereby helping to maintain the stability of the AC / DC output circuit. Optionally, the power isolation unit includes a DCDC converter, a first capacitor and a second capacitor. Specifically, the input end of the DCDC converter is connected to the external power supply, and the input end of the DCDC converter is connected to the grounded first capacitor. The output end of the DCDC converter is used to provide an operating voltage for the circuit, and the output end of the DCDC converter is connected to the grounded second capacitor. It can be understood that the input and output of the DCDC converter are filtered by the first capacitor and the second capacitor, thereby filtering out the ripple components in the external power supply and filtering out the ripple in the output voltage, thereby stabilizing the voltage of the input and output ends of the DCDC converter; and the DCDC converter is equivalent to a transformer, which completely isolates the input power supply (i.e., the external power supply) from the output load, avoids the transmission of electrical interference, and achieves electrical isolation.

[0031] For example, Figure 2 As shown, Figure 2 A schematic diagram of the circuit structure of a signal isolation module provided in an embodiment of the present application, in one embodiment, the signal isolation module is connected to the main control device through a first resistor R1, and the first resistor R1 is also connected to the emitting anode end of the first photoelectric coupler U1, the receiving collector end of the first photoelectric coupler U1 is connected to the working voltage (such as a 12V working voltage), the receiving emitter end of the first photoelectric coupler U1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is grounded. In addition, the input end of the DCDC converter U2 is connected to an external power supply, and the input end of the DCDC converter U2 is connected to the grounded first capacitor C1, and the output end of the DCDC converter U2 is connected to the grounded second capacitor C2, and then the above-mentioned working voltage is provided to the circuit through the output end of the DCDC converter U2. Therefore, when the main control device outputs a high-level control signal, the first photoelectric coupler U1 is turned on, thereby increasing the potential of the second resistor R2, thereby providing a high-level signal to the drive module, so that the drive module can provide a larger driving voltage to the main loop module.

[0032] It should be noted that, in some embodiments, the power isolation unit may also use an isolated DCDC circuit such as a DCM flyback converter circuit or a single-switch forward converter circuit to achieve electrical isolation between the external power supply and the circuit load.

[0033] Figure 3 A schematic diagram of the circuit structure of a driving module provided in an embodiment of the present application is shown in FIG. Figure 3As shown, in one embodiment, the driving module includes a third resistor R3, a first NPN transistor Q1, a first PNP transistor Q2 and a fourth resistor R4. The driving module forms a push-pull output circuit through the first NPN transistor Q1 and the first PNP transistor Q2, so that only one transistor is turned on when the driving module is working, thereby being able to feed current to the subsequent stage, thereby providing a driving voltage to the main control module through the corresponding resistor (such as the fourth resistor R4 in the figure), and also extracting current from the subsequent stage to provide a discharge channel for the main control module.

[0034] Specifically, the first end of the third resistor R3 serves as the input of the driver module to receive the control signal. The second end of the third resistor R3 is connected to the base of the first NPN transistor Q1 and the base of the first PNP transistor Q2. The first end of the fourth resistor R4 is connected to the emitter of the first NPN transistor Q1 and the emitter of the first PNP transistor Q2. The second end of the fourth resistor R4 serves as the output of the driver module to connect to the input of the main circuit module. The collector of the first NPN transistor Q1 is connected to the operating voltage; the collector of the first PNP transistor Q2 is grounded.

[0035] It is understood that when a high-level signal is applied to the third resistor R3, the first NPN transistor Q1 is turned on and the first PNP transistor Q2 is turned off, thereby amplifying the applied drive current and providing a larger drive current to the subsequent main circuit module via the fourth resistor R4, thereby driving the main circuit module to conduct. In addition, when a low-level signal is applied to the third resistor R3, the first NPN transistor Q1 is turned off and the first PNP transistor Q2 is turned on, thereby providing a discharge channel for the subsequent circuit via the fourth resistor R4.

[0036] Therefore, the AC / DC output circuit can improve the driving capability of the circuit through the driving module, and can increase the size of the driving current, thereby avoiding the situation where the driving capability of the control signal is small and the main loop circuit cannot be quickly switched on and off, which helps to achieve fast switching control.

[0037] Figure 4 A circuit structure diagram of a main circuit module provided in one embodiment of the present application is shown in the figure. As shown in the figure, in one embodiment, the main circuit module includes a first NMOS transistor Q3, a second NMOS transistor Q4, a fifth resistor R5, a sixth resistor R6, a TVS (Transient Voltage Suppressor) transistor D1, an overcurrent fuse F1 and a temperature fuse KF1.

[0038] Specifically, the gate terminal of the first NMOS Q3 is connected to the gate terminal of the second NMOS Q4, the source terminal of the first NMOS Q3 is connected to the fifth resistor R5 grounded, the drain terminal of the first NMOS Q3 is connected to one end of the over-current fuse F1, the source terminal of the second NMOS Q4 is connected to the sixth resistor R6 grounded, the first terminal of the TVS D1 is connected to the drain terminal of the first NMOS Q3, the second terminal of the TVS D1 is connected to one end of the temperature fuse KF1, and the other end of the temperature fuse KF1 is connected to the drain terminal of the second NMOS Q4.

[0039] The source terminal of the first NMOS Q3 is the first short-circuit prompt terminal of the main circuit module, the source terminal of the second NMOS Q4 is the second short-circuit prompt terminal of the main circuit module, the other end of the over-current fuse F1 and the drain terminal of the second NMOS Q4 are used for connecting the subsequent circuit, and the other end of the over-current fuse F1 and the drain terminal of the second NMOS Q4 are the output terminals of the main circuit module. In addition, the over-current fuse F1 is fused when the subsequent circuit is short-circuited or over-current, and the temperature fuse KF1 is placed adjacent to the TVS D1, and when the temperature of the TVS D1 rises to the melting point temperature of the temperature fuse KF1, the temperature fuse KF1 is disconnected, thereby preventing the occurrence of fire and smoke and other fire safety problems.

[0040] It can be understood that the fifth resistor R5 and the sixth resistor R6 are connected in common source to ground, and the connection can reversely connect the body diodes of the two MOS tubes to each other, thereby achieving AC load control. Meanwhile, the gate terminals of the two MOS tubes are connected, so that the two MOS tubes are simultaneously controlled by controlling the voltage of the gate terminal. The fifth resistor R5 and the sixth resistor R6 collect the main circuit current and provide an electrical signal for triggering short-circuit protection for the short-circuit protection module. When the gate terminals of the first NMOS Q3 and the second NMOS Q4 are connected to a high-level signal, the first NMOS Q3 and the second NMOS Q4 are turned on, thereby providing a conducting circuit for the subsequent circuit, i.e., providing an electrical signal corresponding to the on-off state of the subsequent circuit. When the subsequent circuit is short-circuited, the main circuit current rises, causing the voltage across the fifth resistor R5 and the sixth resistor R6 to also rise, thereby triggering short-circuit protection, so that the driving of the two MOS tubes is stopped, and the MOS tubes are turned off and the conducting circuit is turned off.

[0041] Therefore, the MOS tubes in the main circuit module in the circuit can provide on-off control of the circuit for the subsequent circuit, and can be turned off in time when short-circuited, thereby improving the reliability of the circuit.

[0042] In some embodiments, the short-circuit protection module includes a short-circuit shutdown unit and a signal feedback unit, wherein the first input end of the short-circuit shutdown unit serves as the first short-circuit detection end of the short-circuit protection module, the second input end of the short-circuit shutdown unit serves as the second short-circuit detection end of the short-circuit protection module, the power supply end of the short-circuit shutdown unit serves as the power supply input end of the short-circuit protection module and is connected to the output end of the signal isolation module, the output end of the short-circuit shutdown unit is connected to the signal receiving end of the signal feedback unit, the power supply end of the signal feedback unit is connected to the power supply end of the short-circuit shutdown unit, and the output end of the signal feedback unit is connected to the main control device.

[0043] It is understood that the short-circuit shutdown unit is used to provide a ground path for the driver module when a voltage signal corresponding to a short circuit is connected to the first input terminal and / or the second input terminal, thereby controlling the driver module to stop driving the main circuit module, while the signal feedback unit is used to output a short-circuit signal to the main control device when the output terminal of the short-circuit shutdown unit provides a ground path for the driver module. In other words, the short-circuit protection module controls the driver module to shut down through the short-circuit shutdown unit thereon, thereby shutting down the corresponding circuit. At the same time as the shutdown control is being performed, the short-circuit signal is also output to the main control device through the signal feedback unit thereon, so that the main control device can determine that a short circuit exists.

[0044] For example, Figure 5 As shown, Figure 5 This is a circuit structure diagram of a short-circuit shutdown unit provided in one embodiment of the present application. In one embodiment, the short-circuit shutdown unit includes a first diode D2, a second diode D3, a second PNP transistor Q5, a second NPN transistor Q6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and a third capacitor C3.

[0045] Among them, the anode end of the first diode D2 and the anode end of the second diode D3 serve as the first input end and the second input end of the short-circuit shutdown unit respectively to be turned on when the corresponding short-circuit voltage signal is connected, the cathode end of the first diode D2 and the cathode end of the second diode D3 are connected, and the cathode end of the first diode D2 is also connected to the collector end of the second PNP transistor Q5.

[0046] The emitter end of the second PNP transistor Q5 is connected to one end of the seventh resistor R7, and the other end of the seventh resistor R7 serves as the power supply end of the short-circuit shutdown unit. The base end of the second PNP transistor Q5 is connected to the first end of the eighth resistor R8, and the second end of the eighth resistor R8 serves as the output end of the short-circuit shutdown unit.

[0047] The collector terminal of the second NPN transistor Q6 is connected to the second end of the eighth resistor R8, the base terminal of the second NPN transistor Q6 is connected to the emitter terminal of the second NPN transistor Q6 through the ninth resistor R9, the third capacitor C3 is connected in parallel to the ninth resistor R9, the base terminal of the second NPN transistor Q6 is also connected to the collector terminal of the second PNP transistor Q5 through the tenth resistor R10, and the emitter terminal of the second NPN transistor Q6 is grounded.

[0048] It is understandable that when a short circuit occurs, the main loop current rises rapidly, causing the voltage connected to the first diode D2 and the second diode D3 to also rise rapidly. This voltage can form a loop through the first diode D2, the second diode D3, the tenth resistor R10, and the second NPN transistor Q6 to provide a drive current to the base terminal of the second NPN transistor Q6. Then, when the base terminal voltage of the second NPN transistor Q6 meets the conduction condition, the second NPN transistor Q6 is turned on, pulling down the input of the driver module, thereby achieving shutdown, so that the main loop module no longer provides a conductive loop for the subsequent circuit. In addition, the RC filter circuit formed by the ninth resistor R9 and the third capacitor C3 can filter out interference generated during voltage jumps to prevent the second NPN transistor Q6 from being misdirected.

[0049] At the same time, the conduction of the second NPN transistor Q6 causes the eighth resistor R8 to be connected to a low level, thereby turning on the second PNP transistor Q5, thereby providing a conduction loop for the base terminal of the second NPN transistor Q6 through the seventh resistor R7, the second PNP transistor Q5, the tenth resistor R10, and the second NPN transistor Q6, and forming positive feedback, so that the second NPN transistor Q6 remains conductive when the main circuit module is also turned off, thereby continuously pulling the input of the driver module low.

[0050] Therefore, through the short-circuit shutdown unit, the circuit can be shut down in time when a short circuit occurs, and can also achieve positive feedback to maintain shutdown, which helps to improve the reliability of the circuit.

[0051] For example, Figure 6 As shown, Figure 6A schematic diagram of the circuit structure of a signal feedback unit provided in one embodiment of the present application, in one embodiment, the signal feedback unit includes an eleventh resistor R11, a twelfth resistor R12, a fourth capacitor C4, and a second photoelectric coupler U3. The anode end of the second photoelectric coupler U3 is connected to the first end of the eleventh resistor R11, the second end of the eleventh resistor R11 serves as the power supply end of the signal feedback unit, and the cathode end of the second photoelectric coupler U3 serves as the signal receiving end of the signal feedback unit. The receiving collector end of the second photoelectric coupler U3 is connected to an external power supply, the receiving emitter end of the second photoelectric coupler is connected to a main control device, and the receiving emitter end of the second photoelectric coupler U3 is also connected to the grounded twelfth resistor R12, and the fourth capacitor C4 is connected in parallel to the twelfth resistor R12.

[0052] It is understood that after the input circuit of the second photocoupler U3 is turned on, it can output a short-circuit signal to the master device, allowing the master device to pull down the control signal or shut down the output of the control signal, thereby shutting down the output of the signal isolation module. The fourth capacitor C4 and the twelfth resistor R12 can form an RC filter, thereby allowing the second photocoupler to provide a stable short-circuit signal to the master device.

[0053] As can be seen from the above scheme, the short-circuit protection module can achieve short-circuit protection for the output circuit, preventing equipment from being damaged by short circuits. In the case of compatibility with AC and DC loads, the circuit provides corresponding short-circuit protection to make the circuit more practical and reliable.

[0054] Figure 7 This is a schematic diagram of the circuit structure of an AC / DC output circuit provided in one embodiment of the present application, as shown in FIG. Figure 7 As shown, in one embodiment, the AC / DC output circuit includes a signal isolation module 110 , a drive module 120 , a main circuit module 130 and a short circuit protection module 140 .

[0055] In the signal isolation module 110, a first resistor R1 is connected to the main control device and is also connected to the anode terminal of a first photocoupler U1. The collector terminal of the first photocoupler U1 is connected to an operating voltage (e.g., a 12V operating voltage). The emitter terminal of the first photocoupler U1 is connected to the first terminal of a second resistor R2, and the second terminal of the second resistor R2 is grounded. In addition, the input terminal of the DCDC converter U2 is connected to an external power supply, the input terminal of the DCDC converter U2 is connected to a grounded first capacitor C1, and the output terminal of the DCDC converter U2 is connected to a grounded second capacitor C2, thereby providing the aforementioned operating voltage to the circuit through the output terminal of the DCDC converter U2.

[0056] In the driver module 120, a first end of a third resistor R3 is connected to the first photocoupler U1, and a second end of the third resistor R3 is connected to the base terminal of the first NPN transistor Q1 and the base terminal of the first PNP transistor Q2. A first end of a fourth resistor R4 is connected to the emitter terminal of the first NPN transistor Q1 and the emitter terminal of the first PNP transistor Q2. The collector terminal of the first NPN transistor Q1 is connected to the operating voltage; the collector terminal of the first PNP transistor Q2 is grounded.

[0057] In the main circuit module 130, the gate terminal of the first NMOS transistor Q3 is connected to the gate terminal of the second NMOS transistor Q4, and the gate terminals of the first NMOS transistor Q3 and the second NMOS transistor Q4 are both connected to the second end of the fourth resistor R4. The source terminal of the first NMOS transistor Q3 is connected to the grounded fifth resistor R5, the drain terminal of the first NMOS transistor Q3 is connected to one end of the overcurrent fuse F1, the source terminal of the second NMOS transistor Q4 is connected to the grounded sixth resistor R6, the first end of the TVS transistor D1 is connected to the drain terminal of the first NMOS transistor Q3, the second end of the TVS transistor D1 is connected to one end of the thermal fuse KF1, and the other end of the thermal fuse KF1 is connected to the drain terminal of the second NMOS transistor Q4.

[0058] In the short-circuit protection module 140, the anode terminal of the first diode D2 is connected to the source terminal of the first NMOS transistor Q3, and the anode terminal of the second diode D3 is connected to the source terminal of the second NMOS transistor Q4, so as to be turned on when the voltage signal corresponding to the short circuit is connected. The cathode terminal of the first diode D2 is connected to the cathode terminal of the second diode D3, and the cathode terminal of the first diode D2 is also connected to the collector terminal of the second PNP transistor Q5. The emitter terminal of the second PNP transistor Q5 is connected to one end of the seventh resistor R7, and the other end of the seventh resistor R7 serves as the power supply terminal of the short-circuit shutdown unit. The base terminal of the second PNP transistor Q5 is connected to the first end of the eighth resistor R8, and the second end of the eighth resistor R8 serves as the output terminal of the short-circuit shutdown unit. The collector terminal of the second NPN transistor Q6 is connected to the second end of the eighth resistor R8, the base terminal of the second NPN transistor Q6 is connected to the emitter terminal of the second NPN transistor Q6 through the ninth resistor R9, the third capacitor C3 is connected in parallel to the ninth resistor R9, the base terminal of the second NPN transistor Q6 is also connected to the collector terminal of the second PNP transistor Q5 through the tenth resistor R10, and the emitter terminal of the second NPN transistor Q6 is grounded.

[0059] In addition, the anode end of the second photocoupler U3 is connected to the first end of the eleventh resistor R11, the second end of the eleventh resistor R11 serves as the power supply end of the signal feedback unit, and the cathode end of the second photocoupler U3 serves as the signal receiving end of the signal feedback unit. The receiving collector end of the second photocoupler U3 is connected to an external power supply, the receiving emitter end of the second photocoupler U3 is connected to the main control device, and the receiving emitter end of the second photocoupler U3 is also connected to the grounded twelfth resistor R12. The fourth capacitor C4 is connected in parallel with the twelfth resistor R12.

[0060] In this regard, in this circuit, when the main control device outputs a high-level control signal, the first optocoupler U1 is turned on, thereby increasing the potential of the second resistor R2, and thus causing the third resistor R3 to receive the high-level signal. When the third resistor R3 receives the high-level signal, the first NPN transistor Q1 is turned on and the first PNP transistor Q2 is turned off, thereby amplifying the received drive current, thereby providing a larger drive current to the subsequent main loop module 130 via the fourth resistor R4. It can be understood that in circuit analysis, the gate terminal of the first NMOS transistor Q3 and the gate terminal of the second NMOS transistor Q4 can be equivalent to a capacitor. When a large drive current is received, the voltage value of the capacitor can be quickly raised, so that the voltage of the gate terminal of the first NMOS transistor Q3 and the gate terminal of the second NMOS transistor Q4 can reach the conduction voltage value more quickly, thereby shortening the conduction time of the MOS transistor.

[0061] After amplification by the first NPN transistor Q1, the gate terminals of the first NMOS transistor Q3 and the second NMOS transistor Q4 can quickly reach voltage values ​​that meet the conduction conditions, and then the first NMOS transistor Q3 and the second NMOS transistor Q4 are both turned on, thereby providing an open circuit for the subsequent circuit.

[0062] When a short circuit occurs, the current in the main loop rises rapidly, causing the voltage connected to the first diode D2 and the second diode D3 to also rise rapidly. This voltage can form a loop through the first diode D2, the second diode D3, the tenth resistor R10, and the second NPN transistor Q6 to provide a drive current for the base terminal of the second NPN transistor Q6. Then, when the base terminal voltage of the second NPN transistor Q6 meets the conduction condition, the second NPN transistor Q6 is turned on, so that the base terminal of the first NPN transistor Q1 and the base terminal of the first PNP transistor Q2 are connected to a low level. The first NPN transistor Q1 is turned off, and the first PNP transistor Q2 is turned on. As a result, the driver module no longer provides a drive voltage to the first NMOS transistor Q3 and the second NMOS transistor Q4. The first NMOS transistor Q3 and the second NMOS transistor Q4 are turned off and no longer provide a conductive loop for the subsequent circuit.

[0063] When the second NPN transistor Q6 is turned on, the U3 input circuit is also turned on through the first photocoupler U1, the eleventh resistor R11, the second photocoupler U2, and the sixth NPN transistor Q6, thereby triggering the control signal isolation circuit to output a short-circuit signal to the main control device through DOUT_FAULT, so that the main control device can pull down the control signal output by DOUT after receiving the short-circuit signal, thereby turning off the output of the first photocoupler U1, and then pulling down the input of the driver module. At the same time, the conduction circuit at the base end of the second NPN transistor Q6 is also closed, thereby canceling the trigger state of the short-circuit protection module.

[0064] It can be seen from the above scheme that the AC / DC circuit achieves compatibility with AC / DC loads. The drive of the push-pull circuit can further accelerate the response speed of the output circuit and achieve a fast response to the control signal. The output capacity is large so that the circuit can drive a larger load. Moreover, by utilizing the short-circuit protection function provided, the output circuit can be quickly shut down when a short circuit occurs in the load, thereby effectively ensuring the safety of the equipment and improving the reliability of the circuit.

[0065] An embodiment of the present application also provides a circuit board, which includes the AC / DC output circuit provided in the above embodiment, which can achieve compatibility with AC / DC loads, and through the drive module thereon, can further accelerate the response speed of the output circuit, achieve a rapid response to the control signal, and has a large output capacity so that the circuit can drive a larger load, and through the short-circuit protection module thereon, can quickly shut down the output circuit when a short circuit occurs in the subsequent circuit, thereby effectively ensuring the safety of the equipment and improving the reliability of the circuit.

[0066] An embodiment of the present application also provides a driving device, which includes the circuit board provided in the above embodiment. The driving device is compatible with AC and DC loads, has a faster response speed to the control signal output by the main control device, and can also provide short-circuit protection, so that the safety of the device is guaranteed and the reliability of the device is effectively improved.

[0067] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0068] Note that the above are only preferred embodiments of the present application and the technical principles employed. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present application. The scope of the present application is determined by the scope of the appended claims.

Claims

1. An AC / DC output circuit, characterized in that: The AC / DC output circuit is used to receive a control signal output by a main control device and output a signal corresponding to the switch state to a subsequent circuit, and output a short-circuit signal to the main control device in the event of a short circuit. The AC / DC output circuit includes: a signal isolation module, wherein an input end of the signal isolation module is connected to the main control device, and the signal isolation module is used to isolate the signal of the main control device and transmit the control signal when receiving the control signal; a driving module, wherein an input end of the driving module is connected to an output end of the signal isolation module, the driving module is configured to output an amplified driving current when receiving the control signal, and provide a discharge path for a subsequent circuit when not receiving the control signal; A main circuit module, wherein the input end of the main circuit module is connected to the output end of the driving module, and the output end of the main circuit module is used to connect to the subsequent circuit; A short-circuit protection module, wherein the power supply input end of the short-circuit protection module is connected to the output end of the signal isolation module, the drive control end of the short-circuit protection module is connected to the signal providing end of the drive module, the first short-circuit detection end of the short-circuit protection module is connected to the first short-circuit prompt end of the main circuit module, the second short-circuit detection end of the short-circuit protection module is connected to the second short-circuit prompt end of the main circuit module, and the output end of the short-circuit protection module is connected to the main control device. The short-circuit protection module is used to control the drive module to stop driving the main circuit module when a short circuit is detected, and output a short-circuit signal to the main control device; Wherein, the short-circuit protection module includes a short-circuit shutdown unit and a signal feedback unit, the first input end of the short-circuit shutdown unit serves as the first short-circuit detection end of the short-circuit protection module, the second input end of the short-circuit shutdown unit serves as the second short-circuit detection end of the short-circuit protection module, the power supply end of the short-circuit shutdown unit serves as the power supply input end of the short-circuit protection module and is connected to the output end of the signal isolation module, the output end of the short-circuit shutdown unit is connected to the signal receiving end of the signal feedback unit, and the short-circuit shutdown unit is used to provide a grounding path for the driving module when the first input end and / or the second input end are connected to a voltage signal corresponding to a short circuit, so as to control the driving module to stop driving the main loop module; The power supply end of the signal feedback unit is connected to the power supply end of the short-circuit shutdown unit, the output end of the signal feedback unit is connected to the main control device, and the signal feedback unit is used to output the short-circuit signal to the main control device when the output end of the short-circuit shutdown unit provides a grounding path for the driving module.

2. The AC / DC output circuit according to claim 1, characterized in that: The signal isolation module includes a first resistor, a first photoelectric coupler and a second resistor; The transmitting anode terminal of the first photoelectric coupler is connected to the main control device through the first resistor, the transmitting cathode terminal of the first photoelectric coupler is grounded, the receiving collector terminal of the first photoelectric coupler is connected to the operating voltage, the receiving emitter terminal of the first photoelectric coupler is connected to the first end of the second resistor, and the second end of the second resistor is grounded.

3. The AC / DC output circuit according to claim 1 or 2, characterized in that: The signal isolation module further includes a power isolation unit, and the power isolation unit includes a DCDC converter, a first capacitor and a second capacitor; The input end of the DCDC converter is connected to an external power supply, and the input end of the DCDC converter is connected to the grounded first capacitor. The output end of the DCDC converter is used to provide an operating voltage for the circuit, and the output end of the DCDC converter is connected to the grounded second capacitor.

4. The AC / DC output circuit according to claim 1, characterized in that: The driving module includes a third resistor, a first NPN transistor, a first PNP transistor and a fourth resistor; The first end of the third resistor serves as the input end of the driving module to access the control signal, and the second end of the third resistor is connected to the base end of the first NPN transistor and the base end of the first PNP transistor; the first end of the fourth resistor is connected to the emitter end of the first NPN transistor and the emitter end of the first PNP transistor, and the second end of the fourth resistor serves as the output end of the driving module to connect to the input end of the main loop module; the collector end of the first NPN transistor is connected to the operating voltage; and the collector end of the first PNP transistor is grounded.

5. The AC / DC output circuit according to claim 1, characterized in that: The main circuit module includes a first NMOS transistor, a second NMOS transistor, a fifth resistor, a sixth resistor, a TVS transistor, an overcurrent fuse and a temperature fuse; The gate terminal of the first NMOS transistor is connected to the gate terminal of the second NMOS transistor, the source terminal of the first NMOS transistor is connected to the grounded fifth resistor, the drain terminal of the first NMOS transistor is connected to one end of the overcurrent fuse, the other end of the overcurrent fuse is used to connect to the subsequent circuit, and the source terminal of the first NMOS transistor serves as the first short-circuit prompt terminal of the main loop module; The source terminal of the second NMOS transistor is connected to the grounded sixth resistor, the drain terminal of the second NMOS transistor is used to connect to the subsequent circuit, and the source terminal of the second NMOS transistor serves as the second short-circuit prompt terminal of the main loop module; The first end of the TVS tube is connected to the drain end of the first NMOS tube, the second end of the TVS tube is connected to one end of the thermal fuse, and the other end of the thermal fuse is connected to the drain end of the second NMOS tube. The thermal fuse is used to disconnect when the temperature of the TVS tube rises to the melting point.

6. The AC / DC output circuit according to claim 1, characterized in that: The short-circuit shutdown unit includes a first diode, a second diode, a second PNP transistor, a second NPN transistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor and a third capacitor; The anode end of the first diode and the anode end of the second diode serve as the first input end and the second input end of the short-circuit shutdown unit, respectively, to be turned on when a voltage signal corresponding to a short circuit is input, the cathode end of the first diode and the cathode end of the second diode are connected, and the cathode end of the first diode is also connected to the collector end of the second PNP transistor; The emitter terminal of the second PNP transistor is connected to one end of the seventh resistor, and the other end of the seventh resistor serves as the power supply terminal of the short-circuit shutdown unit. The base terminal of the second PNP transistor is connected to the first end of the eighth resistor, and the second end of the eighth resistor serves as the output terminal of the short-circuit shutdown unit. The collector terminal of the second NPN transistor is connected to the second end of the eighth resistor, the base terminal of the second NPN transistor is connected to the emitter terminal of the second NPN transistor through the ninth resistor, the third capacitor is connected in parallel to the ninth resistor, the base terminal of the second NPN transistor is also connected to the collector terminal of the second PNP transistor through the tenth resistor, and the emitter terminal of the second NPN transistor is grounded.

7. The AC / DC output circuit according to claim 1 or 6, characterized in that: The signal feedback unit includes an eleventh resistor, a twelfth resistor, a fourth capacitor and a second photoelectric coupler; The emitting anode end of the second photoelectric coupler is connected to the first end of the eleventh resistor, the second end of the eleventh resistor serves as the power supply end of the signal feedback unit, and the emitting cathode end of the second photoelectric coupler serves as the signal receiving end of the signal feedback unit; The receiving collector end of the second photocoupler is connected to an external power supply, the receiving emitter end of the second photocoupler is connected to the main control device, and the receiving emitter end of the second photocoupler is also connected to the grounded twelfth resistor, and the fourth capacitor is connected in parallel to the twelfth resistor.

8. A circuit board, characterized in that: The device comprises an AC / DC output circuit as claimed in any one of claims 1 to 7.

9. A driving device, characterized in that: Comprising the circuit board as claimed in claim 8.

Images