Alternating current and direct current output circuit, circuit board and driving equipment

Abstract

The invention provides an alternating current and direct current output circuit, a circuit board and driving equipment, relates to the technical field of electronic circuits, solves the problem of poor practicability and reliability of an output circuit in the related technology, realizes compatibility of alternating current and direct current loads, can further accelerate the response speed of the output circuit through driving of a driving module, and improves the reliability of the output circuit. According to the utility model, the control signal is quickly responded, the output capacity is large, so that the circuit can drive a relatively large load, and the output loop can be quickly switched off through the short-circuit protection module when a post-stage circuit is short-circuited, so that the safety of equipment is effectively guaranteed, and the reliability of the circuit is improved.

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] In devices that need to output two switch states, such as relays, solenoid valves, lamps, motors, etc., it is necessary to control the drive output switch signal, and an output circuit needs to be set to achieve the output of the two switch states. In the related art, the commonly used output circuit usually adopts the following implementation methods: mechanical relay output method, solid-state relay output method, etc.

[0003] Among them, the mechanical relay output mode has a slow response speed, and the mechanical relay has a limited life span, which makes the circuit less practical; and although the solid-state relay output mode can have a faster response speed and no life span limit, its output capacity is small and it is difficult to apply it in large current control scenarios, which leads to poor practicality of the circuit. Moreover, the open 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. In this regard, the practicality and reliability of the open 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. The present solution is compatible with AC / DC loads, so that the circuit has a faster response speed while also improving the output capacity, and short-circuit protection for the circuit is provided, which helps to make the circuit more practical and reliable.

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

[0006] The 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;

[0007] The input end of the driving module is connected to the output end of the signal isolation module, and the driving module is used to output the amplified driving current when receiving the control signal, and provide a discharge path for the subsequent circuit when not receiving the 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 switching 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, achieve a quick response to the control signal, and has a large output capacity so that the circuit can drive a larger load. The short-circuit protection module can quickly shut down the output loop 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 principle block diagram of an AC / DC output circuit provided in an 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 is to be understood that the specific embodiments described herein are only 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 the parts related to the embodiments of the present application rather than all structures are shown in the accompanying drawings, and those skilled in the art should be able to think of it after reading the specification of this application that as long as the technical features do not contradict each other, any combination of the technical features can constitute an optional implementation method.

[0021] The terms "first", "second", etc. in the specification and claims of the present 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 when 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 a class, 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 represents that the objects associated before and after are in an "or" relationship. In the description of the present application, "multiple" means two or more, and "several" means one or more.

[0022] In devices that need to output two switch states, such as relays, solenoid valves, lamps, motors, etc., it is necessary to control the drive output switch signal, and an output circuit needs to be set to achieve the output of the two switch states. In the related art, the commonly used output circuit usually adopts the following implementation methods: mechanical relay output method, solid-state relay output method, etc.

[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 practical. Although 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 and it is difficult to apply it in large current control scenarios, which 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. In this regard, the practicality and reliability of the output circuit in the related art are poor, and it is difficult to be widely used in a variety of 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 switching circuit, which can be applied to relay protection devices, relay coils, solenoid valves, lamps, motors, etc. as a corresponding driving unit. Of course, the circuit can also play the role of transmitting switching signals. Figure 1 A principle block diagram of an AC / DC switching circuit provided in one embodiment of the present application is provided. The circuit is compatible with AC / DC loads, has a faster response speed, can improve output capacity, and can also provide short-circuit protection, which helps to make the circuit more practical and reliable.

[0025] It can be understood that the AC / DC output circuit is connected to the main control device, such as by connecting to the I / O interface on the main control device to receive the control signal output by the main control device or send a short-circuit signal to the main control device, that is, 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, a drive circuit, etc.), and output a short-circuit signal to the main control device when a short circuit occurs. Among them, the switch state includes an open state and an off state. For this, the AC / DC output circuit can provide a signal corresponding to the open state or a signal corresponding to the off state to the subsequent circuit 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. Among them, 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 can be understood that the signal isolation module 110 performs signal isolation on the main control device and transmits the control signal when receiving the control signal. The drive module 120 outputs the amplified drive current when receiving the control signal to shorten the conduction time of the main circuit module 130; in addition, the drive module 120 provides a discharge path for the subsequent circuit when not receiving 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, and 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, stop providing a large drive voltage, so that the main circuit module 130 no longer provides a conductive circuit for the subsequent circuit, realizes shutdown, and outputs 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 response speed of the output circuit can be further accelerated by the drive module, and a fast response to the control signal can be achieved, and the output capacity is large so that the circuit can drive a larger load, and the output circuit can be quickly shut down by the short circuit protection module 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 transmitting anode end of the first photoelectric coupler is connected to the main control device through the first resistor, the transmitting cathode end of the first photoelectric coupler is grounded, the receiving collector end of the first photoelectric coupler is connected to the working voltage, the receiving 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 the first photoelectric coupler is connected to the 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 transmitting end thereon provides an optical signal to the receiving end, so that the receiving emitter end on one side of the receiving end is connected to the output high-level signal, that is, the potential of the first end of the second resistor as a pull-down resistor is increased, and then a high-level signal is provided to the driving module. Of course, when the low-level signal provided by the main control device, the first photoelectric coupler does not meet the conduction condition, and the signal isolation module no longer provides a high-level signal to the driving module, so that the driving module stops driving, and provides a discharge path for the subsequent circuit. Therefore, through the isolation of the first photoelectric coupler, the small signal fluctuation 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 also 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 a working 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 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 (ie, 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 for 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 transmitting 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), and 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 drive voltage for 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, a single-switch forward converter circuit, etc. 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, and then current can be fed 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 current can also be drawn from the subsequent stage to provide a discharge channel for the main control module.

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

[0035] It can be understood that when the third resistor R3 is connected to a high-level signal, the first NPN transistor Q1 is turned on and the first PNP transistor Q2 is turned off, thereby amplifying the connected drive current, thereby providing a larger drive current to the subsequent main circuit module through the fourth resistor R4 to drive the main circuit module to turn on. In addition, when the third resistor R3 is connected to a low-level signal, 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 by 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, which helps to achieve fast switching control.

[0037] Figure 4 A circuit structure diagram of a main circuit module provided for an 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 tube Q3, a second NMOS tube Q4, a fifth resistor R5, a sixth resistor R6, a TVS (Transient Voltage Suppressor) tube D1, an overcurrent fuse F1 and a temperature fuse KF1.

[0038] Specifically, the gate end of the first NMOS tube Q3 is connected to the gate end of the second NMOS tube Q4, the source end of the first NMOS tube Q3 is connected to the grounded fifth resistor R5, the drain end of the first NMOS tube Q3 is connected to one end of the overcurrent fuse F1, the source end of the second NMOS tube Q4 is connected to the grounded sixth resistor R6, the first end of the TVS tube D1 is connected to the drain end of the first NMOS tube Q3, the second end of the TVS tube 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 end of the second NMOS tube Q4.

[0039] Among them, the source end of the first NMOS tube Q3 is used as the first short circuit prompt end of the main circuit module, the source end of the second NMOS tube Q4 is used as the second short circuit prompt end of the main circuit module, and the other end of the overcurrent fuse F1 and the drain end of the second NMOS tube Q4 are used to connect the subsequent circuit, that is, the other end of the overcurrent fuse F1 and the drain end of the second NMOS tube Q4 are respectively used as the output end of the main circuit module. In addition, the overcurrent fuse F1 is blown when the subsequent circuit is short-circuited or overcurrent, and the temperature fuse KF1 is placed adjacent to the TVS tube D1. When the temperature of the TVS tube D1 rises to the melting point temperature of the temperature fuse KF1, the temperature fuse KF1 is disconnected, thereby preventing fire problems such as smoke and fire.

[0040] It can be understood that the fifth resistor R5 and the sixth resistor R6 are connected in series with the common source electrode to ground, and this connection can cut off the body diodes of the two MOS tubes in reverse series to realize AC load control. At the same time, the gates of the two MOS tubes are connected, so the simultaneous switch control of the two MOS tubes is realized by controlling the voltage of the gate. The fifth resistor R5 and the sixth resistor R6 collect the main circuit current and provide an electrical signal for triggering the short circuit protection module. When the gate end of the first NMOS tube Q3 and the gate end of the second NMOS tube Q4 are connected to the high level signal, the first NMOS tube Q3 and the second NMOS tube Q4 are turned on, thereby providing a conductive loop for the subsequent circuit, that is, providing an electrical signal corresponding to the switch state for the subsequent circuit. When the subsequent circuit is short-circuited, the main loop current increases, causing the voltage across the fifth resistor R5 and the sixth resistor R6 to also increase, thereby triggering the short-circuit protection, so that the drive of the two MOS tubes stops, and then the MOS tubes are turned off and the conduction loop is turned off.

[0041] Therefore, the MOS tube through the main loop module in the circuit can provide loop switching control for the subsequent circuit and can be shut down in time when a short circuit occurs, 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 can be understood that the short-circuit shutdown unit is used to provide a grounding path for the driving module when the first input terminal and / or the second input terminal are connected to a voltage signal corresponding to the short circuit, so as to control the driving module to stop driving the main circuit module, and 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 grounding path for the driving module. That is, the short-circuit protection module controls the driving module to shut down through the short-circuit shutdown unit thereon to shut down the corresponding circuit, and at the same time of the shutdown control, it also outputs a short-circuit signal to the main control device through the signal feedback unit thereon, so that the main control device determines that there is a short circuit at present.

[0044] For example, Figure 5 As shown, Figure 5 A circuit structure diagram of a short-circuit shutdown unit provided for an 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 to the ninth resistor R9 in parallel, 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 can be understood that when a short circuit occurs, the main circuit current rises rapidly, causing the voltage connected to the first diode D2 and the second diode D3 to rise rapidly, and the 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 driving current for the base terminal of the second NPN transistor Q6, and then when the base terminal voltage of the second NPN transistor Q6 meets the conduction condition, the second NPN transistor Q6 is turned on, and the input of the driving module is pulled down, thereby achieving shutdown, so that the main circuit module no longer provides a conducting 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 the interference generated when the voltage jumps to avoid the second NPN transistor Q6 from being mis-conducted.

[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 is still turned on when the main loop module is also turned off, thereby continuously pulling down the input of the driving module.

[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 for an 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. Among them, the emission 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 emission 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 the 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 can be understood that after the input loop of the second photocoupler U3 is turned on, it can output a short-circuit signal to the main control device, so that the main control device can pull down the control signal or turn off the output of the control signal, so that the output of the signal isolation module is turned off. The fourth capacitor C4 and the twelfth resistor R12 can form an RC filter, so that the second photocoupler provides a stable short-circuit signal for the main control device.

[0053] From the above scheme, it can be known that the short-circuit protection module can realize short-circuit protection of the output circuit to prevent the equipment from being damaged by short circuit. In the case of compatible AC and DC loads, the circuit provides corresponding short-circuit protection to make the circuit more practical and reliable.

[0054] Figure 7 A schematic diagram of the circuit structure of an AC / DC output circuit provided in an embodiment of the present application is 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, the first resistor R1 is connected to the main control device, and the first resistor R1 is also connected to the transmitting anode terminal of the first photoelectric coupler U1, the receiving collector terminal of the first photoelectric coupler U1 is connected to the working voltage (such as a 12V working voltage), the receiving emitter terminal 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 the above-mentioned working voltage is provided to the circuit through the output end of the DCDC converter U2.

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

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

[0058] In the short-circuit protection module 140, the anode end of the first diode D2 is connected to the source end of the first NMOS transistor Q3, and the anode end of the second diode D3 is connected to the source end 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 end of the first diode D2 is connected to the cathode end of the second diode D3, and the cathode end of the first diode D2 is also connected to the collector end of the second PNP transistor Q5. 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. 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 to the ninth resistor R9 in parallel, 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 transmitting anode terminal 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 transmitting cathode terminal of the second photoelectric coupler U3 serves as the signal receiving end of the signal feedback unit. The receiving collector terminal of the second photoelectric coupler U3 is connected to the external power supply, the receiving emitter terminal of the second photoelectric coupler is connected to the main control device, and the receiving emitter terminal 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.

[0060] In this regard, in the circuit, when the main control device outputs a high-level control signal, the first photocoupler U1 is turned on, thereby increasing the potential of the second resistor R2, thereby allowing the third resistor R3 to access the high-level signal. When the third resistor R3 is connected to the high-level signal, the first NPN transistor Q1 is turned on and the first PNP transistor Q2 is turned off, thereby amplifying the connected 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 the circuit analysis, the gate end of the first NMOS tube Q3 and the gate end of the second NMOS tube Q4 can be equivalent to a capacitor. When a larger drive current is connected, the voltage value of the capacitor can be quickly raised, so that the voltage of the gate end of the first NMOS tube Q3 and the gate end of the second NMOS tube Q4 can reach the conduction voltage value more quickly, thereby shortening the conduction time of the MOS tube.

[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 loop 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. The 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 driving 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, so that the driving module no longer provides a driving voltage for the first NMOS transistor Q3 and the second NMOS transistor Q4, and 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 loop 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 driving module, and at the same time also turning off the conduction loop at the base end of the second NPN transistor Q6, 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, achieve a fast response to the control signal, and 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 can further accelerate the response speed of the output circuit through the drive module thereon, 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, it can quickly shut down the output loop 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 "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0068] Note that the above are only preferred embodiments of the present application and the technical principles used. 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 is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and 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 switching circuit is used to receive a control signal output by a main control device and output a signal corresponding to a 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 switching circuit includes: A signal isolation module, the input end of which is connected to the main control device, and the signal isolation module is used to perform signal isolation on 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, and the driving module is used to output an amplified driving current when receiving the control signal, and to provide a discharge path for a subsequent circuit when not receiving the control signal; A main circuit module, 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, the output end of the short-circuit protection module is connected to the main control device, and 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.

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 photocoupler is connected to the main control device through the first resistor, the transmitting cathode terminal of the first photocoupler is grounded, the receiving collector terminal of the first photocoupler is connected to the working voltage, the receiving emitter terminal of the first photocoupler 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 first grounded 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 second grounded 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 working 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 tube, a second NMOS tube, a fifth resistor, a sixth resistor, a TVS tube, an overcurrent fuse and a temperature fuse; The gate end of the first NMOS tube is connected to the gate end of the second NMOS tube, the source end of the first NMOS tube is connected to the grounded fifth resistor, the drain end of the first NMOS tube 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 end of the first NMOS tube serves as the first short circuit prompt end of the main loop module; The source terminal of the second NMOS tube is connected to the grounded sixth resistor, the drain terminal of the second NMOS tube is used to connect to the subsequent circuit, and the source terminal of the second NMOS tube 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 temperature fuse, the other end of the temperature fuse is connected to the drain end of the second NMOS tube, and the temperature 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 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 is connected to a voltage signal corresponding to a short circuit, so as to control the driving module to stop driving the main circuit 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.

7. The AC / DC output circuit according to claim 6, 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 connected, 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, the other end of the seventh resistor is used 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 is used as the output end 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.

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

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

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

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