Remote startup and shutdown circuit and charging system

Abstract

The utility model discloses a far-end on-off circuit and a charging system, the far-end on-off circuit comprises a first switch end, a second switch end, a control circuit and an optocoupler protection circuit, the control circuit comprises a linear voltage stabilization source and an action circuit, a first input end of the linear voltage stabilization source is connected with the first switch end, a second input end of the linear voltage stabilization source is connected with the second switch end, and the action circuit is connected with the optocoupler protection circuit. The linear voltage stabilizing source is used for receiving input voltage through the first switch end and the second switch end and stabilizing the input voltage within a preset range; the action circuit outputs an enable signal in response to the stabilized input voltage; the optocoupler protection circuit responds to the enable signal and outputs a switch control signal by using the voltage signal of the first switch end. According to the invention, normal operation of the remote on-off circuit in a wide input voltage range can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy vehicle charging, in particular to a remote switch-on-off circuit and a charging system. BACKGROUND

[0002] With the widespread use of electric vehicles, the safety and reliability of charging infrastructure have become increasingly important. Remote switch-on-off can automatically turn on and off the power supply according to the instructions of the charging station or the state of the battery, thereby remotely controlling the start and stop of the electric vehicle charging process, avoiding overcharging or overdischarging, improving charging efficiency and battery life, and ensuring the safety and flexibility of the charging system. In addition, the remote switch-on-off circuit can also cut off the power supply in time when a fault occurs during the charging process, preventing the battery from overheating or other safety hazards, and helping to ensure the stable operation of the charging system and the safety of users.

[0003] In most applications, the input voltage range of the remote switch-on-off port is required to be wide, but when the input voltage is large, it will cause damage to the internal components of the circuit, thereby affecting the normal operation of the circuit.

[0004] The above content is only used to assist in understanding the technical solutions of the present application and does not represent the acknowledgement of the above content as prior art. UTILITY MODEL CONTENT

[0005] The main purpose of the present application is to provide a remote switch-on-off circuit and a charging system, which aims to solve the technical problem that the internal components of the circuit will be damaged when the input voltage is too large in the existing remote switch-on-off circuit.

[0006] To achieve the above purpose, the present application provides a remote switch-on-off circuit, comprising: a first switch end, a second switch end, a control circuit and an optocoupler protection circuit, the control circuit comprising: a linear voltage regulator, a first input end of the linear voltage regulator being connected to the first switch end, a second input end of the linear voltage regulator being connected to the second switch end, the linear voltage regulator being used to receive an input voltage through the first switch end and the second switch end and to stabilize the input voltage within a preset range; an action circuit, a control end of the action circuit being connected to an output end of the linear voltage regulator, a first end of the action circuit being grounded, a second end of the action circuit being connected to an input end of the optocoupler protection circuit, another input end of the optocoupler protection circuit being connected to the first switch end, the action circuit outputting an enable signal in response to the stabilized input voltage; wherein the optocoupler protection circuit outputs a switch control signal in response to the enable signal and using the voltage signal of the first switch end.

[0007] Optionally, the linear voltage regulator comprises: a Zener tube, an anode of which is connected to the second switch end, and a cathode of which is connected to the second node; a first resistor, one end of which is connected to the second node, and the other end of which is connected to the first switch end; and a first transistor, a control electrode of which is connected to the second node, a first electrode of which is used as an output end of the linear voltage regulator, and a second electrode of which is connected to the other end of the first resistor and forms a first node.

[0008] Optionally, the action circuit comprises: a fourth diode, an anode of which is connected to the first electrode of the first transistor and forms a third node, and a cathode of which is connected to the first node; a second capacitor, one end of which is connected to the third node, and the other end of which is grounded; a second resistor, one end of which is connected to the third node, and the other end of which is connected to a fourth node; a third resistor, one end of which is connected to the fourth node, and the other end of which is grounded; a third capacitor, which is connected in parallel to the third resistor; and a second transistor, a control end of which is connected to the fourth node, a first end of which is grounded, and a second end of which is used as a second end of the action circuit.

[0009] Optionally, the first transistor is a triode, and the second transistor is a MOS transistor.

[0010] Optionally, the remote switch-on-off circuit further comprises: a first diode, which is connected in series between the linear voltage regulator and the first switch end, and an anode of which is connected to the first switch end and a cathode of which is connected to the first node.

[0011] Optionally, the opto-coupler protection circuit comprises: an opto-coupler, an opto-coupler anti-reverse connection branch, and a current-limiting module; one end of the current-limiting module is connected to the first switch end, and the other end of the current-limiting module is connected to a first end of a primary side of the opto-coupler; a second end of the primary side of the opto-coupler is connected to a second end of the action circuit, a first end of a secondary side of the opto-coupler receives a set voltage, and a second end of the secondary side of the opto-coupler is grounded; the opto-coupler anti-reverse connection branch is connected in parallel to both ends of the primary side of the opto-coupler, and the opto-coupler anti-reverse connection branch is used for shunting a reverse voltage loaded on the primary side of the opto-coupler.

[0012] Optionally, the opto-coupler anti-reverse connection branch comprises: a fifth resistor, one end of which is connected to the first end of the primary side of the opto-coupler; and a third diode, an anode of which is connected to the second end of the primary side of the opto-coupler, and a cathode of which is connected to the other end of the fifth resistor.

[0013] Optionally, the opto-coupler anti-reverse connection branch comprises: a fifth diode, an anode of which is connected to the other end of the current-limiting module, and a cathode of which is connected to the first end of the primary side of the opto-coupler; a fifth capacitor, which is connected in parallel to both ends of the fifth diode; and a fourth capacitor, which is connected in parallel to both ends of the primary side of the opto-coupler.

[0014] Optionally, the remote switch-on-off circuit further comprises: a first capacitor, which is connected to the first switch end and the second switch end respectively, and is used for filtering a voltage between the first switch end and the second switch end.

[0015] Further, to achieve the above object, the application further provides a charging system, comprising the remote switch-off circuit and a control chip, wherein the output end of the remote switch-off circuit is connected with the control chip, and the output switch control signal is used to enable the output of the control chip.

[0016] The remote switch-off circuit and the charging system provided by the application can stabilize the input voltage in a preset range when the input voltage of the remote switch-off circuit is large, solve the problem that the internal components of the circuit are damaged when the input voltage is too large in the prior art, and realize the normal operation of the remote switch-off circuit in a wide input voltage range. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a first structural schematic diagram of a remote switch-off circuit provided by an embodiment of the application;

[0018] Figure 2 FIG. 2 is a second structural schematic diagram of a remote switch-off circuit provided by an embodiment of the application;

[0019] Figure 3 FIG. 3 is a third structural schematic diagram of a remote switch-off circuit provided by an embodiment of the application.

[0020] The implementation, functional features and advantages of the application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application but not all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0022] In the application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, can be detachable connection, or can be integrated; can be mechanical connection, can be electrical connection; can be direct connection, can be indirect connection through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meanings of the above terms in the application can be understood according to the specific circumstances.

[0023] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. For example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art. When the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0024] With the development of power electronics, the industrial control industry has more and more functional requirements for high-power switching power supply, such as remote compensation, remote switching and other functions. Remote switching circuit can automatically start and stop the power supply according to the instruction of the charging station or the state of the battery, thereby remotely controlling the start and stop of the electric vehicle charging process, avoiding overcharging or overdischarging, improving the charging efficiency and battery life, and ensuring the safety and flexibility of the charging system.

[0025] Remote switching can realize the isolation control function of the circuit through relay and optocoupler. However, due to the relatively high cost of relay control, in order to save cost, optocoupler is more commonly used to realize the isolation control of power supply. Optocoupler is a common component that can isolate the power supply circuit and the control circuit from each other, thereby protecting the circuit from interference.

[0026] In most applications, the input voltage range of the remote switching port is required to be wide (0V-18V). In order to ensure the normal operation of the remote switching circuit, firstly, how to avoid damage to the internal circuit when the input voltage is high needs to be considered, and at the same time, how to avoid damage to the internal circuit when the input end of the remote switching circuit is reversed needs to be considered. In particular, the reverse voltage level of the light emitting diode inside the optocoupler is generally about 5V. When the reverse voltage is greater than the reverse breakdown voltage of the light emitting diode inside the optocoupler, the remote switching circuit will fail. In addition to the damage of the optocoupler, other components in the remote switching circuit will also be damaged to different degrees when the input end is reversed.

[0027] To solve the above problems, the present application provides a remote switching circuit and a charging system. The present application will be described in detail below.

[0028] Please refer to Figure 1 , Figure 1A first structure diagram of a remote switch-on / off circuit provided by an embodiment of the present application can include: a first switch end PS_ON, a second switch end PS_OFF, a control circuit 100, and an optocoupler protection circuit 200. The control circuit includes: a linear voltage regulator 110 and an action circuit 120. The first input end of the linear voltage regulator 110 is connected to the first switch end PS_ON, and the second input end of the linear voltage regulator 110 is connected to the second switch end PS_OFF. The linear voltage regulator 110 is configured to receive an input voltage through the first switch end PS_ON and the second switch end PS_OFF, and to stabilize the input voltage within a preset range. The control end of the action circuit 120 is connected to the output end of the linear voltage regulator 110, the first end of the action circuit 120 is grounded, and the second end of the action circuit 120 is connected to an input end of the optocoupler protection circuit 200. Another input end of the optocoupler protection circuit 200 is connected to the first switch end PS_ON. The action circuit 120 outputs an enable signal in response to the stabilized input voltage, and the optocoupler protection circuit 200 outputs a switch control signal PS_CTR in response to the enable signal and using the voltage signal of the first switch end PS_ON.

[0029] It should be noted that the traditional remote switch-on / off circuit does not have the linear voltage regulator 110, so when the voltage range of the input signal is wide, the voltage input by other elements in the traditional remote switch-on / off circuit will change with the voltage fluctuation of the input end, thereby causing damage to other elements in the remote switch-on / off circuit.

[0030] Therefore, based on the traditional remote switch-on / off circuit, the embodiment of the present application adds the linear voltage regulator 110, which can be configured to receive the input voltage of the first switch end PS_ON and the second switch end PS_OFF, and to adjust the input voltage within a preset range, thereby reducing the damage to other elements in the remote switch-on / off circuit and realizing the normal operation of the remote switch-on / off circuit within a wide input voltage range.

[0031] It can be understood that the linear voltage regulator 110 can convert unstable input voltage into stable output voltage, in other words, the linear voltage regulator 110 can be configured to stabilize the input voltage and prevent the input voltage from being too high to damage the internal subsequent circuit.

[0032] It should be noted that the current traditional remote switch-on / off circuit also has the following deficiencies: In order to save costs, the traditional remote switch-on / off circuit usually uses an optocoupler for isolation. However, when the input end of the traditional remote switch-on / off circuit is reversely connected, the reverse voltage will cause the light-emitting diode inside the optocoupler to be broken down. At the same time, the high voltage caused by the reverse connection of the input end will cause damage to other elements in the remote switch-on / off circuit, thereby causing the circuit to fail.

[0033] Therefore, based on the above embodiment,Figure 2 FIG. 2 is a second structural schematic diagram of a remote switch-on / off circuit according to an embodiment of the present application, Figure 2 Figure 1 a preferred embodiment of the remote switch-on / off circuit corresponding thereto.

[0034] Please refer to Figure 2 The remote switch-on / off circuit can include a first switch end PS_ON, a second switch end PS_OFF, a control circuit 100, and an optocoupler protection circuit 200. The optocoupler protection circuit 200 can include an optocoupler U1, an optocoupler anti-reverse connection branch 210, and a current limiting module 220. One end of the current limiting module 220 is connected to the first switch end PS_ON, and the other end of the current limiting module 220 is connected to a first end of a primary side of the optocoupler U1. A second end of the primary side of the optocoupler U1 is connected to a second end of an action circuit 120. A first end of a secondary side of the optocoupler U1 receives a set voltage, and a second end of the secondary side of the optocoupler U1 is grounded. The optocoupler anti-reverse connection branch 210 is connected in parallel to both ends of the primary side of the optocoupler U1, and the optocoupler anti-reverse connection branch 210 is used to shunt the reverse voltage loaded on the primary side of the optocoupler U1.

[0035] The current limiting module 220 can be a current limiting resistor, i.e., a fourth resistor R4 in the figure. The first end of the secondary side of the optocoupler U1 can receive a set voltage through a sixth resistor R6. The optocoupler protection circuit 200 can further include a fourth capacitor connected in parallel to both ends of the secondary side of the optocoupler U1. An output end of the remote switch-on / off circuit is connected between the sixth resistor R6 and the first end of the secondary side of the optocoupler U1.

[0036] In the present exemplary embodiment, when the input end is connected in normal, the first switch end PS_ON is usually connected to a positive voltage, and the second switch end PS_OFF is usually connected to a negative voltage. When the input end is connected in reverse, the first switch end PS_ON is connected to a negative voltage, and the second switch end PS_OFF is connected to a positive voltage.

[0037] It can be understood that when the input end is connected in reverse, the current flows into the optocoupler protection circuit 200 from a second end of a second transistor Q2. The reverse voltage flowing into the optocoupler protection circuit 200 is loaded on a light-emitting diode in the optocoupler U1. The reverse breakdown voltage of the light-emitting diode in the optocoupler U1 is usually 5V. When the reverse voltage is greater than 5V, the reverse voltage will damage the light-emitting diode in the optocoupler U1.

[0038] Therefore, the present embodiment connects an optocoupler anti-reverse connection branch 210 in parallel to the primary side of the optocoupler U1, which can prevent the light-emitting diode in the optocoupler U1 from being broken down by high voltage when the input end is connected in reverse. This effectively avoids damage to the optocoupler U1 in the remote switch-on / off circuit when connected in reverse.

[0039] Please continue to refer to Figure 2 ​The light coupling anti-reverse connection branch 420 can include a fifth resistor R5 and a third diode D3. One end of the fifth resistor R5 is connected to the first end of the primary side of the light coupling U1. The anode of the third diode D3 is connected to the second end of the primary side of the light coupling U1, and the cathode of the third diode D3 is connected to the other end of the fifth resistor R5.

[0040] In the example embodiment, when the input end is reversely connected, the third diode D3 is turned on, and the third diode D3 and the fifth resistor R5 clamp the reverse voltage between the light emitting diodes in the light coupling U1 to below 5V, so as to ensure that the light emitting diodes in the light coupling U1 will not be damaged when reversely connected, and to achieve the purpose of protecting the light emitting diodes in the light coupling U1.

[0041] The specific structure of the linear voltage regulator 110 and the action circuit 120 will be further introduced below.

[0042] Please continue to refer to Figure 2 The remote switch-on / off circuit can include a first switch end PS_ON, a second switch end PS_OFF, a control circuit 100, and a light coupling protection circuit 200. The control circuit can include a linear voltage regulator 110 and an action circuit 120. The linear voltage regulator 110 can include a voltage stabilizing tube D2, a first resistor R1, and a first transistor Q1. The anode of the voltage stabilizing tube D2 is connected to the second switch end PS_OFF, and the cathode of the voltage stabilizing tube D2 is connected to a second node N2. One end of the first resistor R1 is connected to the second node N2, and the other end of the first resistor R1 is connected to the first switch end PS_ON. The control electrode of the first transistor Q1 is connected to the second node N2, the first electrode of the first transistor Q1 is used as the first output end of the linear voltage regulator 110, and the second electrode of the first transistor Q1 is connected to the other end of the first resistor R1 and forms a first node N1.

[0043] The action circuit 120 can include a fourth diode D4, a second capacitor C2, a second resistor R2, a third resistor R3, a third capacitor C3, and a second transistor Q2. The anode of the fourth diode D4 is connected to the first electrode of the first transistor Q1 and forms a third node N3, and the cathode of the fourth diode D4 is connected to the first node N1. One end of the second capacitor C2 is connected to the third node N3, and the other end of the second capacitor C2 is grounded. One end of the second resistor R2 is connected to the third node N3, and the other end of the second resistor R2 is connected to a fourth node N4. One end of the third resistor R3 is connected to the fourth node N4, and the other end of the third resistor R3 is grounded. The third capacitor C3 is connected in parallel to the two ends of the third resistor R3. The control end of the second transistor Q2 is connected to the fourth node N4, the first end of the second transistor Q2 is grounded, and the second end of the second transistor Q2 is used as the second end of the action circuit 120.

[0044] It should be noted that the first transistor Q1 in this embodiment can be a triode, the control electrode of which can be a base, the first electrode can be an emitter, and the second electrode can be a collector. Of course, in other embodiments, the first electrode can also be a collector, and the second electrode can also be an emitter. The second transistor Q2 can be a MOS tube, and accordingly, the control end of the second transistor Q2 can be a gate, the first end can be a source, and the second end can be a drain. Of course, in other embodiments, the first end can also be a drain, and the second end can also be a source.

[0045] When the input end is reversed, the current flows from the second switch end PS_OFF and passes through the third resistor R3 and the second resistor R2, at this time the fourth diode D4 is turned on, and the fourth diode D4 clamps the voltage between the first electrode and the second electrode of the first transistor Q1.

[0046] It can be understood that the fourth diode D4 can be used to protect the first transistor Q1 from being broken down when the input end is reversed.

[0047] When the input end is positive, the input voltage is divided by the second resistor R2 and the third resistor R3 after passing through the linear voltage regulator 110, and when the divided voltage is greater than the turn-on voltage of the control end of the second transistor Q2, the second transistor Q2 is turned on. After the second transistor Q2 is turned on, there is a current flowing through the inside of the optocoupler U1, and the inside light-emitting diode and triode are both turned on, and the optocoupler U1 outputs a switch control signal PS_CTR from the output end of the remote switch circuit. At this time, the switch control signal PS_CTR is at a low level.

[0048] It should be noted that the switch control signal PS_CTR is used to control the working state of the switching power supply system. When the input end is short-circuited or the input is at a low level, the second transistor Q2 is turned off, the branch of the optocoupler U1 is broken, and the light-emitting diode inside the optocoupler U1 is not turned on. At this time, the switch control signal PS_CTR output by the optocoupler U1 is at a high level. As can be seen, the high and low levels of the first switch end PS_ON and the second switch end PS_OFF can be controlled to control the input state of the switching power supply system, thereby achieving the purpose of remotely controlling the charging and discharging of the power supply.

[0049] It can be understood that when the first switch end PS_ON and the second switch end PS_OFF are positive, the second capacitor C2 can be used as an output voltage stabilizing device of the linear voltage regulator, that is, as a filter capacitor of the linear voltage regulator 110. The second resistor R2 and the third resistor R3 constitute a voltage dividing circuit for dividing the input voltage and loading it to the control end of the second transistor Q2. The third capacitor C3 is used to filter the electrical signal output after the second resistor R2 and the third resistor R3 are divided.

[0050] Please continue to refer to Figure 2The remote switch-on-off circuit further comprises a first diode D1 connected in series between the linear voltage stabilizer 110 and the first switch end PS_ON, with the anode of the first diode D1 connected to the first switch end PS_ON and the cathode of the first diode D1 connected to the first node N1.

[0051] It should be noted that the fourth diode D4 clamps the voltage between the first electrode and the second electrode of the first transistor Q1 and adds the voltage to both ends of the first diode D1. It can be understood that the first diode D1 and the fourth diode D4 jointly protect the first transistor Q1 from being broken down when the input end of the circuit is reversely connected.

[0052] Please continue to refer to Figure 2 The remote switch-on-off circuit further comprises a first capacitor C1 connected to the first switch end PS_ON and the second switch end PS_OFF, respectively. The first capacitor C1 can be used to filter the voltage between the first switch end PS_ON and the second switch end PS_OFF.

[0053] It can be understood that the first capacitor C1 can be used as an input port EMS protection device to protect the input port of the remote switch-on-off circuit from external electromagnetic signals such as electromagnetic interference (EMI) and electromagnetic pulse (EMP). EMS (Electromagnetic Susceptibility) is the electromagnetic anti-interference capability. In addition, the first capacitor C1 can also be used to smooth the power supply signal input by the input port, reduce noise or transient interference during power supply switching.

[0054] It should be noted that most of the current remote switch-on-off circuits use optocouplers for isolation to save costs, but in general design, the range of remote switch-on-off input voltage and anti-reverse connection scheme are rarely considered. In particular, when the input end is reversely connected, the high reverse voltage that occurs at this time can cause the light-emitting diode inside the optocoupler to be broken down, thereby causing the remote switch-on-off circuit to fail. In addition, when the reverse voltage is high, other control circuits inside the remote switch-on-off circuit can also fail. In addition, if the control circuit is directly connected when the remote switch-on-off input voltage is high, the control circuit can fail, so the input voltage signal needs to be processed.

[0055] Based on this, the embodiment of the present application provides a remote switch-on-off circuit. By connecting an optocoupler anti-reverse connection branch in anti-parallel with the original optocoupler, the high reverse voltage that occurs when the input end of the remote switch-on-off circuit is reversely connected can be prevented from breaking down the light-emitting diode inside the optocoupler. At the same time, the embodiment of the present application also prevents the overvoltage damage of the transistor in the control circuit caused by the reverse high voltage by adding the first diode and the fourth diode. In addition, the embodiment of the present application also adds a linear voltage stabilizing circuit in the control circuit, which effectively prevents the damage to the control circuit caused by the excessively high input voltage.

[0056] Therefore, the remote switch-on / off circuit provided by the embodiment of the present application can ensure normal operation of the remote switch-on / off circuit in a wide input voltage range and can also ensure that the internal circuit of the remote switch-on / off circuit is not damaged when the input end of the remote switch-on / off circuit is reversely connected.

[0057] Referring to Figure 3 , Figure 3 FIG. 3 is a third structural schematic diagram of a remote switch-on / off circuit according to an embodiment of the present application, Figure 3 FIG. 4 is another embodiment of a remote switch-on / off circuit corresponding to the remote switch-on / off circuit based on Figure 2 FIG. 4.

[0058] It should be noted that Figure 3 the embodiment provided by the present application is different from the embodiment provided by the present application only in the optical coupling anti-reverse connection branch 210, and other circuit components are the same. Figure 2

[0059] Referring to Figure 3 , the remote switch-on / off circuit can include a first switch end PS_ON, a second switch end PS_OFF, a control circuit 300, an optical coupling protection circuit 400, the optical coupling protection circuit 400 including an optical coupling U1, an optical coupling anti-reverse connection branch 210, and a current limiting module 220, one end of the current limiting module 220 being connected to the first switch end PS_ON and the other end being connected to a first end of a primary side of the optical coupling U1, wherein the optical coupling anti-reverse connection branch 210 can include a fifth diode D5, a fourth capacitor C4, and a fifth capacitor C5, an anode of the fifth diode D5 being connected to the other end of the current limiting module 220, a cathode of the fifth diode D5 being connected to the first end of the primary side of the optical coupling U1, the fourth capacitor C4 being connected in parallel to both ends of the primary side of the optical coupling U1, and the fifth capacitor C5 being connected in parallel to both ends of the fifth diode D5.

[0060] In the present exemplary embodiment, when the input end is reversely connected, current flows through the fourth capacitor C4 and the fifth capacitor C5, and the fourth capacitor C4 and the fifth capacitor C5 adjust the voltage across the fifth diode D5 and the voltage across the light-emitting diode in the optical coupling U1, so that the voltage across the fifth diode D5 is relatively large, and the voltage across the light-emitting diode in the optical coupling U1 is relatively small.

[0061] It can be understood that the present embodiment distributes the voltage across the fifth diode D5 and the voltage across the light-emitting diode in the optical coupling U1 through the fifth capacitor C5 and the fourth capacitor C4, so as to ensure that the voltage of the light-emitting diode in the optical coupling is lower than 5V when the input end of the circuit is reversely connected, and prevent the light-emitting diode from being damaged when the input end is reversely connected.

[0062] ​Another embodiment of the present application also provides a charging system, which can include a remote switch circuit and a control chip, wherein an output end of the remote switch circuit is connected with the control chip, and the control chip is enabled by a switch control signal output by the remote switch circuit.

[0063] In the specific implementation process, the switch control signal PS_CTR output by the remote switch circuit can be selected as high level when the switching power supply system normally works, and as low level when the switching power supply system stops working according to different control logics; or the switch control signal PS_CTR output by the remote switch circuit can be selected as high level when the switching power supply system stops working, and as low level when the switching power supply system normally works.

[0064] It can be understood that the remote switch circuit is connected with the enable pin of the control chip, different control logics, i.e. the characteristics of the enable pin connected with the remote switch circuit, the remote switch circuit and the control chip can work together to remotely control the start and stop of the charging process of the electric vehicle.

[0065] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A remote switch-on-off circuit, characterized by comprising: The application relates to a remote switch-on-off circuit. The remote switch-on-off circuit comprises a first switch end, a second switch end, a control circuit and an optocoupler protection circuit. The control circuit comprises a linear voltage stabilizer, an action circuit and an optocoupler protection circuit. The first input end of the linear voltage stabilizer is connected with the first switch end, the second input end of the linear voltage stabilizer is connected with the second switch end, the linear voltage stabilizer is used for receiving an input voltage through the first switch end and the second switch end and stabilizing the input voltage in a preset range, the control end of the action circuit is connected with the output end of the linear voltage stabilizer, the first end of the action circuit is grounded, the second end of the action circuit is connected with one input end of the optocoupler protection circuit, the other input end of the optocoupler protection circuit is connected with the first switch end, and the action circuit outputs an enable signal in response to the stabilized input voltage. The optocoupler protection circuit outputs a switch control signal in response to the enable signal and by using the voltage signal of the first switch end.

2. The remote switch-on-off circuit according to claim 1, characterized in that, The linear voltage stabilizer comprises a stabilizing tube, a first resistor, a first transistor and a second resistor. The anode of the stabilizing tube is connected with the second switch end, the cathode of the stabilizing tube is connected with a second node, one end of the first resistor is connected with the second node, the other end of the first resistor is connected with the first switch end, the control end of the first transistor is connected with the second node, the first end of the first transistor is used as the output end of the linear voltage stabilizer, and the second end of the first transistor is connected with the other end of the first resistor and forms a first node. The action circuit comprises a fourth diode, a second capacitor, a second resistor, a third resistor, a third capacitor and a second transistor. The anode of the fourth diode is connected with the first end of the first transistor and forms a third node, the cathode of the fourth diode is connected with the first node, one end of the second capacitor is connected with the third node, the other end of the second capacitor is grounded, one end of the second resistor is connected with the third node, the other end of the second resistor is connected with a fourth node, one end of the third resistor is connected with the fourth node, the other end of the third resistor is grounded, the third capacitor is connected in parallel with the third resistor, the control end of the second transistor is connected with the fourth node, the first end of the second transistor is grounded, and the second end of the second transistor is used as the second end of the action circuit.

3. The remote switch-on-off circuit according to claim 2, wherein The first transistor is a triode, and the second transistor is a MOS transistor. The remote switch-on-off circuit further comprises a first diode. The first diode is connected in series between the linear voltage stabilizer and the first switch end, the anode of the first diode is connected with the first switch end, and the cathode of the first diode is connected with the first node. The optocoupler protection circuit comprises an optocoupler, an optocoupler anti-reverse connection branch and a current limiting module. One end of the current limiting module is connected with the first switch end, the other end of the current limiting module is connected with the first end of the primary side of the optocoupler, the second end of the primary side of the optocoupler is connected with the second end of the action circuit, the first end of the secondary side of the optocoupler receives a set voltage, the second end of the secondary side of the optocoupler is grounded, the optocoupler anti-reverse connection branch is connected in parallel with the two ends of the primary side of the optocoupler, and the optocoupler anti-reverse connection branch is used for shunting the reverse voltage loaded on the primary side of the optocoupler. The optocoupler anti-reverse connection branch comprises a fifth resistor and a third diode. One end of the fifth resistor is connected with the first end of the primary side of the optocoupler, and the anode of the third diode is connected with the second end of the primary side of the optocoupler.

4. The remote switch-on-off circuit according to claim 3, wherein The optocoupler anti-reverse connection branch comprises a fifth diode and a fifth capacitor.

5. The remote switch-on-off circuit according to claim 2, wherein The anode of the fifth diode is connected with the other end of the current limiting module, the cathode of the fifth diode is connected with the first end of the primary side of the optocoupler, the fifth capacitor is connected in parallel with the two ends of the fifth diode. ​ 6. The remote switch-on-off circuit according to claim 1, wherein ​ ​ ​ ​ 7. The remote switch-on-off circuit according to claim 6, wherein ​ ​ ​ 8. The remote switch-on-off circuit according to claim 6, wherein ​ ​ ​ A fourth capacitor is connected in parallel to the two ends of the primary side of the optocoupler.

9. The remote switch-on-off circuit according to claim 1, wherein The remote switch-on-off circuit further comprises: A first capacitor is connected to the first switch end and the second switch end respectively, and is used for filtering the voltage between the first switch end and the second switch end.

10. A charging system, characterized by Comprise: The remote switch-on-off circuit according to any one of claims 1-9; A control chip; The output end of the remote switch-on-off circuit is connected to the control chip, and the output switch control signal is used for enabling the output of the control chip.

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