Relay driving circuit and charging equipment

Abstract

The utility model discloses a relay driving circuit and charging equipment, and the driving circuit is connected with a relay through a first node, and comprises a coupling module, a first driving module, a second driving module and a first current limiting module. The coupling module is used for transmitting a voltage signal of the signal input end to a sixth node or turning off a connection path between the signal input end and the sixth node; the first driving module is used for responding to a voltage signal of the sixth node to connect the first node and the third node or turn off a connection path of the two nodes; and the second driving module is used for responding to the voltage signal of the signal input end to connect the seventh node and the third node or turn off the connection path of the two nodes. The first driving module and the second driving module are driven by the same path of driving I-O signals, and compared with an existing mode that two paths of driving I-O signals are controlled respectively, control resources are saved. And the problems of low starting speed and low power reduction amplitude of the relay are solved while reliable pull-in is ensured.

Description

Technical Field

[0001] The present application relates to the field of power electronics, and in particular to a relay drive circuit and a charging device. Background Art

[0002] Conventional relay drivers use transistor drivers, which are usually connected in series with fixed resistors to meet both the pull-in voltage requirement and the steady-state power reduction requirement. However, the current relay driver uses a 12V full power supply, which has a larger steady-state loss than conventional relays. Although the series resistor can meet both the startup and power reduction requirements, the startup speed and power reduction range are relatively small. There are also relay drivers that use dual-channel switch drivers, each with a series resistor for adjustment, but the two-channel driver occupies control resources. Summary of the invention

[0003] The main purpose of the present application is to provide a driving circuit, aiming to solve the technical problems of the existing two-way driving circuit controlling the relay with small starting speed and power reduction amplitude.

[0004] To achieve the above-mentioned purpose, the present application provides a relay driving circuit, the driving circuit is connected to the relay through a first node, and the driving circuit includes: a coupling module, connecting the signal input end and the sixth node, the coupling module is used to transmit the voltage signal of the signal input end to the sixth node or cut off the connection path between the signal input end and the sixth node; a first driving module, connecting the sixth node, the first node and the third node, the first driving module is used to connect the first node and the third node or cut off the connection path between the first node and the third node in response to the voltage signal of the sixth node; a first current limiting module, connecting the first node and the seventh node; a second driving module, connecting the signal input end, the seventh node and the third node, the second driving module is used to connect the seventh node and the third node in response to the voltage signal of the signal input end or cut off the connection path between the seventh node and the third node.

[0005] Optionally, the coupling module includes: a first capacitor, two ends of which are respectively connected to the sixth node and the signal input terminal; the first current limiting module includes a first resistor, two ends of which are respectively connected to the first node and the seventh node.

[0006] Optionally, the first driving module includes: a first switch unit, a control end connected to the second node, a first end connected to the first node, and a second end connected to the third node, the first switch unit being used to respond to the voltage difference between the second node and the third node to turn on or off the connection path between the first node and the third node; a second current limiting module, two ends of which are respectively connected to the sixth node and the second node; the second driving module includes: a second switch unit, a control end connected to the eighth node, a first end connected to the seventh node, and a second end connected to the third node, the second switch unit being used to respond to the voltage difference between the eighth node and the third node to turn on or off the connection path between the seventh node and the third node; a third current limiting module, two ends of which are respectively connected to the signal input end and the eighth node.

[0007] Optionally, the first switching unit includes a first voltage-controlled transistor; the control end of the first voltage-controlled transistor is connected to the second node, the first end is connected to the first node, and the second end is connected to the third node; the second current limiting module includes: a second resistor, whose two ends are respectively connected to the sixth node and the second node; the second switching unit includes a second voltage-controlled transistor; the control end of the second voltage-controlled transistor is connected to the eighth node, the first end is connected to the seventh node, and the second end is connected to the third node; the third current limiting module includes: a third resistor, whose two ends are respectively connected to the signal input end and the eighth node.

[0008] Optionally, the first driving module also includes: a first protection unit, wherein the two ends of the first protection unit are respectively connected to the second node and the third node, so as to form an electrostatic release path of the first switch unit; the second driving module also includes: a second protection unit, wherein the two ends of the second protection unit are respectively connected to the eighth node and the third node, so as to form an electrostatic release path of the second switch unit.

[0009] Optionally, the first protection unit includes: a fourth resistor, two ends of which are respectively connected to the second node and the third node; the second protection unit includes: a fifth resistor, two ends of which are respectively connected to the eighth node and the third node.

[0010] Optionally, the first driving module further includes: a third protection unit connected to the second node and the third node, the third protection unit being configured to be turned on when the potential of the second node is lower than the potential of the third node and to be turned off when the potential of the second node is higher than the potential of the third node.

[0011] Optionally, the third protection unit includes: a first diode, a cathode of which is connected to the second node, and an anode of which is connected to the third node.

[0012] Optionally, the first switch unit includes: a first transistor, the control electrode is connected to the second node, the first electrode is connected to the third node, and the second electrode is connected to the first node; the second switch unit includes: a second transistor, the control electrode is connected to the eighth node, the first electrode is connected to the third node, and the second electrode is connected to the seventh node.

[0013] Optionally, the first driving module also includes: a fourth protection unit, wherein two ends of the fourth protection unit are respectively connected to the second node and the third node, and is used to be turned on when the potential of the second node is lower than the potential of the third node and to be turned off when the potential of the second node is higher than the potential of the third node.

[0014] Optionally, the fourth protection unit includes: a second diode, a cathode of which is connected to the second node, and an anode of which is connected to the third node.

[0015] Optionally, the driving circuit also includes: a fifth protection unit, whose two ends are respectively connected to the fifth node and the fourth node, and is used to be turned off when the potential of the fifth node is higher than the potential of the fourth node, or to be turned on when the potential of the fifth node is lower than the potential of the fourth node; wherein the fifth node is connected to a set voltage source, and the fourth node is connected to the first node; a fourth current limiting module, which is connected in series between the fourth node and the first node.

[0016] Optionally, the fifth protection unit includes: a third diode, a cathode of which is connected to the fifth node, and an anode of which is connected to the fourth node; the fourth current limiting module includes: a sixth resistor, which is connected in series between the first node and the relay.

[0017] A relay drive circuit proposed in an embodiment of the present application, wherein a first drive module and a second drive module are driven by the same drive IO signal and are jointly controlled, which saves control resources compared to the existing two drive IO signals being controlled separately; when the first drive module and the second drive module are both closed, the first drive module can meet the relay's transient voltage or current requirements for closure, ensure reliable closure, and accelerate the start-up of the relay; when the first drive module is disconnected, the second drive module drives the relay alone, which can gradually reduce the drive voltage or current, maintain a steady-state low drive loss state, reduce relay heating, and improve drive efficiency.

[0018] In addition, to achieve the above-mentioned purpose, the present application also provides a charging device, including the relay driving circuit described in any embodiment of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A structural block diagram of a relay drive circuit according to an embodiment of the present application;

[0020] Figure 2 A structural block diagram of a relay driving circuit according to another embodiment of the present application;

[0021] Figure 3 A schematic diagram of the structure of a relay drive circuit according to an embodiment of the present application;

[0022] Figure 4 This is a structural schematic diagram of a relay drive circuit according to another embodiment of the present application;

[0023] Figure 5 This is a schematic diagram of the structure of a relay drive circuit according to another embodiment of the present application.

[0024] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] The main solutions of the embodiments of this application are:

[0027] When the prior art uses a single transistor to drive a relay, the relay's starting speed is low and the power reduction amplitude is small; when a two-way driving circuit is used to drive the relay, two driving IO signals need to be controlled separately, resulting in a waste of resources.

[0028] The present application provides a driving circuit, which can drive a relay by optimizing two driving circuits. The working principle and specific circuit structure of the driving circuit of the present application are further analyzed below in conjunction with the accompanying drawings.

[0029] Figure 1 is a structural block diagram of a relay drive circuit according to an embodiment of the present application, such as Figure 1 As shown, the driving circuit is connected to the relay 110 via the first node N1, and the relay driving circuit may include: a coupling module 120, a first driving module 130, a first current limiting module 140 and a second driving module 150, wherein the coupling module 120 is connected to the signal input terminal IO and the sixth node N6, and the coupling module 120 can be used to transmit the voltage signal of the signal input terminal IO to the sixth node N6 or to cut off the connection path between the signal input terminal IO and the sixth node N6; the first driving module 130 is connected to the sixth node N6, the first node N1 and the third node N3, and the first driving module 130 can be used to connect the first node N1 and the third node N3 or to cut off the connection path between the first node N1 and the third node N3 in response to the voltage signal of the sixth node N6; the first current limiting module 140 is connected to the first node N1 and the seventh node N7; the second driving module 150 is connected to the signal input terminal IO, the seventh node N7 and the third node N3, and the second driving module 150 can be used to connect the seventh node N1 and the third node N3 or to cut off the connection path between the seventh node N1 and the third node N3 in response to the voltage signal of the signal input terminal IO.

[0030] In the driving circuit provided by the present application, the first driving module 130 and the second driving module 150 are driven by the same driving IO signal and controlled together, which saves control resources compared to the existing two-way driving IO signal being controlled separately; when the first driving module 130 and the second driving module 150 are both closed, the first driving module 130 can meet the requirements of the transient voltage or current of the relay 110, ensure reliable attraction, and accelerate the start-up of the relay 110; when the first driving module 130 is disconnected, the second driving module 150 drives the relay 110 alone, which can gradually reduce the driving voltage or current, maintain a steady-state low driving loss state, reduce the heating of the relay 110, and improve the driving efficiency. In some embodiments, the third node N3 can be a ground node.

[0031] The node in the present application can be understood as an electrical connection point, that is, an electrical connection point formed by connecting multiple sub-circuits. For example, the first node N1 is an electrical connection point formed by connecting the relay 110 and the first driving module 130.

[0032] Further, when the signal input terminal IO is at the on-level, the coupling module 120 is turned on during the signal step, thereby transmitting the on-level of the signal input terminal IO to the sixth node N6, and under the control of the on-level of the sixth node N6, the first driving module 130 is turned on. At the same time, the second driving module 150 is also turned on under the control of the on-level provided by the signal input terminal IO. At this time, due to the presence of the first current limiting module 140, the first driving module 130 bypasses the second driving module 150, so that only the driving relay 110 is started, accelerating the start of the driving relay 110.

[0033] After the relay 110 is started up, a short circuit is formed between the signal input terminal IO and the sixth node N6 due to the action of the coupling module 120, thereby turning off the first driving module 130, so that the relay 110 is driven only by the second driving module 150, providing a steady-state driving current for the relay 110. In the process of steady-state driving of the relay 110, due to the current limiting effect of the first current limiting module 140, the current can be reduced, thereby reducing the consumption of the relay 110.

[0034] When the signal input terminal IO is at a non-conductive level, the second driving module 150 is turned off. At the same time, the coupling module 120 discharges and reversely charges the first driving module 130, and the driving voltage of the first driving module 130 becomes a negative voltage, the first driving module 130 is turned off, and then gradually reduces the consumption to 0V.

[0035] In this embodiment, the first current limiting module 140 may include a first resistor R1, with two ends of the first resistor R1 connected to the first node N1 and the seventh node N7 respectively. The coupling module 120 may include a first capacitor C1, with two ends of the first capacitor C1 connected to the sixth node N6 and the signal input terminal IO respectively.

[0036] When the signal input terminal IO is at the on-level, the first capacitor C1 is relatively large. When the input signal rises, C1 is approximately short-circuited, and the on-level of the signal input terminal IO is transmitted to the sixth node N6. Under the control of the on-level of the sixth node N6, the first driving module 130 is turned on; and then the first node N1 is connected to the third node N3 through the first driving module 130 to form a first driving loop. At the same time, the second driving module 150 is turned on, and the second driving module 150 connects the first node N1 to the third node N3 to form a second driving loop. Due to the existence of the first resistor R1, the impedance of the second driving loop is relatively large and is bypassed by the first driving module 130. At this time, the first driving module 130 forms a transient acceleration drive on the relay 110. As time goes by, the voltage drop of the first capacitor C1 gradually increases, and the driving voltage of the first driving module 130 gradually decreases. After the driving voltage of the first driving module 130 decreases to a certain level Vth, it is turned off, and a short circuit is formed between the sixth node N6 and the signal input terminal IO, so that the first driving module 130 is turned off, and only the second driving module 150 drives the relay 110. At this time, the first resistor R1 performs voltage division, which can reduce the current and play an effect of reducing the consumption of the relay 110.

[0037] When the signal input terminal IO is at a non-conducting level, the first capacitor C1 discharges and reversely charges the first driving module 130. At this time, the input voltage of the first driving module 130 is negative, the first driving module 130 is turned off, and the second driving module 150 is turned off.

[0038] It is worth noting that the conduction level described in the embodiment of the present application refers to a level that can conduct the first driving module 130 and the second driving module 150, and the non-conduction level refers to a level that can control the first driving module 130 and the second driving module 150 to be turned off. For example, the conduction level can be a high level, and the non-conduction level can be a low level.

[0039] Figure 2 FIG. 1 is a structural block diagram of a relay driving circuit according to another embodiment of the present application, such as Figure 2As shown, in the relay driving circuit, the first driving module 130 may include a first switch unit 131 and a second current limiting module 132, wherein the control end of the first switch unit 131 is connected to the second node N2, the first end is connected to the first node N1, and the second end is connected to the third node N3, and the first switch unit 131 can be used to respond to the voltage difference between the second node N2 and the third node N3 to turn on or off the connection path between the first node N1 and the third node N3; the first end of the second current limiting module 132 is connected to the sixth node N6, and the second end is connected to the second node N2; the second driving module 150 may include a second switch unit 151 and a third current limiting module 152, wherein the control end of the second switch unit 151 is connected to the eighth node N8, the first end is connected to the seventh node N7, and the second end is connected to the third node N3, and the second switch unit 151 can be used to respond to the voltage difference between the eighth node N8 and the third node N3 to turn on or off the connection path between the seventh node N7 and the third node N3; the first end of the third current limiting module 152 is connected to the signal input terminal IO, and the second end is connected to the eighth node N8.

[0040] In this embodiment, the current limiting module may be implemented by a current limiting resistor. For example, the second current limiting module 132 may include a second resistor R2, and the third current limiting module 152 may include a third resistor R3.

[0041] In this embodiment, when the signal input terminal IO is at the on-level, the first capacitor C1 is approximately short-circuited during the signal step, and the on-level of the signal input terminal IO is transmitted to the sixth node N6. After the on-level of the sixth node N6 is limited by the second resistor R2, under the voltage control after the current limiting, the first switch unit 131 is turned on in response to the voltage difference between the sixth node N6 and the third node N3, so that the first node N1 is connected to the third node N3, that is, the first switch unit 131 is turned on. At the same time, after the on-level provided by the signal input terminal IO is limited by the third resistor R3, the second switch unit 151 is controlled to be turned on in response to the voltage difference between the signal input terminal IO and the third node N3, so that the first node N1 is connected to the third node N3, that is, the second switch unit 151 is turned on.

[0042] Figure 3 FIG. 1 is a schematic diagram of a relay driving circuit according to an embodiment of the present application. Figure 3As shown, in the relay driving circuit, the first switch unit 131 may include a first voltage-controlled transistor M1; the control end of the first voltage-controlled transistor M1 is connected to the second node N2, the first end is connected to the first node N1, and the second end is connected to the third node N3; the first driving module 130 may also include a first protection unit 133, the first end is connected to the second node N2, the second end is connected to the third node N3, and the first protection unit 133 can be used to form an electrostatic release path for the first switch unit 131; the first protection unit 133 may include a fourth resistor R4; the second switch unit 151 may include a second voltage-controlled transistor M2; the control end of the second voltage-controlled transistor M2 is connected to the eighth node N8, the first end is connected to the seventh node N7, and the second end is connected to the third node N3; the second driving module 150 may also include a second protection unit 153, the first end is connected to the eighth node N8, the second end is connected to the third node N3, and the second protection unit 153 can be used to form an electrostatic release path for the second switch unit 151; the second protection unit 153 may include a fifth resistor R5.

[0043] In this embodiment, the voltage-controlled transistor may be, for example, a MOS transistor, or an IGBT, etc. The following is an exemplary description using the first voltage-controlled transistor M1 as a first MOS transistor and the second voltage-controlled transistor M2 as a second MOS transistor.

[0044] The gate of the first MOS tube is connected to the second node N2, the drain is connected to the first node N1, and the source is connected to the third node N3; the gate of the second MOS tube is connected to the signal input terminal IO, the drain is connected to the seventh node N7, and the source is connected to the third node N3. When the signal input terminal IO is at the on level, the first capacitor C1 is approximately short-circuited during the signal step, and the on level of the signal input terminal IO is transmitted to the sixth node N6. After the second resistor R2 limits the current, the first MOS tube is controlled to close, and the connection between the drain and the source is connected, so that the third node N3 is connected to the first node N1. At the same time, because the first resistor R1 exists on the branch where the second MOS tube is located, the first MOS tube bypasses the branch where the second MOS tube is located. In this process, only the first MOS tube drives the relay 110, accelerating the start-up of the driving relay 110.

[0045] As the voltage of the first capacitor C1 increases, the current flowing through the second resistor R2 decreases, and finally the first MOS tube is turned off, so that only the second MOS tube drives the relay 110, providing a steady-state driving current for the relay 110. At this time, due to the existence of the first resistor R1, the current is reduced, thereby reducing the power of the steady-state relay 110.

[0046] When the signal input terminal IO is at a non-conducting level, the second MOS transistor is turned off, and the connection between the third node N3 and the first node N1 is disconnected. At the same time, the first capacitor C1 is discharged in the positive direction, the driving voltage of the first MOS transistor is negative, and the first MOS transistor is turned off. When the first MOS transistor and the second MOS transistor are turned off, due to the static electricity accumulation in the parasitic capacitance of the MOS transistor, at this time, the fourth resistor R4 and the fifth resistor R5 are respectively formed with the static electricity release path, and the fourth resistor R4 and the fifth resistor R5 can respectively release the accumulated static electricity charge, so that the first MOS transistor and the second MOS transistor can be prevented from being broken down.

[0047] In this embodiment, since the gate current of the MOS tube is generally large, the second resistor R2 and the third resistor R3 can be selected to have a smaller resistance, such as 10 ohm level.

[0048] Figure 4 FIG. 1 is a schematic diagram of a relay driving circuit according to another embodiment of the present application. Figure 4 As shown, in the relay driving circuit, the first driving module 130 may further include a third protection unit 134, which may be used to be turned on when the potential of the second node N2 is lower than the potential of the third node N3 and turned off when the potential of the second node N2 is higher than the potential of the third node N3. The third protection unit 134 may include a first diode D1, the cathode D1 of the first diode is connected to the second node N2, and the anode is connected to the third node N3.

[0049] Specifically, continuing to take the first switch unit 131 as the first MOS tube as an example, when the signal input terminal IO is at the on level, the first capacitor C1 is approximately short-circuited during the signal step, and the on level of the signal input terminal IO is transmitted to the second node N2 through the sixth node N6. At this time, the potential of the second node N2 is higher than the potential of the third node N3, and the first diode D1 is turned off.

[0050] When the signal input terminal IO is at a non-conducting level, the first capacitor C1 is discharged, the driving voltage of the first MOS tube is a negative voltage, the first MOS tube is turned off, and the potential of the second node N2 is lower than the potential of the third node N3. At this time, if the next startup time is close, the input voltage of the first capacitor C1 cannot be quickly reduced to 0V only through the fourth resistor R4, which affects its effect. At this time, the first diode D1 is anti-parallel connected to the fourth resistor R4 to increase the speed of reducing the input voltage of the first capacitor C1 and quickly reduce it to 0V.

[0051] Figure 5 FIG. 1 is a schematic diagram of a relay driving circuit according to another embodiment of the present application. Figure 5As shown, in the relay driving circuit, the first switch unit 131 may include a first transistor Q1, the base of the first transistor Q1 is connected to the second node N2, the source is connected to the third node N3, and the drain is connected to the first node N1; the second switch unit 151 may include a second transistor Q2, the base of the second transistor Q2 is connected to the eighth node N8, the source is connected to the third node N3, and the drain is connected to the seventh node N7; the first driving module 130 may also include a fourth protection unit 135, the two ends of the fourth protection unit 135 are respectively connected to the second node N2 and the third node N3, and can be used to turn on when the potential of the second node N2 is lower than the potential of the third node N3 and turn off when the potential of the second node N2 is higher than the potential of the third node N3. The fourth protection unit 135 may include a second diode D2, the cathode of the second diode D2 is connected to the second node N2, and the anode is connected to the third node N3.

[0052] In this embodiment, the first switch unit 131 is a first transistor Q1. When the signal input terminal IO is at a high level, the first capacitor C1 is approximately short-circuited during the signal step, and the conduction level of the signal input terminal IO is transmitted to the sixth node N6, and then transmitted to the second node N2 after the second resistor R2 limits the current, and the first transistor Q1 is controlled to close, and the connection between the third node N3 and the first node N1 is connected. At this time, the potential of the second node N2 is higher than the potential of the third node N3, and the first diode D1 is turned off. At the same time, because the first resistor R1 exists on the branch where the second transistor Q2 is located, the first transistor bypasses the branch where the second MOS tube is located. In this process, only the first transistor Q1 drives the relay 110, and the start-up of the driving relay 110 is accelerated.

[0053] As the voltage of the first capacitor C1 increases, the current flowing through the second resistor R2 decreases, and finally the first transistor Q1 is turned off, so that the relay 110 is driven only by the second transistor Q2. At this time, due to the existence of the first resistor R1, the current is reduced, thereby reducing the power of the steady-state relay 110.

[0054] When the signal input terminal IO is at a non-conducting level, the second transistor Q2 is turned off. At the same time, the first capacitor C1 is discharged, and the driving voltage of the first transistor Q1 is negative, which directly enters the emitter of the first transistor Q1, and easily causes the first transistor Q1 to be damaged; since the voltage of the second node N2 is lower than the voltage of the third node N3 at this time, the second diode D2 is reversely connected in parallel to the first transistor Q1, and the second diode D2 reversely conducts the clamping voltage to avoid damage to the first transistor Q1.

[0055] In this embodiment, since the base current of the transistor is generally at the mA level, the second resistor R2 and the third resistor R3 can be selected to have a larger resistance value, such as the kΩ level.

[0056] Continue to refer to Figure 5 The driving circuit of the present application may also include a fifth protection unit 160 and a fourth current limiting module 170, wherein the two ends of the fifth protection unit 160 are respectively connected to the fifth node N5 and the fourth node N4, and can be used to shut down when the potential of the fifth node N5 is higher than the potential of the fourth node N4, or to turn on when the potential of the fifth node N5 is lower than the potential of the fourth node N4; wherein the fifth node N5 is connected to a set voltage source, and the fourth node N4 is connected to the first node N1; and the fourth current limiting module 170 is connected in series between the fourth node N4 and the first node N1.

[0057] Exemplarily, the fifth protection unit 160 may include a third diode D3 , the cathode of which is connected to the fifth node N5 , and the anode of which is connected to the fourth node N4 . The fourth current limiting module 170 may include a sixth resistor R6 , which is connected in series between the first node N1 and the relay 110 .

[0058] In this embodiment, when the first switch unit 131 and the second switch unit 151 jointly drive the relay 110, due to the existence of the first resistor R1, the circuit where the second switch unit 151 is located is bypassed, and the relay 110 is driven only by the first switch unit 131. At this time, since the sixth resistor R6 is relatively small, compared with the resistance after the first resistor R1 and the sixth resistor R6 are connected in series, the starting current in the circuit where the first switch unit 131 is located is still relatively large, so the start-up of the relay 110 is still driven only by the first switch unit 131. When the first switch unit 131 is turned off, the circuit where the second switch unit 151 is located (the second driving circuit) is the first resistor R1 and the sixth resistor R6 connected in series, and the resistance is relatively large, thereby further reducing the current and reducing the consumption of the relay 110.

[0059] In this embodiment, the third diode D3 is connected in reverse parallel to the relay 110. When the first switch unit 131 or the second switch unit 151 is closed, the potential of the fifth node N5 is higher than the potential of the fourth node N4, and the third diode D3 is turned off.

[0060] When the first switch unit 131 or the second switch unit 151 is turned off, inductive energy remains in the relay 110. At this time, the potential of the fifth node N5 is lower than the potential of the fourth node N4, so that the third diode D3 and the relay 110 form a loop to consume the inductive energy and prevent damage to the first switch unit 131 or the second switch unit 151. After the inductive energy is consumed, the third diode D3 is turned off.

[0061] In addition, based on the above embodiments, the embodiments of the present application also provide a charging device, which includes the relay drive circuit described in any embodiment of the present application. It should be understood that the charging device described in the present application has the beneficial effects described in any of the above embodiments, which will not be repeated here.

[0062] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A relay drive circuit, characterized in that: The drive circuit is connected to the relay via a first node, and the drive circuit comprises: A coupling module, connected to the signal input terminal and the sixth node, the coupling module is used to transmit the voltage signal of the signal input terminal to the sixth node or cut off the connection path between the signal input terminal and the sixth node; a first driving module, connected to the sixth node, the first node and the third node, the first driving module being used to connect the first node and the third node or cut off the connection path between the first node and the third node in response to the voltage signal of the sixth node; A first current limiting module, connecting the first node and the seventh node; A second driving module is connected to the signal input terminal, the seventh node and the third node. The second driving module is used to connect the seventh node and the third node or cut off the connection path between the seventh node and the third node in response to the voltage signal of the signal input terminal.

2. The relay drive circuit according to claim 1, characterized in that: The coupling module comprises: A first capacitor, two ends of which are respectively connected to the sixth node and the signal input end; The first current limiting module comprises: A first resistor, wherein two ends of the first resistor are respectively connected to the first node and the seventh node.

3. The relay drive circuit according to claim 1, characterized in that: The first driving module comprises: a first switch unit, a control end connected to the second node, a first end connected to the first node, and a second end connected to the third node, the first switch unit being used to switch on or off a connection path between the first node and the third node in response to a voltage difference between the second node and the third node; A second current limiting module, two ends of which are respectively connected to the sixth node and the second node; The second driving module comprises: a second switch unit, a control end connected to the eighth node, a first end connected to the seventh node, a second end connected to the third node, the second switch unit being used to switch on or off a connection path between the seventh node and the third node in response to a voltage difference between the eighth node and the third node; The third current limiting module has two ends connected to the signal input end and the eighth node respectively.

4. The relay driving circuit according to claim 3, characterized in that: The first switch unit includes a first voltage-controlled transistor; The control end of the first voltage-controlled transistor is connected to the second node, the first end is connected to the first node, and the second end is connected to the third node; The second current limiting module includes: A second resistor, two ends of which are respectively connected to the sixth node and the second node; The second switch unit includes a second voltage-controlled transistor; The control end of the second voltage-controlled transistor is connected to the eighth node, the first end is connected to the seventh node, and the second end is connected to the third node; The third current limiting module comprises: The third resistor has two ends connected to the signal input end and the eighth node respectively.

5. The relay driving circuit according to claim 4, characterized in that: The first driving module further includes: A third protection unit is connected to the second node and the third node, and is used to be turned on when the potential of the second node is lower than the potential of the third node and to be turned off when the potential of the second node is higher than the potential of the third node.

6. The relay driving circuit according to claim 3, characterized in that: The first switch unit comprises: a first triode, wherein a control electrode is connected to the second node, a first electrode is connected to the third node, and a second electrode is connected to the first node; The second switch unit comprises: The second triode has a control electrode connected to the eighth node, a first electrode connected to the third node, and a second electrode connected to the seventh node.

7. The relay driving circuit according to claim 6, characterized in that: The first driving module further includes: A fourth protection unit, wherein both ends of the fourth protection unit are respectively connected to the second node and the third node, and is configured to be turned on when the potential of the second node is lower than the potential of the third node and to be turned off when the potential of the second node is higher than the potential of the third node.

8. The relay driving circuit according to claim 1, characterized in that: The driving circuit further includes: a fifth protection unit, the two ends of which are respectively connected to a fifth node and a fourth node, and configured to be turned off when the potential of the fifth node is higher than the potential of the fourth node, or to be turned on when the potential of the fifth node is lower than the potential of the fourth node; wherein the fifth node is connected to a set voltage source, and the fourth node is connected to the first node; A fourth current limiting module is connected in series between the fourth node and the first node.

9. The relay driving circuit according to claim 8, characterized in that: The fifth protection unit comprises: a third diode, a cathode connected to the fifth node, and an anode connected to the fourth node; The fourth current limiting module includes: A sixth resistor is connected in series between the first node and the relay.

10. A charging device, characterized in that: A relay drive circuit comprising any one of claims 1 to 9.

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