Relay control circuit, vehicle-mounted charger and vehicle

Abstract

The embodiment of the utility model provides a relay control circuit, a vehicle-mounted charger and a vehicle. The relay control circuit comprises a first voltage control module, a second voltage control module, a coil control module and a control module, under the condition that the first signal output end of the control module outputs a driving signal and the second signal output end of the control module outputs a starting signal, the relay is in a pull-in state; when the relay is in a pull-in state, the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the maintaining signal, the relay is in a maintaining state. Power consumption of the relay can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic circuits, in particular to a relay control circuit, a vehicle-mounted charger and a vehicle. BACKGROUND

[0002] A relay is a key component of a new energy vehicle electrical system, and has high-voltage resistance, high-temperature resistance, impact resistance and strong breaking capacity. The relay is a switching device that can control a larger current with a smaller current and has a protection function. The relay can be used in a vehicle-mounted charger of a vehicle. When the vehicle-mounted charger is running, the coil of the relay is powered on, the armature of the relay is closed to connect the alternating current (AC) mains and the charging circuit, and the AC mains supplies power to the charging circuit to charge the vehicle.

[0003] However, maintaining the closure of the armature of the power relay requires continuous power supply to the coil of the relay, and the continuous power-on of the coil will generate additional heat dissipation and has safety hazards. CONTENT OF THE UTILITY MODEL

[0004] The embodiments of the present application provide a relay control circuit, a vehicle-mounted charger and a vehicle, which can reduce the power consumption of the relay.

[0005] The first aspect of the embodiments of the present application provides a relay control circuit, comprising a first voltage control module, a second voltage control module, a coil control module and a control module; the output end of the first voltage control module is connected to the output end of the second voltage control module and the first end of the coil of the relay, the second end of the coil of the relay is connected to the first end of the coil control module, the output end of the first voltage control module outputs a first voltage, the output end of the second voltage control module outputs a second voltage or a third voltage, the voltage at the first end of the coil of the relay is the maximum value of the voltage at the output end of the first voltage control module and the voltage at the output end of the second voltage control module, the first voltage is less than the second voltage, and the third voltage is less than the first voltage;

[0006] The control module comprises a first signal output end and a second signal output end, the second end of the coil control module is connected to the first signal output end, and the control end of the second voltage control module is connected to the second signal output end;

[0007] In the case that the first signal output end outputs a driving signal and the second signal output end outputs a starting signal, the relay is in an attracted state;

[0008] In the case that the relay is in the attracted state, the first signal output end outputs the driving signal, and the second signal output end outputs a maintaining signal, the relay is in a maintaining state.

[0009] The relay is in a maintaining state, which is a state of the relay in the attracted state and maintaining in the attracted state. The maintaining state can also be referred to as a maintaining attracted state.

[0010] In the embodiment of the application, when the first signal output end of the control module outputs the driving signal and the second signal output end of the control module outputs the starting signal, the voltage at the first end of the coil of the relay is the second voltage, so that the relay is in the attracted state; when the relay is in the attracted state, the first signal output end of the control module outputs the driving signal and the second signal output end of the control module outputs the maintaining signal, the voltage at the first end of the coil of the relay is the first voltage, so that the relay is in the maintaining state. Since the first voltage is less than the second voltage, the power consumption required for the relay to maintain the attracted state can be reduced, thereby reducing the power consumption of the relay.

[0011] Optionally, the first voltage control module comprises a first capacitor, a second capacitor, a first diode and a direct current conversion unit, the first end of the first capacitor is connected to the first end of the second capacitor, the positive electrode of the first diode and the output end of the direct current conversion unit, the input end of the direct current conversion unit is connected to the output end of the power supply, the second end of the first capacitor and the second end of the second capacitor are grounded, and the negative electrode of the first diode is connected to the first end of the coil of the relay.

[0012] In the embodiment of the application, the first voltage control module can output the first voltage when the relay is in the attracted state, so that the relay is in the maintaining state. Since the first voltage is less than the second voltage, the power consumption required for the relay to maintain the attracted state can be reduced, thereby reducing the power consumption of the relay.

[0013] Optionally, the second voltage control module comprises a third capacitor, a fourth capacitor, a fifth capacitor, a second diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a first switch tube and a second switch tube; the negative electrode of the second diode is connected to the first end of the third capacitor and the first end of the coil of the relay, the positive electrode of the second diode is connected to the first end of the first switch tube, the second end of the first switch tube is connected to the first end of the first resistor, the first end of the fourth capacitor and the output end of the power supply, the second end of the fourth capacitor is connected to the second end of the first resistor, the third end of the first switch tube and the first end of the second resistor, the second end of the second resistor is connected to the first end of the second switch tube, the third end of the second switch tube is connected to the first end of the fifth capacitor, the first end of the third resistor and the first end of the fourth resistor, the second end of the fourth resistor is connected to the second signal output end of the control module, and the second end of the second switch tube, the second end of the fifth capacitor, the second end of the third resistor and the second end of the third capacitor are grounded.

[0014] In the embodiment of the application, the second voltage control module can output the second voltage to switch the relay from the open state to the attracted state when the relay is in the open state, so as to enable the smooth attraction of the relay.

[0015] Optionally, the relay control circuit further comprises a filter circuit, and an output end of the first voltage control module is connected to a first end of the coil of the relay through the filter circuit.

[0016] The filter circuit comprises a fifth resistor, a sixth resistor, a sixth capacitor and a seventh capacitor, a first end of the fifth resistor is connected to a first end of the sixth resistor, a first end of the sixth capacitor, an output end of the first voltage control module and an output end of the second voltage control module, a second end of the fifth resistor is connected to a second end of the sixth resistor, a first end of the seventh capacitor and a first end of the coil of the relay, and a second end of the sixth capacitor and a second end of the seventh capacitor are grounded.

[0017] In the embodiment of the application, the filter circuit can control the current flowing through the coil of the relay through the fifth resistor and the sixth resistor, so as to control the relay to be in the open state or the attracted state.

[0018] Optionally, the relay comprises the coil, a third diode, a first contact and a second contact, a first end of the coil is connected to a negative electrode of the third diode, a second end of the coil is connected to a positive electrode of the third diode, when there is no current in the coil, the first contact of the relay and the second contact of the relay are disconnected, and the relay is in the open state, when the current in the coil is switched from no current to greater than a first current threshold, the first contact of the relay and the second contact of the relay are attracted, and the relay is in the attracted state, when the current in the coil is switched from greater than the first current threshold to greater than a second current threshold, the first contact of the relay and the second contact of the relay are attracted, and the relay is in the maintained state, and the first current threshold is greater than the second current threshold.

[0019] In the embodiment of the application, when the first signal output end of the control module does not output the driving signal, no current exists in the coil, the first contact of the relay and the second contact of the relay are disconnected, and the relay is in the disconnected state; in the case that the first signal output end of the control module outputs the driving signal and the second signal output end of the control module outputs the starting signal, the second voltage control module outputs the second voltage, when the current in the coil is switched from no current to greater than the first current threshold, the first contact of the relay and the second contact of the relay are attracted, and the relay is in the attracted state; in the case that the relay is in the attracted state, the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the maintaining signal, the first voltage control module outputs the first voltage, when the current in the coil is switched from greater than the first current threshold to greater than the second current threshold, the first contact of the relay and the second contact of the relay are attracted, and the relay is in the maintaining state. Since the first voltage is less than the second voltage, the power consumption required for the relay to maintain the attracted state can be reduced, thereby reducing the power consumption of the relay.

[0020] Optionally, the coil control module comprises a third switch tube, an eighth capacitor, a seventh resistor and an eighth resistor; the first end of the third switch tube is connected to the second end of the coil of the relay, the third end of the third switch tube is connected to the first end of the eighth capacitor, the first end of the seventh resistor and the first end of the eighth resistor, the second end of the third switch tube, the second end of the eighth capacitor and the second end of the seventh resistor are grounded, and the second end of the eighth resistor is connected to the first signal output end of the control module.

[0021] In the embodiment of the application, when the first signal output end of the control module outputs the driving signal, current exists in the coil of the relay, so that the relay is attracted. When the first signal output end of the control module does not output the driving signal, no current exists in the coil of the relay, so that the relay is disconnected.

[0022] Optionally, the first voltage control module further comprises a ninth resistor, a tenth resistor, a ninth capacitor and a tenth capacitor; the input end of the direct current conversion unit is connected to the first end of the ninth capacitor, the first end of the tenth capacitor and the output end of the power supply, the output end of the direct current conversion unit is connected to the first end of the ninth resistor and the first end of the first capacitor, the second end of the ninth resistor is connected to the voltage adjustment port of the direct current conversion unit and the first end of the tenth resistor, and the second end of the tenth resistor, the second end of the ninth capacitor and the second end of the tenth capacitor are grounded.

[0023] In the embodiment of the present application, the voltage at the output end of the DC conversion unit is less than the voltage at the output end of the power supply, the voltage at the output end of the power supply can be used as the input end of the DC conversion unit, and the DC conversion unit can convert the voltage at the output end of the power supply into the voltage at the output end of the DC conversion unit, so that two independent power supplies do not need to be additionally arranged, and the cost can be reduced.

[0024] Optionally, the DC conversion unit comprises a low dropout linear regulator (LDO) or a DC-DC converter.

[0025] The second aspect of the embodiment of the present application provides a vehicle charger, which comprises the relay control circuit and the relay according to any one of the first aspect of the embodiment of the present application.

[0026] The third aspect of the embodiment of the present application provides a vehicle, which comprises the vehicle charger according to the third aspect of the embodiment of the present application.

[0027] The relay control circuit of the embodiment of the present application comprises a first voltage control module, a second voltage control module, a coil control module and a control module; the output end of the first voltage control module is connected with the output end of the second voltage control module and the first end of the coil of the relay, the second end of the coil of the relay is connected with the first end of the coil control module, the output end of the first voltage control module outputs a first voltage, the output end of the second voltage control module outputs a second voltage or a third voltage, the voltage of the first end of the coil of the relay is the maximum value of the voltage of the output end of the first voltage control module and the voltage of the output end of the second voltage control module, the first voltage is smaller than the second voltage, and the third voltage is smaller than the first voltage; the control module comprises a first signal output end and a second signal output end, the second end of the coil control module is connected with the first signal output end, and the control end of the second voltage control module is connected with the second signal output end; in the case that the first signal output end of the control module outputs a driving signal and the second signal output end of the control module outputs an enabling signal, the voltage of the first end of the coil of the relay is the second voltage, and the relay switches from a disconnection state to an attraction state; in the case that the relay is in the attraction state, the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs a maintaining signal, the voltage of the first end of the coil of the relay is the first voltage, and the relay is in a maintaining state. In the embodiment of the present application, in the case that the first signal output end of the control module outputs the driving signal and the second signal output end of the control module outputs the enabling signal, the voltage of the first end of the coil of the relay is the second voltage, so that the relay is in the attraction state; in the case that the relay is in the attraction state, the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the maintaining signal, the voltage of the first end of the coil of the relay is the first voltage, so that the relay is in the maintaining state, and since the first voltage is smaller than the second voltage, the power consumption required for the relay to maintain the attraction state can be reduced, thereby reducing the power consumption of the relay. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0029] Figure 1 is a structural schematic diagram of a relay control circuit provided by the embodiment of the present application;

[0030] Figure 2 is a structural schematic diagram of another relay control circuit provided by the embodiment of the present application;

[0031] Figure 3is a structural schematic diagram of another relay control circuit provided by an embodiment of the present application. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person skilled in the art without creative work fall within the scope of protection of the present application.

[0033] The terms “first”, “second”, and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms “include” and “have” and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, product, or device.

[0034] In the present application, “embodiment” means that the specific features, structures, or properties described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by a person skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0035] The relay K1 (such as a power relay K1) is a key component of the electrical system of a new energy vehicle, with high voltage resistance, high temperature resistance, impact resistance, and strong breaking capacity. The relay K1 is a switching device that can control a larger current with a smaller current and has a protection function. The relay K1 can be used in a vehicle-mounted charger of a vehicle. When the vehicle-mounted charger is running, the coil of the relay K1 is powered on, and the armature of the relay K1 is closed to connect the alternating current (AC) mains and the charging circuit, and the AC mains supplies power to the charging circuit to charge the vehicle.

[0036] However, maintaining the closure of the armature of the power relay K1 requires continuous power supply to the coil of the relay K1, and continuous power-on of the coil will generate additional heat dissipation and pose a safety hazard.

[0037] An embodiment of the present application designs a relay control circuit that can reduce the power consumption of the relay K1.

[0038] Please refer to Figure 1 , Figure 1 is a structural schematic diagram of a relay control circuit provided by an embodiment of the present application. As shown inFigure 1 As shown, the relay control circuit 100 includes a first voltage control module 10, a second voltage control module 20, a coil control module 30, and a control module 40; the output terminal of the first voltage control module 10 is connected to the output terminal of the second voltage control module 20 and the first terminal of the coil of the relay K1 (e.g., ...). Figure 1 Port 4 in K1 shown), the second terminal of the coil of relay K1 (as shown) Figure 1 Port 3 in K1 is connected to the first terminal of the coil control module 30. The output terminal of the first voltage control module 10 outputs a first voltage, and the output terminal of the second voltage control module 20 outputs a second voltage or a third voltage. The voltage at the first terminal of the coil of the relay K1 is the maximum value of the voltage at the output terminal of the first voltage control module 10 and the voltage at the output terminal of the second voltage control module 20. The first voltage is less than the second voltage, and the third voltage is less than the first voltage.

[0039] The control module 40 includes a first signal output terminal and a second signal output terminal. The second terminal of the coil control module 30 is connected to the first signal output terminal of the control module 40, and the control terminal of the second voltage control module 20 is connected to the second signal output terminal of the control module 40.

[0040] When the control module 40 outputs a drive signal at its first signal output terminal and a start signal at its second signal output terminal, the voltage at the first terminal of the coil of the relay K1 is the second voltage, so that the relay K1 is in the energized state.

[0041] When the relay K1 is in the energized state, the first signal output terminal of the control module outputs the drive signal, and the second signal output terminal of the control module outputs the sustaining signal, the voltage at the first terminal of the coil of the relay K1 is the first voltage, so that the relay K1 is in the sustaining state.

[0042] In the embodiment of the present application, when the first signal output end of the control module does not output the driving signal, and there is no current in the coil of the relay K1, the relay K1 is in the open state; when the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the starting signal, the voltage at the first end of the coil of the relay K1 is the second voltage, and the current in the coil is switched from no current to greater than the first current threshold, at this time, the relay K1 is in the attracted state; when the relay K1 is in the attracted state, the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the maintaining signal, the voltage at the first end of the coil of the relay K1 is the first voltage, and the current in the coil is switched from greater than the first current threshold to greater than the second current threshold, at this time, the relay K1 is in the maintaining state. Since the first voltage is less than the second voltage, the power consumption required for the relay K1 to maintain the attracted state can be reduced, thereby reducing the power consumption of the relay K1. The first current threshold is greater than the second current threshold.

[0043] The output end of the first voltage control module 10 and the output end of the second voltage control module 20 are connected, diodes can be arranged in the first voltage control module 10 and the second voltage control module 20, and the negative poles of the two diodes are connected.

[0044] When the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the starting signal, the voltage at the first end of the coil of the relay K1 is the second voltage; when the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the maintaining signal, the voltage at the first end of the coil of the relay K1 is the first voltage.

[0045] In the embodiment of the present application, when the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the starting signal, the voltage at the first end of the coil of the relay K1 is the second voltage, so that the relay K1 is switched from the open state to the attracted state; when the relay K1 is in the attracted state, the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the maintaining signal, the voltage at the first end of the coil of the relay K1 is the first voltage, so that the relay K1 is in the maintaining state. Since the first voltage is less than the second voltage, the power consumption required for the relay K1 to maintain the attracted state can be reduced, thereby reducing the power consumption of the relay K1.

[0046] Please refer to Figure 2 , Figure 2 is a structural schematic diagram of another relay control circuit provided in the embodiment of the present application. As shown in Figure 2As shown, the first voltage control module 10 comprises a first capacitor C1, a second capacitor C2, a first diode D1 and a DC conversion unit 11. The first end of the first capacitor C1 is connected to the first end of the second capacitor C2, the positive pole of the first diode D1 and the output end of the DC conversion unit 11. The input end of the DC conversion unit 11 is connected to the output end of the power supply. The second end of the first capacitor C1 and the second end of the second capacitor C2 are grounded. The negative pole of the first diode D1 is connected to the first end of the coil of the relay K1.

[0047] The first capacitor C1 and the second capacitor C2 can filter the voltage, so as to stabilize the voltage at the output end of the first voltage control module 10. The first diode D1 can prevent the voltage at the output end of the first voltage control module 10 from flowing back into the first voltage control module 10, so as to improve the safety of the first voltage control module 10.

[0048] The voltage at the output end of the DC conversion unit 11 is V1. For example, V1 is 6.3V. When the conduction voltage drop of the first diode D1 is 0.3V, the first voltage output by the first voltage control module 10 is 6V.

[0049] The voltage at the output end of the power supply is V2. For example, V2 can be 12V.

[0050] For example, the third voltage can be 0V.

[0051] In the embodiment, the first voltage control module 10 can output the first voltage when the relay K1 is in the attracted state, so as to make the relay K1 in the maintaining state. Since the first voltage is less than the second voltage, the power consumption required for the relay K1 to maintain the attracted state can be reduced, so as to reduce the power consumption of the relay K1.

[0052] Optionally, as shown in FIG. 2, the first voltage control module 10 can further comprise a third capacitor C3. The first end of the third capacitor C3 is connected to the second end of the first capacitor C1 and the second end of the second capacitor C2. The second end of the third capacitor C3 is connected to the negative pole of the first diode D1. Figure 2As shown, the second voltage control module 20 comprises a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a second diode D2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first switch Q1 and a second switch Q2. The negative electrode of the second diode D2 is connected to the first end of the third capacitor C3 and the first end of the coil of the relay K1, the positive electrode of the second diode D2 is connected to the first end of the first switch Q1, the second end of the first switch is connected to the first end of the first resistor R1, the first end of the fourth capacitor C4 and the output end of the power supply, the second end of the fourth capacitor C4 is connected to the second end of the first resistor R1, the third end of the first switch and the first end of the second resistor R2, the second end of the second resistor R2 is connected to the first end of the second switch Q2, the third end of the second switch Q2 is connected to the first end of the fifth capacitor C5, the first end of the third resistor R3 and the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the second signal output end of the control module, and the second end of the second switch Q2, the second end of the fifth capacitor C5, the second end of the third resistor R3 and the second end of the third capacitor C3 are grounded.

[0053] When the second signal output end of the control module outputs a high level, the third resistor R3 and the fourth resistor R4 form a voltage divider circuit, so that the second switch Q2 is turned on, and the fifth capacitor C5 can keep the voltage at the third end of the second switch stable. When the second switch Q2 is turned on, the first resistor R1 and the second resistor R2 form a voltage divider circuit, so that the first switch Q1 is turned on. The third capacitor C3 can ensure that the voltage at the output end of the first voltage control module 10 and the output end of the second voltage control module 20 is stable, thereby providing a stable power supply voltage for the relay K1.

[0054] In the embodiment of the application, the second voltage control module 20 can output a second voltage when the relay K1 is in the open state, so as to switch the relay K1 from the open state to the attracted state, and make the relay K1 smoothly attracted.

[0055] The voltage at the output end of the power supply is V2. For example, V2 can be 12V. When the conduction voltage drop of the second diode D2 is 0.3V, the second voltage output at the output end of the second voltage control module 20 is 11.7V.

[0056] In this configuration, the cathode of the first diode D1 is connected to the cathode of the second diode D2. The first diode D1 and the second diode D2 act as reverse cutoff terminals. Simultaneously, at the output terminals of both the first voltage control module 10 and the second voltage control module 20, because the voltage at the output terminal of the second voltage control module 20 is higher, the voltage at the first terminal of the coil of relay K1 becomes the second voltage, thus supplying the second voltage to relay K1. When the first voltage control module 10 outputs the first voltage, and the output terminal of the second voltage control module 20 has no voltage output, because the voltage at the output terminal of the first voltage control module 10 is higher, the voltage at the first terminal of the coil of relay K1 becomes the first voltage, thus supplying the first voltage to relay K1.

[0057] Optional, such as Figure 2 As shown, the relay K1 includes a coil, a third diode D3, a first contact 1, and a second contact 2. The first end of the coil is connected to the negative terminal of the third diode D3, and the second end of the coil is connected to the positive terminal of the third diode D3. When there is no current in the coil, the first contact 1 and the second contact 2 of the relay K1 are disconnected, and the relay K1 is in an open state. When the current in the coil changes from no current to a value greater than a first current threshold, the first contact 1 and the second contact 2 of the relay K1 are engaged, and the relay K1 is in an engaged state. When the current in the coil changes from a value greater than the first current threshold to a value greater than a second current threshold, the first contact 1 and the second contact 2 of the relay K1 are engaged, and the relay K1 is in a sustained state. The first current threshold is greater than the second current threshold.

[0058] In the embodiment of the present application, when the first signal output end of the control module does not output the driving signal, and there is no current in the coil, the first contact 1 of the relay K1 and the second contact 2 of the relay K1 are disconnected, at this time, the relay K1 is in the disconnected state; in the case that the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the starting signal, the second voltage control module 20 outputs the second voltage, when the current in the coil is switched from no current to greater than the first current threshold, the first contact 1 of the relay K1 and the second contact 2 of the relay K1 are attracted, at this time, the relay K1 is in the attracted state; in the case that the relay K1 is in the attracted state, the first signal output end of the control module outputs the driving signal, and the second signal output end of the control module outputs the maintaining signal, the first voltage control module 10 outputs the first voltage, when the current in the coil is switched from greater than the first current threshold to greater than the second current threshold, the first contact 1 of the relay K1 and the second contact 2 of the relay K1 are attracted, at this time, the relay K1 is in the maintaining state. Since the first voltage is less than the second voltage, the power consumption required for the relay K1 to maintain the attracted state can be reduced, thereby reducing the power consumption of the relay K1.

[0059] The third diode D3 is a freewheeling diode, when the relay K1 is switched from the attracted state to the disconnected state, the self-induced electromotive force will be generated in the coil of the relay K1, if the self-induced electromotive force directly acts on other elements (such as sensitive elements such as transistors, microcontrollers, etc.) in the circuit, damage may be caused. By connecting the third diode D3 in parallel across the coil of the relay K1, a discharge current loop can be provided for the self-induced electromotive force when the relay K1 is disconnected, that is, the third diode D3 plays a role in freewheeling.

[0060] Optionally, as shown in Figure 2 The coil control module 30 includes a third switch tube Q3, an eighth capacitor C8, a seventh resistor R7 and an eighth resistor R8; the first end of the third switch tube Q3 is connected to the second end of the coil of the relay K1, the third end of the third switch tube Q3 is connected to the first end of the eighth capacitor C8, the first end of the seventh resistor R7 and the first end of the eighth resistor R8, the second end of the third switch tube Q3, the second end of the eighth capacitor C8 and the second end of the seventh resistor R7 are grounded, and the second end of the eighth resistor R8 is connected to the first signal output end of the control module.

[0061] The seventh resistor R7 and the eighth resistor R8 constitute a voltage dividing circuit, and the eighth capacitor C8 is a voltage stabilizing capacitor, which can ensure the stability of the voltage at the third end of the third switch tube Q3, thereby stably controlling the conduction or cutoff of the third switch tube Q3.

[0062] In the embodiment of the present application, when the control module outputs the driving signal at the first signal output end, the current exists in the coil of the relay K1, so that the relay K1 is attracted. When the control module does not output the driving signal at the first signal output end, the current does not exist in the coil of the relay K1, so that the relay K1 is disconnected.

[0063] Optionally, as shown in Figure 2 The first voltage control module 10 further includes a ninth resistor R9, a tenth resistor R10, a ninth capacitor C9 and a tenth capacitor C10. The input end of the DC conversion unit 11 is connected with the first end of the ninth capacitor C9, the first end of the tenth capacitor C10 and the output end of the power supply. The output end of the DC conversion unit 11 is connected with the first end of the ninth resistor R9 and the first end of the first capacitor C1. The second end of the ninth resistor R9 is connected with the voltage regulation port of the DC conversion unit 11 and the first end of the tenth resistor R10. The second end of the tenth resistor R10, the second end of the ninth capacitor C9 and the second end of the tenth capacitor C10 are grounded.

[0064] The ninth capacitor C9 and the tenth capacitor C10 are filter capacitors. The ninth resistor R9 and the tenth resistor R10 can play a role of discharge, so as to protect the DC conversion unit 11. For example, when the DC conversion unit 11 needs to be restarted after power-off, the first capacitor C1 and the second capacitor C2 can be quickly discharged through the ninth resistor R9 and the tenth resistor R10.

[0065] In the embodiment of the present application, the voltage of the output end of the DC conversion unit 11 is less than the voltage of the output end of the power supply. The voltage of the output end of the power supply can be used as the input end of the DC conversion unit 11. The DC conversion unit 11 can convert the voltage of the output end of the power supply into the voltage of the output end of the DC conversion unit 11. Therefore, two independent power supplies are not needed, and the cost can be reduced.

[0066] Please refer to Figure 3 , Figure 3 is another structure diagram of a relay control circuit provided by the embodiment of the present application. As shown in Figure 3 The relay control circuit further includes a filter circuit 50. The output end of the first voltage control module 10 is connected with the first end of the coil of the relay K through the filter circuit 50. The output end of the second voltage control module 20 is connected with the first end of the coil of the relay K through the filter circuit 50.

[0067] The filter circuit 50 comprises a fifth resistor R5, a sixth resistor R6, a sixth capacitor C6 and a seventh capacitor C7; a first end of the fifth resistor R5 is connected to a first end of the sixth resistor R6, a first end of the sixth capacitor C6, an output end of the first voltage control module 10 and an output end of the second voltage control module 20, a second end of the fifth resistor R5 is connected to a second end of the sixth resistor R6, a first end of the seventh capacitor C7 and a first end of a coil of the relay K1, and a second end of the sixth capacitor C6 and a second end of the seventh capacitor C7 are grounded.

[0068] In the embodiment, the fifth resistor R5 and the sixth resistor R6 are current limiting resistors, and the current flowing through the coil of the relay K1 can be controlled by the fifth resistor R5 and the sixth resistor R6, so as to control the relay K1 to be in the open state or the attracted state. The sixth capacitor C6 and the seventh capacitor C7 are voltage stabilizing capacitors, which can ensure the stability of the voltage input to the relay K1.

[0069] Optionally, the direct current conversion unit 11 comprises a low dropout regulator (LDO) or a direct current-direct current (DC-DC) converter. The DC-DC converter can also be referred to as a DC / DC converter. Figure 2 And Figure 3 The direct current conversion unit 11 takes the LDO as an example.

[0070] The first switch Q1, the second switch Q2 and the third switch can be any device that can be used as a switch, such as a triode or a field effect transistor. Figure 2 And Figure 3 The first switch Q1 is a P-type metal-oxide-semiconductor field-effect transistor (MOSFET), which is referred to as a PMOS transistor. Figure 2 And Figure 3 The second switch Q2 is an N-type metal-oxide-semiconductor field-effect transistor, which is referred to as an NMOS transistor. Figure 2 And Figure 3 The third switch Q3 is an NPN triode.

[0071] As shown in Figure 2 Or Figure 3 The signal output by the first signal output end of the control module 40 is an IN_RELAY_CTL signal. When the IN_RELAY_CTL signal is at a high level, the IN_RELAY_CTL signal is a driving signal. When the IN_RELAY_CTL signal is at a low level, the KF_CONTROL signal is a stop signal.

[0072] The IN_RELAY_CTL signal can also be a Pulse Width Modulation (PWM) signal. When the IN_RELAY_CTL signal is a PWM signal, the on-time of the third switch Q3 can be adjusted by adjusting the duty cycle of the IN_RELAY_CTL signal, thereby controlling the current flowing through the coil of relay K1.

[0073] like Figure 2 or Figure 3 As shown, the signal output by the second signal output terminal of the control module 40 is the KF_CONTROL signal. When the KF_CONTROL signal is high, it is a start signal; when the KF_CONTROL signal is low, it is a sustain signal.

[0074] When the KF_CONTROL signal is high, the second switch Q2 is turned on, and then the first switch Q1 is turned on. The voltage V2 at the output terminal of the second power supply is output to the relay K1 through the second diode D2.

[0075] When the KF_CONTROL signal is low, the second switch Q2 is turned off, and then the first switch Q1 is turned off. The voltage V2 at the output of the second power supply cannot be output to the relay K1 through the second diode D2.

[0076] V1 is the voltage maintained after the circuit is engaged. It is converted from the voltage connected to the output terminal of the second power supply by the DC-DC converter 11 and output to the relay K1 through the first diode D1.

[0077] When relay K1 starts up (for example, when the on-board charger is turned on), it first provides the KF_CONTROL signal, and outputs V2 through the second diode D2 (ignoring the forward voltage drop of the second diode D2) to relay K1, while the first diode D1 is not turned on.

[0078] When relay K1 is energized, the KF_CONTROL signal is turned off. At this time, the first diode D1 is turned on and the second diode D2 is turned off. The output V1 (ignoring the forward voltage drop of the first diode D1) is sent to relay K1, and relay K1 remains in a low-power energized state.

[0079] The KF CONTROL signal can also be a pulse width modulation (PWM) signal. When the KF CONTROL signal is a PWM signal, by adjusting the duty cycle of the KF CONTROL signal, thereby adjusting the on time of the KF CONTROL, the time when the third capacitor C3 is connected to V2 can be adjusted, and finally the voltage value on the third capacitor C3 can be adjusted.

[0080] In the embodiments of the present application, V2 can be used to change the armature (such as the armature connected to port 1 in the relay K1 shown in Figure 2 or Figure 3 ) from a disconnection (such as the disconnection of port 1 and port 2 in the relay K1 shown in Figure 2 or Figure 3 ) to a attracted state (such as the connection of port 1 and port 2 in the relay K1 shown in Figure 1 or Figure 1 ), and then the rear switch is used to supply power to the coil using V1 to keep the armature in a maintained state. Since the voltage value of V1 is less than the voltage value of V2, the voltage value required to maintain the armature in the attracted state during the charging process is reduced, thereby reducing the heat generation power of the coil and the heat dissipation power generated by the power relay K1 when the vehicle charger is running. By changing the duty cycle of the KF CONTROL signal, the voltage on the filter capacitor (third capacitor C3) can be changed to adapt to different brands and different coil voltage relays K1.

[0081] The embodiments of the present application also provide a vehicle charger, which can include Figure 2 the relay control circuit 100 and the relay K1.

[0082] The specific structure of the relay control circuit 100 can refer to the circuits shown in the above Figure 3 , ​ or ​ .

[0083] The embodiments of the present application also provide a vehicle, which includes the above vehicle charger.

[0084] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can refer to the related description of other embodiments.

[0085] In several embodiments provided in the present application, it should be understood that the disclosed relay K1 control circuit can be implemented in other ways. For example, the above-described relay K1 control circuit embodiments are only illustrative, for example, the division of the units is only a logical functional division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

Claims

1. A relay control circuit, characterized by comprising: The relay control circuit comprises a first voltage control module, a second voltage control module, a coil control module and a control module; an output end of the first voltage control module is connected with an output end of the second voltage control module and a first end of a coil of a relay, a second end of the coil of the relay is connected with a first end of the coil control module, an output end of the first voltage control module outputs a first voltage, an output end of the second voltage control module outputs a second voltage or a third voltage, a voltage of the first end of the coil of the relay is a maximum value of the voltage of the output end of the first voltage control module and the voltage of the output end of the second voltage control module, the first voltage is smaller than the second voltage, and the third voltage is smaller than the first voltage; the control module comprises a first signal output end and a second signal output end, a second end of the coil control module is connected with the first signal output end, and a control end of the second voltage control module is connected with the second signal output end; in a case where a driving signal is output from the first signal output end and a starting signal is output from the second signal output end, the relay is in an attraction state; in a case where the relay is in the attraction state, the driving signal is output from the first signal output end, and a maintaining signal is output from the second signal output end, the relay is in a maintaining state.

2. The relay control circuit according to claim 1, characterized by the first voltage control module comprises a first capacitor, a second capacitor, a first diode and a direct current conversion unit, a first end of the first capacitor is connected with a first end of the second capacitor, a positive electrode of the first diode and an output end of the direct current conversion unit, an input end of the direct current conversion unit is connected with an output end of a power supply, a second end of the first capacitor and a second end of the second capacitor are grounded, and a negative electrode of the first diode is connected with a first end of the coil of the relay.

3. The relay control circuit of claim 1, wherein, the second voltage control module comprises a third capacitor, a fourth capacitor, a fifth capacitor, a second diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a first switch tube and a second switch tube; a negative electrode of the second diode is connected with a first end of the third capacitor and a first end of the coil of the relay, a positive electrode of the second diode is connected with a first end of the first switch tube, a second end of the first switch tube is connected with a first end of the first resistor, a first end of the fourth capacitor and an output end of the power supply, a second end of the fourth capacitor is connected with a second end of the first resistor, a third end of the first switch tube and a first end of the second resistor, a second end of the second resistor is connected with a first end of the second switch tube, a third end of the second switch tube is connected with a first end of the fifth capacitor, a first end of the third resistor and a first end of the fourth resistor, a second end of the fourth resistor is connected with a second signal output end of the control module, and a second end of the second switch tube, a second end of the fifth capacitor, a second end of the third resistor and a second end of the third capacitor are grounded.

4. The relay control circuit of claim 1, wherein, the relay control circuit further comprises a filter circuit, and the output end of the first voltage control module is connected with the first end of the coil of the relay through the filter circuit. The filter circuit comprises a fifth resistor, a sixth resistor, a sixth capacitor and a seventh capacitor; a first end of the fifth resistor is connected with a first end of the sixth resistor, a first end of the sixth capacitor, an output end of the first voltage control module and an output end of the second voltage control module; a second end of the fifth resistor is connected with a second end of the sixth resistor, a first end of the seventh capacitor and a first end of a coil of the relay; a second end of the sixth capacitor and a second end of the seventh capacitor are grounded.

5. The relay control circuit of claim 1, wherein, The relay comprises the coil, a third diode, a first contact and a second contact; a first end of the coil is connected with a negative electrode of the third diode; a second end of the coil is connected with a positive electrode of the third diode; when there is no current in the coil, the first contact of the relay and the second contact of the relay are disconnected, and the relay is in an off state; When the current in the coil is switched from no current to greater than a first current threshold, the first contact of the relay and the second contact of the relay are attracted, and the relay is in the attracted state; When the current in the coil is switched from greater than the first current threshold to greater than a second current threshold, the first contact of the relay and the second contact of the relay are attracted, and the relay is in the maintained state; the first current threshold is greater than the second current threshold.

6. The relay control circuit of claim 1, wherein, The coil control module comprises a third switch tube, an eighth capacitor, a seventh resistor and an eighth resistor; a first end of the third switch tube is connected with a second end of the coil of the relay; a third end of the third switch tube is connected with a first end of the eighth capacitor, a first end of the seventh resistor and a first end of the eighth resistor; a second end of the third switch tube, a second end of the eighth capacitor and a second end of the seventh resistor are grounded; a second end of the eighth resistor is connected with a first signal output end of the control module.

7. The relay control circuit of claim 2, wherein, The first voltage control module further comprises a ninth resistor, a tenth resistor, a ninth capacitor and a tenth capacitor; an input end of the direct current conversion unit is connected with a first end of the ninth capacitor, a first end of the tenth capacitor and an output end of the power supply; an output end of the direct current conversion unit is connected with a first end of the ninth resistor and a first end of the first capacitor; a second end of the ninth resistor is connected with a voltage regulation port of the direct current conversion unit and a first end of the tenth resistor; a second end of the tenth resistor, a second end of the ninth capacitor and a second end of the tenth capacitor are grounded.

8. The relay control circuit of claim 7, wherein, The direct current conversion unit comprises a low dropout linear regulator (LDO).

9. An on-board charger, characterized by, The relay control circuit and the relay according to any one of claims 1-8 are included.

10. A vehicle characterized by comprising: The on-board charger according to claim 9 is included.

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