Detection circuit for relay and power supply device

Abstract

The invention discloses a detection circuit for a relay and a power supply device. The detection circuit comprises a live wire relay detection circuit and a first enable control circuit. The live wire relay detection circuit comprises a first switch module and a first signal conversion circuit. The first signal conversion circuit comprises a first signal input end and is used for receiving a signal from the output end of the live wire relay; the second signal input end is used for receiving a signal from the input end of the zero line relay through the first switch module; the live wire signal output end is used for outputting a live wire detection signal; wherein the first signal conversion circuit is used for generating a live wire detection signal based on signals received by the first signal input end and the second signal input end, a first state of the live wire detection signal is used for indicating that the live wire relay does not have a fault, and a second state of the live wire detection signal is used for indicating that the live wire relay has a fault; the first enable control circuit is used for controlling the first switch module to be closed based on a first enable signal at a first level.

Description

Technical Field

[0001] The present application relates to the technical field of relays, and more particularly, to a detection circuit and a power supply device for a relay. Background Art

[0002] In the application of Alternative Current (AC) charging piles, the start or end of the process of charging from the AC charging pile to an electric device such as an electric vehicle can be controlled by controlling the closing or opening of a relay. The high-voltage circuit is controlled by a low voltage through a relay, ensuring a safe, accurate and efficient charging operation. However, during the charging process, it may happen that the live wire relay (also referred to as the "L-terminal relay" in this article) or the neutral wire relay (also referred to as the "N-terminal relay" in this article) fails. For example, when trying to disconnect the relay to stop the charging process, the relay cannot be completely disconnected (for example, adhesion occurs). This may cause the AC charging pile to fail to switch the working state normally, thereby affecting the overall performance and reliability of the charging pile. Summary of the Invention

[0003] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

[0004] According to one aspect of the present invention, a detection circuit for a relay is provided, wherein the detection circuit includes a live wire relay detection circuit and a first enable control circuit, the live wire relay detection circuit including: a first switch module; and a first signal conversion circuit, the first signal conversion circuit including: a first signal input terminal configured to receive a signal from the output terminal of the live wire relay; a second signal input terminal configured to receive a signal from the input terminal of the neutral wire relay via the first switch module; a live wire signal output terminal configured to output a live wire detection signal; wherein the first signal conversion circuit is configured to generate the live wire detection signal based on the signals received by the first signal input terminal and the second signal input terminal, the first state of the live wire detection signal being used to indicate that there is no fault in the live wire relay, and the second state of the live wire detection signal being used to indicate that there is a fault in the live wire relay; wherein the first enable control circuit is configured to control the first switch module to close based on a first enable signal at a first level.

[0005] In the above-mentioned detection circuit, when the first enable control circuit is provided with the first enable signal at the first level, in response to the first signal input terminal of the first signal conversion circuit not receiving a signal, the live wire detection signal is in the first state, thereby indicating that there is no fault in the live wire relay; in response to the first signal input terminal of the first signal conversion circuit receiving a signal, the live wire detection signal is in the second state, thereby indicating that there is a fault in the live wire relay.

[0006] In the above-mentioned detection circuit, when the device to be charged is disconnected from the power supply device including the detection circuit, the first enable control circuit is provided with the first enable signal at the first level; or the first enable control circuit is periodically provided with the first enable signal at the first level.

[0007] In the above-mentioned detection circuit, the first enable control circuit includes a triode module and a MOS transistor module, and the output end of the triode module is electrically coupled to the control end of the MOS transistor module, wherein the control end of the triode module is configured to receive the first enable signal at the first level, and the output end of the MOS transistor module is configured to output a control signal based on the first enable signal at the first level to control the first switch module to close.

[0008] In the above detection circuit, the first switch module includes an electromagnetic relay.

[0009] In the above detection circuit, the first signal conversion circuit includes an optical coupler module.

[0010] In the above detection circuit, the live wire relay detection circuit further includes a first filtering circuit, which is electrically coupled to the first signal conversion circuit to smooth the live wire detection signal.

[0011] In the above-mentioned detection circuit, the detection circuit further includes a neutral line relay detection circuit and a second enable control circuit, the neutral line relay detection circuit includes: a second switch module; and a second signal conversion circuit, the second signal conversion circuit includes: a third signal input terminal, configured to receive a signal from the output terminal of the neutral line relay; a fourth signal input terminal, configured to receive a signal from the input terminal of the live line relay via the second switch module; a neutral line signal output terminal, configured to output a neutral line detection signal; wherein, the second signal conversion circuit is configured to generate the neutral line detection signal based on the signals received by the third signal input terminal and the fourth signal input terminal, the third state of the neutral line detection signal is used to indicate that there is no fault in the neutral line relay, and the fourth state of the neutral line detection signal is used to indicate that there is a fault in the neutral line relay; wherein, the second enable control circuit is configured to control the second switch module to close based on the second enable signal at the first level.

[0012] In the above-mentioned detection circuit, when the second enable control circuit is provided with the second enable signal at the first level, in response to the third signal input terminal of the second signal conversion circuit not receiving a signal, the neutral line detection signal is in the third state, thereby indicating that there is no fault in the neutral line relay; in response to the third signal input terminal of the second signal conversion circuit receiving a signal, the neutral line detection signal is in the fourth state, thereby indicating that there is a fault in the neutral line relay.

[0013] In the above detection circuit, the second state of the live wire detection signal and the fourth state of the neutral wire detection signal are used to jointly indicate that both the live wire relay and the neutral wire relay are faulty and / or there is a short circuit between the live wire and the neutral wire.

[0014] In the above detection circuit, the first enable control circuit and the second enable control circuit are the same enable control circuit.

[0015] According to another aspect of the present invention, a power supply device is provided, comprising: a live wire relay and a neutral wire relay provided on the live wire and the neutral wire of an AC line; and a detection circuit as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention may be better understood by describing exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0017] Figure 1A A schematic diagram showing the connection of the L-end relay and the N-end relay;

[0018] Figure 1BA schematic connection diagram of a detection circuit for an L-terminal relay in the prior art is shown;

[0019] Figure 2 A block diagram of a detection circuit for a relay according to an embodiment of the present invention is shown;

[0020] Figure 3 FIG2 shows a block diagram of a detection circuit for a relay according to another embodiment of the present invention;

[0021] Figure 4 shows a block diagram of a detection circuit for a relay according to yet another embodiment of the present invention;

[0022] Figure 5 shows a schematic connection diagram of a detection circuit for a relay according to one embodiment of the present invention;

[0023] Figure 6 shows a block diagram of a detection circuit for a relay according to yet another embodiment of the present invention;

[0024] Figure 7 shows a schematic connection diagram of a detection circuit for a relay according to another embodiment of the present invention;

[0025] Figure 8 A block diagram of a power supply device according to an embodiment of the present invention is shown;

[0026] Figure 9 A schematic connection diagram of a power supply device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0027] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but the invention is not limited thereto but only by the claims. In the drawings, for illustrative purposes, the dimensions of some of the elements may be exaggerated and not drawn to scale. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts.

[0028] Although the terms used in the present invention are selected from commonly known and commonly used terms, some of the terms mentioned in the present invention specification may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description herein. In addition, it is required to understand the present invention not only by the actual terms used, but also by the meaning implied by each term.

[0029] In the description provided herein, numerous specific details are set forth. However, it should be understood that embodiments of the present invention may be practiced without these specific details. In other instances, well-known methods, structures, and techniques are not shown in detail to avoid obscuring an understanding of the present invention.

[0030] Figure 1A A schematic diagram of the connection of the L-end relay and the N-end relay is shown. The L-end relay and the N-end relay are arranged in the main circuit of the AC charging pile. The input ends of the L-end relay and the N-end relay receive L_IN and N_IN signals from the live wire and the neutral wire, respectively. When the charging process needs to be started, the L-end relay and the N-end relay are closed so that the L_IN and N_IN signals can flow through the L-end relay and the N-end relay respectively to be output as L_OUT and N_OUT signals at the corresponding output ends; when the charging process needs to be stopped, the L-end relay and the N-end relay are disconnected so that the L_IN and N_IN signals cannot flow through. However, if the L-end relay or the N-end relay fails, such as adhesion, it may cause the device containing the above relay to be energized, posing a safety hazard such as electric shock, and even accelerate the aging and performance degradation of components associated with the device, affecting the service life of the device. In addition, during the initiation of the charging process for the device to be charged, excessive impact may be generated, thereby causing safety hazards such as damage to the device to be charged. Because the L-terminal relay is electrically coupled to the live wire (associated with the control of the high-voltage circuit), if a fault such as adhesion occurs in the L-terminal relay, the initiated charging process may not be stopped properly, creating a greater electrical safety risk. Therefore, it is necessary to detect whether the L-terminal relay has stuck in the appropriate scenario.

[0031] Figure 1B FIG. 1 shows a schematic diagram of the connection of a detection circuit for an L-terminal relay in the prior art. Figure 1A The input terminal of the N-terminal relay and the output terminal of the L-terminal relay are electrically coupled to the Figure 1B The detection circuit shown in Figure 1 shows a circuit diagram. If the L-end relay is stuck, the N_IN signal and the L_OUT signal output at the output of the L-end relay pass through electronic components such as resistors and diodes, turning on the optocoupler U2. This circuit can detect the presence of a sticking fault in the L-end relay. However, this method keeps the detection circuit in a constant operating state, resulting in high power consumption and an inability to control the detection time.

[0032] In view of the above problems, the present application proposes a detection circuit for a relay.

[0033] Figure 2 FIG2 is a block diagram of a detection circuit 200 for a relay according to an embodiment of the present invention. The detection circuit 200 may include a live relay detection circuit 210 and a first enable control circuit 220 , wherein the live relay detection circuit 210 and the first enable control circuit 220 are electrically coupled.

[0034] The live wire relay detection circuit 210 may include a first switch module 212 and a first signal conversion circuit 214 , and the first switch module 212 is electrically coupled to the first signal conversion circuit 214 .

[0035] In one embodiment, the first switch module 212 may include an electromagnetic relay, which is suitable for industrial-grade high-power scenarios.

[0036] The first signal conversion circuit 214 may include a first signal input terminal, a second signal input terminal, and a live signal output terminal. The first signal input terminal may be configured to receive a signal L_OUT from the output terminal of the L-terminal relay. The second signal input terminal may be configured to receive a signal N_IN from the input terminal of the N-terminal relay via the first switch module 212. When the first switch module 212 is closed, the signal N_IN from the input terminal of the N-terminal relay can pass through the first switch module 212 to the second signal input terminal. The live signal output terminal may be configured to output a live detection signal. The first signal conversion circuit 214 may be configured to generate a live detection signal based on the signals received from the first signal input terminal and the second signal input terminal, respectively, and output the live detection signal at the signal output terminal. The first state of the live detection signal indicates that the live relay is not faulty. The second state of the live detection signal indicates that a fault exists in the live relay. Such a fault may be, for example, a sticking relay.

[0037] The first enable control circuit 220 may be provided with a first enable signal to control the first switch module 212 to be closed or opened. For example, the first enable signal may be provided to the first enable control circuit 220 by a main control unit.

[0038] When the first enable signal is at a first level (e.g., a high level), the first enable control circuit 220 can control the first switch module 212 to close, so that the second signal input terminal can receive the signal N_IN from the input terminal of the N-terminal relay via the first switch module 212, thereby enabling the live wire relay detection circuit 210 to detect the L-terminal relay. Although the first level is described herein as a high level, it should be understood that when using an enable control circuit with a different configuration, the first level can also be a low level.

[0039] In one embodiment, when the first enable control circuit 220 is provided with a first enable signal at a first level to control the first switch module 212 to close, for example, if the first signal input terminal of the first signal conversion circuit 214 does not receive a signal, the hot wire detection signal is in a first state, thereby indicating that the L-end relay is not faulty. For another example, if the first signal input terminal of the first signal conversion circuit 214 receives a signal, the hot wire detection signal is in a second state, thereby indicating that the L-end relay is faulty. For example, the first state of the hot wire detection signal can be a high level, and the second state of the hot wire detection signal can be a periodic alternation of a high level and a low level.

[0040] In one embodiment, a hot wire detection signal can be transmitted to a main control unit (such as a microcontroller) to indicate whether the L-end relay is faulty. For example, if the first state of the hot wire detection signal is recognized by the main control unit as a logic 1, it indicates that the L-end relay is not faulty. For another example, if the second state of the hot wire detection signal is recognized by the main control unit as a logic 0, it indicates that the L-end relay is faulty.

[0041] In one embodiment, when the device to be charged is disconnected from the power supply device including the above-mentioned detection circuit, the first enable control circuit 220 may be provided with a first enable signal at a first level. For example, when the power supply device is installed, the first enable control circuit 220 may be provided with a first enable signal at a first level. For another example, before the device to be charged is electrically coupled to the power supply device to start the charging process, the first enable control circuit 220 may be provided with a first enable signal at a first level. For another example, after the device to be charged is electrically decoupled from the power supply device to stop the charging process after charging has completed, the first enable control circuit 220 may be provided with a first enable signal at a first level.

[0042] In one embodiment, the first enable control circuit 220 may be periodically provided with a first enable signal at a first level to implement periodic detection of the L-terminal relay. The detection period and the number of detections may be set by the main control unit. For example, if the detection period is set to seven days and the number of detections is set to three times, the first enable signal is provided to the first enable control circuit 220 three times every seven days.

[0043] By providing the first enable signal to the first enable control circuit as needed, the detection circuit can be actively controlled to be on and off, reducing system power consumption and extending the system's service life. By setting the detection timing, detection cycle, and number of detections as needed, the controllability and flexibility of the system are greatly enhanced.

[0044] In addition, since the first switch module is used to control the on and off of the circuit loop, the front-stage circuit (including the input end of the L-end relay) and the rear-stage circuit (including the first signal conversion circuit) are isolated. In the event of failure of the front-stage and rear-stage circuits, effective protection of the control end and detection end devices of the circuit can be achieved, and the insulation withstand voltage requirements of GB / T18487.1-2023 are met.

[0045] In one embodiment, the first signal conversion circuit 214 may further include an optical coupling module or other electronic components such as an isolation chip. By using the above electronic components, the isolation of strong current and weak current and the conversion of electrical signals are achieved.

[0046] In one embodiment, the first signal conversion circuit 214 may further include one or more resistors connected in series or in parallel. The ability of the first signal conversion circuit 214 to detect the L-terminal relay can be configured by adjusting the equivalent resistance value of the one or more resistors, thereby adjusting the sensitivity of the above-mentioned detection process.

[0047] Figure 3 FIG. 3 is a block diagram of a detection circuit 300 for a relay according to another embodiment of the present invention. For example, the detection circuit 300 may be Figure 2 The detection circuit 300 may include a live wire relay detection circuit 310 and a first enabling control circuit 320, and the live wire relay detection circuit 310 is electrically coupled to the first enabling control circuit 320. For example, the live wire relay detection circuit 310 may be Figure 2 The live wire relay detection circuit 210 in the embodiment of the present invention and the first enabling control circuit 320 may be Figure 2 The first enabling control circuit 220 in the hot wire relay detection circuit 310 may include a first switch module 312 and a first signal conversion circuit 314. For example, the first switch module 312 may be Figure 2 The first switch module 212 in the embodiment, and the first signal conversion circuit 314 can be Figure 2 The first signal conversion circuit 214 in.

[0048] In one embodiment, the first enable control circuit 320 may include a transistor module 322 and a MOS transistor module 324, wherein the output end of the transistor module 322 is electrically coupled to the control end of the MOS transistor module 324. The control end of the transistor module 322 may be configured to receive a first enable signal. The output end of the MOS transistor module 324 may be configured to output a control signal based on the first enable signal to control the first switch module 312 to be closed or opened. For example, a first enable signal at a first level (e.g., a high level) may be provided to the control end of the transistor module 322, and then the output end of the MOS transistor module 324 may output a control signal based on the first enable signal at the first level to control the first switch module 312 to be closed.

[0049] By utilizing triode modules and MOS tube modules, the response speed of the circuit is accelerated, the power consumption of the circuit is reduced, and flexible control of the circuit is achieved.

[0050] In another embodiment, the first enable control circuit 320 may further include a diode electrically coupled to the MOS transistor module 324. The MOS transistor module 324 may output a control signal based on the first enable signal at the first level to control the first switch module 312 to be closed via the diode.

[0051] Since the MOS tube module is used to control the closing of the first switch module via the diode, an energy discharge path can be provided for the first switch module, thereby protecting the safety of electronic components in the circuit.

[0052] Figure 4 FIG. 4 is a block diagram of a detection circuit 400 for a relay according to another embodiment of the present invention. For example, the detection circuit 400 may be Figure 2 、 Figure 3 The detection circuit 400 may include a live wire relay detection circuit 410 and a first enabling control circuit 420, and the live wire relay detection circuit 410 is electrically coupled to the first enabling control circuit 420. For example, the live wire relay detection circuit 410 may be Figure 2 、 Figure 3 The live wire relay detection circuit 210, 310 in the embodiment of the present invention and the first enabling control circuit 420 may be Figure 2 、 Figure 3 The first enabling control circuit 220, 320 in the hot wire relay detection circuit 410 may include a first switch module 412 and a first signal conversion circuit 414. For example, the first switch module 412 may be Figure 2 、 Figure 3 The first switch modules 212, 312 in the embodiment and the first signal conversion circuit 414 can be Figure 2 、 Figure 3The first signal conversion circuit 214, 314 in.

[0053] In one embodiment, the hot wire relay detection circuit 410 may further include a first filtering circuit 416 electrically coupled to the first signal conversion circuit 414. The first filtering circuit 416 may be configured to smooth the hot wire detection signal output by the first signal conversion circuit 414, making it easier to identify whether the smoothed hot wire detection signal is in the first state or the second state, thereby indicating whether the hot wire relay is faulty. In one embodiment, the first filtering circuit 416 may be comprised of a capacitive component, which may include one or more capacitors. For example, the first state of the smoothed hot wire detection signal may be a high level, and the second state of the smoothed hot wire detection signal may be a low level with a ramp.

[0054] Figure 5 A schematic connection diagram of a detection circuit 500 for a relay according to one embodiment of the present invention is shown. As shown, the first enable control circuit includes a transistor module consisting of resistors R1, R2 and a transistor Q17, a MOS transistor module consisting of a resistor R20 and a MOS transistor Q15, and a diode D7. The live relay detection circuit includes a resistor R118, a first switch module K3, a resistor R121, an optocoupler module OC3, a resistor R122, and a resistor R115. The first filter circuit includes a capacitor C80. In the detection circuit 500, the control end of the transistor module is configured to receive a first enable signal. The output end of the MOS transistor module is configured to output a control signal based on the first enable signal to control the first switch module K3 to close or open. Diode D7 is electrically coupled in parallel with the first switch module K3 and acts as a freewheeling diode to achieve energy dissipation.

[0055] Regarding the detection of the L-terminal relay, for example, a first enable signal SC_EN can be provided from the control terminal of the transistor module to the first enable control circuit. When the control terminal of transistor Q17 receives the first enable signal SC_EN at a high level via resistors R1 and R2, transistor Q17 turns on, thereby driving MOS transistor Q15 to conduct a 5V DC voltage to the first switch module K3, causing the first switch module K3 to close.

[0056] When the L-terminal relay is stuck, the output terminal of the L-terminal relay generates the L_OUT signal. The N_IN signal forms a loop with the L_OUT signal through resistor R118, the closed first switch module K3, resistor R121, the optocoupler module OC3, and resistor R122. Because the input between the first and second terminals of the optocoupler module OC3 is an AC sinusoidal signal, this signal passes through the dual light-emitting diodes to control the conduction or shutoff of the transistors. For example, when the AC signal input between the first and second terminals of the optocoupler module OC3 reaches the rated value of one of the LEDs in the dual light-emitting diodes, the LED turns on, emitting light to control the conduction of its associated transistor, and the L_SC signal is output at the fourth terminal of the optocoupler module OC3. The L_SC signal is electrically coupled to a 3.3V DC voltage through pull-up resistor R115 and then to ground through filter capacitor C80.

[0057] In one embodiment, when the L_SC signal is at a high level, it indicates that the L-end relay has not experienced a sticking fault; when the L_SC signal is at a low level including a ramp change, it indicates that the L-end relay has experienced a sticking fault. In another embodiment, the L_SC signal can be output to the main control unit for identification. For example, when the L_SC signal is identified by the main control unit as a logic 1 (corresponding to a high level), it indicates that the L-end relay has not experienced a sticking fault; when the L_SC signal is identified by the main control unit as a logic 0 (corresponding to a low level including a ramp change), it indicates that the L-end relay has experienced a sticking fault.

[0058] It should be understood that the filter capacitor C80 in the detection circuit 500 is not necessary, that is, the L_SC signal can be outputted without the filter capacitor C80.

[0059] In the case where the filter capacitor C80 is omitted, in one embodiment, when the L_SC signal is at a high level, it indicates that the L-end relay has not had a sticking fault; when the L_SC signal is a periodically alternating high level and low level, it indicates that the L-end relay has had a sticking fault. In another embodiment, the L_SC signal can be output to the main control unit for identification. For example, when the L_SC signal is identified by the main control unit as a logic 1 (corresponding to a high level), it indicates that the L-end relay has not had a sticking fault; when the L_SC signal is identified by the main control unit as a logic 0 (corresponding to a periodically alternating high level and low level), it indicates that the L-end relay has had a sticking fault.

[0060] It should be understood that the above correspondence between logic 1 and logic 0 and high level and low level is only an example, and the opposite correspondence may also be adopted in other examples.

[0061] Since the N-terminal relay is electrically coupled to the neutral line (associated with low voltage), detecting faults in the N-terminal relay can also help reduce safety hazards during the charging process and help meet relevant standards for dielectric strength and insulation withstand voltage.

[0062] Figure 6 FIG. 6 is a block diagram of a detection circuit 600 for a relay according to another embodiment of the present invention. For example, the detection circuit 600 may be Figure 2 、 Figure 3 、 Figure 4 The detection circuit 600 may include a live relay detection circuit 610 and a first enabling control circuit 620, as well as a neutral relay detection circuit 630 and a second enabling control circuit 640. The live relay detection circuit 610 is electrically coupled to the first enabling control circuit 620, and the neutral relay detection circuit 630 is electrically coupled to the second enabling control circuit 640. For example, the live relay detection circuit 610 may be Figure 2 、 Figure 3 、 Figure 4 The live wire relay detection circuit 210, 310, 410 in the embodiment of the present invention and the first enabling control circuit 620 may be Figure 2 、 Figure 3 、 Figure 4 The first enabling control circuit 220, 320, 420 in the hot wire relay detection circuit 610 may include a first switch module 612 and a first signal conversion circuit 614. For example, the first switch module 612 may be Figure 2 、 Figure 3 、 Figure 4 The first switch modules 212, 312, 412 in the embodiment of the present invention and the first signal conversion circuit 614 can be Figure 2 、 Figure 3 、 Figure 4 The first signal conversion circuits 214, 314, and 414 in FIG.

[0063] The neutral relay detection circuit 630 may include a second switch module 632 and a second signal conversion circuit 634 , and the second switch module 632 is electrically coupled to the second signal conversion circuit 634 .

[0064] In one embodiment, the second switch module 632 may include an electromagnetic relay, which is suitable for industrial-grade high-power scenarios.

[0065] The second signal conversion circuit 634 may include a third signal input, a fourth signal input, and a neutral signal output. The third signal input may be configured to receive a signal N_OUT from the output of the N-terminal relay. The fourth signal input may be configured to receive a signal L_IN from the input of the L-terminal relay via the second switch module 632. When the second switch module 632 is closed, the signal L_IN from the input of the L-terminal relay can pass through the second switch module 632 to the fourth signal input. The neutral signal output may be configured to output a neutral detection signal. The second signal conversion circuit 634 may be configured to generate a neutral detection signal based on the signals received from the third and fourth signal inputs, respectively, and output the neutral detection signal at the signal output. The third state of the neutral detection signal indicates that the neutral relay is not faulty. The fourth state of the neutral detection signal indicates that the neutral relay is faulty. Such a fault may be, for example, relay sticking.

[0066] The second enable control circuit 640 may be provided with a second enable signal to control the second switch module 632 to be closed or opened. For example, the second enable signal may be provided to the second enable control circuit 640 by the main control unit.

[0067] When the second enable signal is at a first level (e.g., a high level), the second enable control circuit 640 can control the second switch module 632 to close, so that the third signal input terminal can receive the signal from the input terminal of the L-terminal relay via the second switch module 632, thereby enabling the neutral relay detection circuit 630 to detect the N-terminal relay. Although the first level is described herein as a high level, it should be understood that when using an enable control circuit with a different configuration, the first level can also be a low level.

[0068] In one embodiment, when the second enable control circuit 640 is provided with a second enable signal at a first level to control the second switch module 632 to close, for example, if the third signal input terminal of the second signal conversion circuit 634 does not receive a signal, the neutral line detection signal is in a third state, thereby indicating that the N-terminal relay is not faulty. For another example, if the third signal input terminal of the second signal conversion circuit 634 receives a signal, the neutral line detection signal is in a fourth state, thereby indicating that the N-terminal relay is faulty. For example, the first state may be a high level, and the second state may be a periodic alternation of a high level and a low level.

[0069] In one embodiment, the neutral line detection signal can be transmitted to a main control unit (such as a microcontroller) to indicate whether the N-terminal relay is faulty. For example, if the first state of the neutral line detection signal is recognized by the main control unit as a logic 1, it indicates that the N-terminal relay is not faulty. For another example, if the second state of the neutral line detection signal is recognized by the main control unit as a logic 0, it indicates that the N-terminal relay is faulty.

[0070] In one embodiment, when the device to be charged is disconnected from the power supply device including the above-mentioned detection circuit, the second enable control circuit 640 may be provided with a second enable signal at a first level. For example, when the power supply device is installed, the second enable control circuit 640 may be provided with a second enable signal at a first level. For another example, before the device to be charged is electrically coupled to the power supply device to start the charging process, the second enable control circuit 640 is provided with a second enable signal at a first level. For another example, after the device to be charged is electrically decoupled from the power supply device to stop the charging process after charging has completed, the second enable control circuit 640 is provided with a second enable signal at a first level.

[0071] In one embodiment, the second enable control circuit 640 may be periodically provided with a second enable signal at a first level to implement periodic detection of the N-terminal relay. The detection period and the number of detections may be set by the main control unit. For example, if the detection period is set to seven days and the number of detections is set to three, the second enable control circuit 640 may be provided with the second enable signal three times every seven days.

[0072] By providing a second enable signal to the second enable control circuit as needed, the detection circuit can be actively controlled to be on and off, reducing system power consumption and extending the system's service life. By customizing the detection timing, detection cycle, and number of detections, the system's controllability and flexibility are greatly enhanced.

[0073] In addition, since a second switch module is used to control the on and off of the circuit loop, the front-stage circuit (including the input end of the N-end relay) and the rear-stage circuit (including the second signal conversion circuit) are isolated. In the event of failure of the front-stage and rear-stage circuits, effective protection of the control end and detection end devices of the circuit can be achieved, and the insulation withstand voltage requirements of GB / T18487.1-2023 are met.

[0074] In one embodiment, the second signal conversion circuit 634 may further include an optical coupling module, or other electronic components such as an isolation chip. By using the above electronic components, the isolation of strong current and weak current and the conversion of electrical signals are achieved.

[0075] In one embodiment, the second signal conversion circuit 634 may further include one or more resistors connected in series or in parallel. The ability of the second signal conversion circuit 634 to detect the N-terminal relay can be configured by adjusting the equivalent resistance value of the one or more resistors, thereby adjusting the sensitivity of the detection process.

[0076] In one embodiment, the first enable control circuit 620 and the second enable control circuit 640 can be the same enable control circuit, and the first enable signal and the second enable signal can be the same signal. Thus, the same signal can be used to control the closing of the first switch module and the second switch module, reducing the number of components in the circuit and lowering the cost of system design.

[0077] In one embodiment, the second state of the live wire detection signal and the fourth state of the neutral wire detection signal can be used to indicate a short circuit fault between the output terminals of the L-end relay and the N-end relay. Thus, the second state of the live wire detection signal and the fourth state of the neutral wire detection signal can be used to jointly indicate that both the L-end relay and the N-end relay are faulty and / or that a short circuit exists between the output terminals of the L-end relay and the N-end relay.

[0078] Figure 7 FIG2 shows a schematic connection diagram of a detection circuit 700 for a relay according to another embodiment of the present invention. As shown in the figure, the first enable control circuit and the second enable control circuit are the same enable control circuit (hereinafter referred to as the "enable control circuit"), and the first enable signal and the second enable signal can be the same signal (hereinafter referred to as the "enable signal") as an example for description. However, the first enable control circuit and the second enable control circuit can also be separate enable control circuits, and the present invention is not limited to Figure 7 The enable control circuit includes a transistor module consisting of resistors R1, R2 and a transistor Q17, a MOS transistor module consisting of a resistor R20 and a MOS transistor Q15, and a diode D7. The live wire relay detection circuit includes a resistor R118, a first switch module K3, a resistor R121, an optocoupler module OC3, a resistor R122, and a resistor R115. The neutral wire relay detection circuit includes a resistor R110, a second switch module K1, a resistor R111, a resistor R59, an optocoupler module OC1, and a resistor R113. In the detection circuit 700, the control end of the transistor module is configured to receive an enable signal. The output end of the MOS transistor module is configured to output a control signal based on the enable signal to control both the second switch module K1 and the first switch module K3 to be closed or opened. The diode D7 is electrically coupled in parallel with the second switch module K1 and the first switch module K3, acting as a freewheeling diode to achieve energy discharge.

[0079] Due to the above combination Figure 5 The embodiment regarding the detection of the L-end relay has been described, and will not be repeated here to avoid redundancy.

[0080] Regarding the detection of the N-terminal relay, for example, an enable signal SC_EN can be provided from the control terminal of the transistor module to the enable control circuit. When the control terminal of transistor Q17 receives the enable signal SC_EN at a high level via resistors R1 and R2, transistor Q17 turns on, thereby driving MOS transistor Q15 to conduct a 5V DC voltage to the second switch module K1, causing the second switch module K1 to close.

[0081] When the N-terminal relay is stuck, the N-terminal relay's output terminal generates an N_OUT signal. The L_IN signal forms a loop with the N_OUT signal via resistor R110, the closed second switch module K1, resistor R111, the optocoupler module OC1, and resistor R59. Since the input between the first and second terminals of the optocoupler module OC1 is an AC sinusoidal signal, this signal passes through a dual-LED to control the conduction or shutoff of a transistor. For example, when the AC signal input between the first and second terminals of the optocoupler module OC1 reaches the rated value of one of the LEDs in the dual-LED, the LED turns on, emitting light to control the conduction of its associated transistor, and the N_SC signal is output at the fourth terminal of the optocoupler module OC1. The N_SC signal is electrically coupled to a 3.3V DC voltage via pull-up resistor R113 and then to ground via filter capacitor C79.

[0082] In one embodiment, when the N_SC signal is at a high level, it indicates that the N-terminal relay has not experienced a sticking fault; when the N_SC signal is at a low level including a ramp change, it indicates that the N-terminal relay has experienced a sticking fault. In another embodiment, the N_SC signal can be output to a main control unit for identification. When the N_SC signal is identified by the main control unit as a logic 1 (corresponding to a high level), it indicates that the N-terminal relay has not experienced a sticking fault; when the N_SC signal is identified by the main control unit as a logic 0 (corresponding to a low level including a ramp change), it indicates that the N-terminal relay has experienced a sticking fault.

[0083] It should be understood that the filter capacitor C79 in the above circuit is not necessary, that is, the N_SC signal can be outputted without omitting the filter capacitor C79.

[0084] In the case where the filter capacitor C79 is omitted, in one embodiment, when the N_SC signal is at a high level, it indicates that the N-end relay has not had a sticking fault; when the N_SC signal is a periodically alternating high level and low level, it indicates that the L-end relay has had a sticking fault. In another embodiment, the N_SC signal can be output to the main control unit for identification. For example, when the N_SC signal is identified by the main control unit as a logic 1 (corresponding to a high level), it indicates that the L-end relay has not had a sticking fault; when the N_SC signal is identified by the main control unit as a logic 0 (corresponding to a periodically alternating high level and low level), it indicates that the L-end relay has had a sticking fault.

[0085] It should be understood that the above correspondence between logic 1 and logic 0 and high level and low level is only an example, and the opposite correspondence may also be adopted in other examples.

[0086] When there is a short circuit between the live wire and the neutral wire (the output terminals of the L-end relay and the N-end relay are short-circuited), resistor R59 is short-circuited with resistor R122, and the L_IN signal forms a loop with the N_IN signal via resistor R110, the closed second switch module K1, resistor R111, the optical coupler module OC1, resistor R59, resistor R122, the optical coupler module OC3, resistor R121, the closed first switch module K3, and resistor R118. In this case, both the L_SC signal and the N_SC signal are at a low level. Thus, in one embodiment, when both the L_SC signal and the N_SC signal are at a low level, it indicates that a short circuit fault has occurred at the output terminals of the L-end relay and the N-end relay and / or that both the L-end relay and the N-end relay have a adhesion fault. In another embodiment, when both the L_SC signal and the N_SC signal are recognized as a logic 0 by the main control unit, it indicates that a short circuit fault has occurred at the output terminals of the L-end relay and the N-end relay and / or that both the L-end relay and the N-end relay have a adhesion fault.

[0087] Table 1 below describes the corresponding relationship between the logic states of the L_SC signal and the N_SC signal and the faults occurring in the L-end relay and / or the N-end relay, where the SC_EN signal being at logic 1 means that the SC_EN signal is at a high level:

[0088] Table 1

[0089] Signal Logical state Logical state Logical state SC_EN 1 1 1 N_SC 0 1 0 L_SC 0 0 1 Determine the fault Short circuit and / or double circuit sticking N-terminal relay sticking L-end relay is stuck

[0090] Figure 8 FIG1 shows a block diagram of a power supply device 800 according to an embodiment of the present invention. The power supply device 800 may include: an L-terminal relay and an N-terminal relay provided on the live wire and the neutral wire of the AC line; and a detection circuit 802. The detection circuit 802 may be as follows: Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 The detection circuit of any one of the detection circuits 200, 300, 400, 500, 600, and 700. The input ends of the L-end relay and the N-end relay are used to receive L_IN and N_IN signals from the live wire and the neutral wire, respectively. In appropriate scenarios, the L_IN signal and the N_IN signal and the L_OUT signal and the N_OUT signal of the corresponding output end are used to detect whether the L-end relay and / or the N-end relay have adhesion and / or short circuit faults, and the N_SC signal and the L_SC signal are used to determine whether the above faults exist. For example, if the status of the L_SC signal and / or the N_SC signal indicates that the L-end relay and / or the N-end relay have the above faults, the power supply device 800 is disabled. For another example, if the status of the L_SC signal and the N_SC signal indicates that neither the L-end relay nor the N-end relay has the above faults, the power supply device 800 is enabled to charge the device to be charged. In one embodiment, the device to be charged may be an electric vehicle. In one embodiment, the power supply device 800 may be a charging pile.

[0091] Since the power supply device 800 is disabled when the above-mentioned fault occurs, potential safety hazards during the charging process are avoided, and the safety of the power supply device in supplying power is ensured.

[0092] Figure 9 FIG1 shows a schematic connection diagram of a power supply device 900 according to an embodiment of the present invention. For example, the power supply device 900 may be Figure 8 The power supply device 800 in FIG. As shown, the RELAY_EN1 signal is an enable signal for the power supply device 900. When the RELAY_EN1 signal is low, the power supply device 900 is disabled. When the RELAY_EN1 signal is high, the power supply device 900 is enabled. When the control terminal of transistor Q16 receives the high-level RELAY_EN1 signal via resistors R3 and R4, transistor Q16 turns on, thereby driving MOS transistor Q14 to conduct the 12V DC voltage to the L-end relay K2 and the N-end relay K4, causing the L-end relay K2 and the N-end relay K4 to close, thereby enabling the power supply device 900 to charge the device to be charged. Diode D19 is electrically coupled in parallel with the L-end relay K2 and the N-end relay K4, acting as a freewheeling diode to achieve energy discharge.

[0093] Since the above has been combined Figure 7 The embodiments regarding the detection of the L-end relay and the N-end relay have been described, and will not be repeated here to avoid redundancy.

[0094] The above describes a detection circuit and a power supply device for a relay according to an exemplary embodiment of the present application. By providing a first enable signal to a first enable control circuit as needed, the on-off of the detection circuit can be actively controlled, which reduces the power consumption of the system and extends the service life of the system. By setting the detection timing, detection cycle, number of detections, etc. as needed, the controllability and flexibility of the system are greatly enhanced. Since the first switch module is used to control the on-off of the circuit loop, the front-stage circuit (including the input end of the L-end relay) is isolated from the rear-stage circuit (including the first signal conversion circuit), etc., in the event of failure of the front- and rear-stage circuits, it is possible to achieve effective protection of the control end and detection end devices of the circuit, and meet the requirements of the insulation withstand voltage GB / T18487.1-2023.

[0095] References throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all references to the same embodiment, but may refer to the same embodiment. Furthermore, in one or more embodiments, the particular features, structures, or characteristics may be combined in any suitable manner, as will be apparent to one of ordinary skill in the art from this disclosure.

[0096] Similarly, it should be appreciated that in the description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, inventive aspects lie in fewer features than all of the features of a single preceding disclosed embodiment. Accordingly, the claims appended hereto are hereby expressly incorporated into this detailed description, with each claim itself representing a separate embodiment of the present invention.

[0097] Furthermore, although some embodiments described herein include some features included in other embodiments but not other features included in other embodiments, combinations of features from different embodiments are intended to fall within the scope of the present invention and form different embodiments as will be understood by those skilled in the art. For example, in the appended claims, any of the claimed embodiments may be used in any combination.

[0098] As used herein, module refers to any combination of hardware, software, and / or firmware. As an example, a module includes hardware such as a microcontroller associated with a non-transient medium, and the non-transient medium is used to store code suitable for being executed by the microcontroller. Therefore, in one implementation, reference to a module refers to hardware that is specifically configured to identify and / or execute code to be stored on a non-transient medium. In addition, in another implementation, the use of a module refers to a non-transient medium comprising code that is specifically adapted to be executed by a microcontroller to perform a predetermined operation. And as can be inferred, in yet another implementation, the term module can refer to a combination of a microcontroller and a non-transient medium. Typically, the boundaries of modules illustrated as separate can vary and potentially overlap. For example, a first module and a second module can share hardware, software, firmware, or a combination thereof while potentially retaining some independent hardware, software, or firmware.

[0099] Embodiments of the mechanisms disclosed herein may be implemented in hardware, software, firmware, or a combination of such implementations. Embodiments of the present invention may be implemented as a computer program or program code executed on a programmable system comprising at least one processor, a storage system (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device.

[0100] It will be apparent to those skilled in the art that various modifications and variations may be made to the above exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention cover modifications and variations of the present invention that fall within the scope of the appended claims and their equivalent technical solutions.

Claims

1. A detection circuit for a relay, wherein: The detection circuit includes a live wire relay detection circuit and a first enabling control circuit. The live wire relay detection circuit comprises: a first switch module; and A first signal conversion circuit, wherein the first signal conversion circuit comprises: A first signal input terminal is configured to receive a signal from an output terminal of a live relay; a second signal input terminal, configured to receive a signal from an input terminal of a neutral line relay via the first switch module; The firewire signal output terminal is configured to output a firewire detection signal; Wherein, the first signal conversion circuit is configured to generate the live wire detection signal based on the signals received by the first signal input terminal and the second signal input terminal, the first state of the live wire detection signal is used to indicate that there is no fault in the live wire relay, and the second state of the live wire detection signal is used to indicate that there is a fault in the live wire relay; The first enable control circuit is configured to control the first switch module to close based on a first enable signal at a first level.

2. The detection circuit according to claim 1, wherein: When the first enable control circuit is provided with the first enable signal at the first level, In response to the first signal input terminal of the first signal conversion circuit not receiving a signal, the live wire detection signal is in the first state, thereby indicating that the live wire relay is not faulty; In response to the first signal input terminal of the first signal conversion circuit receiving a signal, the live wire detection signal is in the second state, thereby indicating that the live wire relay is faulty.

3. The detection circuit according to claim 1, wherein: When the device to be charged is disconnected from the power supply device including the detection circuit, the first enable control circuit is provided with the first enable signal at the first level; or The first enable control circuit is periodically provided with the first enable signal at the first level.

4. The detection circuit according to claim 1, wherein: The first enable control circuit includes a triode module and a MOS tube module, wherein the output end of the triode module is electrically coupled to the control end of the MOS tube module, wherein the control end of the triode module is configured to receive the first enable signal at the first level, and the output end of the MOS tube module is configured to output a control signal based on the first enable signal at the first level to control the first switch module to close.

5. The detection circuit according to claim 1, wherein: The first switch module includes an electromagnetic relay.

6. The detection circuit according to claim 1, wherein: The first signal conversion circuit includes an optical coupler module.

7. The detection circuit according to claim 1, wherein: The live wire relay detection circuit further includes a first filtering circuit electrically coupled to the first signal conversion circuit to smooth the live wire detection signal.

8. The detection circuit according to claim 1, wherein: The detection circuit further includes a neutral line relay detection circuit and a second enabling control circuit, The neutral line relay detection circuit comprises: a second switch module; and A second signal conversion circuit, wherein the second signal conversion circuit comprises: a third signal input terminal configured to receive a signal from an output terminal of a neutral relay; a fourth signal input terminal, configured to receive a signal from an input terminal of a live wire relay via the second switch module; A zero line signal output terminal is configured to output a zero line detection signal; Wherein, the second signal conversion circuit is configured to generate the neutral line detection signal based on the signals received by the third signal input terminal and the fourth signal input terminal, the third state of the neutral line detection signal is used to indicate that there is no fault in the neutral line relay, and the fourth state of the neutral line detection signal is used to indicate that there is a fault in the neutral line relay; The second enable control circuit is configured to control the second switch module to close based on a second enable signal at the first level.

9. The detection circuit according to claim 8, wherein: When the second enable control circuit is provided with the second enable signal at the first level, In response to the third signal input terminal of the second signal conversion circuit not receiving a signal, the neutral line detection signal is in the third state, thereby indicating that the neutral line relay is not faulty; In response to the third signal input terminal of the second signal conversion circuit receiving a signal, the neutral line detection signal is in the fourth state, thereby indicating that the neutral line relay is faulty.

10. The detection circuit according to claim 8, wherein: The second state of the live wire detection signal and the fourth state of the neutral wire detection signal are used to jointly indicate that both the live wire relay and the neutral wire relay are faulty and / or there is a short circuit between the live wire and the neutral wire.

11. The detection circuit according to claim 8, wherein: The first enable control circuit and the second enable control circuit are the same enable control circuit.

12. A power supply device, comprising: A live wire relay and a neutral wire relay provided on the live wire and the neutral wire in the AC line; as well as A detection circuit as claimed in any one of claims 1 to 11.

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