Relay detection circuit and relay board card

Abstract

The utility model provides a detection circuit of a relay and a relay board card. The detection circuit of the relay in the embodiment of the utility model comprises a controller, a coil control circuit and a contact detection circuit, the controller is configured to output a voltage control signal to the coil control circuit through a first control end and output a current direction control signal to the coil control circuit through a second control end so as to control the coil control circuit to output a driving current to a coil of the relay to be tested; a voltage and current signal of the coil fed back by the coil control circuit is received through the first receiving end; a first control signal is output to a contact detection circuit through a third control end so as to control the contact detection circuit to enable a first access end electrically connected with a first contact of a relay to be detected to access a reference voltage, and the voltage of a second access end correspondingly electrically connected with a second contact of the relay to be detected is compared with a current direction control signal. And receiving a comparison result fed back by the contact detection circuit through a second receiving end. According to the embodiment of the invention, the fault can be accurately positioned.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of electronic devices, and in particular to a detection circuit of a relay and a relay board card. BACKGROUND

[0002] Relays are widely used in industrial control, such as power systems, automated production lines, etc. In the field of communication, relays are mainly used as switches or converters of AC and DC power supplies. In the field of household appliances, relays are also widely used in appliance control circuits, such as air conditioners, refrigerators, washing machines, etc. With the increasing use of relays, the reliability requirements for relays are also increasing. Conventional relay fault detection is mainly for specific use cases: such as detection of grid-connected relays in inverters, fault detection of charging circuit relays, etc. Or it can only detect the good or bad of a single relay, which is only suitable for relay use cases that are not soldered, and requires different relays to make test fixtures. For relays used in relay board cards, either the soldered relays are removed for detection, or the board card is removed for detection by an external detection fixture, which has problems such as communication and real-time control of the detection system with the control system. Some on-board relay detection circuits cannot be completely physically disconnected from the contact signal, and the detection of the signal is achieved by adding an isolated power supply to each group of contacts. The power supply scheme is complex. By comparing the control and contact signals to make fault judgments, it can only simply determine whether the contacts are closed, cannot locate faults, and has a single detection function. CONTENT OF THE UTILITY MODEL

[0003] To solve at least one of the above problems, the present disclosure provides a detection circuit of a relay, comprising a controller, a coil control circuit and a contact detection circuit.

[0004] The first controlled end of the coil control circuit is electrically connected to the first control end of the controller, the second controlled end is electrically connected to the second control end of the controller, the feedback end is electrically connected to the first receiving end of the controller, the first connection end is electrically connected to the first end of the coil of the relay to be tested, and the second connection end is electrically connected to the second end of the coil of the relay to be tested.

[0005] The controlled end of the contact detection circuit is electrically connected to the third control end of the controller, the feedback end is electrically connected to the second receiving end of the controller, the first access end is electrically connected to the first contact of the relay to be tested, and the second access end is electrically connected to the second contact of the relay to be tested.

[0006] The controller is configured to output a voltage control signal to the coil control circuit through a first control terminal and output a current direction control signal to the coil control circuit through a second control terminal to control the coil control circuit to output a driving current to the coil of the relay under test, receive a voltage and current signal of the coil fed back by the coil control circuit through a first receiving terminal, output a first control signal to the contact detection circuit through a third control terminal to control the contact detection circuit to connect the first access terminal to a reference voltage and compare a voltage corresponding to the second access terminal with the current direction control signal, and receive a comparison result fed back by the contact detection circuit through a second receiving terminal.

[0007] Optionally, the contact detection circuit comprises a contact access circuit, a signal conversion circuit, and a comparison circuit, the contact access circuit comprises the first access terminal and the second access terminal, an output terminal of the contact access circuit is electrically connected to an input terminal of the signal conversion circuit, an output terminal of the signal conversion circuit is electrically connected to a first input terminal of the comparison circuit, and a second input terminal of the comparison circuit is electrically connected to the second control terminal of the controller.

[0008] The controller is configured to output a first control signal to the contact access circuit through a third control terminal to control the contact access circuit to connect the first access terminal to a reference voltage to form a first voltage signal at the first input terminal of the comparison circuit through the first contact, the second contact, the second access terminal, and the signal conversion circuit, and receive a comparison result fed back by the comparison circuit by comparing the first voltage signal with the current direction control signal through the second receiving terminal.

[0009] Optionally, the contact access circuit comprises a first switch tube and a first relay, a coil of the first relay is electrically connected to the first switch tube, one end of a first contact switch of the first relay serves as the first access terminal, and the other end is electrically connected to a reference voltage terminal, one end of a second contact switch of the first relay serves as the second access terminal, and the other end serves as an output terminal of the contact access circuit.

[0010] The controller is configured to output a first control signal to a control electrode of the first switch tube through a third control terminal to control the first switch tube to be turned on and control the first contact switch and the second contact switch to be closed, connect the first access terminal to a reference voltage to form a first intermediate voltage signal at the input terminal of the signal conversion circuit through the first contact, the second contact, and the second access terminal, and thereby form a first voltage signal at the first input terminal of the comparison circuit.

[0011] Optionally, the signal conversion circuit comprises an optocoupler circuit, configured to output a first voltage signal at an output end in response to a first intermediate voltage signal received at an input end.

[0012] Optionally, the comparison circuit comprises an AND gate, a first input end of the AND gate serving as a first input end of the comparison circuit, a second input end of the AND gate serving as a second input end of the comparison circuit, and an output end of the AND gate serving as an output end of the comparison circuit.

[0013] Optionally, the contact detection circuit further comprises an impedance detection circuit, an input end of the impedance detection circuit being electrically connected to an output end of the contact access circuit, a controlled end of the impedance detection circuit being electrically connected to a fourth control end of the controller, and an output end of the impedance detection circuit being electrically connected to a third receiving end of the controller.

[0014] The controller is configured to output a current control signal to the impedance detection circuit through the fourth control end to control the first access end to access a reference voltage and the current passing through the first contact, the second contact and the second access end, and to receive a detection result of the impedance detection circuit detecting a difference between the first intermediate voltage signal and the reference voltage through the third receiving end.

[0015] Optionally, the impedance detection circuit comprises a constant current source circuit and a second analog-digital detection circuit, and the controller is configured to output a current control signal to the constant current source circuit through the fourth control end to control the first access end to access a reference voltage and the current passing through the first contact, the second contact and the second access end, and to receive a detection result of the second analog-digital detection circuit detecting a difference between the first intermediate voltage signal and the reference voltage through the third receiving end.

[0016] Optionally, the coil control circuit comprises a DC-DC converter, a first analog-digital sampling circuit and a coil driving circuit, an input end of the DC-DC converter accessing a power supply voltage, an output end of the DC-DC converter being electrically connected to an input end of the coil driving circuit, a first output end of the coil driving circuit serving as the first connection end, a second output end of the coil driving circuit serving as the second connection end, and the first analog-digital sampling circuit being electrically connected to the first output end and the second output end.

[0017] The controller is configured to output a voltage control signal to a controlled end of the DC-DC converter through the first control end and output a current direction control signal to a controlled end of the coil driving circuit through the second control end to control the coil driving circuit to output a driving current to the coil of the relay to be tested in response to a voltage output by the DC-DC converter, and to receive a voltage and current signal of the coil detected and fed back by the first analog-digital sampling circuit through the first receiving end.

[0018] Optionally, the coil driving circuit comprises an H-bridge circuit, and the controller is configured to output a current direction control signal to a controlled end of the H-bridge circuit through a second control end.

[0019] The second aspect of the present disclosure provides a relay board card comprising a relay and the detection circuit described above.

[0020] The present disclosure has the following advantages:

[0021] The present disclosure aims to solve the existing problems and provides a detection circuit for a relay and a relay board card. The detection circuit can detect whether the coil is faulty through the coil control circuit, and comprehensively determine whether the relay is faulty by combining the current direction control signal and the voltage of the corresponding second access end reflecting the contact action. If the coil is not faulty but the relay is faulty, the fault can be located at the contact. The impedance detection circuit can also be used to detect the impedance of the contact alone. The present disclosure solves the problem in the related art that only the coil fault can be detected, and the contact fault cannot be effectively determined, thereby reducing the risk of contact burnout caused by excessive contact impedance.

[0022] The detection circuit of the present disclosure has the advantages of small size, low cost, convenient detection, strong scalability, and wide application prospects. It can be integrated in a relay board card as needed, and can be set in an electronic device comprising the relay board card, or can be realized alone in a detection substrate. For example, when the detection circuit is integrated in the relay board card, the controller can be instructed by the upper computer to detect the relay in real time when the electronic device system is running, which can effectively avoid the risk of system failure caused by damaged relays in the relay board card. The relays can also be detected in a timely manner. In addition, if the relay board card itself has a control unit, the controller function in the detection circuit can be integrated into the control unit. In the related art relay board card, the detection circuit of the present disclosure can be added to realize the function of real-time detection of relays in the relay board card without removing the relay board card from the device. In addition, the detection circuit of the present disclosure adjusts the driving current output by the coil control circuit through the voltage control signal and the current direction control signal, which has compatibility and does not affect the normal control function of the relay to be detected. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and for those skilled in the art, other drawings can be obtained based on these drawings without creative labor.

[0024] Figure 1 A circuit schematic diagram of a detection circuit according to an embodiment of the present disclosure is shown.

[0025] Figure 2 A circuit schematic diagram of a contact detection circuit in the detection circuit shown is shown. Figure 1 A circuit schematic diagram of a contact access circuit in the contact detection circuit shown is shown.

[0026] Figure 3 A circuit schematic diagram of a signal conversion circuit in the contact detection circuit shown is shown. Figure 2 A circuit schematic diagram of a comparison circuit in the contact detection circuit shown is shown.

[0027] Figure 4 A circuit schematic diagram of an impedance detection circuit in the contact detection circuit shown is shown. Figure 2 A circuit schematic diagram of a coil control circuit in the detection circuit shown is shown.

[0028] Figure 5 A circuit schematic diagram of a direct current-direct current converter and a first analog-digital sampling circuit part in the coil control circuit shown is shown. Figure 2 A circuit schematic diagram of a forward-reverse control access circuit and a coil driving circuit part in the coil control circuit shown is shown.

[0029] Figure 6 A circuit schematic diagram of a coil control circuit in the detection circuit shown is shown. Figure 2 A circuit schematic diagram of a coil control circuit in the detection circuit shown is shown.

[0030] Figure 7 A circuit schematic diagram of a coil control circuit in the detection circuit shown is shown. Figure 1 A circuit schematic diagram of a coil control circuit in the detection circuit shown is shown.

[0031] Figure 8 A circuit schematic diagram of a coil control circuit in the detection circuit shown is shown. Figure 7 A circuit schematic diagram of a direct current-direct current converter and a first analog-digital sampling circuit part in the coil control circuit shown is shown.

[0032] Figure 9 A circuit schematic diagram of a forward-reverse control access circuit and a coil driving circuit part in the coil control circuit shown is shown. Figure 7 A circuit schematic diagram of a forward-reverse control access circuit and a coil driving circuit part in the coil control circuit shown is shown. DETAILED DESCRIPTION

[0033] In order to more clearly illustrate the present disclosure, the present disclosure will be further described below in conjunction with preferred embodiments and drawings. Similar components are denoted by the same reference numerals in the drawings. It should be understood by those skilled in the art that the following specific description is illustrative rather than limiting, and should not limit the scope of protection of the present disclosure.

[0034] It should be noted that the technical terms or scientific terms used in the present disclosure should be understood as the common meanings understood by those with ordinary skills in the art to which the present disclosure pertains, unless otherwise defined. The terms "first", "second", and the like used in the present disclosure do not represent any order, number, or importance, but are used to distinguish different components. Similarly, the terms "one", "a", or "the" and the like do not represent a number limitation, but represent the existence of at least one. The terms "include", "contain", and the like mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and the like are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0035] In the present disclosure, "electrically connected" includes a case where the constituent elements are connected together through an element having a certain electrical effect. The element having a certain electrical effect is not particularly limited as long as it can perform the transmission and reception of electrical signals between the connected constituent elements. Examples of the element having a certain electrical effect include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, other elements having various functions, and the like.

[0036] As used in the present disclosure, "parallel", "perpendicular", and "equal" include the stated cases and cases similar to the stated cases within an acceptable deviation range, which is determined by those of ordinary skill in the art taking into account the measurement being discussed and the error related to the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "equal" includes absolute equality and approximate equality, where the acceptable deviation range of approximate equality may, for example, be a difference between the two of less than or equal to 5% of either.

[0037] Referring to Figure 1 The detection circuit of the relay according to the present disclosure is provided with a controller, a coil control circuit, and a contact detection circuit.

[0038] The first control end of the controller is electrically connected to the first control end of the coil control circuit, the second control end of the controller is electrically connected to the second control end of the coil control circuit, the feedback end of the coil control circuit is electrically connected to the first receiving end of the controller, the first connection end of the coil control circuit is electrically connected to the first end of the coil of the relay to be detected, and the second connection end of the coil control circuit is electrically connected to the second end of the coil of the relay to be detected.

[0039] The controlled end of the contact detection circuit is electrically connected to the third control end of the controller, the feedback end is electrically connected to the second receiving end of the controller, the first access end is electrically connected to the first contact of the relay to be detected, and the second access end is electrically connected to the second contact of the relay to be detected.

[0040] The controller is configured to output a voltage control signal to the coil control circuit through the first control end and output a current direction control signal to the coil control circuit through the second control end to control the coil control circuit to output a driving current to the coil of the relay to be detected, receive a voltage current signal of the coil fed back by the coil control circuit through the first receiving end, output a first control signal to the contact detection circuit through the third control end to control the contact detection circuit to connect the first access end to a reference voltage and compare the voltage corresponding to the second access end with the current direction control signal, and receive a comparison result fed back by the contact detection circuit through the second receiving end.

[0041] In one specific example, for example Figure 1 As shown, the detection circuit 1 of the relay includes a controller 11, a coil control circuit 12, and a contact detection circuit 13, wherein the controller 11 is a microcontroller unit (MCU) for example, mainly realizing the functions of detection process control and detection result determination. The detection process control includes outputting a voltage control signal V Set to the coil control circuit 12 through the first control end to control the coil driving voltage, outputting a current direction control signal Ctr coil L and Ctr coil R to the coil control circuit 12 through the second control end to control the direction (forward or reverse) of the driving current output by the coil control circuit 12, combining the above-mentioned voltage control signal and current direction control signal to control the driving current output by the coil control circuit 12 to the relay to be detected 2, outputting a first control signal Ctr1 to the contact detection circuit 13 through the third control end to control the contact detection circuit 13 to connect the first contact of the relay to be detected 2 (shown as contact 1 in the middle) to a reference voltage through the first access end, and output the voltage of the second access end electrically connected to the second contact of the relay to be detected 2 (shown as contact 2 in the middle) and compare it with the current direction control signal, and the detection result determination includes judging whether the coil is faulty according to the voltage current signal Vs / Is of the coil fed back by the coil control circuit 12, and judging whether the relay is faulty according to the comparison result signal Fault1 fed back by the contact detection circuit 13. Figure 1 Figure 1

[0042] ​​In some alternative embodiments, the contact detection circuit comprises a contact access circuit, a signal conversion circuit and a comparison circuit, the contact access circuit comprises the first access end and the second access end, an output end of the contact access circuit is electrically connected to an input end of the signal conversion circuit, an output end of the signal conversion circuit is electrically connected to a first input end of the comparison circuit, a second input end of the comparison circuit is electrically connected to a second control end of the controller;

[0043] The controller is configured to output a first control signal to the contact access circuit through the third control end to control the contact access circuit to access the first access end to a reference voltage to form a first voltage signal at the first input end of the comparison circuit through the first contact, the second contact, the second access end and the signal conversion circuit, and output a comparison result of the comparison between the first voltage signal and the current direction control signal fed back by the comparison circuit through the second receiving end.

[0044] In the foregoing examples, for example Figure 2 As shown, the contact detection circuit 13 comprises a contact access circuit 131, a signal conversion circuit 132 and a comparison circuit 133, the controller 11 outputs a first control signal Ctr1 to the contact access circuit 131 through the third control end to control the contact access circuit 131 to access the first access end to a reference voltage to form a voltage signal Contact at the second access end through the first contact and the second contact and output to the signal conversion circuit 132 by the contact access circuit 131, the signal conversion circuit 132 converts the voltage signal Contact into a first voltage signal Contact_sig (high-low level signal) and outputs, thereby forming the first voltage signal Contact_sig at the first input end of the comparison circuit 133, the comparison circuit 133 compares the first voltage signal Contact_sig with the current direction control signal Ctr_coil_L or Ctr_coil_R (for example, depending on whether the forward current is needed, the controller 11 outputs the current direction control signal Ctr_coil_L, or the reverse current is needed, the controller 11 outputs the current direction control signal Ctr_coil_R) received by the second input end and outputs a comparison result signal Fault1, and the controller 11 receives the comparison result signal Fault1 through the second receiving end.

[0045] In some alternative embodiments, the contact access circuit comprises a first switch tube and a first relay, a coil of the first relay is electrically connected to the first switch tube, one end of a first contact switch of the first relay is the first access end, and the other end is electrically connected to a reference voltage end, one end of a second contact switch of the first relay is the second access end, and the other end is an output end of the contact access circuit;

[0046] the controller is configured to output a first control signal to the control electrode of the first switch tube through the third control end to control the first switch tube to be turned on, so as to control the first contact switch and the second contact switch to be closed, and the first access end to access the reference voltage, so as to form a first intermediate voltage signal at the input end of the signal conversion circuit through the first contact, the second contact and the second access end, thereby forming a first voltage signal at the first input end of the comparison circuit.

[0047] In the foregoing examples, for example Figure 3 As shown, the contact access circuit 131 includes the first switch tube Q1 and the first relay LS1, one end of the coil of the first relay LS1 is electrically connected to the C electrode of the first switch tube Q1 through the pin 12, and the other end is connected to the 5V voltage source through the pin 1, one end of the first contact switch of the first relay LS1 is electrically connected to the first contact (contact 1) of the relay under test 2 through the pin 8 as the first access end, and the other end is electrically connected to the reference voltage end (5V voltage source) through the pin 9, one end of the second contact switch of the first relay LS1 is electrically connected to the second contact (contact 2) of the relay under test 2 through the pin 5 as the second access end, and the other end is used as the output end of the contact access circuit 131 for outputting the first intermediate voltage signal Contact, and the controller 11 outputs the first control signal Ctr1 to the control electrode B electrode of the first switch tube Q1 through the third control end to control the first switch tube Q1 to be turned on, so as to receive the driving current through the coil of the first relay LS1, control the first contact switch and the second contact switch to be closed, and the first contact switch to be switched from open to closed, i.e. Figure 3 The pin 9 electrically connected to the reference voltage end is changed from the contact empty pin 10 to the pin 8 electrically connected to the contact 1, and the second contact switch is switched from open to closed, i.e. Figure 3 The pin 4 used as the output end of the contact access circuit 131 is changed from the contact empty pin 3 to the pin 5 electrically connected to the contact 2, so that under the condition that the controller 11 outputs the voltage control signal to the coil control circuit 12 through the first control end and outputs the current direction control signal to the coil control circuit 12 through the second control end to control the coil control circuit 12 to output the driving current to the coil of the relay under test 2, so that the first contact (contact 1) and the second contact (contact 2) of the relay under test 2 are turned on, the first intermediate voltage signal Contact is formed at the input end of the signal conversion circuit 132 through the first contact (contact 1), the second contact (contact 2) and the second access end, thereby forming the first voltage signal Contact_sig at the first input end of the comparison circuit 133.

[0048] In some alternative embodiments, the signal conversion circuit comprises an optocoupler circuit configured to output a first voltage signal at an output end in response to a first intermediate voltage signal received at an input end.

[0049] In the foregoing example, for example Figure 4 As shown, the signal conversion circuit 132 comprises an optocoupler circuit U3 configured to output a first voltage signal Contact_sig at an output end to a first input end of the comparison circuit 133 in response to a first intermediate voltage signal Contact received at an input end.

[0050] In some alternative embodiments, the comparison circuit comprises an AND gate, a first input end of the AND gate as a first input end of the comparison circuit, a second input end of the AND gate as a second input end of the comparison circuit, and an output end of the AND gate as an output end of the comparison circuit.

[0051] In the foregoing example, for example Figure 5 As shown, the comparison circuit 133 comprises an AND gate U1, a first input end of the AND gate U1 as a first input end of the comparison circuit 133 to receive the first voltage signal Contact_sig, a second input end of the AND gate U1 as a second input end of the comparison circuit 133 to receive the current direction control signal Ctr_coil_L or Ctr_coil_R (selected by the setting signal selection circuit according to whether Ctr_coil_L or Ctr_coil_R is output by the current controller 11 at present), and an output end of the AND gate U1 as an output end of the comparison circuit 133 to feed back a comparison result signal Fault1 to a second receiving end of the current controller 11. Thus, if the relay 2 under test is fault-free, when the current controller 11 controls the coil of the relay 2 under test to make the first contact (contact 1) and the second contact (contact 2) of the relay 2 under test conductive, both of the input ends of the AND gate U1 should input high-level signals, so that the output end of the AND gate U1 outputs a high-level signal. If the coil or the contacts of the relay 2 under test is faulty, when the current controller 11 controls the coil of the relay 2 under test to make the first contact (contact 1) and the second contact (contact 2) of the relay 2 under test conductive, the second input end of the AND gate U1 inputs a high-level signal while the first input end inputs a low-level signal, so that the output end of the AND gate U1 outputs a low-level signal. Then, the current controller 11 can determine whether the relay 2 under test is faulty according to whether the output end of the AND gate U1 outputs a high-level signal or a low-level signal when outputting the control signal.

[0052] In some optional embodiments, the contact detection circuit further comprises an impedance detection circuit, an input end of the impedance detection circuit is electrically connected to an output end of the contact access circuit, a control end is electrically connected to the fourth control end of the controller, and an output end is electrically connected to the third receiving end of the controller.

[0053] The controller is configured to output a current control signal to the impedance detection circuit through the fourth control end to control the first access end to access a reference voltage and the current through the first contact, the second contact and the second access end, and receive a detection result of detection of a difference between the first intermediate voltage signal and the reference voltage by the impedance detection circuit through the third receiving end.

[0054] In the foregoing examples, for example Figure 2 As shown, the contact detection circuit 13 further comprises an impedance detection circuit 134, and the controller 11 outputs a current control signal DA_ISet to the impedance detection circuit through the fourth control end to control the first access end to access a reference voltage and the current through the first contact, the second contact and the second access end, and receives a detection result of detection of a difference between the first intermediate voltage signal and the reference voltage by the impedance detection circuit 134 through the third receiving end, wherein the difference between the first intermediate voltage signal and the reference voltage corresponds to a voltage difference between the first contact and the second contact of the relay under test 2, and according to the voltage difference, the contact impedance of the relay under test 2 can be detected.

[0055] In some optional embodiments, the impedance detection circuit comprises a constant current source circuit and a second analog-digital detection circuit, and the controller is configured to output a current control signal to the constant current source circuit through the fourth control end to control the first access end to access a reference voltage and the current through the first contact, the second contact and the second access end, and receive a detection result of detection of a difference between the first intermediate voltage signal and the reference voltage by the second analog-digital detection circuit through the third receiving end.

[0056] In the foregoing examples, for example Figure 6As shown, the impedance detection circuit 134 comprises a constant current source circuit 1341 and a second analog-digital detection circuit 1342, the controller 11 outputs a current control signal DA_ISet to the constant current source circuit 1341 through the fourth control terminal to control the first access terminal to access the reference voltage and the detection current in the constant current source circuit 1341 through the first contact, the second contact, the second access terminal, the switch Q2 in the constant current source circuit 1341, and further generate a corresponding voltage difference AV between the first contact (contact 1) and the second contact (contact 2) of the relay under test 2. Since the first relay LS1 in the contact access circuit 131 directly connects the first contact (contact 1) with the 5V voltage source, the voltage of the second contact (contact 2) is taken as the first intermediate voltage signal Contact output by the contact access circuit 131, and the second analog-digital detection circuit 1342 accesses the reference voltage of the 5V voltage source and the first intermediate voltage signal Contact output by the contact access circuit 131 into the subtracter U3A respectively to obtain the voltage difference AV between the first contact (contact 1) and the second contact (contact 2), and output the voltage difference detection result signal AD_Contact1 to the third receiving terminal of the controller 11, thereby realizing the contact impedance detection of the relay under test 2.

[0057] In some optional embodiments, the coil control circuit comprises a DC-DC converter, a first analog-digital sampling circuit and a coil driving circuit, the input terminal of the DC-DC converter is connected with a power supply voltage, the output terminal of the DC-DC converter is electrically connected with the input terminal of the coil driving circuit, the first output terminal of the coil driving circuit is taken as the first connection terminal, the second output terminal of the coil driving circuit is taken as the second connection terminal, and the first analog-digital sampling circuit is electrically connected with the first output terminal and the second output terminal.

[0058] The controller is configured to output a voltage control signal to the controlled terminal of the DC-DC converter through the first control terminal and output a current direction control signal to the controlled terminal of the coil driving circuit through the second control terminal to control the coil driving circuit to output a driving current to the coil of the relay under test in response to the voltage output by the DC-DC converter, and receive the voltage and current signal of the coil detected and fed back by the first analog-digital sampling circuit through the first receiving terminal.

[0059] In the foregoing examples, for example Figure 7 As shown, the coil control circuit 12 comprises a DC-DC converter 121, a first analog-digital sampling circuit 122 and a coil driving circuit 123, the input terminal of the DC-DC converter 121 is connected with a power supply voltage Vin, the output terminal of the DC-DC converter 121 is electrically connected with the input terminal of the coil driving circuit 123, the first output terminal of the coil driving circuit 123 is electrically connected with the first end of the coil of the relay under test 2 as the first connection terminal, the second output terminal of the coil driving circuit 123 is electrically connected with the second end of the coil of the relay under test 2 as the second connection terminal, and the first analog-digital sampling circuit 122 is electrically connected with the first output terminal and the second output terminal.

[0060] The controller 11 outputs a voltage control signal V Set to the controlled terminal of the DC / DC converter 121 through the first control terminal and outputs a current direction control signal Ctr coil L or Ctr coil R to the controlled terminal of the coil driving circuit 123 through the second control terminal via the positive and negative direction control access circuit in the coil control circuit 12 to control the coil driving circuit 123 to output a driving current to the coil of the relay 2 to be tested in response to the voltage Vo output by the DC / DC converter 121, and receives the voltage and current signal Vs / Is of the coil detected and fed back by the first analog-digital sampling circuit 123 through the first receiving terminal.

[0061] In some optional embodiments, the coil driving circuit includes an H-bridge circuit, and the controller is configured to output a current direction control signal to the controlled terminal of the H-bridge circuit through the second control terminal.

[0062] In the foregoing examples, Figure 8 The circuit principle of the DC / DC converter 121 and the first analog-digital sampling circuit 122 in the coil control circuit 12 is shown, the DC / DC converter 121 includes a DC / DC chip, and the first analog-digital sampling circuit 122 includes an AD sampling circuit. Figure 9 The circuit principle of the positive and negative direction control access circuit and the coil driving circuit 123 in the coil control circuit 12 is shown, the H-bridge circuit includes four NMOS tubes Q3, Q4, Q5 and Q6 to meet the requirement of controlling the driving current in positive and negative directions during the use of the relay, the control signals L H and L L can be output through the positive and negative direction control access circuit by the current direction control signal Ctr coil L, so as to control the NMOS tubes Q3 and Q5 to be turned on, thereby realizing that the driving current flows from the Coil L end to the Coil R end of the coil, and the control signals R H and R L can be output through the positive and negative direction control access circuit by the current direction control signal Ctr coil R, so as to control the NMOS tubes Q4 and Q6 to be turned on, thereby realizing that the driving current flows from the Coil R end to the Coil L end of the coil.

[0063] In the foregoing examples, Figure 1 As shown, the detection circuit of the embodiment further includes a communication circuit 15 for realizing the communication between the controller 11 and the upper computer, and the controller 11 can upload the information about the coil fault of the relay to be tested, the relay to be tested, the contact impedance of the relay to be tested, etc. to the upper computer for display through the communication circuit 15.

[0064] In the foregoing examples, Figures 1-9As shown, the detection circuit further comprises a power supply circuit 14 configured to convert the input fixed supply voltage Uin into a voltage used by the detection circuit, for example, 5V, a voltage used by the controller 11, for example, 3.3V, a positive and negative power supply required by the detection circuit, an isolated power supply used by the communication circuit 15, and the like.

[0065] Based on the same inventive concept, the embodiments of the present disclosure further provide a relay board card comprising the relay and the detection circuit described in the above embodiments. Integrating the above detection circuit in the relay board card can realize real-time detection of the relay without disassembling the relay.

[0066] Based on the same inventive concept, the embodiments of the present disclosure further provide an electronic device comprising the relay board card described in the above embodiments. The electronic device can be any device or component comprising the above relay board card, such as an industrial control device, a power supply, a household appliance, and the like, and the present embodiments are not limited thereto.

[0067] Obviously, the above embodiments of the present disclosure are merely examples for clearly illustrating the present disclosure, and are not intended to limit the implementation manners of the present disclosure. For those skilled in the art, on the basis of the above description, other different forms of changes or modifications can also be made, and it is impossible to enumerate all the implementation manners here. Any changes or modifications falling within the scope of the technical solutions of the present disclosure shall still fall within the protection scope of the present disclosure.

Claims

1. A detection circuit of a relay, characterized by comprising: The controller, the coil control circuit and the contact detection circuit are connected in series. The first controlled end of the coil control circuit is electrically connected to the first control end of the controller, the second controlled end is electrically connected to the second control end of the controller, the feedback end is electrically connected to the first receiving end of the controller, the first connecting end is electrically connected to the first end of the coil of the relay to be tested, and the second connecting end is electrically connected to the second end of the coil of the relay to be tested. The controlled end of the contact detection circuit is electrically connected to the third control end of the controller, the feedback end is electrically connected to the second receiving end of the controller, the first access end is electrically connected to the first contact of the relay to be tested, and the second access end is electrically connected to the second contact of the relay to be tested. The controller is configured to output a voltage control signal to the coil control circuit through the first control end and output a current direction control signal to the coil control circuit through the second control end to control the coil control circuit to output a driving current to the coil of the relay to be tested, receive a voltage current signal of the coil fed back by the coil control circuit through the first receiving end, output a first control signal to the contact detection circuit through the third control end to control the contact detection circuit to access a reference voltage to the first access end and compare the voltage corresponding to the second access end with the current direction control signal, and receive a comparison result fed back by the contact detection circuit through the second receiving end.

2. The detection circuit of claim 1, wherein, The contact detection circuit comprises a contact access circuit, a signal conversion circuit and a comparison circuit, the contact access circuit comprises the first access end and the second access end, the output end of the contact access circuit is electrically connected to the input end of the signal conversion circuit, the output end of the signal conversion circuit is electrically connected to the first input end of the comparison circuit, and the second input end of the comparison circuit is electrically connected to the second control end of the controller. The controller is configured to output a first control signal to the contact access circuit through the third control end to control the contact access circuit to access a reference voltage to the first access end to form a first voltage signal at the first input end of the comparison circuit through the first contact, the second contact, the second access end and the signal conversion circuit, and receive a comparison result fed back by the comparison circuit by comparing the first voltage signal with the current direction control signal through the second receiving end.

3. The detection circuit of claim 2, wherein, The contact access circuit comprises a first switch tube and a first relay, the coil of the first relay is electrically connected to the first switch tube, one end of the first contact switch of the first relay serves as the first access end, and the other end is electrically connected to a reference voltage end, one end of the second contact switch of the first relay serves as the second access end, and the other end serves as the output end of the contact access circuit. The controller is configured to output a first control signal to the control electrode of the first switch tube through the third control terminal to control the first switch tube to be turned on, thereby controlling the first contact switch and the second contact switch to be closed, and the first access terminal to access the reference voltage, so as to form a first intermediate voltage signal at the input terminal of the signal conversion circuit through the first contact, the second contact and the second access terminal, and thereby form a first voltage signal at the first input terminal of the comparison circuit.

4. The detection circuit of claim 3, wherein, The signal conversion circuit comprises an optocoupler circuit configured to output the first voltage signal at the output terminal in response to the first intermediate voltage signal received at the input terminal.

5. The detection circuit of claim 4, wherein, The comparison circuit comprises an AND gate, the first input terminal of the AND gate serving as the first input terminal of the comparison circuit, the second input terminal of the AND gate serving as the second input terminal of the comparison circuit, and the output terminal of the AND gate serving as the output terminal of the comparison circuit.

6. The detection circuit of claim 3, wherein, The contact detection circuit further comprises an impedance detection circuit, the input terminal of the impedance detection circuit being electrically connected to the output terminal of the contact access circuit, the control terminal of the impedance detection circuit being electrically connected to the fourth control terminal of the controller, and the output terminal of the impedance detection circuit being electrically connected to the third receiving terminal of the controller. The controller is configured to output a current control signal to the impedance detection circuit through the fourth control terminal to control the first access terminal to access the reference voltage and the current through the first contact, the second contact and the second access terminal, and to receive, through the third receiving terminal, a detection result of the impedance detection circuit detecting the difference between the first intermediate voltage signal and the reference voltage.

7. The detection circuit of claim 6, wherein, The impedance detection circuit comprises a constant current source circuit and a second analog-digital detection circuit, and the controller is configured to output a current control signal to the constant current source circuit through the fourth control terminal to control the first access terminal to access the reference voltage and the current through the first contact, the second contact and the second access terminal, and to receive, through the third receiving terminal, a detection result of the second analog-digital detection circuit detecting the difference between the first intermediate voltage signal and the reference voltage.

8. The detection circuit of claim 1, wherein, The coil control circuit comprises a DC-DC converter, a first analog-digital sampling circuit and a coil driving circuit, the input terminal of the DC-DC converter accesses a power supply voltage, the output terminal of the DC-DC converter is electrically connected to the input terminal of the coil driving circuit, the first output terminal of the coil driving circuit serves as the first connection terminal, the second output terminal of the coil driving circuit serves as the second connection terminal, and the first analog-digital sampling circuit is electrically connected to the first output terminal and the second output terminal. The controller is configured to output a voltage control signal to the control terminal of the DC-DC converter through the first control terminal and output a current direction control signal to the control terminal of the coil driving circuit through the second control terminal to control the coil driving circuit to output a driving current to the coil of the relay to be tested in response to the voltage output by the DC-DC converter, and receive, through the first receiving terminal, a voltage and current signal of the coil detected and fed back by the first analog-digital sampling circuit.

9. The detection circuit of claim 8, wherein, The coil driving circuit comprises an H-bridge circuit and the controller is configured to output a current direction control signal to a controlled end of the H-bridge circuit through a second control end.

10. A relay board card, characterized by, The detection circuit as claimed in any one of claims 1-9, comprising a relay.

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