A protective device for high current connector

Abstract

The present invention relates to the field of connector technology and discloses a protective device for high-current connectors. This device aims to address the safety hazards associated with poor contact in existing connectors. The connectors include: a first connector and a second connector, wherein the first connector includes at least a first connection terminal, a second connection terminal, and a fifth connection terminal; the second connector includes at least a third connection terminal, a fourth connection terminal, and a sixth connection terminal, the sixth connection terminal being connected to the fourth connection terminal. The protective device includes: a first comparison circuit and a control circuit. The first comparison circuit is configured to send a first fault signal to the control circuit if the contact voltage between the second connection terminal and the fourth connection terminal is greater than a first reference voltage when the first and second connectors are connected. The control circuit is configured to cut off power to the first connector upon receiving the first fault signal. This invention improves connector safety.

Description

Technical Field

[0001] The present invention relates to the technical field of connectors, and in particular to a protection device for a high-current connector. Background Art

[0002] Connectors are widely used in various electrical devices, including common household electrical plugs, internal electrical connections in various industrial equipment, and mobile phone and car charging plugs. When these connectors are used in high-current scenarios (for a given voltage, higher power means higher current), the high current can easily lead to poor contact caused by wear, dirt, or loose insertion, which can easily cause the connectors to heat up and burn, or even burn and cause serious accidents.

[0003] Existing solutions primarily focus on improving the contact quality of high-current connectors through aspects such as connector structure and material. These efforts include adding protective covers to prevent dust intrusion and increasing the elasticity of metal pins to enhance contact strength. However, wear and deformation are inevitable during use, and as dust accumulates over time, poor contact persists. Consequently, the risk of burnout persists in high-current applications. Summary of the Invention

[0004] The present invention aims to solve the problem that existing connectors are prone to potential safety hazards due to poor contact, and proposes a protective device for high-current connectors.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A protection device for a high-current connector, the connector comprising: a first connector and a second connector, the first connector having at least a first connection terminal and a second connection terminal, the second connector having at least a third connection terminal corresponding to the first connection terminal and a fourth connection terminal corresponding to the second connection terminal, the first connector further having at least a fifth connection terminal, the second connector further having at least a sixth connection terminal corresponding to the fifth connection terminal, the sixth connection terminal being connected to the fourth connection terminal, the protection device comprising: a first comparison circuit and a control circuit;

[0007] The first comparison circuit is configured to send a first fault signal to the control circuit if a contact voltage between the second connection terminal and the fourth connection terminal is greater than a first reference voltage when the first connector is connected to the second connector;

[0008] The control circuit is used to cut off the power supply of the first connector after receiving the first fault signal.

[0009] Furthermore, the protection device further comprises: a thermistor and a second comparison circuit;

[0010] The thermistor is configured to change a resistance value according to a temperature of the first connector when the first connector is connected to the second connector;

[0011] The second comparison circuit is configured to convert the resistance value of the thermistor into a corresponding voltage value, and send a second fault signal to the control circuit according to a magnitude relationship between the voltage value and the first reference voltage;

[0012] The control circuit is further configured to cut off power supply to the first connector after receiving the second fault signal.

[0013] Furthermore, the thermistor is a positive temperature coefficient thermistor, and the second comparison circuit is specifically configured to send a second fault signal to the control circuit when the voltage value is greater than the first reference voltage; or

[0014] The thermistor is a negative temperature coefficient thermistor, and the second comparison circuit is specifically configured to send a second fault signal to the control circuit when the voltage value is less than a first reference voltage.

[0015] Furthermore, the first fault signal and the second fault signal are low-level signals, and the control circuit includes: a first AND gate and a first switch circuit, the output end of the first comparison circuit is connected to the first input end of the first AND gate, the output end of the second comparison circuit is connected to the second input end of the first AND gate, and the output end of the first AND gate is connected to the first switch circuit, and the first switch circuit is used to cut off the power supply to the first connector after receiving the low-level signal; or

[0016] The first fault signal and the second fault signal are high-level signals, and the control circuit includes: a first OR gate and a second switching circuit, the output end of the first comparison circuit is connected to the first input end of the first OR gate, the output end of the second comparison circuit is connected to the second input end of the first OR gate, the output end of the first OR gate is connected to the second switching circuit, and the second switching circuit is used to cut off the power supply to the first connector after receiving the high-level signal.

[0017] Furthermore, the first comparison circuit includes: a first reference voltage input port, a first comparator, a first resistor and a second resistor, the first reference voltage input port is connected to the positive phase input terminal of the first comparator through the first resistor, the positive phase input terminal of the first comparator is connected to the fifth connection terminal through the second resistor and then grounded, the negative phase input terminal of the first comparator is connected to the second connection terminal, and the output terminal of the first comparator is the output terminal of the first comparison circuit.

[0018] Furthermore, the second comparison circuit includes: a second comparator, a third resistor and a fourth resistor, one end of the thermistor is connected to the first reference voltage input port through the third resistor, the other end of the thermistor is connected to the positive phase input terminal of the second comparator and grounded through the fourth resistor, the negative phase input terminal of the second comparator is connected to the positive phase input terminal of the first comparator, and the output terminal of the second comparator is the output terminal of the second comparison circuit.

[0019] Furthermore, the protection device further comprises: a third comparison circuit;

[0020] the third comparison circuit being configured to send a first alarm signal to the control circuit if, when the first connector is connected to the second connector, a contact voltage between the second connection terminal and the fourth connection terminal is greater than a second reference voltage, the second reference voltage being less than the first reference voltage;

[0021] The control circuit is further configured to issue an alarm after receiving the first alarm signal.

[0022] Furthermore, the protection device further comprises: a fourth comparison circuit;

[0023] The fourth comparison circuit is used to convert the resistance value of the thermistor into a corresponding voltage value, and send a second alarm signal to the control circuit according to the magnitude relationship between the voltage value and the second reference voltage;

[0024] The control circuit is further configured to issue an alarm after receiving the second alarm signal.

[0025] Furthermore, the thermistor is a positive temperature coefficient thermistor, and the fourth comparison circuit is specifically configured to send a second alarm signal to the control circuit when the voltage value is greater than a second reference voltage; or

[0026] The thermistor is a negative temperature coefficient thermistor, and the fourth comparison circuit is specifically configured to send a second alarm signal to the control circuit when the voltage value is less than a second reference voltage.

[0027] Furthermore, the first alarm signal and the second alarm signal are low-level signals, and the control circuit further includes: a second AND gate and a first alarm circuit, the output end of the third comparison circuit is connected to the first input end of the second AND gate, the output end of the fourth comparison circuit is connected to the second input end of the second gate, the output end of the second AND gate is connected to the first alarm circuit, and the first alarm circuit is used to issue an alarm after receiving a low-level signal; or

[0028] The first alarm signal and the second alarm signal are high-level signals. The control circuit also includes: a second OR gate and a second alarm circuit. The output end of the third comparison circuit is connected to the first input end of the second OR gate, the output end of the fourth comparison circuit is connected to the second input end of the second OR gate, and the output end of the second OR gate is connected to the second alarm circuit. The second alarm circuit is used to issue an alarm after receiving a high-level signal.

[0029] The beneficial effects of the present invention are as follows: The protective device for a high-current connector of the present invention provides corresponding auxiliary terminals for at least one pair of connection terminals of the connector, and provides a first comparison circuit and a control circuit based on the auxiliary terminals. After the connector is connected, the first comparison circuit determines the impedance of the connection terminals. When the impedance of the connection terminals exceeds the maximum contact resistance, the control circuit automatically cuts off the power supply, thereby preventing the connector from burning. By providing a thermistor and a second comparison circuit, after the connector is connected, the thermistor determines the temperature of the connector. When the temperature exceeds the maximum allowable temperature, the control circuit automatically cuts off the power supply, further preventing the connector from burning. Furthermore, by providing third and fourth comparison circuits, the control circuit issues an alarm when the impedance of the connection terminals is about to exceed the maximum contact resistance, and also when the temperature is about to exceed the maximum allowable temperature. This allows the user to be informed of abnormal conditions of the connector in advance, further improving the safety of the connector. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic structural diagram of a connector according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the first principle structure of the protection device for the high-current connector according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of a first circuit structure of a protection device for a high-current connector according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of a second circuit structure of the protection device for a high-current connector according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of a second principle structure of the protection device for a high-current connector according to an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of a third circuit structure of the protection device for a high-current connector according to an embodiment of the present invention;

[0036] Figure 7This is a schematic diagram of a fourth circuit structure of the protection device for a high-current connector according to an embodiment of the present invention;

[0037] Description of reference numerals:

[0038] A-first connector; B-second connector; 1-first connecting terminal; 2-second connecting terminal; 3-third connecting terminal; 4-fourth connecting terminal; 5-fifth connecting terminal; 6-sixth connecting terminal; R1-first resistor; R2-second resistor; R3-third resistor; R4-fourth resistor; R5-fifth resistor; R6-sixth resistor; R7-seventh resistor; R8-eighth resistor; RT1-thermistor; U1-first comparator; U2-second comparator; U3-third comparator; U4-fourth comparator; AND1-first AND gate; AND2-second AND gate; OR1-first OR gate; OR2-second OR gate; VERF1-first reference voltage input port; VERF2-second reference voltage input port. DETAILED DESCRIPTION

[0039] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] The present invention aims to prevent a connector from being burned and proposes a protection device for a high-current connector, the connector comprising: a first connector and a second connector, the first connector being provided with at least a first connection terminal and a second connection terminal, the second connector being provided with at least a third connection terminal corresponding to the first connection terminal and a fourth connection terminal corresponding to the second connection terminal, the first connector also being provided with at least a fifth connection terminal, the second connector also being provided with at least a sixth connection terminal corresponding to the fifth connection terminal, the sixth connection terminal being connected to the fourth connection terminal, the protection device comprising: a first comparison circuit and a control circuit; the first comparison circuit being used to send a first fault signal to the control circuit when the first connector is connected to the second connector, if the contact voltage between the second connection terminal and the fourth connection terminal is greater than a first reference voltage; the control circuit being used to cut off the power supply to the first connector after receiving the first fault signal.

[0041] In this embodiment, the first reference voltage may be set based on rated parameters of the connector.

[0042] Specifically, when the connection terminals of the connector have poor contact, for example, when the connector terminals are dirty, deformed, or not fully inserted, the contact resistance may exceed the maximum contact resistance, causing the connector to heat up or burn. Accordingly, when the contact resistance of the connection terminals increases, the corresponding contact voltage will also increase. Based on this, the present invention uses a first comparison circuit to compare the contact voltage of the connection terminals with a first reference voltage. When the contact voltage is greater than the first reference voltage, it indicates that the contact resistance is large, which may cause the connector to heat up or burn. At this time, the power supply to the connector is cut off by the control circuit, thereby protecting the connector.

[0043] Example

[0044] See also Figure 1 The connector described in the embodiment of the present invention includes: a first connector A and a second connector B, the first connector A is provided with a first connecting terminal 1 and a second connecting terminal 2, the second connector B is provided with a third connecting terminal 3 corresponding to the first connecting terminal 1 and a fourth connecting terminal 4 corresponding to the second connecting terminal 2, that is, when the first connector A and the second connector B are connected, the first connecting terminal 1 is connected to the third connecting terminal 3, and the second connecting terminal 2 is connected to the fourth connecting terminal 4.

[0045] This embodiment uses the second and fourth connection terminals 2 and 4 as an example to explain the implementation of the present invention in detail. In this embodiment, first connector A is the power supply terminal, and second connector B is the power receiving terminal. In practical applications, corresponding protection devices can be provided for any one or more pairs of connection terminals to implement impedance detection for each pair of connection terminals. If the contact voltage of any pair of connection terminals exceeds the maximum contact voltage, an alarm will be issued or power will be cut off.

[0046] First, set up auxiliary terminals for contact detection for the connection terminals that need to be protected. Figure 1 In this embodiment, a corresponding auxiliary connection terminal is set for the second connection terminal 2: the fifth connection terminal 5, and a corresponding auxiliary connection terminal is set for the fourth connection terminal 4: the sixth connection terminal 6, and the fourth connection terminal 4 and the sixth connection terminal 6 are connected inside the second connector B.

[0047] In this embodiment, the connection terminals can be pins. Since this embodiment is a high-current connector, the first connection terminal 1, the second connection terminal 2, the third connection terminal 3 and the fourth connection terminal 4 are relatively thick pins, while the fifth connection terminal 5 and the sixth connection terminal 6 are used to detect signals. There are no special requirements for the size of the pins, and the size and cost of the connector are little affected.

[0048] Optionally, in this embodiment, it is only illustrated by way of example that a pair of auxiliary connection terminals can be added to implement the setting of a protective device for the connector. In actual use by users, multiple pairs of auxiliary connection terminals can also be set to implement the setting of a protective device for the connector. The specific technical implementation when multiple pairs of auxiliary connection terminals are set is similar to the specific technical implementation when one pair of auxiliary connection terminals is set, and will not be repeated here.

[0049] See also Figure 2 Based on the fifth and sixth connection terminals 5 and 6, the protection device in this embodiment includes a first comparison circuit and a control circuit. The first comparison circuit is configured to send a first fault signal to the control circuit if the contact voltage between the second connection terminal 2 and the fourth connection terminal 4 is greater than a first reference voltage when the first connector A and the second connector B are connected. The control circuit is configured to cut off power to the first connector A upon receiving the first fault signal.

[0050] Specifically, when the first connector A and the second connector B are connected, the second connection terminal 2 is connected to the fourth connection terminal 4. When the second connection terminal 2 and the fourth connection terminal 4 are in poor contact, the contact resistance between the second connection terminal 2 and the fourth connection terminal 4 increases, and the contact voltage also increases accordingly. The first comparison circuit determines whether to send a first fault signal to the control circuit by comparing the contact voltage between the second connection terminal 2 and the fourth connection terminal 4 with the first reference voltage, thereby cutting off the power supply to the first connector A when the second connection terminal 2 and the fourth connection terminal 4 are in poor contact and may cause the connector to heat up or burn, thereby achieving the purpose of protecting the connector.

[0051] See also Figure 2 The protection device in this embodiment further includes a thermistor RT1 and a second comparison circuit. The thermistor RT1 is configured to change its resistance value based on the temperature of the first connector A when the first connector A is connected to the second connector B. The second comparison circuit is configured to convert the thermistor's resistance value into a corresponding voltage value and, based on the relationship between the converted voltage value and the first reference voltage, send a second fault signal to the control circuit. The control circuit is further configured to cut off power to the first connector A upon receiving the second fault signal.

[0052] Specifically, thermistor RT1 can sense the temperature of first connector A by being placed in close contact with the connector (by gluing or screwing) or embedded in the connector (by implanting thermistor RT1 during connector production). When the temperature of first connector A changes, the resistance value of thermistor RT1 also changes accordingly. A second comparison circuit converts the resistance change into a voltage change. Based on the relationship between the voltage value and a first reference voltage, it is determined whether the temperature of first connector A exceeds the maximum allowable temperature. If so, a first fault signal is sent to the control circuit. This, in turn, cuts off power to the connector when the connector temperature is abnormal, thereby protecting the connector.

[0053] In practical applications, thermistors RT1 with different temperature coefficients can be selected. When thermistor RT1 is a positive temperature coefficient thermistor, the second comparison circuit is specifically configured to send a second fault signal to the control circuit when the voltage value is greater than the first reference voltage. When thermistor RT1 is a negative temperature coefficient thermistor, the second comparison circuit is specifically configured to send a second fault signal to the control circuit when the voltage value is less than the first reference voltage.

[0054] It can be understood that the resistance of a positive temperature coefficient thermistor increases with increasing temperature. When the connector temperature rises, the corresponding voltage value also increases due to the increase in resistance. That is, the higher the connector temperature, the larger the corresponding voltage value. When the voltage value is greater than the first reference voltage, it indicates that the connector temperature exceeds the maximum allowable temperature. In this case, the power supply to the connector is cut off, achieving the purpose of connector protection. The resistance of a negative temperature coefficient thermistor decreases with increasing temperature. When the connector temperature rises, the corresponding voltage value also decreases due to the decrease in resistance. That is, the higher the connector temperature, the smaller the corresponding voltage value. When the voltage value is less than the first reference voltage, it indicates that the connector temperature exceeds the maximum allowable temperature. In this case, the power supply to the connector is cut off, achieving the purpose of connector protection.

[0055] See also Figure 3 The first comparison circuit described in this embodiment includes: a first reference voltage input port VERF1, a first comparator U1, a first resistor R1, and a second resistor R2. The first reference voltage input port VERF1 is connected to the non-inverting input terminal of the first comparator U1 through the first resistor R1. The non-inverting input terminal of the first comparator U1 is connected to the fifth connection terminal 5 through the second resistor R2 and then to ground. The negative input terminal of the first comparator U1 is connected to the second connection terminal 2. The output terminal of the first comparator U1 is the output terminal of the first comparison circuit.

[0056] It is understood that when the connecting terminals are dirty, deformed, or not fully inserted, the contact resistance may exceed the maximum allowable contact resistance, resulting in the problem of connector heating or burning. To address the above problem, in this embodiment, it is assumed that the first connector A and the second connector B are fully connected, the maximum allowable contact resistance of the second connecting terminal 2 and the fourth connecting terminal 4 is 5 milliohms, and the maximum allowable current is 10 amperes. The corresponding first reference voltage is 50 millivolts. When the second connecting terminal 2 and the fourth connecting terminal 4 pass the rated current of 10 amperes, the maximum contact resistance is 5 milliohms. Therefore, the maximum voltage between the second connecting terminal 2 and the fourth connecting terminal 4 under normal circumstances is 50 millivolts (5 milliohms × 10 amperes). The voltage of the second connecting terminal 2 is directly connected to the input of the first comparator U1, and the voltage of the fourth connecting terminal 4 is connected to the fifth connecting terminal 5 via the sixth connecting terminal 6 (looped back at the second connector B). The fifth connecting terminal 5 is connected to the signal ground that is the same as the signal ground referenced by the first comparator U1. When the contact voltage between the second connection terminal 2 and the fourth connection terminal 4 is greater than the first reference voltage, the first comparator U1 sends a first fault signal to the control circuit, which indicates that the contact resistance between the second connection terminal 2 and the fourth connection terminal 4 exceeds the maximum allowable contact resistance. After receiving the first fault signal, the control circuit cuts off the power supply to the connector.

[0057] See also Figure 3 The second comparison circuit described in this embodiment includes: a second comparator U2, a third resistor R3, and a fourth resistor R4. One end of the thermistor RT1 is connected to the first reference voltage input port VERF1 through the third resistor R3. The other end of the thermistor RT1 is connected to the positive phase input terminal of the second comparator U2 and is grounded through the fourth resistor R4. The negative phase input terminal of the second comparator U2 is connected to the positive phase input terminal of the first comparator U1. The output terminal of the second comparator U2 serves as the output terminal of the second comparison circuit.

[0058] Understandably, if a short circuit or overcurrent occurs at the receiving end, the current draw exceeds the design specification of 10 amperes, causing the connector to overheat and burn. To address this issue, a thermistor RT1, whose resistance value varies with temperature, is configured to sense the temperature of the first connector A. When the temperature exceeds the maximum allowable temperature, a second fault signal is sent to the control circuit. Upon receiving the second fault signal, the control circuit disconnects power to the connector, thereby protecting the connector. In practical applications, thermistor RT1 can be either a positive temperature coefficient thermistor or a negative temperature coefficient thermistor.

[0059] See also Figure 3In this embodiment, using negative temperature coefficient thermistor RT1 as an example, if the contact point between the second connection terminal 2 and the fourth connection terminal 4 becomes abnormally hot, the temperature of the thermistor RT1 will rise, and its resistance will decrease. This decrease in the resistance of thermistor RT1 will cause the voltage at the non-inverting input of the second comparator U2 to decrease. When the voltage of the second comparator U2 falls below the first reference voltage, the second comparator U2 sends a second fault signal to the control circuit, indicating that the connector temperature has exceeded the maximum allowable temperature. Upon receiving the second fault signal, the control circuit disconnects power to the connector.

[0060] In this embodiment, the fault signals output by the first comparator U1 and the second comparator U2 can be high level signals or low level signals. Figure 3 When the first fault signal and the second fault signal are low-level signals, the control circuit includes: a first AND gate AND1 and a first switch circuit, the output end of the first comparison circuit is connected to the first input end of the first AND gate AND1, the output end of the second comparison circuit is connected to the second input end of the first AND gate AND1, and the output end of the first AND gate AND1 is connected to the first switch circuit. The first switch circuit is used to cut off the power supply to the first connector after receiving the low-level signal.

[0061] Specifically, when the first comparator U1 outputs a low-level fault signal, regardless of the signal output by the second comparator U2, the first AND gate AND1 will output a low-level signal, thereby controlling the first switch circuit to cut off the power supply to the first connector. Similarly, when the second comparator U2 outputs a low-level fault signal, regardless of the signal output by the first comparator U1, the first AND gate AND1 will output a low-level signal, thereby controlling the first switch circuit to cut off the power supply to the first connector.

[0062] See also Figure 4 When the first fault signal and the second fault signal are high-level signals, the control circuit includes: a first OR gate OR1 and a second switch circuit, the output end of the first comparison circuit is connected to the first input end of the first OR gate OR1, the output end of the second comparison circuit is connected to the second input end of the first OR gate OR1, and the output end of the first OR gate OR1 is connected to the second switch circuit. The second switch circuit is used to cut off the power supply to the first connector after receiving the high-level signal.

[0063] Specifically, when the first comparator U1 outputs a high-level fault signal, regardless of the signal output by the second comparator U2, the first OR gate OR1 will output a high-level signal, thereby controlling the second switch circuit to cut off the power supply to the first connector. Similarly, when the second comparator U2 outputs a high-level fault signal, regardless of the signal output by the first comparator U1, the first OR gate OR1 will output a high-level signal, thereby controlling the second switch circuit to cut off the power supply to the first connector.

[0064] Through the above circuit, whether the contact resistance between the second connection terminal 2 and the fourth connection terminal 4 is abnormal or the connector is abnormally heated, the power supply to the connector can be cut off, thereby achieving multiple protections for the connector and further improving the safety of the connector.

[0065] See also Figure 5 In order to achieve the purpose of reminding the user, the protection device described in this embodiment further includes: a third comparison circuit; the third comparison circuit is used to send a first alarm signal to the control circuit when the first connector A and the second connector B are connected, if the contact voltage between the second connection terminal 2 and the fourth connection terminal 4 is greater than the second reference voltage, and the second reference voltage is less than the first reference voltage; the control circuit is also used to issue an alarm after receiving the first alarm signal.

[0066] It can be understood that the third comparison circuit is substantially the same as the first comparison circuit, the only difference being the reference voltage. Figure 6 In this embodiment, the third comparison circuit includes: a second reference voltage input port VERF2, a third comparator U3, a fifth resistor R5, and a sixth resistor R6. The second reference voltage input port VERF2 is connected to the non-inverting input terminal of the third comparator U3 through the fifth resistor R5. The non-inverting input terminal of the third comparator U3 is connected to the fifth connection terminal 5 through the sixth resistor R6 and then to ground. The negative input terminal of the third comparator U3 is connected to the second connection terminal 2. The output terminal of the third comparator U3 is the output terminal of the third comparison circuit.

[0067] In this embodiment, the second reference voltage can be set by de-rating the first reference voltage by a certain percentage. This is generally set by the user based on actual usage, and the specific de-rating percentage is not specifically limited. For example, in this embodiment, taking the first reference voltage of 50 mV as an example, a second reference voltage of 40 mV is selected based on an 80% de-rating. This sets the contact voltage alarm threshold to 40 mV. When the contact voltage exceeds the second reference voltage, i.e., 40 mV, an alarm signal is issued to alert the user to a connector abnormality.

[0068] Specifically, in this embodiment, when the contact voltage between the second connection terminal 2 and the fourth connection terminal 4 is greater than the second reference voltage, the third comparator U3 sends a first alarm signal to the control circuit. This indicates that the contact resistance between the second connection terminal 2 and the fourth connection terminal 4 exceeds the alarm threshold value. The control circuit issues an alarm after receiving the first alarm signal, thereby achieving the purpose of reminding the user.

[0069] See also Figure 5The protection device described in this embodiment further includes: a fourth comparison circuit; the fourth comparison circuit is used to convert the resistance value of the thermistor RT1 into a corresponding voltage value, and send a second alarm signal to the control circuit based on the relationship between the converted voltage value and the second reference voltage; the control circuit issues an alarm after receiving the second alarm signal.

[0070] It can be understood that the fourth comparison circuit is substantially the same as the second comparison circuit, the only difference being the reference voltage. Figure 6 In this embodiment, the fourth comparison circuit includes: a fourth comparator U4, a seventh resistor R7, and an eighth resistor R8. One end of the thermistor RT1 is connected to the second reference voltage input port VERF2 through the seventh resistor R7. The other end of the thermistor RT1 is connected to the positive phase input terminal of the fourth comparator U4 and is grounded through the eighth resistor R8. The negative phase input terminal of the fourth comparator U4 is connected to the positive phase input terminal of the third comparator U3. The output terminal of the fourth comparator U4 is the output terminal of the fourth comparison circuit.

[0071] In this embodiment, taking the negative temperature coefficient thermistor RT1 as an example, when the voltage value of the fourth comparator U4 is lower than the second reference voltage value, it sends a second alarm signal to the control circuit, indicating that the connector temperature exceeds the alarm threshold value. The control circuit issues an alarm after receiving the second alarm signal, thereby achieving the purpose of reminding the user.

[0072] Similarly, the alarm signals output by the third comparator U3 and the fourth comparator U4 in this embodiment can also be high-level signals or low-level signals. Figure 6 When the first alarm signal and the second alarm signal are low-level signals, the control circuit also includes: a second AND gate AND2 and a first alarm circuit, the output end of the third comparison circuit is connected to the first input end of the second AND gate AND2, the output end of the fourth comparison circuit is connected to the second input end of the second gate, the output end of the second AND gate AND2 is connected to the first alarm circuit, and the first alarm circuit is used to issue an alarm after receiving a low-level signal.

[0073] Specifically, when the third comparator U3 outputs a low-level alarm signal, regardless of the signal output by the fourth comparator U4, the second AND gate AND2 will output a low-level signal, thereby controlling the first alarm circuit to sound an alarm. Similarly, when the fourth comparator U4 outputs a low-level alarm signal, regardless of the signal output by the third comparator U3, the second AND gate AND2 will output a low-level signal, thereby controlling the first alarm circuit to sound an alarm.

[0074] See also Figure 7When the first alarm signal and the second alarm signal are high-level signals, the control circuit also includes: a second OR gate OR2 and a second alarm circuit, the output end of the third comparison circuit is connected to the first input end of the second OR gate OR2, the output end of the fourth comparison circuit is connected to the second input end of the second OR gate OR2, and the output end of the second OR gate OR2 is connected to the second alarm circuit, and the second alarm circuit is used to issue an alarm after receiving a high-level signal.

[0075] Specifically, when the third comparator U3 outputs a high-level alarm signal, regardless of the signal output by the fourth comparator U4, the second OR gate OR2 will output a high-level signal, thereby controlling the second alarm circuit to sound an alarm. Similarly, when the fourth comparator U4 outputs a high-level alarm signal, regardless of the signal output by the third comparator U3, the second OR gate OR2 will output a high-level signal, thereby controlling the second alarm circuit to sound an alarm.

[0076] Through the above circuit, whether the contact resistance between the second connection terminal 2 and the fourth connection terminal 4 is abnormal or the connector heats up abnormally, an alarm can be issued for the connector abnormality, thereby reminding the user and further improving the safety of the connector.

[0077] In summary, the high-current connector protection device described in this embodiment provides corresponding auxiliary terminals for at least one pair of connector terminals, and provides a first comparison circuit and a control circuit based on the auxiliary terminals. After the connector is connected, the first comparison circuit determines the impedance of the connector terminals. When the impedance of the connector terminals exceeds the maximum contact resistance, the control circuit automatically cuts off the power supply, thereby preventing the connector from burning. By providing a thermistor RT1 and a second comparison circuit, after the connector is connected, the thermistor RT1 is used to determine the connector temperature. When the temperature exceeds the maximum allowable temperature, the control circuit automatically cuts off the power supply, further preventing the connector from burning. Furthermore, by providing third and fourth comparison circuits, the control circuit issues an alarm when the impedance of the connector terminals is about to exceed the maximum contact resistance, and also when the temperature is about to exceed the maximum allowable temperature. This allows the user to be notified of any abnormal connector conditions in advance, further improving connector safety.

Claims

1. A protective device for a high current connector, characterized in that: The connector includes: a first connector and a second connector, the first connector having at least a first connection terminal and a second connection terminal, the second connector having at least a third connection terminal corresponding to the first connection terminal and a fourth connection terminal corresponding to the second connection terminal, the first connector also having at least a fifth connection terminal, the second connector also having at least a sixth connection terminal corresponding to the fifth connection terminal, the sixth connection terminal being connected to the fourth connection terminal, and the protection device including: a first comparison circuit and a control circuit; The first comparison circuit includes a first comparator, a negative phase input terminal of the first comparator is connected to the second connection terminal, and a positive phase input terminal of the first comparator is connected to the fifth connection terminal; The first comparison circuit is configured to send a first fault signal to the control circuit if a contact voltage between the second connection terminal and the fourth connection terminal is greater than a first reference voltage when the first connector is connected to the second connector; The control circuit is configured to cut off power supply to the first connector after receiving the first fault signal.

2. The protection device for a high current connector according to claim 1, wherein: The protection device further comprises: a thermistor and a second comparison circuit; The thermistor is configured to change a resistance value according to a temperature of the first connector when the first connector is connected to the second connector; The second comparison circuit is configured to convert the resistance value of the thermistor into a corresponding voltage value, and send a second fault signal to the control circuit according to a magnitude relationship between the voltage value and the first reference voltage; The control circuit is further configured to cut off power supply to the first connector after receiving a second fault signal.

3. The protection device for a high current connector according to claim 2, wherein: The thermistor is a positive temperature coefficient thermistor, and the second comparison circuit is specifically configured to send a second fault signal to the control circuit when the voltage value is greater than the first reference voltage; or The thermistor is a negative temperature coefficient thermistor, and the second comparison circuit is specifically configured to send a second fault signal to the control circuit when the voltage value is less than a first reference voltage.

4. The protection device for a high current connector according to claim 2, wherein: The first fault signal and the second fault signal are low-level signals, and the control circuit includes: a first AND gate and a first switch circuit, the output end of the first comparison circuit is connected to the first input end of the first AND gate, the output end of the second comparison circuit is connected to the second input end of the first AND gate, and the output end of the first AND gate is connected to the first switch circuit, and the first switch circuit is used to cut off the power supply to the first connector after receiving the low-level signal; or The first fault signal and the second fault signal are high-level signals, and the control circuit includes: a first OR gate and a second switching circuit, the output end of the first comparison circuit is connected to the first input end of the first OR gate, the output end of the second comparison circuit is connected to the second input end of the first OR gate, the output end of the first OR gate is connected to the second switching circuit, and the second switching circuit is used to cut off the power supply to the first connector after receiving the high-level signal.

5. The protection device for a high current connector according to claim 2, wherein: The first comparison circuit also includes: a first reference voltage input port, a first resistor and a second resistor. The first reference voltage input port is connected to the non-inverting input terminal of the first comparator through the first resistor. The non-inverting input terminal of the first comparator is connected to the fifth connection terminal through the second resistor and then to ground. The output terminal of the first comparator is the output terminal of the first comparison circuit.

6. The protection device for a high current connector according to claim 5, characterized in that: The second comparison circuit includes: a second comparator, a third resistor and a fourth resistor, one end of the thermistor is connected to the first reference voltage input port through the third resistor, the other end of the thermistor is connected to the positive phase input terminal of the second comparator and grounded through the fourth resistor, the negative phase input terminal of the second comparator is connected to the positive phase input terminal of the first comparator, and the output terminal of the second comparator is the output terminal of the second comparison circuit.

7. The protection device for a high current connector according to any one of claims 2 to 6, characterized in that: The protection device further includes: a third comparison circuit; the third comparison circuit being configured to send a first alarm signal to the control circuit if, when the first connector is connected to the second connector, a contact voltage between the second connection terminal and the fourth connection terminal is greater than a second reference voltage, the second reference voltage being less than the first reference voltage; The control circuit is further configured to issue an alarm after receiving the first alarm signal.

8. The protection device for a high current connector according to claim 7, wherein: The protection device further includes: a fourth comparison circuit; The fourth comparison circuit is used to convert the resistance value of the thermistor into a corresponding voltage value, and send a second alarm signal to the control circuit according to the magnitude relationship between the voltage value and the second reference voltage; The control circuit is further configured to issue an alarm after receiving the second alarm signal.

9. The protection device for a high current connector according to claim 8, characterized in that: The thermistor is a positive temperature coefficient thermistor, and the fourth comparison circuit is specifically configured to send a second alarm signal to the control circuit when the voltage value is greater than a second reference voltage; or The thermistor is a negative temperature coefficient thermistor, and the fourth comparison circuit is specifically configured to send a second alarm signal to the control circuit when the voltage value is less than a second reference voltage.

10. The protection device for a high current connector according to claim 8, wherein: The first alarm signal and the second alarm signal are low-level signals, the control circuit further includes: a second AND gate and a first alarm circuit, the output end of the third comparison circuit is connected to the first input end of the second AND gate, the output end of the fourth comparison circuit is connected to the second input end of the second gate, the output end of the second AND gate is connected to the first alarm circuit, and the first alarm circuit is configured to issue an alarm after receiving a low-level signal; or The first alarm signal and the second alarm signal are high-level signals. The control circuit also includes: a second OR gate and a second alarm circuit. The output end of the third comparison circuit is connected to the first input end of the second OR gate, the output end of the fourth comparison circuit is connected to the second input end of the second OR gate, and the output end of the second OR gate is connected to the second alarm circuit. The second alarm circuit is used to issue an alarm after receiving a high-level signal.

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