Control circuit and direct current contactor

Abstract

A control circuit and a direct current contactor, the control circuit comprises an action loop and a main control circuit, the connection and disconnection of the action loop are controlled by a switching tube, so that a coil of a direct current electromagnetic system connected to the action loop is connected or disconnected, the main control circuit is connected with a driving circuit, and the driving circuit controls the connection and disconnection of the switching tube. The system further comprises a voltage sampling circuit and a current sampling circuit, the voltage sampling circuit is connected between the main control circuit and the action loop and used for collecting voltage signals of the coil, the current sampling circuit is connected between the main control circuit and the action loop and used for collecting current signals flowing through the coil, and the main control circuit is connected with a feedback unit. The feedback unit is used for feeding back operation states of the coil and the contact mechanism. According to the utility model, the main control circuit obtains the working current and the working voltage of the coil and the operation state data of the coil in real time, and then feeds back the operation states of the coil and the contact mechanism through the feedback unit, so that when a fault occurs, the fault can be quickly and accurately eliminated.

Description

Technical Field

[0001] The utility model relates to the field of low-voltage electrical appliances, in particular to a control circuit and a DC contactor. Background Art

[0002] A DC contactor is a contactor in which the action of the iron core is controlled by a DC coil. Its load is DC or AC and is suitable for occasions with frequent start and stop. At present, DC contactors usually need to use high-power excitation at startup and maintain working state at low power consumption. It can be completed by using a control circuit and a single-winding coil. During its operation, it can run at high power through the control circuit and delay switching to low-power operation, which can also save energy and be environmentally friendly. The working state of the main contact can be determined by collecting the auxiliary contact signal interlocked with the main contact. However, in existing products, it lacks a feedback unit and cannot intuitively obtain the operating data of the coil and contact mechanism under working state. When the coil fails, the fault needs to be eliminated step by step. When the main contact is sticky, it is necessary to first identify the fault signal from the background and then lock the faulty product. It takes a long time and is easy to miss the best window period for solving the problem. Summary of the Invention

[0003] The purpose of the present utility model is to overcome at least one defect of the prior art and provide a control circuit and a DC contactor.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] The utility model provides a control circuit, including an action loop and a main control circuit, wherein the connection and disconnection of the action loop are controlled by a switch tube, so that the coil of a DC electromagnetic system connected to the action loop is connected or disconnected, the main control circuit is connected to a drive circuit, the drive circuit controls the connection and disconnection of the switch tube, and further includes a voltage sampling circuit and a current sampling circuit, the voltage sampling circuit is connected between the main control circuit and the action loop for collecting the voltage signal of the coil, the current sampling circuit is connected between the main control circuit and the action loop for collecting the current signal flowing through the coil, the main control circuit is connected to a feedback unit, and the feedback unit is used to feedback the operating status of the coil and the contact mechanism.

[0006] Preferably, the main control circuit is further connected to an auxiliary circuit, and the auxiliary circuit is connected to a thermal device, and the thermal device is used to obtain the temperature of the contact chamber provided with the contact mechanism in a working state.

[0007] Preferably, the feedback unit includes an indicator light and / or a display screen, the indicator light is connected between the coil and the main control circuit, and / or the indicator light is connected to the contact mechanism and the main control circuit, and the display screen is connected to the main control circuit.

[0008] Preferably, the feedback unit further includes a communication unit, and the communication unit is connected to an external background device for feeding back the operating status of the coil and the contact chamber.

[0009] Preferably, it further includes an EMC circuit and a rectifier circuit, and the external power supply is connected to the action circuit after passing through the EMC circuit and the rectifier circuit in sequence.

[0010] Preferably, it further includes a power supply module, which supplies power to the main control circuit and the drive circuit, and the power supply module is connected to the output end of the rectifier circuit.

[0011] Preferably, the main control circuit includes a circuit board and an MCU controller, the feedback unit includes an indicator light and / or a display screen arranged on the circuit board, and the circuit board is provided with lead pins.

[0012] The utility model also provides a DC contactor, comprising a shell, wherein a contact system and an electromagnetic system are arranged in the shell, and the control circuit as described above is also arranged in the shell, and the coil in the electromagnetic system is connected to the control circuit.

[0013] Furthermore, it also includes a contact chamber, the contact mechanism includes a main contact group and an auxiliary contact group arranged in the contact chamber, the main contact group includes an active contact and a main static contact that cooperate with each other, the active contact is driven by the electromagnetic system to contact or separate with the main static contact, the auxiliary contact group includes an auxiliary moving contact and an auxiliary static contact, the auxiliary moving contact moves with the active contact to achieve contact or separation with the auxiliary static contact,

[0014] The feedback unit includes a first indicator light and a second indicator light, wherein the first indicator light is connected to the coil, and the second indicator light is connected to the auxiliary contact group.

[0015] Furthermore, the housing is provided with an observation area, and the observation area is used to observe the states of the first indicator light and the second indicator light.

[0016] Furthermore, a refractive element is provided in the housing, and the refractive element cooperates with the display screen in the feedback unit.

[0017] Furthermore, the electromagnetic system includes a coil assembly and a moving assembly driven by the coil assembly. The contact system is arranged above the electromagnetic system. The contact system includes a ceramic cover. A contact mechanism is arranged in the ceramic cover as a contact chamber.

[0018] The control circuit includes a first circuit board and a second circuit board connected to each other. The first circuit board and the second circuit board are arranged on adjacent sides outside the contact chamber. The first circuit board is arranged in a direction parallel to the track of the moving component, and the first circuit board and the contact mechanism are arranged side by side. The second circuit board is arranged outside the contact chamber away from one end of the electromagnetic system.

[0019] Furthermore, a first indicator light and a second indicator light are provided on the first circuit board, and a thermal sensor is provided on a side of the second circuit board facing the contact chamber.

[0020] Furthermore, the first circuit board is provided with a lead-out pin, which is led out of the housing and is arranged in a plug of the housing.

[0021] The control circuit and DC contactor of the present invention are characterized by a main control circuit that acquires the working current and working voltage of the coil in real time through a voltage sampling circuit and a current sampling circuit, and can promptly obtain the operating status data of the coil, and then feed back the operating status of the coil and the contact mechanism through a feedback unit, so that when a fault occurs, the fault can be quickly and accurately eliminated.

[0022] In addition, the main control circuit obtains the temperature of the contact chamber through the auxiliary circuit, realizes the monitoring of the contact chamber temperature, and provides more accurate feedback on the operating status of the contact chamber.

[0023] In addition, the working status of the contact chamber and coil can be displayed on the display screen of the main control circuit, and can also be transmitted to the background equipment through the communication unit, making it convenient to observe the operating status of the contact mechanism and coil.

[0024] In addition, by setting up an EMC circuit to isolate electromagnetic interference, the stability and reliability of the overall operation of the control circuit are improved; the rectifier circuit rectifies the external input AC power or DC power into a DC power with a fixed current direction, achieving AC and DC universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the control circuit in the utility model;

[0026] Figure 2 This is a schematic diagram of the control circuit in the first embodiment of the present utility model;

[0027] Figure 3 This is a schematic diagram of the control circuit in the second embodiment of the present utility model;

[0028] Figure 4 This is a schematic diagram of the control circuit in the third embodiment of the present utility model;

[0029] Figure 5 is a cross-sectional view of the DC contactor of the present invention;

[0030] Figure 6 1 is an exploded schematic diagram of the DC contactor of the present invention;

[0031] Figure 7 It is a structural diagram of the cover plate and the plug in the present invention;

[0032] Figure 8 It is a schematic diagram of the coordination of the control circuit, electromagnetic system and contact system in the present invention;

[0033] Figure 9 yes Figure 8 Side view of;

[0034] Figure 10 yes Figure 8 A top view of

[0035] Figure 11 It is a structural diagram of the control circuit (including the first indicator light and the second indicator light);

[0036] Figure 12 yes Figure 11 Side view of

[0037] Figure 13 yes Figure 11 A top view of

[0038] Figure 14 It is a structural diagram of the control circuit (including display screen);

[0039] Figure 15 yes Figure 14 Side view of

[0040] Figure 16 yes Figure 14 A top view of

[0041] Reference numerals:

[0042] 1-cover, 2-plug, 3-contact system, 4-electromagnetic system, 5-control circuit, 501-first circuit board, 502-second circuit board, 503-first indicator light, 504-second indicator light, 505-thermal sensor, 506-connecting pin, 507-lead pin, 508-display screen, 6-base. DETAILED DESCRIPTION

[0043] The following embodiments are provided in conjunction with the accompanying drawings to further illustrate the specific implementation of the control circuit and DC contactor of the present invention. The control circuit and DC contactor of the present invention are not limited to the description of the following embodiments.

[0044] The DC contactor generally includes a shell and an electromagnetic system 4 and a contact system 3 arranged in the shell, wherein the electromagnetic system 4 includes a coil assembly and a moving assembly driven by the coil assembly, the coil assembly generally includes a coil skeleton and a coil wound on the outside of the coil skeleton, the moving assembly includes at least a moving iron core that can be driven by the coil, the contact system 3 is arranged on the electromagnetic system 4, the contact system 3 includes a contact chamber, a contact mechanism and an arc extinguishing assembly are arranged in the contact chamber, the contact mechanism includes a main contact group and an auxiliary contact group, the main contact group includes an active contact and a main static contact, the main static contact is fixedly arranged in the contact chamber, and the active contact is driven by the moving assembly of the electromagnetic system 4 to contact or separate with the main static contact, thereby realizing the contact. The auxiliary contact group includes an auxiliary moving contact and an auxiliary static contact. The auxiliary moving contact is arranged on the active contact and contacts or separates with the auxiliary static contact fixed in the contact chamber as the active contact moves. The contact or separation of the auxiliary moving contact and the auxiliary static contact can be used to feedback the working status of the main contact mechanism. Specifically, since the auxiliary moving contact and the auxiliary static contact are usually connected to the external electrical circuit of the contactor, when the auxiliary moving contact and the auxiliary static contact are in contact, the circuit is connected to generate an electrical signal in the electrical circuit. Conversely, when the circuit is disconnected, there is no electrical signal in the electrical circuit. That is, when an electrical signal is generated in the electrical circuit, it is considered that the main contact group is in contact. When there is no electrical signal in the electrical circuit, it is considered that the main contact group is separated. The arc extinguishing assembly cooperates with the contact mechanism to extinguish the arc generated when the main contact is opened.

[0045] A control circuit 5 is also provided in the housing. The electromagnetic system 4 drives the contact mechanism to perform opening and closing actions, which is driven by the control circuit 5. Usually, the control circuit 5 usually includes an action circuit and a main control circuit. The connection and disconnection of the action circuit are controlled by the switch tube, so that the coil connected to the action circuit is connected or disconnected; the main control circuit includes a drive circuit, and the drive circuit controls the conduction and disconnection of the switch tube in the action circuit. The main control circuit is integrated on the circuit board. The main control circuit includes a circuit board and an MCU controller arranged on the circuit board. The coil of the electromagnetic system 4 is connected to the circuit board, thereby being connected to the main control circuit.

[0046] The improvement of the present application is that it also includes a voltage sampling circuit and a current sampling circuit. The voltage sampling circuit is connected between the main control circuit and the action circuit to collect the voltage signal of the coil, and the current sampling circuit is connected between the main control circuit and the action circuit to collect the current signal flowing through the coil. The main control circuit is connected to a feedback unit, and the feedback unit is used to feedback the operating status of the coil and the contact mechanism.

[0047] In this way, the main control circuit obtains the real-time working current and working voltage of the coil through the voltage sampling circuit and the current sampling circuit, and can obtain the operating status data of the coil in time, and then feedback the operating status of the coil and the contact mechanism through the feedback unit, so that when a fault occurs, the fault can be eliminated quickly and accurately.

[0048] Preferably, the main control circuit obtains the real-time working temperature of the coil through the current sampling circuit, the voltage sampling circuit and the resistance calculation of the coil. The main control circuit is also connected to an auxiliary circuit, and the auxiliary circuit is connected to a thermistor 505. The thermistor 505 is used to obtain the temperature of the contact chamber in the working state. Usually, the thermistor 505 is a thermistor, and the thermistor 505 is arranged close to the contact chamber. The main control circuit calculates the temperature of the contact chamber based on the change in its resistance value.

[0049] Furthermore, the feedback unit includes an indicator light and / or a display screen 508. The indicator light is connected between the coil and the main control circuit and is used to feedback the operating status of the coil. For example, the indicator light can indicate whether the coil is connected or disconnected by turning on and off. The indicator light can also be connected between the contact mechanism and the main control circuit and is used to feedback the operating status of the contact mechanism. For example, the indicator light can indicate whether the contact mechanism is connected or disconnected by turning on and off. It should be noted that the indicator lights corresponding to the coil and the contact mechanism are indicator lights with different display states, such as different colors. Of course, the indicator light can also be used to indicate abnormal temperature of the coil or contact chamber. For example, the indicator light corresponding to the coil or contact mechanism flashes to indicate abnormal temperature. The display screen 508 is connected to the main control circuit, and the main control circuit controls the content displayed on the display screen 508. For example, the operating parameters of the coil or contact mechanism are displayed in text and / or numbers. For example, the operating current, operating voltage, resistance, and temperature of the coil and the operating current, operating voltage, resistance, and contact chamber temperature of the contact mechanism are displayed on the display screen 508.

[0050] Furthermore, the display screen 508 can be integrated with the main control circuit on the same circuit board, which is convenient for intuitive observation of the operating status of the contact mechanism and the coil. It can also be the display screen 508 on an external background device. When the display screen 508 is located on the external background device, the feedback unit also includes a communication unit. The main control circuit is connected to the external background device through the communication unit to feedback the temperature of the contact chamber and the operating current, operating voltage and operating temperature of the coil. The data transmission between the communication unit and the external background device can be wired transmission or wireless transmission.

[0051] Furthermore, the control circuit may also include an EMC circuit, a rectifier circuit, and a power module. The EMC circuit can isolate the external electromagnetic interference to the internal circuit and the external electromagnetic interference during its own operation, thereby improving the stability and reliability of the system. The rectifier circuit facilitates the realization of AC and DC universality, and there is no need to distinguish between positive and negative poles when DC input is used. The power module can supply power to the main control circuit separately.

[0052] Combine Figure 1 、 2 A first embodiment of the control circuit 5 is provided.

[0053] like Figure 1 、 2 As shown, the control circuit 5 includes an action loop and a main control circuit, and the main control circuit is connected to a drive circuit, wherein the action loop is connected to a switch tube and a coil in the electromagnetic system 4, and the switch tube controls the conduction and disconnection of the action loop, thereby connecting or disconnecting the coil. The main control circuit is integrated on a circuit board, and an MCU controller is provided on the circuit board. The main control circuit controls the connection and disconnection of the switch tube through the drive circuit. Usually, the MCU controller can preset thresholds of relevant parameters. After the MCU controller compares and analyzes the acquired parameters with the relevant thresholds, the action program stored in the MCU controller is executed accordingly, thereby controlling the connection and disconnection of the switch tube through the drive circuit. The parameter thresholds are preset in the MCU controller, and the functions of processing, analyzing, comparing and judging the acquired parameters, storing and running relevant programs, etc. can adopt existing technologies.

[0054] like Figure 2 As shown, the control circuit 5 is further connected to an EMC circuit and a rectifier circuit. The external power supply is connected to the action loop through the EMC circuit and the rectifier circuit in sequence. The EMC circuit isolates the external electromagnetic interference to the internal part and the external electromagnetic interference during its own operation, thereby improving the stability and reliability of the system. The rectifier circuit rectifies the external input AC power or DC power into a DC power supply with a fixed current direction, thereby achieving universal AC and DC, and there is no need to distinguish between positive and negative poles when DC input is used. Of course, the EMC circuit and the rectifier circuit can also be used to connect to the action loop.

[0055] In this embodiment, the control circuit 5 also includes a power supply module, which supplies power to the main control circuit and the drive circuit respectively. The power supply module is connected to the output end of the rectifier circuit. The power supply module steps down and stabilizes the voltage input by the rectifier circuit to form a low-voltage signal that can supply power to the main control circuit and the drive circuit. Of course, when the control circuit 5 also includes other functional circuits that require power supply, they can also be powered by the power supply module.

[0056] The main control circuit is also connected to a sampling unit, which obtains relevant parameters of the electromagnetic system 4 operation. In this embodiment, Figure 1 、 2As shown, the sampling unit includes a current sampling circuit and a voltage sampling circuit. The current sampling circuit and the voltage sampling circuit respectively collect the working voltage and working current of the coil in the working state from the action loop. Correspondingly, the starting threshold preset in the MCU controller corresponds to the working voltage of the coil. The main control circuit judges whether to turn on the action loop based on the comparison result of the working voltage of the coil and the starting threshold. When the action loop is turned on, current flows through the coil of the electromagnetic system 4. At this time, the electromagnetic system 4 can drive the contact mechanism. When the action loop is disconnected, the coil of the electromagnetic system 4 has no current. At this time, the electromagnetic system 4 cannot drive the contact mechanism; the operating threshold preset in the MCU controller corresponds to the working current of the coil. The main control circuit judges whether it is necessary to execute the stored coincidence program or protection program based on the comparison result of the working current of the coil and the operating threshold. The coincidence program is used to drive the electromagnetic system 4 to perform a closing action, and the protection program is used to drive the electromagnetic system 4 to perform an opening action and maintain it in the opening state.

[0057] The working process of this embodiment is as follows: the main control circuit obtains the working voltage of the coil from the action circuit through the voltage sampling circuit, and compares it with the preset starting threshold value. When the working voltage of the coil is greater than the starting threshold value, the main control circuit turns on the switch tube through the drive circuit, thereby turning on the action circuit; when the action circuit is turned on, the main control circuit obtains the working current of the coil from the action circuit through the current sampling circuit, and compares it with the preset operating threshold value. When the working current of the coil is less than the operating threshold value, it indicates that there is an abnormality in the action circuit, that is, the coil is operating abnormally, and the electromagnetic system 4 has not completed the closing of the contact mechanism. The main control circuit executes the reclosing program, and the reclosing program drives the electromagnetic system 4 to close again. When the working current of the coil is greater than the operating threshold value, it indicates that there is a short circuit fault in the coil. The main control circuit executes the protection program, and the electromagnetic system 4 drives the contact mechanism to open and maintain it in the open state to avoid serious consequences. When the working voltage of the coil is less than the starting threshold value, the main control circuit turns off the switch tube through the drive circuit, thereby disconnecting the action circuit.

[0058] A feedback unit is also connected to the main control circuit. In this embodiment, the feedback unit includes a first indicator light 503 and a second indicator light 504. The first indicator light 503 and the second indicator light 504 are light-emitting diodes of different colors. For example, the first indicator light 503 is a green light-emitting diode and the second indicator light 504 is a red light-emitting diode. Preferably, the first indicator light 503 and the second indicator light 504 are arranged on the circuit board of the integrated main control circuit. The first indicator light 503 is connected to the coil to indicate the working status of the coil, that is, the first indicator light 503 is always on to indicate that the coil is connected, and the first indicator light 503 is off to indicate that the coil is disconnected. The second indicator light 504 is connected to the contact mechanism to indicate the working status of the contact mechanism. Preferably, the second indicator light 504 is connected to the auxiliary contact assembly in the contact mechanism, that is, the second indicator light 504 is always on to indicate that the contact mechanism is connected, and the second indicator light 504 is off to indicate that the contact mechanism is disconnected. Of course, the second indicator light 504 can also be connected to the main contact, for example, the second indicator light 504 can be connected to the main static contact in the main contact group.

[0059] In this embodiment, at least the main control circuit is integrated on a circuit board, and the lead end of the electromagnetic system 4 is welded to the circuit board, thereby connecting the control circuit 5 to the electromagnetic system 4. In addition, a lead pin 507 is provided on the circuit board, and the lead pin 507 is used to connect to external equipment.

[0060] Combine Figure 1 、 3 A second embodiment of the control circuit 5 is provided.

[0061] like Figure 1 、 3 As shown, the control circuit 5 includes an action circuit, a main control circuit and a drive circuit, and the main control circuit and the drive circuit are powered by a power module, wherein the action circuit, the power module and the drive circuit are the same as those in the first embodiment, and the action circuit can be connected to the same EMC circuit and rectifier circuit as in the first embodiment, or the EMI circuit and rectifier circuit.

[0062] Similar to the first embodiment, the main control circuit is also integrated on a circuit board, on which an MCU controller is provided, so that the main control circuit can output a control signal to control the drive circuit, thereby controlling the connection and disconnection of the switch tube. The MCU controller also has preset thresholds for relevant parameters. After the MCU controller compares and analyzes the acquired parameters with the relevant thresholds, it executes the action program stored in the MCU controller accordingly, thereby controlling the connection and disconnection of the switch tube through the drive circuit. The MCU controller presets parameter thresholds, processes and analyzes the acquired parameters, compares and judges, stores and runs relevant programs, and other functions, and can adopt existing technologies.

[0063] The main control circuit is connected to a sampling unit and a feedback unit, and the sampling unit obtains relevant parameters of the operation of the electromagnetic system 4. In this embodiment, in addition to the current sampling circuit and voltage sampling circuit that are the same as those in the first embodiment, the sampling unit also includes a temperature sampling circuit. In this embodiment, the temperature sampling circuit includes an auxiliary circuit. Preferably, the auxiliary circuit is integrated on another circuit board. A thermistor 505 is connected to the auxiliary circuit. Preferably, the thermistor 505 can be coated with thermal grease. The thermistor 505 is arranged near the contact chamber and is used to collect the contact chamber temperature in the working state. The thermistor 505 is usually a thermistor. The temperature of the contact chamber is obtained by obtaining the change in its resistance and performing temperature compensation. The feedback unit includes a first indicator light 503 and a second indicator light 504, wherein the indication function of the first indicator light 503 is the same as that in the first embodiment. In addition to having the same indication function as the first embodiment, the second indicator light 504 is also used to feedback that the contact chamber temperature is in an abnormal state.

[0064] Correspondingly, the MCU controller is preset with the same startup threshold and execution threshold as those in the first embodiment, and its working principle is the same as that in the first embodiment. The difference from the first embodiment is that the MCU controller is also preset with a contact chamber temperature safety value. When the thermistor 505 feedbacks that the temperature of the contact chamber exceeds the contact chamber temperature safety value, the main control circuit outputs a control signal to make the second indicator light 504 flash to indicate that the temperature of the contact chamber is abnormal.

[0065] In this embodiment, the main control circuit and the auxiliary circuit are respectively integrated on two circuit boards, and the two circuit boards are connected together through a connecting pin 506. The control circuit 5 is connected to the electromagnetic system 4 for driving the electromagnetic system 4. In addition, a lead-out pin 507 is provided on the circuit board integrated with the main control circuit, and the lead-out pin 507 cooperates with the housing to be led out for external wiring.

[0066] Combine Figure 1 、 4 A third embodiment of the control circuit 5 is provided.

[0067] like Figure 1 、 4 As shown, the control circuit 5 includes an action circuit and a main control circuit, the main control circuit is connected to a drive circuit, and the main control circuit and the drive circuit are powered by a power module, wherein the action circuit, the power module and the drive circuit are the same as those in the first embodiment, and the action circuit can be connected to the same EMC circuit and rectifier circuit as in the first embodiment, or the EMI circuit and rectifier circuit.

[0068] Similar to the first embodiment, the main control circuit is also integrated on a circuit board, on which an MCU controller is provided, so that the main control circuit can output a control signal to control the drive circuit, thereby controlling the connection and disconnection of the switch tube. The MCU controller also has preset thresholds for relevant parameters. After the MCU controller compares and analyzes the acquired parameters with the relevant thresholds, it executes the action program stored in the MCU controller accordingly, thereby controlling the connection and disconnection of the switch tube through the drive circuit. The MCU controller presets parameter thresholds, processes and analyzes the acquired parameters, compares and judges, stores and runs relevant programs, and other functions, and can adopt existing technologies.

[0069] The main control circuit is connected to a sampling unit and a feedback unit, and the sampling unit obtains relevant parameters of the operation of the electromagnetic system 4. In this embodiment, the sampling unit includes a current sampling circuit, a voltage sampling circuit, and a temperature sampling circuit. The current sampling circuit and the voltage sampling circuit respectively collect the working voltage and working current of the coil in the working state from the action circuit. The temperature sampling circuit includes an auxiliary circuit, wherein the auxiliary circuit is integrated on another circuit board. The auxiliary circuit is connected to a thermistor 505, which is arranged near the contact chamber. The thermistor 505 is typically a thermistor. The main control circuit obtains the temperature of the contact chamber in the working state based on the resistance change of the thermistor and temperature compensation. The temperature sampling circuit also includes a coil temperature sampling circuit, and the temperature sampling circuit obtains the working temperature of the coil. The temperature sampling circuit can also be similar to the auxiliary circuit in the second embodiment, using the thermistor 505 to obtain the coil temperature. In this embodiment, the working temperature of the coil is preferably obtained through the current sampling circuit and the voltage sampling circuit. Specifically, the main control circuit calculates the working temperature of the coil based on the real-time collection of the working current, working voltage, and resistance of the coil, which facilitates real-time and accurate acquisition of the working temperature of the coil.

[0070] The feedback unit includes the same first indicator light 503 and second indicator light 504 as those in the first embodiment. However, the difference from the first embodiment is that the first indicator light 503 is used not only to indicate the connection and disconnection of the coil, but also to indicate abnormal temperature of the coil. The second indicator light 504 is used not only to indicate the connection and disconnection of the contact mechanism, but also to indicate whether there is abnormal temperature in the contact chamber. In addition, the feedback unit includes the first indicator light 503 and the second indicator light 504, and also includes a display screen 508. The display screen 508 is connected to the main control circuit and displays the operating parameters of the coil and the contact mechanism in the form of text or numbers under the control of the main control circuit, such as the working current, working voltage, resistance and temperature of the coil, the working current, working voltage and contact chamber temperature of the contact mechanism, etc. The display screen 508 can be integrated with the main control circuit. On the same circuit board, the display screen 508 is an LED display screen, or it can be a display screen of a background device. The main control circuit controls the display screen 508 to display the working temperature of the coil and the temperature of the contact chamber. When the display screen 508 is a background device arranged outside the DC contactor, the feedback unit is also provided with a communication unit connected to the background device. The communication connection between the communication unit and the background device can be a wired connection or a wireless connection, such as transmission via Bluetooth or WiFi, so that the working temperature of the coil and the temperature of the contact chamber are displayed on the background device. Of course, the shell is configured with a display screen 508 on the circuit board and the external device at the same time, so that the working current, working voltage, resistance and temperature parameters of the coil, and the contact of the contact are displayed on the display screen 508 and / or the background device. Of course, when the display screen 508 is configured, the first indicator light 503 and the second indicator light 504 can be omitted in this embodiment.

[0071] In this embodiment, the starting threshold preset in the MCU controller corresponds to the working voltage of the coil. The main control circuit determines whether to turn on the action circuit based on the comparison result of the working voltage of the coil and the starting threshold. When the action circuit is turned on, current flows through the coil of the electromagnetic system 4. At this time, the electromagnetic system 4 can drive the contact mechanism. When the action circuit is disconnected, the coil of the electromagnetic system 4 has no current, and the electromagnetic system 4 cannot drive the contact mechanism. The operating threshold preset in the MCU controller corresponds to the working current of the coil. The main control circuit determines whether it is necessary to execute the stored coincidence program or protection program based on the comparison result of the working current of the coil and the operating threshold. The coincidence program is used to drive the electromagnetic system 4 to perform the closing action. , the protection program is used to drive the electromagnetic system 4 to perform a tripping action and maintain it in the tripping state. For details of this control process, please refer to the first embodiment; the MCU controller also presets a contact chamber temperature safety value and a coil temperature safety value. When the temperature of the contact chamber is greater than the contact chamber temperature safety value, the main control circuit outputs a control signal to make the second indicator light 504 flash to indicate that the temperature of the contact chamber is abnormal; when the operating temperature of the coil calculated by the MCU controller is greater than the coil temperature safety value, the main control circuit outputs a control signal to drive the first indicator light 503 to flash to indicate that the operating temperature of the coil is abnormal. At the same time, the main control circuit controls the drive circuit to disconnect the switch tube, thereby cutting off the circuit of the action loop to protect the coil.

[0072] In this embodiment, the main control circuit and the auxiliary circuit are respectively integrated on two circuit boards, and the two circuit boards are connected together through a connecting pin 506. The control circuit 5 is connected to the electromagnetic system 4 for driving the electromagnetic system 4. In addition, a lead-out pin 507 is provided on the circuit board integrated with the main control circuit, and the lead-out pin 507 cooperates with the housing to be led out for external wiring.

[0073] like Figure 5-16 As shown, the DC contactor includes a shell, in which an electromagnetic system 4, a contact system 3 and any one of the control circuits 5 mentioned in the above embodiments are arranged. The shell, the electromagnetic system 4 and the contact system 3 can all adopt existing technologies. The control circuit 5 is arranged in the shell and connected to the electromagnetic system 4. At least a circuit board integrating a main control circuit is provided with a lead-out pin 507. After the lead-out pin 507 is led out of the shell, it is correspondingly arranged in the plug 2 of the shell. The lead-out pin 507 corresponds to the plug 2, which is convenient for connection with external equipment.

[0074] like Figure 5 、 6As shown, the housing usually includes a base 6 and a cover 1 that is snapped onto the base 6. The electromagnetic system 4 is fixed on the base 6. The contact system 3 is arranged above the electromagnetic system 4 and closer to the cover 1. The contact system 3 includes a ceramic cover, an arc extinguishing assembly and a contact mechanism. A contact chamber is formed by the interior of the ceramic cover, and the contact mechanism and the arc extinguishing assembly are arranged in the contact chamber; the ceramic cover is installed on the yoke of the contact mechanism, the mounting frame of the contact mechanism is located in the ceramic cover, the arc extinguishing assembly is mounted on the outer wall of the ceramic cover, and two main static contacts and two auxiliary static contacts distributed in a cross shape are provided on the top wall of the ceramic cover. The two main static contacts are symmetrically arranged, and one end of the main static contact passes through the top wall of the ceramic cover and extends into the ceramic cover; the two auxiliary static contacts are symmetrically arranged, and one end of the auxiliary static contact passes through the top wall of the ceramic cover and extends into the ceramic cover. The other ends of the two auxiliary static contacts of the contact system 3 are respectively welded and fixed to the control circuit 5, and the plug 2 is installed in the jack on the housing and electrically connected to the control circuit 5.

[0075] like Figure 8-16 As shown, in this embodiment, the control circuit 5 is integrated on the circuit board. When the control circuit 5 includes an auxiliary circuit for collecting temperature signals, the control circuit 5 is preferably arranged on two circuit boards, and the two circuit boards are connected together by a connecting pin 506, that is, the auxiliary circuit for collecting temperature signals is separately integrated on one circuit board, and the rest of the control circuit 5, such as the main control circuit, the drive circuit, etc., are integrated on another circuit board. For the convenience of description, the auxiliary circuit is integrated on the second circuit board 502, and the rest of the control circuit 5 is integrated on the first circuit board 501, wherein the first circuit board 501 is arranged along the side position inside the shell, and the board surface of the first circuit board 501 is parallel to the moving track of the moving component in the electromagnetic system 4, and the second circuit board 502 is arranged along the outside of the contact chamber, that is, it is arranged on the outside of the ceramic cover, so that the thermistor 505 on the auxiliary circuit obtains the temperature of the contact chamber. Figure 8-10 In the figure, the first circuit board 501 and the second circuit board 502 are arranged along two adjacent outer walls of the ceramic cover, the first circuit board 501 and the contact mechanism are arranged side by side outside the contact chamber, the first circuit board 501 is connected to the lead-out end of the electromagnetic system 4, thereby connecting the electromagnetic system 4 and the control circuit 5 together, the second circuit board 502 is located outside the end of the contact chamber away from the electromagnetic system 4, that is, the second circuit board 502 is located outside the ceramic cover near the auxiliary static contact, the second circuit board 502 is connected to the lead-out end of the auxiliary static contact, that is, the second circuit board 502 is connected to the auxiliary static contact, shortening the wiring distance between the second circuit board 502 and the auxiliary static contact, and the thermistor 505 is arranged on the side of the second circuit board 502 facing the contact chamber.

[0076] like Figure 10-13As shown, a first indicator light 503 and a second indicator light 504 are provided on the first circuit. The first indicator light 503 is connected to the lead-out end of the coil, and the second indicator light 504 is connected to the lead-out end of the auxiliary static contact. Figure 14-16 As shown, when the control circuit 5 is configured with a display screen 508, the display screen 508 is provided on the first circuit board 501. In this embodiment, the first indicator light 503, the second indicator light 504 and the display screen 508 are provided on the side of the first circuit board 501 facing away from the electromagnetic system 4, that is, the first indicator light 503, the second indicator light 504 and the display screen 508 face the side wall of the shell for easy observation. Of course, the first circuit board 501 can be configured with the first indicator light 503, the second indicator light 504 and the display screen 508 at the same time; in addition, the first circuit board 501 is provided with a lead pin 507, which extends from the side of the shell and cooperates with the plug 2 of the shell. Figure 5-7 In the embodiment, the plug 2 is arranged on the cover plate to facilitate the connection between the control circuit 5 and the external device.

[0077] Furthermore, the shell is provided with an observation area (not shown), which corresponds to the first indicator light 503 and the second indicator light 504 and is used to observe the status of the first indicator light 503 and the second indicator light 504. When a display screen 508 is configured, the observation area may also correspond to the display screen 508. Furthermore, in order to take into account the sealing of the shell and the internal space, an optical element may be configured in the shell. For example, the optical element is a refractive sheet, a convex lens, etc. The optical element is located between the observation window and the feedback unit to facilitate observation of the first indicator light 503, the second indicator light 504 and the display screen 508. Preferably, a refractive element is also provided in the shell, and the refractive element cooperates with the indicator light and / or the display screen 508 to adjust the display direction of the display result. For example, when the refractive element is not provided, the text and / or numbers displayed on the display screen 508 cannot be displayed in the observation area or the display result direction is not conducive to observation. After the refractive element is installed, the parameter information on the display screen 508 is displayed in the observation area in an upright direction through the refractive element.

[0078] It should be noted that, except for the control circuit 5 , the rest of the DC contactor can adopt existing technologies.

[0079] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, or are conventionally placed directions or positional relationships during use. They are intended solely for ease of description and do not imply that the devices or components referred to must have a specific direction. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used solely for distinction and description and should not be construed as indicating relative importance.

[0080] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A control circuit comprising an action circuit and a main control circuit, wherein the action circuit is turned on and off by a switch tube, so that a coil of a DC electromagnetic system (4) connected to the action circuit is turned on or off, and the main control circuit is connected to a drive circuit, and the drive circuit controls the conduction and disconnection of the switch tube, characterized in that: It also includes a voltage sampling circuit and a current sampling circuit. The voltage sampling circuit is connected between the main control circuit and the action circuit to collect the voltage signal of the coil. The current sampling circuit is connected between the main control circuit and the action circuit to collect the current signal flowing through the coil. The main control circuit is connected to a feedback unit, which is used to feedback the operating status of the coil and the contact mechanism.

2. The control circuit according to claim 1, wherein: The main control circuit is further connected to an auxiliary circuit, and the auxiliary circuit is connected to a thermal sensor (505). The thermal sensor (505) is used to obtain the temperature of a contact chamber provided with a contact mechanism in a working state.

3. The control circuit according to claim 1, wherein: The feedback unit includes an indicator light and / or a display screen (508), wherein the indicator light is connected between the coil and the main control circuit, and / or the indicator light is connected to the contact mechanism and the main control circuit, and the display screen (508) is connected to the main control circuit.

4. The control circuit according to claim 1 or 3, characterized in that: The feedback unit further includes a communication unit, which is connected to an external background device for feeding back the operating status of the coil and the contact chamber.

5. The control circuit according to claim 1, wherein: It also includes an EMC circuit and a rectifier circuit. The external power supply is connected to the action circuit after passing through the EMC circuit and the rectifier circuit in sequence.

6. The control circuit according to claim 5, wherein: It also includes a power supply module, which supplies power to the main control circuit and the drive circuit, and is connected to the output end of the rectifier circuit.

7. The control circuit according to claim 1, wherein: The main control circuit includes a circuit board and an MCU controller, the feedback unit includes an indicator light and / or a display screen arranged on the circuit board, and the circuit board is provided with a lead pin (507).

8. A DC contactor comprising a housing, wherein a contact system (3) and an electromagnetic system (4) are arranged in the housing, characterized in that: A control circuit (5) according to any one of claims 1 to 7 is also provided in the housing, and the coil in the electromagnetic system (4) is connected to the control circuit (5).

9. The DC contactor according to claim 8, characterized in that: The device also includes a contact chamber, wherein the contact mechanism includes a main contact group and an auxiliary contact group arranged in the contact chamber, wherein the main contact group includes an active contact and a main static contact that cooperate with each other, wherein the active contact is driven by the electromagnetic system (4) to make contact with or separate from the main static contact, and wherein the auxiliary contact group includes an auxiliary moving contact and an auxiliary static contact, wherein the auxiliary moving contact moves with the active contact to make contact with or separate from the auxiliary static contact. The feedback unit comprises a first indicator light (503) and a second indicator light (504), wherein the first indicator light (503) is connected to the coil, and the second indicator light (504) is connected to the auxiliary contact group.

10. The DC contactor according to claim 9, characterized in that: The housing is provided with an observation area, and the observation area is used to observe the states of the first indicator light (503) and the second indicator light (504).

11. The DC contactor according to claim 10, characterized in that: A refractive element is provided in the housing, and the refractive element cooperates with a display screen (508) in the feedback unit.

12. The DC contactor according to claim 10, characterized in that: The electromagnetic system (4) includes a coil assembly and a moving assembly driven by the coil assembly. The contact system (3) is arranged above the electromagnetic system (4). The contact system (3) includes a ceramic housing. A contact mechanism is provided in the ceramic housing as a contact chamber. The control circuit (5) comprises a first circuit board (501) and a second circuit board (502) connected to each other, wherein the first circuit board (501) and the second circuit board (502) are arranged on adjacent sides outside the contact chamber, the first circuit board (501) is arranged in a direction parallel to the track of the moving component, and the first circuit board (501) and the contact mechanism are arranged side by side, and the second circuit board (502) is arranged outside the contact chamber away from one end of the electromagnetic system (4).

13. The DC contactor according to claim 12, characterized in that: A first indicator light (503) and a second indicator light (504) are provided on the first circuit board (501), and a thermal sensor (506) is provided on a side of the second circuit board (502) facing the contact chamber.

14. The DC contactor according to claim 12, characterized in that: The first circuit board (501) is provided with a lead-out pin (507), which is led out of the housing and is arranged in a plug (2) of the housing.

Images