Contactor coil control circuit and contactor

Abstract

The invention relates to the technical field of contactor coil control, and discloses a contactor coil control circuit and a contactor, and the control circuit comprises a position detection module, a control module, an energy-saving switch module and an auxiliary switch module. The position detection module is used for detecting the attraction state of a magnet of the contactor; the output end of the auxiliary switch module is connected with a coil of a contactor; when the auxiliary switch module is initially electrified, the auxiliary switch module is in a conducting state, so that a coil of the contactor is electrified; the input end of the control module is connected with the output end of the position detection module; the control module is used for controlling the auxiliary switch module to be switched off and the energy-saving switch module to be switched on when a magnet of the contactor is attracted so as to maintain the power-on state of a coil of the contactor; and the control module is also used for controlling the energy-saving switch module to be switched off and the auxiliary switch module to be switched on when the magnet of the contactor is not attracted, so that the coil of the contactor is attracted again. The working reliability of the coil of the contactor can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of contactor coil control, and in particular to a control circuit of a contactor coil and a contactor. Background Art

[0002] Contactor is one of the important components in automatic control system. It is often used in the control end of motors, factory equipment, electric heaters, machine tools and various power units because it can quickly cut off the AC and DC main circuits and can frequently connect large current control.

[0003] The contactor consists of an electromagnetic system (iron core, static iron core, electromagnetic coil), a contact system (normally open contact and normally closed contact) and an arc extinguishing device. When the current passes through the electromagnetic coil to generate a magnetic field, the contacts are attracted, thereby achieving the purpose of controlling the load electrical appliance.

[0004] In order to achieve the purpose of energy saving, the currently used electronic AC and DC contactors have an input voltage that is connected in series with a MOS tube and then directly enters the coil of the contactor. When only energy saving is considered, the reliability of the contactor coil will be reduced. Summary of the invention

[0005] In view of this, an embodiment of the present application provides a control circuit and a contactor for a contactor coil, which can effectively solve the problem of low reliability of the contactor coil.

[0006] In a first aspect, an embodiment of the present application provides a control circuit for a contactor coil, including a position detection module, a control module, an energy-saving switch module, and an auxiliary switch module;

[0007] The input end of the control module is connected to the output end of the position detection module; the output end of the control module is connected to the input end of the energy-saving switch module and the input end of the auxiliary switch module; the output end of the energy-saving switch module and the output end of the auxiliary switch module are both used to connect the coil of the contactor;

[0008] The auxiliary switch module is used to be in a conducting state when the control circuit is initially powered on, so as to energize the coil of the contactor;

[0009] The position detection module is used to detect the attraction state of the magnet of the contactor;

[0010] The control module is used to control the auxiliary switch module to be disconnected and the energy-saving switch module to be turned on when the magnet of the contactor is attracted, so as to maintain the energized state of the coil of the contactor; and, when the magnet of the contactor is not attracted, control the energy-saving switch module to be disconnected and the auxiliary switch module to be turned on, so as to make the coil of the contactor attracted again.

[0011] In some embodiments, the control circuit further includes a voltage acquisition module, and the output end of the voltage acquisition module is connected to the processing unit of the control module;

[0012] The voltage acquisition module is used to collect the working voltage of the contactor;

[0013] The control module is further used to adjust the duty cycle of a control signal used to control the energy-saving switch module according to the working voltage.

[0014] In some embodiments, the auxiliary switch module includes a current limiting resistor and a first relay;

[0015] The first end of the current limiting resistor is connected to the fixed contact of the first relay; the second end of the current limiting resistor is used to connect the coil of the contactor; the normally closed contact of the first relay is grounded;

[0016] A first end of the coil of the first relay is connected to an output end of the control module, and a second end of the coil of the first relay is grounded.

[0017] In some embodiments, the energy-saving switch module includes a MOS tube and a diode;

[0018] The gate of the MOS tube is connected to the output end of the control module; the source of the MOS tube is grounded, and the drain of the MOS tube is connected to the coil of the contactor;

[0019] The anode of the diode is connected to the source of the MOS tube, and the cathode of the diode is connected to the drain of the MOS tube.

[0020] In some embodiments, the position detection module includes a travel switch, the distance between the travel switch and the magnet of the contactor is a set value, and the travel switch is used to detect the attraction state of the magnet of the contactor.

[0021] In some embodiments, the control module includes a processing unit and a driving unit;

[0022] The input end of the processing unit is connected to the output end of the position detection module; the processing unit receives the pull-in state and processes the pull-in state to obtain a control signal;

[0023] The input end of the driving unit is connected to the output end of the processing unit; the driving unit drives the energy-saving switch module or the auxiliary switch module to conduct according to the control signal.

[0024] In some embodiments, the control circuit further includes a power management module and a voltage processing module;

[0025] The power supply module adopts an AC power supply or a DC power supply; the power supply module provides input voltage for the control circuit;

[0026] The input end of the voltage processing module is connected to the output end of the power module; the voltage processing module is used to process the input voltage to obtain a plurality of different operating voltages.

[0027] In some embodiments, the voltage processing module includes a filtering unit and a plurality of voltage reduction units;

[0028] The input end of the filter unit is connected to the output end of the power module; the output end of the filter unit is connected to the contactor and the input end of the voltage acquisition module; the filter unit is used to filter the input voltage to obtain a filtered voltage, and use the filtered voltage as the working voltage of the contactor;

[0029] The input end of each of the step-down units is connected to the output end of the filtering unit, and the output ends of different step-down units are respectively connected to the power supply end of the position detection module, the power supply end of the control module and the power supply end of the voltage acquisition module; the step-down unit is used to step down the filtered voltage to obtain multiple voltage signals; different voltage signals are respectively used as working voltages of the position detection module, the control module and the voltage acquisition module.

[0030] In some embodiments, the control circuit also includes an output module; the output module includes a second relay; the coil of the second relay is connected to the output end of the control module, and the switch contacts of the second relay serve as the output end of the output module for connecting to a host computer.

[0031] In a second aspect, an embodiment of the present application provides a contactor, including a control circuit for the contactor coil described above.

[0032] The embodiments of the present application have the following beneficial effects:

[0033] The control circuit of the contactor coil of the present application can be powered on quickly during the initial power-on. When the contactor coil is powered on, the contactor magnet is attracted, and the contactor coil is switched to the energy-saving switch module to maintain the power-on state of the contactor coil, thereby achieving the effect of energy saving. When the control circuit is abnormal or the external force causes the contactor magnet to be disconnected (i.e., not attracted), switching to the auxiliary switch module can ensure that the contactor coil is quickly powered on again. Therefore, the auxiliary switch module can be used normally without affecting the circuit board damage, and the load equipment connected to the contactor will not be shut down. Moreover, through the mutual cooperation of the auxiliary switch module and the energy-saving switch module, the contactor coil can be kept in the power-on state, thereby ensuring the reliability of the contactor coil operation. In addition, the position detection module detects the contactor attraction state, realizes the control logic closed loop, and avoids the contactor being unable to quickly resume attraction after being released due to the influence of external force during the use of the contactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram showing the principle structure of a control circuit of a contactor coil according to an embodiment of the present application is shown;

[0036] Figure 2 A circuit connection diagram of a control circuit of a contactor coil according to an embodiment of the present application is shown.

[0037] Description of main component symbols:

[0038] 10-power supply module; 20-voltage processing module; 21-filter unit; 22-step-down unit; 30-position detection module; 40-control module; 41-processing unit; 42-drive unit; 50-voltage acquisition module; 60-output module; 70-energy-saving switch module; 80-auxiliary switch module; 90-contactor; 91-magnet; 92-coil. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0040] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0041] Hereinafter, the terms "including", "having" and their cognates that can be used in various embodiments of the present application are intended only to indicate specific features, numbers, steps, operations, elements, components or a combination of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or a combination of the foregoing items or increasing the possibility of one or more features, numbers, steps, operations, elements, components or a combination of the foregoing items. In addition, the terms "first", "second", "third" and the like are only used to distinguish descriptions and cannot be understood as indicating or implying relative importance.

[0042] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present application.

[0043] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0044] At present, the voltage at the input end of the electronic AC / DC energy-saving contactor is first rectified before entering the coil. The coil of the contactor is connected in series with a MOS tube, and the on and off of the MOS tube is controlled by a single-chip microcomputer to change the effective value of the voltage at both ends of the coil of the contactor, thereby reducing the current size when the coil of the contactor is closed, thereby achieving the purpose of energy saving; but due to the lack of monitoring of the coil of the contactor, it is impossible to determine whether there is a release caused by external force during the working process, and the contactor coil cannot be restored to work after being damaged; for this reason, the present application proposes a control circuit and a contactor for the contactor coil.

[0045] The control circuit of the contactor coil is described below in conjunction with some specific embodiments.

[0046] Figure 1 A schematic diagram of the principle structure of a control circuit of a contactor coil in an embodiment of the present application is shown. Figure 2A connection diagram of the control circuit of the contactor coil of the embodiment of the present application is shown. Exemplarily, the control circuit of the contactor coil includes a position detection module 30, a control module 40, an energy-saving switch module 70 and an auxiliary switch module 80.

[0047] The position detection module 30 is used to detect the attraction state of the magnet 91 of the contactor 90; the output end of the auxiliary switch module 80 is used to connect the coil 92 of the contactor 90; the auxiliary switch module 80 is used to put the auxiliary switch module 80 in the on state when the control circuit is initially powered on, so as to energize the coil 92 of the contactor 90.

[0048] The input end of the control module 40 is connected to the output end of the position detection module 30; the output end of the control module 40 is connected to the input end of the energy-saving switch module 70 and the input end of the auxiliary switch module 80; the control module 40 is used to control the auxiliary switch module 80 to be disconnected and the energy-saving switch module 70 to be turned on when the magnet 91 of the contactor 90 is attracted, so as to maintain the power-on state of the coil 92 of the contactor 90; and, when the magnet 91 of the contactor 90 is not attracted, control the energy-saving switch module 70 to be disconnected and the auxiliary switch module 80 to be turned on, so that the coil 92 of the contactor 90 is attracted again.

[0049] The control circuit of the contactor coil of this embodiment can enable the contactor coil to be quickly powered on when initially powered on through the mutual cooperation of the auxiliary switch module and the energy-saving switch module. The principle is that the contactor coil is connected in parallel with a freewheeling diode, and the delayed release time after power failure is 60-150ms. The operation time interval of controlling the disconnection of the auxiliary switch module and the conduction of the energy-saving switch module is less than the delayed release time after power failure, so the contactor can be continuously powered on during the switching process. Therefore, when the contactor coil is powered on, the contactor magnet is attracted, and the energy-saving switch module is switched to work to maintain the contactor coil powered on, thereby achieving energy-saving effects. In addition, when the control circuit is abnormal or the external force causes the contactor magnet to be disconnected (i.e., not attracted), the contactor coil can be powered on again by switching to the auxiliary switch module again, so that the magnet is attracted again. In other words, even if the control circuit is abnormal, the contactor coil can still be guaranteed to maintain the powered on state, thereby ensuring the reliability of the contactor coil operation.

[0050] In one embodiment, if Figure 2 As shown, the auxiliary switch module 80 includes a current limiting resistor R and a first relay J1; the first end of the current limiting resistor R is connected to the fixed contact of the first relay J1; the second end of the current limiting resistor R is used to connect the coil of the contactor; the normally closed contact of the first relay J1 is grounded; the first end of the coil of the first relay J1 is connected to the output end of the control module, and the second end of the coil of the first relay J1 is grounded.

[0051] The auxiliary switch module of this embodiment includes a current limiting resistor and a first relay, with fewer components, low cost, and simple control. As other implementations, the auxiliary switch module may also include other types of switch components and auxiliary resistors, capacitors, etc.; as long as the auxiliary switch can be turned on at the initial power-on and can meet the subsequent switching control.

[0052] In some embodiments, the energy-saving switch module 70 includes a MOS tube and a diode; the gate of the MOS tube is connected to the output end of the control module 40; the source of the MOS tube is grounded, and the drain of the MOS tube is connected to the coil of the contactor; the anode of the diode is connected to the source of the MOS tube, and the cathode of the diode is connected to the drain of the MOS tube.

[0053] The energy-saving switch module of this embodiment includes MOS tubes and diodes, which have few components, low cost, and simple control. As other implementations, the energy-saving switch module can also include other types of switch components as long as the energy consumption is lower than that of the auxiliary switch module.

[0054] In some embodiments, the position detection module 30 includes a travel switch, the distance between the travel switch and the magnet of the contactor is a set value, and the travel switch is used to detect the attraction state of the magnet of the contactor.

[0055] Exemplarily, the travel switch is arranged inside the contactor, and when the magnet is attracted, it will squeeze the travel switch, so the travel switch can detect the attracted state of the magnet of the contactor. As another implementation, the position detection module can also use a position sensor, specifically a contact sensor; the present application does not specifically limit the detector of the position detection module, and it only needs to be able to accurately detect the attracted state of the magnet of the contactor.

[0056] In some embodiments, the control module 40 includes a processing unit 41 and a driving unit 42; the input end of the processing unit 41 is connected to the output end of the position detection module 30; the processing unit 41 receives the attraction state, and processes the attraction state to obtain a control signal; the control signal is a PWM pulse signal; the input end of the driving unit 42 is connected to the output end of the processing unit 41; the driving unit 42 drives the energy-saving switch module 70 or the auxiliary switch module 80 to turn on according to the control signal.

[0057] In some embodiments, the control circuit of the coil of the contactor also includes a voltage acquisition module 50; the voltage acquisition module 50 is used to acquire the working voltage of the contactor; the output end of the voltage acquisition module 50 is connected to the processing unit 41 of the control module 40; so that the processing unit 41 adjusts the duty cycle of the control signal according to the working voltage of the contactor 90.

[0058] The higher the working voltage of the contactor obtained by sampling, the smaller the duty cycle is adjusted; for example, the collected working voltage is 100-250V, and the corresponding duty cycle is 100%-40%. Therefore, the control module not only controls the energy-saving switch module to be turned on or the auxiliary switch module to be turned on according to the pull-in state obtained by the position detection module, but also adjusts the control duty cycle according to the working voltage of the contactor sampled by the voltage acquisition module, thereby reducing the energy consumption of the control circuit.

[0059] In some embodiments, the control circuit of the contactor coil also includes a power supply module 10 and a voltage processing module 20; the power supply module 10 adopts an AC power supply or a DC power supply; the power supply module 10 provides an input voltage for the control circuit; the input end of the voltage processing module 20 is connected to the output end of the power supply module 10; the voltage processing module 20 is used to process the input voltage to obtain multiple different working voltages.

[0060] Exemplarily, the voltage processing module 20 includes a filtering unit 21 and a plurality of step-down units 22; the input end of the filtering unit 21 is connected to the output end of the power module 10; the output end of the filtering unit 21 is connected to the input end of the contactor 90 and the voltage acquisition module 50; the filtering unit 21 filters the input voltage to obtain a filtered voltage, and uses the filtered voltage as the working voltage of the contactor; the input end of each step-down unit 22 is connected to the output end of the filtering unit 21, and the output ends of different step-down units 22 are respectively connected to the power end of the position detection module 30, the power end of the control module 40 and the power end of the voltage acquisition module 50; the step-down unit 22 is used to step down the filtered voltage to obtain a plurality of voltage signals; different voltage signals are respectively used as the working voltages of the position detection module 30, the control module 40 and the voltage acquisition module 50.

[0061] In this embodiment, the filtering unit includes an EMI filter, and EMI (Electromagnetic) can effectively prevent external electromagnetic interference from entering the control circuit through the power line, and can also prevent the electromagnetic interference generated by the device itself from entering the power grid through the power line and being transmitted to other sensitive devices.

[0062] The filtering unit of this embodiment includes an MEI filter. As another implementation, an RC filtering structure may also be used. This application does not limit the specific structure of the filtering unit, as long as it can filter the interference signal of the voltage signal.

[0063] In some embodiments, the control circuit of the contactor coil also includes an output module 60; the output module 60 includes a second relay J2; the coil of the second relay J2 is connected to the output end of the control module 40, and the switch contact of the second relay J2 serves as the output end of the output module 60 for connecting to a host computer.

[0064] Exemplarily, the second relay J2 is a single-pole double-throw relay. When the electronic part of the circuit board is damaged or the coil of the contactor is open due to the failure of the magnet to be attracted, the output signal of the single-pole double-throw relay to the host computer or PLC can detect the abnormality of the contactor, which is convenient for maintenance.

[0065] The AC / DC voltage signal is filtered and rectified to supply power to the contactor. The filtered voltage (high voltage signal) is then stepped down to supply power to the control module, position detection module, and voltage acquisition module. The relay J1 in the auxiliary switch module is a normally closed relay. After power-on, the voltage signal passes through the current limiting resistor and the normally closed relay to supply power to the contactor coil, and the contactor magnet is attracted. After the contactor magnet is attracted, the position detection module is triggered. The control module outputs a control signal, i.e., a PWM control signal, based on the collected contactor magnet being in the attracted state, to drive the energy-saving switch module (MOS tube) to turn on, and at the same time drive the relay J1 in the auxiliary switch module to disconnect. The control module determines the voltage signal based on the voltage data collected by the voltage sampling module, adjusts the duty cycle of the PWM signal, ensures that the magnet is attracted while reducing the power consumption of the contactor coil, and achieves the effect of energy saving; when the control circuit is abnormal or the external force causes the contactor magnet to be disconnected (i.e., not attracted), the contactor coil can be powered on again by switching to the auxiliary switch module again, which ensures the reliability of the contactor coil.

[0066] This embodiment also provides a contactor; the contactor includes a control circuit for a contactor coil.

[0067] It can be understood that the contactor coil control circuit options in the above embodiment are also applicable to this embodiment, so they will not be described again here.

[0068] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A control circuit for a contactor coil, characterized in that: It includes a position detection module, a control module, an energy-saving switch module and an auxiliary switch module; The input end of the control module is connected to the output end of the position detection module; the output end of the control module is connected to the input end of the energy-saving switch module and the input end of the auxiliary switch module; the output end of the energy-saving switch module and the output end of the auxiliary switch module are both used to connect the coil of the contactor; The auxiliary switch module is used to be in a conducting state when the control circuit is initially powered on, so as to energize the coil of the contactor; The position detection module is used to detect the attraction state of the magnet of the contactor; The control module is used to control the auxiliary switch module to be disconnected and the energy-saving switch module to be turned on when the magnet of the contactor is attracted, so as to maintain the energized state of the coil of the contactor; and, when the magnet of the contactor is not attracted, control the energy-saving switch module to be disconnected and the auxiliary switch module to be turned on, so as to make the coil of the contactor attracted again.

2. The control circuit of the contactor coil according to claim 1, characterized in that: The control circuit further comprises a voltage acquisition module, the output end of which is connected to the processing unit of the control module; The voltage acquisition module is used to collect the working voltage of the contactor; The control module is further used to adjust the duty cycle of a control signal used to control the energy-saving switch module according to the working voltage.

3. The control circuit of the contactor coil according to claim 1, characterized in that: The auxiliary switch module includes a current limiting resistor and a first relay; The first end of the current limiting resistor is connected to the fixed contact of the first relay; the second end of the current limiting resistor is used to connect the coil of the contactor; the normally closed contact of the first relay is grounded; A first end of the coil of the first relay is connected to an output end of the control module, and a second end of the coil of the first relay is grounded.

4. The control circuit of the contactor coil according to claim 1, characterized in that: The energy-saving switch module includes a MOS tube and a diode; The gate of the MOS tube is connected to the output end of the control module; the source of the MOS tube is grounded, and the drain of the MOS tube is connected to the coil of the contactor; The anode of the diode is connected to the source of the MOS tube, and the cathode of the diode is connected to the drain of the MOS tube.

5. The control circuit of the contactor coil according to claim 1, characterized in that: The position detection module includes a travel switch, the distance between the travel switch and the magnet of the contactor is a set value, and the travel switch is used to detect the attraction state of the magnet of the contactor.

6. The control circuit of the contactor coil according to claim 1, characterized in that: The control module includes a processing unit and a driving unit; The input end of the processing unit is connected to the output end of the position detection module; the processing unit receives the pull-in state and processes the pull-in state to obtain a control signal; The input end of the driving unit is connected to the output end of the processing unit; the driving unit drives the energy-saving switch module or the auxiliary switch module to conduct according to the control signal.

7. The control circuit of the contactor coil according to claim 2, characterized in that: The control circuit also includes a power supply module and a voltage processing module; The power supply module adopts an AC power supply or a DC power supply; the power supply module provides input voltage for the control circuit; The input end of the voltage processing module is connected to the output end of the power module; the voltage processing module is used to process the input voltage to obtain a plurality of different operating voltages.

8. The control circuit of the contactor coil according to claim 7, characterized in that: The voltage processing module includes a filtering unit and a plurality of voltage reduction units; The input end of the filter unit is connected to the output end of the power module; the output end of the filter unit is connected to the contactor and the input end of the voltage acquisition module; the filter unit is used to filter the input voltage to obtain a filtered voltage, and use the filtered voltage as the working voltage of the contactor; The input end of each of the step-down units is connected to the output end of the filtering unit, and the output ends of different step-down units are respectively connected to the power supply end of the position detection module, the power supply end of the control module and the power supply end of the voltage acquisition module; the step-down unit is used to step down the filtered voltage to obtain multiple voltage signals; different voltage signals are respectively used as working voltages of the position detection module, the control module and the voltage acquisition module.

9. The control circuit of the contactor coil according to claim 1, characterized in that: The control circuit also includes an output module; the output module includes a second relay; the coil of the second relay is connected to the output end of the control module, and the switch contact of the second relay serves as the output end of the output module for connecting to a host computer.

10. A contactor, characterized in that: A control circuit comprising a contactor coil as claimed in any one of claims 1 to 9.

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