AC contactor

Abstract

The application relates to an alternating current contactor comprising a rectification filter circuit and a position switch, first ends of which are connected with external alternating current and second ends of which are connected; the first end of the coil module is connected with the third end of the rectification filter circuit, the second end is connected with the fourth end of the rectification filter circuit, and the coil module comprises at least two coils; the first end of the step-down circuit is connected with the first end of the position switch, and the second end is connected with the second end of the position switch; when the contactor is started, the position switch is closed, the coils are in a parallel connection state, starting current flows through the coils, the movable iron core moves towards the static iron core, and a filter energy storage device in the rectification filter circuit stores energy; when the movable iron core moves until the distance between the movable iron core and the static iron core is smaller than a distance threshold value, the position switch is turned on, the voltage reduction circuit reduces the voltage of external alternating current, all the coils are in a series connection state, the filtering energy storage device releases energy, holding current flows through the coils, and the movable iron core and the static iron core are kept in a pull-in state. The AC contactor is simple in structure and low in cost.

Description

Technical Field

[0001] The present application relates to the field of electrical technology, and in particular to an AC contactor. Background Art

[0002] With the vigorous development of the automation industry, artificial intelligence industry, smart sensors, computer technology, control technology, and electronic technology, the role of control appliances has become increasingly important and their uses have become increasingly widespread. There are many types of control appliances, such as AC contactors and DC contactors, which can be used to frequently connect or disconnect various terminal appliances over long distances. Control of common daily life equipment such as motors, transformers, and lighting. It covers a wide range of fields and plays an important role in agriculture, industry, transportation, life, and production, and in people's lives and the development of social and economic benefits.

[0003] At present, both AC contactors and DC contactors are widely used in various industries.

[0004] However, so far, the products launched in the field of energy-saving technology of AC contactors in my country have good energy-saving indicators and their performances are also different. For example, China Patent No. CN1107963C (mechanical self-locking AC contactor) uses mechanical self-locking and electromagnet unlocking to lock the contacts of the AC contactor in a closed state to achieve energy saving. Its disadvantages are complex structure, large product modification range, high modification cost, and failure to automatically disconnect when the power grid suddenly fails, which poses certain safety problems. Similarly, China Patent No. ZL200820302979.8 (AC contactor energy-saving device) uses DC high-voltage start-up. The principle of DC low-voltage operation achieves energy saving. Its disadvantages are high cost, easy aging of electronic components, and not suitable for use in high temperature and high humidity environments. In China Patent No. 201420101284.9 (an energy-saving AC contactor), one iron core is permanent magnet. The other iron core is soft magnetic and is wound with a coil that generates reverse magnetic flux. Permanent magnets are used to lock the contacts of the contactor, keeping them in a closed state to achieve energy saving. When the contactor needs to be restored to its initial state, the coil in the soft iron core is energized to generate reverse magnetic flux to repel the permanent magnet, causing it to return to its original position under the action of the reset spring. The disadvantages are that permanent magnets are easy to demagnetize, soft iron is easy to generate residual magnetism, the electronic circuit is expensive, and if the release circuit fails, there will be safety issues.

[0005] In conclusion, there is an urgent need for an energy-saving contactor with a simple structure and low cost. Utility Model Content

[0006] Based on this, it is necessary to provide an AC energy-saving contactor with a simple structure and low cost to address the above technical problems.

[0007] The present application provides an AC contactor, the contactor comprising:

[0008] A rectifier and filter circuit, a first terminal of which is connected to external alternating current;

[0009] A position switch, a first end of which is connected to external alternating current, and a second end of which is connected to a second end of the rectifying and filtering circuit;

[0010] A coil module, wherein a first end is connected to a third end of the rectifying and filtering circuit, and a second end is connected to a fourth end of the rectifying and filtering circuit, and the coil module comprises at least two coils;

[0011] A step-down circuit, wherein a first end of the step-down circuit is connected to a first end of the position switch, and a second end of the step-down circuit is connected to a second end of the position switch;

[0012] When the contactor is started, the position switch is closed, the coils are in a parallel state, a starting current flows through the coils, so that the moving iron core of the contactor moves toward the static iron core, and the filter energy storage device in the rectifier filter circuit stores energy;

[0013] When the moving iron core moves to a distance less than a distance threshold from the static iron core, the position switch is turned on, the step-down circuit reduces the voltage of the external alternating current, the coils are in a series state, the filtering energy storage device releases energy, and a holding current flows through the coils, so that the moving iron core and the static iron core of the contactor remain in an attracted state.

[0014] In one embodiment, the coil module also includes at least two Zener diodes, the first coil is connected to the third end of the rectifier and filter circuit through the first Zener diode, and the last coil is connected to the fourth end of the rectifier and filter circuit through the second Zener diode. If there are remaining coils, each corresponds to two Zener diodes, and is respectively connected to the third end and the fourth end of the rectifier and filter circuit through the two Zener diodes; when the position switch is closed, the voltage output by the rectifier and filter circuit is greater than or equal to the conduction voltage of each Zener diode, and each Zener diode is turned on; when the position switch is disconnected, the voltage output by the rectifier and filter circuit is less than the conduction voltage of each Zener diode, and each Zener diode is turned off.

[0015] In one embodiment, the positive electrode of the first voltage regulator is connected to the first end of the first coil, the second end of the first coil is connected to the fourth end of the rectifier and filter circuit, and the negative electrode of the first voltage regulator is connected to the third end of the rectifier and filter circuit;

[0016] The two ends of the remaining coils are respectively connected to the positive electrode of the third Zener diode and the negative electrode of the fourth Zener diode, and the negative electrode of the third Zener diode is connected to the third end of the rectifier and filter circuit, and the positive electrode of the fourth Zener diode is connected to the fourth end of the rectifier and filter circuit.

[0017] In one embodiment, the coil module further includes at least one first diode, the first diode corresponds to the coil, and two ends of the first diode are respectively connected to different two ends of an adjacent coil, and the cathode of the fourth voltage regulator is also connected to the anode of the corresponding first diode.

[0018] In one of the embodiments, the voltage at the input end of the coil module is changed to control the conduction or cutoff of the voltage regulator tube connected in series with the coil.

[0019] In one embodiment, the contactor further comprises:

[0020] The anti-electrical shaking circuit has a first end connected to the third end of the rectifying and filtering circuit, and a second end connected to the fourth end of the rectifying and filtering circuit.

[0021] In one embodiment, the anti-power-shake circuit includes:

[0022] a second diode, an anode of which is connected to the first end of the first capacitor, and a cathode of which is connected to the fourth end of the rectifying and filtering circuit;

[0023] a first resistor, a first end of which is connected to the first end of the first capacitor, and a second end of which is connected to the fourth end of the rectifier and filter circuit;

[0024] The first capacitor has a second end connected to the third end of the rectifier and filter circuit.

[0025] In one embodiment, the coil module is an excitation winding, and the excitation winding is divided into at least two coil sections.

[0026] In one of the embodiments, the voltage-reducing circuit includes at least one capacitor or at least one resistor.

[0027] In one of the embodiments, the step-down circuit includes at least two capacitors, and the at least two capacitors are connected in parallel; or the step-down circuit includes at least two resistors, and the at least two resistors are connected in parallel.

[0028] The above-mentioned AC contactor only uses a rectifier filter circuit, a position switch, a coil assembly and a step-down circuit, thereby reducing components, making the structure simple and miniaturized, and all of these components have high reliability operation characteristics. At the same time, because the life of this type of contactor is greatly increased, it also saves a lot of raw material loss for the society and reduces costs. When the contactor is started, the position switch is closed and the coils in the coil module are connected in parallel. Since the coil module includes at least two coils, a large starting current flows through the coil module, causing the moving iron core of the contactor to move quickly toward the stationary iron core, and the filter energy storage device in the rectifier filter circuit stores energy; when the distance between the moving iron core and the stationary iron core is less than the distance threshold, the position switch is opened, the step-down circuit reduces the voltage of the external AC power, the rectifier output DC voltage also decreases, the filter energy storage device releases energy, and the multiple coils in the coil module are converted into series connection, and a small holding current flows through the coil module, so that the moving iron core and the stationary iron core of the contactor remain in the attracted state. In this way, the attracting coil and the holding coil share a group, high voltage and large current are attracted, and low voltage and small current are held, which simplifies the process, saves costs, reduces power consumption, reduces the risk of holding coil failure, and improves product reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A starting circuit diagram of a contactor according to an embodiment;

[0030] Figure 2 for Figure 1 Holding circuit diagram of the contactor in the illustrated embodiment.

[0031] Figure 3 for Figure 1 Assembly drawing of the contactor in the illustrated embodiment.

[0032] Description of reference numerals:

[0033] 100 rectifier and filter circuit, 110 filter energy storage device, 120 rectifier circuit, 200 coil module, 300 step-down circuit, 400 anti-electricity shaking circuit, KF position switch, R1 varistor, AD bridge rectifier circuit, C2 second capacitor, D11~D12 first diode, D10 second diode, R2 first resistor, C3 first capacitor, C1 third capacitor, K1~Kn coils, D1 first Zener diode, D2 second Zener diode, D31~Dn1 third Zener diode, D41~D4n fourth Zener diode, 600 moving iron core, 700 static iron core, 800 reset spring, 900 normally open contact, 910 trigger head. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0039] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0040] The present application provides an AC contactor, combined with Figures 1 to 3 As shown, Figure 1 A starting circuit diagram of an AC contactor according to an embodiment; Figure 2 for Figure 1 A holding circuit diagram of the contactor in the illustrated embodiment; Figure 3 for Figure 1 An assembly diagram of the AC contactor in the illustrated embodiment.

[0041] The AC contactor comprises: a rectifier filter circuit 100, a position switch KF, a coil module 200 and a step-down circuit 300. The first end of the rectifier filter circuit 100 is connected to an external AC power; the first end of the position switch KF is connected to an external AC power, and the second end of the position switch KF is connected to the second end of the rectifier filter circuit 100; the first end of the coil module 200 is connected to the third end of the rectifier filter circuit 100, and the second end of the coil module 200 is connected to the fourth end of the rectifier filter circuit 100; the first end of the step-down circuit 300 is connected to the first end of the position switch KF, and the second end of the step-down circuit 300 is connected to the second end of the position switch KF.

[0042] In one optional embodiment, the first end of the position switch KF can be connected to external AC power through a varistor R1, wherein the first end of the step-down circuit 300 is also connected to external AC power through a varistor R1. The position switch KF is a normally closed position switch.

[0043] The AC contactor in this embodiment includes a coil module 200 , and the coil module 200 may contain at least two coils ( K1 , K2 , K3 ---- Kn).

[0044] When the contactor is started, the position switch KF is closed, each coil is in a parallel state, and a starting current flows through the coil, so that the moving iron core 600 of the contactor moves toward the static iron core 700, and the filter energy storage device 110 in the rectifier filter circuit 100 stores energy; when the moving iron core 600 moves to a distance less than the distance threshold from the static iron core 700, the position switch KF is opened, the step-down circuit 300 reduces the voltage of the external alternating current, each coil is in a series state, the filter energy storage device 110 releases energy, and a holding current flows through the coil, so that the moving iron core 600 and the static iron core 700 of the contactor remain in the attracted state. In the above embodiment, only the rectifier filter circuit 100, the position switch KF, the coil assembly and the step-down circuit 300 are used, thereby reducing components, the structure is simple and miniaturized, and all these components have high reliability operation characteristics. At the same time, because the life of this type of contactor is greatly increased, it also saves a lot of raw material loss for the society and reduces costs. When the contactor is started, the position switch KF is closed, and the coils in the coil module 200 are connected in parallel. Since the coil module 200 includes at least two coils, a large starting current flows through the coil module 200, causing the moving iron core 600 of the contactor to move quickly toward the stationary iron core 700, and the filter energy storage device 110 in the rectifier filter circuit 100 stores energy; when the distance between the moving iron core 600 and the stationary iron core 700 is less than the distance threshold, the position switch KF is opened, the step-down circuit 300 reduces the voltage of the external AC power, the rectifier output DC voltage also decreases, the filter energy storage device 110 releases energy, and the multiple coils in the coil module 200 are converted into series connection, and a small holding current flows through the coil module 200, so that the moving iron core 600 and the stationary iron core 700 of the contactor remain in the attracted state, so that the attracting coil and the holding coil share a group, high voltage and large current are attracted, and low voltage and small current are held, which simplifies the process, saves cost, reduces power consumption, reduces the risk of holding coil failure, and improves product reliability.

[0045] In one optional embodiment, the coil module 200 further includes at least one first diode (D11, D12, D13, ..., D1n), the first diode corresponds to the coil, and two ends of the first diode are respectively connected to different two ends of adjacent coils.

[0046] Combination Figure 1As shown, a diode is included between every two adjacent coils, and the positive electrode of the diode is connected to the second end of the previous coil, and the negative electrode is connected to the first end of the next coil, wherein the first end of each coil is an end directly or indirectly connected to the fourth end of the rectifier and filter circuit 100, and the second end is an end directly or indirectly connected to the third end of the rectifier and filter circuit 100.

[0047] In one of the optional embodiments, the coil module 200 also includes at least two Zener diodes, the first coil is connected to the third end of the rectifier and filter circuit 100 through the first Zener diode D1, and the last coil is connected to the fourth end of the rectifier and filter circuit 100 through the second Zener diode D2. If there are remaining coils, each corresponds to two Zener diodes, and is respectively connected to the third end and the fourth end of the rectifier and filter circuit 100 through the two Zener diodes; when the position switch KF is closed, the voltage output by the rectifier and filter circuit 100 is greater than the conduction voltage of each Zener diode, and each Zener diode is turned on; when the position switch KF is disconnected, the voltage output by the rectifier and filter circuit 100 is less than the conduction voltage of each Zener diode, and each Zener diode is cut off.

[0048] In one of the optional embodiments, by changing the voltage at the input end of the coil module 200, the voltage regulator tube connected in series with the coil is controlled to be turned on or off, so as to achieve the change of the parallel state and the series state of each coil.

[0049] In one of the optional embodiments, the positive electrode of the first voltage regulator tube D1 is connected to the first end of the first coil and the negative electrode of the corresponding first diode D11, the second end of the first coil is connected to the fourth end of the rectification and filtering circuit 100, and the negative electrode of the first voltage regulator tube D1 is connected to the third end of the rectification and filtering circuit 100; the last coil is connected to the fourth end of the rectification and filtering circuit 100 through the second voltage regulator tube D2; the two ends of the remaining coils are respectively connected to the positive electrode of the third voltage regulator tube (D31, D41...) and the negative electrode of the fourth voltage regulator tube (D32, D42...), and the negative electrode of the third voltage regulator tube is connected to the third end of the rectification and filtering circuit 100, the positive electrode of the fourth voltage regulator tube is connected to the fourth end of the rectification and filtering circuit 100, and the negative electrode of the fourth voltage regulator tube is also connected to the positive electrode of the corresponding first diode.

[0050] Specific combination Figure 1 and Figure 2As shown, the coil loop includes a first voltage regulator tube D1, a second voltage regulator tube D2 (conduction voltage VD), voltage regulator tubes D31, D32---Dn1, Dn2 (conduction voltage is about 1 / 2VD) and diodes D11, D13, D14. Each coil corresponds to a group of voltage regulator tubes, for example, the second coil corresponds to voltage regulator tubes D31 and D32, the first end of the second coil is connected to the negative pole of the voltage regulator tube D31, the positive pole of the voltage regulator tube D31 is connected to the fourth end of the rectifier and filter module, the second end of the second coil is connected to the positive pole of the voltage regulator tube D32, and the negative pole of the voltage regulator tube D32 is connected to the third end of the rectifier and filter module.

[0051] When the contactor is started, the position switch KF is closed, and the DC rectifier output voltage V1 is relatively high. Since the conduction voltage VD of each Zener diode is less than V1, all Zener diodes are turned on, and the K1, K2---Kn coils become connected in parallel. A starting current flows through the coils, causing the moving iron core 600 of the contactor to move toward the static iron core 700, and the filter energy storage device 110 in the rectifier filter circuit 100 stores energy.

[0052] When the moving iron core 600 moves to a distance less than the distance threshold from the static iron core 700, the position switch KF is opened, the step-down circuit 300 reduces the voltage of the external AC power, and the DC rectifier output voltage is also reduced to V2. The filter energy storage device 110 releases energy, and the voltage across the coil drops to the rectifier output voltage V2. Since the conduction voltage VD of the voltage regulator tube is greater than V2, all voltage regulator tubes become blocked, and the K1, K2---Kn coils are switched from parallel to series, and a holding current flows through the coil, so that the moving iron core 600 and the static iron core 700 of the contactor remain in the attracted state. For this reason, the coil module 200 in this application is both an attraction coil and a holding coil.

[0053] In the present application, when the contactor is started, the position switch KF is closed, the filter energy storage device 110 is charged and stored to provide high voltage for the coil module 200, and the starting current flows through the coil module 200, so that the moving iron core 600 also moves downward under the action of electromagnetic attraction, that is, the moving iron core 600 of the contactor moves toward the static iron core 700, and the filter energy storage device 110 in the rectifier filter circuit 100 stores energy; when the distance between the moving iron core 600 and the static iron core 700 is less than the distance threshold, the position switch KF is opened, and the step-down circuit 300 reduces the voltage of the external AC power. That is, after the step-down circuit 300 steps down the voltage, the circuit changes from high voltage to low voltage, and then is rectified by the rectifier circuit 120 to become direct current to continue to supply power to the coil module 200. The magnetic force generated by the coil module 200 may be insufficient to continue to move forward or to keep the moving iron core 600 in the attracted position due to the low voltage. However, at this time, the filter energy storage device 110 releases energy, and a holding current flows through the coil module 200, which is sufficient to maintain the moving iron core 600 in the attracted position, so that the moving iron core 600 and the static iron core 700 of the contactor remain in the attracted state.

[0054] In one optional embodiment, the contactor further includes: an anti-power-sway circuit 400 , wherein a first end of the energy storage circuit is connected to a third end of the rectifying and filtering circuit 100 , and a second end of the energy storage circuit is connected to a fourth end of the rectifying and filtering circuit 100 .

[0055] In one of the optional embodiments, the anti-electrical shaking circuit 400 includes: a second diode D10, the positive electrode of which is connected to the first end of the first capacitor C3, and the negative electrode of which is connected to the fourth end of the rectifier and filter circuit 100; a first resistor R2, the first end of which is connected to the first end of the first capacitor C3, and the second end of which is connected to the fourth end of the rectifier and filter circuit 100; a first capacitor C3, the second end of which is connected to the third end of the rectifier and filter circuit 100.

[0056] The anti-electrical sway circuit 400 can be a slow-charging and fast-discharging energy storage circuit; when a large-capacity capacitor is used to store energy in the anti-electrical sway circuit 400, it will not cause an excessive starting current, causing overcurrent in related components, such as the rectifier bridge and position switch KF in this circuit, nor will it cause the starting current to be shunted by a large energy storage capacitor and extend the starting time.

[0057] In one optional embodiment, the coil module 200 is an excitation winding, and the excitation winding is divided into at least two coil sections.

[0058] In this embodiment, the same excitation winding is divided into 2 to N sections. This circuit can greatly increase the starting attraction of the electromagnet, and automatically switch to an energy-saving working state after the start-up is completed. This solution can make the electromagnet or contactor start quickly or the starting force several times greater.

[0059] In one of the optional embodiments, the distance threshold is 1.5 mm, wherein the position switch KF is triggered to open by the electromagnet moving iron core 600 when the air gap between the moving iron core 600 and the static iron core 700 is ≤1.5 mm.

[0060] In this embodiment, after the control power supply is connected, the entire control circuit is powered and operates normally, the filter-compatible energy storage device in the rectifier filter circuit 100 is charged and stored and can provide high voltage for the coil module 200, and the moving iron core 600 also moves downward under the action of electromagnetic suction; when the moving iron core 600 runs to the position switch KF, the position switch KF is opened, and the circuit is changed from high voltage to low voltage after the voltage reduction circuit 300 is reduced, and then rectified by the rectifier filter circuit 100, and the coil module 200 is continued to be powered after becoming direct current. If the connection is not good at this time, the magnetic force generated by the coil module 200 may be insufficient to continue to move forward or keep the moving iron core 600 in the suction position due to the low voltage. The filter and energy storage device in this application will also power the coil module 200, which is enough to make the coil module 200 run to the suction and maintain the moving iron core 600 holding position. In this way, the suction coil and the holding coil share one, high voltage suction, low voltage holding, simplifying the process, saving costs, reducing power consumption, reducing the risk of holding coil failure, and improving the reliability of the product.

[0061] The AC contactor in the above embodiment only uses the rectifier filter circuit 100, the position switch KF, the coil module 200 and the step-down circuit 300, thereby reducing the number of components, making the structure simple and miniaturized, and all of these components have the characteristics of high reliability operation. At the same time, because the life of this type of contactor is greatly increased, it also saves a lot of raw material loss for the society and reduces costs. Figure 1, the position switch KF is closed, the rectifier output DC voltage V1 is relatively high, and since the Zener diode conduction voltage VD is less than the rectifier output DC voltage V1, the Zener diode is turned on, and multiple (2 to N) coils are connected in parallel, and a starting current flows through the coils, so that the moving iron core 600 of the contactor moves toward the static iron core 700, and the filter energy storage device 110 in the rectifier filter circuit 100 stores energy; when the moving iron core 600 moves to a distance less than the distance threshold from the static iron core 700, the position switch KF is opened, and the step-down circuit 300 reduces the voltage of the external AC power , the DC rectifier output voltage also decreases, the filtering energy storage device 110 releases energy, and after the voltage drops to the rectifier output voltage V2, since the Zener diode conduction voltage VD is greater than V2, the Zener diode is blocked, and multiple (2~N) coils are changed from parallel to series, and a holding current flows through the coil, so that the moving iron core 600 and the static iron core 700 of the contactor remain in the attracted state; in this way, the attracting coil and the holding coil share one, high voltage and large current are attracted, and low voltage and small current are held, which simplifies the process, saves cost, reduces power consumption, reduces the risk of holding coil failure, and improves product reliability.

[0062] In one of the optional embodiments, the rectifier filter circuit 100 includes a rectifier circuit 120 and a filter energy storage device 110. The first end of the rectifier circuit 120 is connected to the external alternating current, and the second end of the rectifier circuit 120 is connected to the second end of the position switch KF; the first end of the filter energy storage device 110 is connected to the third end of the rectifier circuit 120, and the second end of the filter energy storage device 110 is connected to the fourth end of the rectifier circuit 120. When the contactor is started, the rectifier circuit 120 rectifies the external alternating current to obtain a starting voltage, so that a starting current flows through the coil module 200, and the filter energy storage device 110 stores energy to increase the starting current.

[0063] In one optional embodiment, the rectified current is a bridge rectified current AD.

[0064] In one optional embodiment, the filtering energy storage device 110 is a second capacitor C2.

[0065] In one optional embodiment, the rectifier circuit 120 is a bridge rectifier circuit. In theory, Vout = 0.9 Vin.

[0066] The filtering energy storage device 110 is located in the filtering loop, and can filter the received direct current to prevent the impurity interference signal from interfering with the driving signal.

[0067] The filter energy storage device 110 increases the starting current during startup, improves the starting attraction, and supplies power to the coil module 200 when the circuit voltage decreases. The filter energy storage device 110 is preferably a capacitor.

[0068] Specifically, the filter energy storage device 110 includes a passive filter circuit and an active filter circuit. The passive filter circuit can be composed of passive components (resistors, capacitors, inductors), and its main forms include capacitor filtering, inductor filtering and compound filtering (including inverted L type, LC filtering, LCπ type filtering and RCπ type filtering, etc.). The active filter circuit can also be composed of active components (bipolar tube, unipolar tube, integrated operational amplifier), and its main form is active RC filtering. In one of the optional embodiments, passive components are used for filtering and energy storage, and the filter energy storage device 110 is a capacitor. In one of the optional embodiments, the capacity of the capacitor is less than the preset value. Only a small energy storage capacitor needs to be added to solve the problem of excessive drop in the starting excitation current before the electromagnetic air gap is 0 during this conversion process, and the smooth attraction of the contactor electromagnet is guaranteed.

[0069] When the contactor is started, the rectifier circuit 120 rectifies the external alternating current to obtain a starting voltage, so that a starting current flows through the coil module 200 .

[0070] In one of the optional embodiments, the step-down circuit includes at least one capacitor or at least one resistor.

[0071] In one of the optional embodiments, the step-down circuit includes at least two capacitors, and the at least two capacitors are connected in parallel; or the step-down circuit includes at least two resistors, and the at least two resistors are connected in parallel.

[0072] The voltage reduction circuit 300 can be a capacitor or a resistor, such as Figure 1 In the figure, the step-down circuit 300 is a third capacitor C1. The step-down circuit 300 preferably uses two capacitors in parallel to change the circuit from a high voltage to a low voltage. A resistor can also be used instead of a capacitor to step down the voltage, but the effective power consumption is increased.

[0073] In one of the optional embodiments, the contactor further includes: a trigger head 910 , which moves with the moving iron core 600 , and when the moving iron core 600 moves toward the static iron core 700 , the position switch KF is pushed open by the trigger head 910 .

[0074] In one optional embodiment, the contactor further includes a reset spring 800 and a normally open contact 900. Under the action of the reset spring 800, the moving iron core 600 and the stationary iron core 700 are pulled apart, and the normally open contact 900 is in an open state.

[0075] In this embodiment, after the control power supply is connected, the entire control circuit is powered and operates normally, the filter-compatible energy storage device in the rectifier filter circuit 100 is charged and stored and can provide high voltage for the coil module 200, and the moving iron core 600 also moves downward under the action of electromagnetic suction, wherein, during the movement of the moving iron core 600, the trigger head 910 moves with the moving iron core 600; when the moving iron core 600 runs to the position switch KF, the position switch KF is pushed open by the trigger head 910, and the circuit is changed from high voltage to low voltage after the voltage reduction circuit 300 reduces the voltage, and then rectified by the rectifier filter circuit 100, it becomes direct current and continues to supply power to the coil module 200. If the connection is not good at this time, the magnetic force generated by the coil module 200 may be insufficient to continue to move forward or keep the moving iron core 600 in the attracted position due to the low voltage, and the filter and energy storage device in this application will also supply power to the coil module 200, which is enough to make the coil module 200 run to the attracted position and maintain the moving iron core 600 in the holding position. In this way, the pull-in coil and the holding coil share one, high voltage pull-in, low voltage holding, simplifying the process, saving costs, reducing power consumption, reducing the risk of holding coil failure, and improving product reliability. When the reset spring 800 is reset later, it pulls the moving iron core 600 and the static iron core 700 apart, so that the normally open contact 900 is in an open state.

[0076] In the above embodiment, high voltage is used during starting to increase the starting current and improve the starting attraction, and low voltage is used during maintenance, which switches to low voltage and low current smoothly and reliably, meeting the first-level energy consumption index of the new energy-saving contactor.

[0077] Take n=2 as an example to illustrate the advantages of this solution (assuming DC input voltage U, current A, coil turns Z, coil resistance R, Zener voltage Uw=0.1U):

[0078] 1. Divide the 8000 turns of 0.14 into two sections: 8000 turns of 0.14 coil has a resistance of about 1000 ohms, divided into two sections of 4000 turns, each section has a resistance of about 500 ohms, and the parallel winding resistance is about 250 ohms;

[0079] 2. Starting current before change = U / R = U / 1000 = 0.001U, starting current after change = U-0.1U / 250 = 0.9U / 250 = 0.0036U; after / before = 0.0036U / 0.001U = 3.6 (times).

[0080] After the modification, the electromagnet winding AZ=U / R×0.5Z=0.0036U×0.5Z=0.0018UZ, before the modification, the electromagnet winding AZ=U / R×Z=0.001U×Z=0.001UZ, after / before=0.0018UZ / 0.001UZ=1.8 times.

[0081] It can be seen that the electromagnet start AZ of the scheme n = 2 increases by 1.8 times;

[0082] In one of the optional embodiments, the present application also provides an electrical device, which includes the AC contactor in any one of the above embodiments.

[0083] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. An AC contactor, characterized in that: The contactor comprises: A rectifier and filter circuit, a first terminal of which is connected to external alternating current; A position switch, a first end of which is connected to external alternating current, and a second end of which is connected to a second end of the rectifying and filtering circuit; A coil module, wherein a first end is connected to a third end of the rectifying and filtering circuit, and a second end is connected to a fourth end of the rectifying and filtering circuit, and the coil module comprises at least two coils; A step-down circuit, wherein a first end of the step-down circuit is connected to a first end of the position switch, and a second end of the step-down circuit is connected to a second end of the position switch; When the contactor is started, the position switch is closed, the coils are in a parallel state, a starting current flows through the coils, so that the moving iron core of the contactor moves toward the static iron core, and the filter energy storage device in the rectifier filter circuit stores energy; When the moving iron core moves to a distance less than a distance threshold from the static iron core, the position switch is turned on, the step-down circuit reduces the voltage of the external alternating current, the coils are in a series state, the filtering energy storage device releases energy, and a holding current flows through the coils, so that the moving iron core and the static iron core of the contactor remain in an attracted state.

2. The AC contactor according to claim 1, characterized in that: The coil module also includes at least two Zener diodes, the first coil is connected to the third end of the rectifier and filter circuit through the first Zener diode, and the last coil is connected to the fourth end of the rectifier and filter circuit through the second Zener diode. If there are remaining coils, each coil corresponds to two Zener diodes, and is respectively connected to the third end and the fourth end of the rectifier and filter circuit through the two Zener diodes; when the position switch is closed, the voltage output by the rectifier and filter circuit is greater than or equal to the conduction voltage of each Zener diode, and each Zener diode is turned on; when the position switch is disconnected, the voltage output by the rectifier and filter circuit is less than the conduction voltage of each Zener diode, and each Zener diode is turned off.

3. The AC contactor according to claim 2, characterized in that: The positive electrode of the first voltage regulator tube is connected to the first end of the first coil, the second end of the first coil is connected to the fourth end of the rectifier and filter circuit, and the negative electrode of the first voltage regulator tube is connected to the third end of the rectifier and filter circuit; The two ends of the remaining coils are respectively connected to the positive electrode of the third Zener diode and the negative electrode of the fourth Zener diode, and the negative electrode of the third Zener diode is connected to the third end of the rectifier and filter circuit, and the positive electrode of the fourth Zener diode is connected to the fourth end of the rectifier and filter circuit.

4. The AC contactor according to claim 3, characterized in that: The coil module further includes at least one first diode, which corresponds to the coil, and two ends of the first diode are respectively connected to different two ends of an adjacent coil, and the cathode of the fourth voltage regulator is also connected to the anode of the corresponding first diode.

5. The AC contactor according to claim 1, characterized in that: By changing the voltage at the input end of the coil module, the voltage regulator tube connected in series with the coil is controlled to be turned on or off.

6. The AC contactor according to claim 1, characterized in that: The contactor also includes: The anti-power-sway circuit has a first end connected to the third end of the rectifying and filtering circuit, and a second end connected to the fourth end of the rectifying and filtering circuit.

7. The AC contactor according to claim 6, characterized in that: The anti-power-sway circuit comprises: a second diode, an anode of which is connected to the first end of the first capacitor, and a cathode of which is connected to the fourth end of the rectifying and filtering circuit; a first resistor, a first end of which is connected to the first end of the first capacitor, and a second end of which is connected to the fourth end of the rectifier and filter circuit; The first capacitor has a second end connected to the third end of the rectifier and filter circuit.

8. The AC contactor according to any one of claims 1 to 7, characterized in that: The coil module is an excitation winding, and the excitation winding is divided into at least two coil sections.

9. The AC contactor according to claim 1, characterized in that: The voltage-reducing circuit includes at least one capacitor or at least one resistor.

10. The AC contactor according to claim 9, characterized in that: The step-down circuit includes at least two capacitors, which are connected in parallel; or the step-down circuit includes at least two resistors, which are connected in parallel.

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