Control circuit of magnetic latching relay and magnetic latching relay device

Abstract

The invention discloses a control circuit of a magnetic latching relay and a magnetic latching relay device, and belongs to the technical field of relays. In the control circuit provided by the invention, the electromagnetic coil is bidirectionally discharged, the energy storage capacitor can store the energy required by the reverse discharge of the coil when the coil is positively discharged, and the energy storage capacitor reversely discharges the coil through the normally closed switch, namely the bounce control switch, when the power is off, so that the switching of the on-off state of the magnetic latching relay is realized; the reverse discharge of the control circuit is carried out under the power-off condition, so that the problem that the magnetic latching relay cannot return to the initial state under the power-off condition can be solved. Besides, in the magnetic latching relay device provided by the invention, the permanent magnet is adopted by the magnetic latching relay to provide the attractive force required for maintaining the movable iron core at the pull-in position, so that the magnetic latching relay device has the advantage that the coil does not need to be continuously electrified when the relay works, and can solve the problems of overlarge noise and vibration, overlarge coil power and serious coil heating when an electromagnetic relay operates.

Description

Technical Field

[0001] The present invention belongs to the technical field of relays, and more specifically, relates to a control circuit of a magnetic latching relay and a magnetic latching relay device. Background Art

[0002] An electromagnetic relay is an electrical control device that controls the operation of large current between moving and static contacts by driving a small current in the coil. It can be used as both a control component and a protection component. In the circuit, it can realize functions such as remote control, safety protection, adjustment detection, and circuit conversion. Therefore, it has extremely wide applications in electronic communications, household and industrial appliances, power system relay protection, aerospace, and other fields.

[0003] In the prior art, electromagnetic relays generally include components such as a coil, an iron core, a moving contact, a stationary contact, and a spring. When current flows through the coil, a magnetic field is generated inside the coil, thereby generating an attractive force on the iron core, causing the moving contact to contact the stationary contact, and the working circuit to close. When the current in the coil disappears, the iron core returns to its initial position under the action of the spring, causing the moving contact to disengage from the stationary contact, and the working circuit to disconnect. However, when the electromagnetic relay is working, the coil needs to be continuously energized, thereby continuously generating an attractive force on the iron core to ensure reliable contact between the moving contact and the stationary contact. During operation, there are problems such as excessive operating noise and vibration, excessive coil power, and severe coil heating.

[0004] The magnetic latching relay is a new type of relay developed in recent years and is also an automatic switch. Like the electromagnetic relay, it automatically connects and disconnects the circuit. The difference is that the normally closed or normally open state of the magnetic latching relay is completely dependent on the action of the permanent magnet, and the switch state conversion is completed by triggering a pulse electrical signal of a certain width. The open and closed states of the contacts of the magnetic latching relay are usually maintained by the magnetic force generated between the permanent magnet and the yoke. When the contacts of the relay need to be opened or closed, it is only necessary to excite the coil with a positive (negative) DC pulse voltage, and the relay will complete the open and closed state conversion in an instant. When the contacts are usually in the holding state, the coil does not need to continue to be energized, and the magnetic force between the permanent magnet and the yoke can maintain the state of the relay unchanged. Although the magnetic latching relay solves the problem that the coil of the electromagnetic relay needs to be continuously energized when working, its reset operation is the same as the switch state switching control under normal operation, and both need to rely on external drive power. For some harsh working conditions such as sudden power outages, the above magnetic latching relay cannot return to the initial switch state. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a control circuit of a magnetic latching relay and a magnetic latching relay device, which are used to solve the technical problem that the prior art cannot return the magnetic latching relay to the initial switching state when the power is off.

[0006] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a control circuit of a magnetic latching relay, comprising: a rectifier bridge module, a DC switch, an energy storage capacitor, a discharge circuit and a controller;

[0007] The rectifier bridge module is connected to both ends of the energy storage capacitor through a DC switch to convert the input AC power into DC power;

[0008] The discharge circuit comprises a first branch and a second branch connected in parallel, and both branches are connected in parallel at both ends of the energy storage capacitor;

[0009] The first branch and the second branch both include: a pull-in control switch, a pop-up control switch and a current limiting resistor connected in series; one end of the pull-in control switch connected to the pop-up control switch is recorded as end B, and the other end is recorded as end C; one end of the current limiting resistor connected to the pop-up control switch is recorded as end D, and the other end is recorded as end E;

[0010] In the first branch, the C end of the pull-in control switch is connected to the positive electrode of the energy storage capacitor, and the E end of the current limiting resistor is connected to the negative electrode of the energy storage capacitor; in the second branch, the C end of the pull-in control switch is connected to the negative electrode of the energy storage capacitor, and the E end of the current limiting resistor is connected to the positive electrode of the energy storage capacitor;

[0011] The B end of the pull-in control switch in the first branch and the second branch is used as the load output end of the control circuit, and is used to connect the electromagnetic coil of the magnetic latching relay;

[0012] The DC switch and the pull-in control switch are both normally open switches, and the pop-up control switch is a normally closed switch;

[0013] The controller is used to control the electromagnetic coil of the magnetic latching relay to perform forward discharge and reverse discharge by controlling the power-on state of the DC switch and each pop-up control switch and each pull-in control switch, thereby controlling the switch state of the magnetic latching relay;

[0014] Wherein, when the magnetic latching relay is switched from an initial switch state to a first switch state opposite to the initial switch state, the controller is used to energize the DC switch and each pop-up control switch so that the DC switch is closed and each pop-up control switch is disconnected, and the energy storage capacitor is charged; after the charging is completed, each pull-in control switch is energized so that each pull-in control switch is closed, so as to discharge the electromagnetic coil in the magnetic latching relay in a forward direction; and during the process of forward discharge of the electromagnetic coil, when the switch state of the magnetic latching relay changes, the power supply to each pull-in control switch is stopped;

[0015] When the magnetic holding relay is switched from the first switching state back to the initial switching state, the controller is used to control each pop-up control switch and each pull-in control switch to be in a power-off state, so that each pop-up control switch is closed and each pull-in control switch is disconnected, thereby reversely discharging the electromagnetic coil in the magnetic holding relay.

[0016] Further preferably, the DC switch is a fully controlled switch device.

[0017] In a second aspect, the present invention provides a magnetic latching relay device, comprising: a magnetic latching relay and the control circuit provided in the first aspect of the present invention.

[0018] Further preferably, the magnetic latching relay comprises: a high-voltage moving contact, a high-voltage static contact, a moving iron core, a linkage component, a magnetic conductive component, an electromagnetic coil and a permanent magnet;

[0019] The high-voltage moving contact is fixedly connected to the moving iron core through a linkage component; the moving iron core is arranged at a position matching the magnetic conductive component, and moves under the excitation of the electromagnetic coil, and performs an attraction or release action with the magnetic conductive component, thereby driving the linkage component to move, so that the high-voltage moving contact contacts or separates from the high-voltage static contact;

[0020] The permanent magnet is used to provide a constant attraction force to the moving iron core and keep it in the attracted position after the moving iron core completes the attraction action.

[0021] Further preferably, the magnetic latching relay further comprises: a fixing platform, a spring fixing sheet and a reaction spring;

[0022] The high-voltage static contact, the fixing platform and the magnetic conductive component are fixed on the back plate in sequence from top to bottom;

[0023] The moving iron core is arranged at a position matching with the magnetic conductive component, and moves up and down along the axis within the aperture of the electromagnetic coil under the excitation of the electromagnetic coil;

[0024] The spring fixing piece is fixed to one end of the moving iron core close to the high-voltage moving contact; one end of the reaction spring is fixed to the spring fixing piece, and the other end is fixed to the magnetic conductive component, and is used to stretch or compress with the movement of the moving iron core;

[0025] The fixed platform is used to limit the moving iron core;

[0026] The permanent magnet is placed inside the magnetic conductive component and below the electromagnetic coil and the moving iron core;

[0027] When the electromagnetic coil is discharged in the forward direction, the electromagnetic coil generates a forward magnetic field, and the moving iron core moves downward along the axis to perform the attraction action with the magnetic conductive component, and is kept in the attracted position under the attraction of the permanent magnet, and the reaction spring is in a compressed state;

[0028] When the electromagnetic coil discharges in the reverse direction, it generates a reverse magnetic field to offset the magnetic field generated by the permanent magnet. The moving iron core moves upward under the action of the reaction spring to release the magnetic conductive component.

[0029] Further preferably, the permanent magnet is located directly below the moving iron core, and its area is the same as the end area of ​​the moving iron core.

[0030] Further preferably, the high-voltage moving contact is cylindrical in shape, and the high-voltage static contact is square plate-shaped.

[0031] Further preferably, the linkage component is a linkage rod.

[0032] Further preferably, the magnetic conductive component is a yoke.

[0033] Further preferably, the moving iron core and the magnetic yoke are both made of laminated silicon steel sheets and are prismatic in shape.

[0034] Further preferably, the magnetic latching relay further comprises: a shock absorbing plate located between the fixing platform and the spring fixing plate, for providing a buffer when the moving iron core bounces up and hits the fixing platform.

[0035] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0036] 1. The present invention provides a control circuit of a magnetic latching relay and a magnetic latching relay device. By bidirectionally discharging the electromagnetic coil, an energy storage capacitor will store the energy required for reverse discharge of the coil when the coil is discharged in the forward direction. When the power is off, the energy storage capacitor will discharge the coil in the reverse direction through a normally closed switch, that is, a pop-up control switch, thereby realizing the switching state of the magnetic latching relay. Since the reverse discharge of the control circuit is performed when the power is off, the problem that the magnetic latching relay cannot return to the initial state when the power is off can be solved.

[0037] 2. In the magnetic latching relay device provided by the present invention, the magnetic latching relay uses a permanent magnet to provide the attractive force required to maintain the moving iron core in the attracted position. Compared with the common electromagnetic relay without a permanent magnet, it has the advantage that the coil does not need to be continuously energized when the relay is working, and can solve the problems of excessive noise and vibration, excessive coil power, and severe coil heating when the electromagnetic relay is running.

[0038] 3. Furthermore, in the magnetic latching relay device provided by the present invention, the permanent magnet in the magnetic latching relay is located directly below the moving iron core, and its area is the same as the end area of ​​the moving iron core, so that the suction force provided by the permanent magnet is the largest when the moving iron core moves to the lowest position, which can reduce the volume of the required permanent magnet; at the same time, due to the symmetry of the structure, when a reverse current flows through the coil, the reverse magnetic field generated to offset the magnetic field of the permanent magnet is also the best.

[0039] 4. Furthermore, in the magnetic latching relay device provided by the present invention, the high-voltage moving contact in the magnetic latching relay is cylindrical in shape, and the high-voltage static contact is square in shape, which can reduce the contact resistance between the moving and static contacts, thereby reducing the heating power at the contacts, avoiding excessive energy loss and even contact welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of the structure of a control circuit of a magnetic latching relay provided in an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of the structure of a magnetic latching relay provided by an embodiment of the present invention;

[0042] Figure 3 A schematic structural diagram of a high-voltage moving contact and a high-voltage static contact in a magnetic latching relay provided in an embodiment of the present invention.

[0043] Figure numerals: pressure spring at the top of the moving contact -1, high-voltage moving contact -2, high-voltage static contact -3, epoxy back plate -4, connecting rod -5, fixing platform -6, rubber shock-absorbing plate -7, spring fixing plate -8, reaction spring -9, iron core -10, coil frame -11, electromagnetic coil -12, yoke -13, permanent magnet -14, rectifier bridge module -A1, DC switch -A2, energy storage capacitor -A3, pull-in control switch -A4, pop-up control switch -A5, current limiting resistor -A6, two ends of the pull-in control switch -B, C, two ends of the current limiting resistor -D, E. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] In order to achieve the above objectives, firstly, Figure 1 As shown, the present invention provides a control circuit of a magnetic latching relay, comprising: a rectifier bridge module A1, a DC switch A2, an energy storage capacitor A3, a discharge circuit and a controller;

[0046] The rectifier bridge module A1 is connected to both ends of the energy storage capacitor A3 through the DC switch A2, and is used to convert the input AC power into DC power; the DC switch A2 is a normally open switch, which is open in normal state and closed after power is turned on; the DC switch A2 can be a fully controlled switch device such as IGBT, MOSFET, etc., preferably an IGBT switch; the DC switch A2 is used to control the on and off of the DC high voltage output by the rectifier bridge module A1;

[0047] The discharge circuit includes a first branch and a second branch connected in parallel, and both branches are connected in parallel at both ends of the energy storage capacitor A3;

[0048] The first branch and the second branch both include: a pull-in control switch A4, a pop-up control switch A5 and a current-limiting resistor A6 connected in series; one end of the pull-in control switch connected to the pop-up control switch is recorded as end B, and the other end is recorded as end C; one end of the current-limiting resistor connected to the pop-up control switch is recorded as end D, and the other end is recorded as end E; wherein, the pull-in control switch is a normally open switch, which is disconnected in normal state and closed after power is supplied; the pop-up control switch is a normally closed switch, which is closed in normal state and disconnected after power is supplied; the current-limiting resistor is used to limit the current flowing through the electromagnetic coil when the electromagnetic coil is reversely discharged, and to realize over-damped discharge; in an optional implementation manner, both the pull-in control switch and the pop-up control switch use small relays, wherein the pull-in control switch uses normally open contacts, and the pop-up control switch uses normally closed contacts.

[0049] In the first branch, the C end of the pull-in control switch is connected to the positive electrode of the energy storage capacitor, and the E end of the current limiting resistor is connected to the negative electrode of the energy storage capacitor; in the second branch, the C end of the pull-in control switch is connected to the negative electrode of the energy storage capacitor, and the E end of the current limiting resistor is connected to the positive electrode of the energy storage capacitor;

[0050] The B end of the pull-in control switch in the first branch and the second branch is used as the load output end of the control circuit, and is used to connect the electromagnetic coil of the magnetic latching relay;

[0051] The controller is used to control the forward discharge and reverse discharge of the electromagnetic coil of the magnetic latching relay by controlling the power-on state of the DC switch and each pop-up control switch and each pull-in control switch, thereby controlling the switch state of the magnetic latching relay; when the electromagnetic coil is discharged in the forward direction, the magnetic latching relay switches from the initial switch state to the current switch state; when the electromagnetic coil is discharged in the reverse direction, the magnetic latching relay switches from the current switch state back to the initial switch state;

[0052] Wherein, when the magnetic latching relay is switched from an initial switch state to a first switch state opposite to the initial switch state, the controller is used to energize the DC switch and each pop-up control switch so that the DC switch is closed and each pop-up control switch is disconnected, and the energy storage capacitor is charged; after the charging is completed, each pull-in control switch is energized so that each pull-in control switch is closed, so as to discharge the electromagnetic coil in the magnetic latching relay in a forward direction; and during the forward discharge process, when the switch state of the magnetic latching relay changes, the power supply to each pull-in control switch is stopped;

[0053] When the magnetic holding relay is switched from the first switching state back to the initial switching state, the controller is used to control each pop-up control switch and each pull-in control switch to be in a power-off state, so that each pop-up control switch is closed and each pull-in control switch is disconnected, thereby reversely discharging the electromagnetic coil in the magnetic holding relay.

[0054] In an optional implementation manner, the energy storage capacitor is an electrolytic capacitor, and the capacitance is determined according to the parameters of the electromagnetic coil.

[0055] In a second aspect, the present invention provides a magnetic latching relay device, comprising: a magnetic latching relay and the control circuit provided in the first aspect of the present invention.

[0056] In an optional implementation manner, the magnetic latching relay comprises: a high-voltage moving contact, a high-voltage static contact, a moving iron core, a linkage component, a magnetic conductive component, an electromagnetic coil and a permanent magnet;

[0057] The high-voltage moving contact is fixedly connected to the moving iron core through a linkage component; the moving iron core is arranged at a position matching the magnetic conductive component, and moves under the excitation of the electromagnetic coil, and performs an attraction or release action with the magnetic conductive component, thereby driving the linkage component to move, so that the high-voltage moving contact contacts or separates from the high-voltage static contact;

[0058] The permanent magnet is used to provide a constant attraction force to the moving iron core and keep it in the attracted position after the moving iron core completes the attraction action.

[0059] In an optional implementation manner, the magnetic latching relay further includes: a fixing platform, a spring fixing sheet and a reaction force spring;

[0060] The high-voltage static contact, the fixing platform and the magnetic conductive component are fixed on the back plate in sequence from top to bottom;

[0061] The moving iron core is arranged at a position matching with the magnetic conductive component, and moves up and down along the axis within the aperture of the electromagnetic coil under the excitation of the electromagnetic coil;

[0062] The spring fixing piece is fixed to one end of the moving iron core close to the high-voltage moving contact; one end of the reaction spring is fixed to the spring fixing piece, and the other end is fixed to the magnetic conductive component, and is used to stretch or compress with the movement of the moving iron core;

[0063] The fixed platform is used to limit the moving iron core;

[0064] The permanent magnet is placed inside the magnetic conductive component and below the electromagnetic coil and the moving iron core;

[0065] When the electromagnetic coil is discharged in the forward direction, the electromagnetic coil generates a forward magnetic field, and the moving iron core moves downward along the axis to perform the attraction action with the magnetic conductive component, and is kept in the attracted position under the attraction of the permanent magnet, and the reaction spring is in a compressed state;

[0066] When the electromagnetic coil discharges in the reverse direction, it generates a reverse magnetic field to offset the magnetic field generated by the permanent magnet. The moving iron core moves upward under the action of the reaction spring to release the magnetic conductive component.

[0067] In an optional implementation, the permanent magnet is located directly below the moving iron core, and its area is the same as the end area of ​​the moving iron core.

[0068] In an optional embodiment, the high-voltage moving contact is cylindrical in shape, and the high-voltage static contact is square plate-shaped, so as to reduce the contact resistance between the moving and static contacts, thereby reducing the heating power at the contacts, avoiding excessive energy loss and even contact welding.

[0069] In an optional implementation, the linkage component is a linkage rod.

[0070] In an optional implementation, the magnetic conductive component is a magnetic yoke.

[0071] In an optional implementation, the moving iron core and the magnetic yoke are both made of silicon steel sheet stacks and are prismatic in shape.

[0072] In an optional implementation manner, the magnetic latching relay further includes: a shock absorbing plate located between the fixing platform and the spring fixing plate, providing a buffer when the moving iron core bounces up and hits the fixing platform.

[0073] Specifically, Figure 2 The figure shows an implementation method of a magnetic holding relay, including: a pressure spring 1 at the top of the moving contact, a high-voltage moving contact 2, a high-voltage static contact 3, an epoxy back plate 4, a linkage rod 5, a fixing platform 6, a rubber shock-absorbing plate 7, a spring fixing plate 8, a reaction spring 9, a moving iron core 10, a coil frame 11, an electromagnetic coil 12, a yoke 13 and a permanent magnet 14.

[0074] Among them, the high-voltage static contact 3, the fixing platform 6, the rubber shock-absorbing sheet 7, the spring fixing sheet 8, and the yoke 13 are fixed on the epoxy back plate 4 from top to bottom in sequence, the coil skeleton 11 is placed inside the yoke 13, and the electromagnetic coil 12 is wound on the coil skeleton 11; the moving iron core 10 is placed in the aperture of the electromagnetic coil; the high-voltage moving contact 3 is fixedly connected with the moving iron core 10 through the connecting rod 5; the moving iron core 10 moves along the axis in the aperture of the electromagnetic coil under the excitation of the electromagnetic coil, thereby driving the connecting rod 5 to move, so that the high-voltage moving contact 2 is in contact with or separated from the high-voltage static contact 3; the high-voltage moving contact 2 and the high-voltage static contact 3 are used to realize the high-voltage side breaking function;

[0075] The spring fixing piece 8 is fixed to one end of the moving iron core close to the high-voltage moving contact; the reaction spring 9 is placed between the spring fixing piece 8 and the yoke 13, with one end fixed to the spring fixing piece 8 and the other end fixed to the yoke 13, and is stretched or compressed with the movement of the moving iron core 10. When the moving iron core 10 completes the attraction action with the yoke 13, the reaction spring 9 is in a compressed state, which is used to provide a reaction force for the bounce of the moving iron core 10; when the moving iron core 10 completes the release action with the yoke 13, the reaction spring 9 is in a stretched state, which is used to provide contact pressure between the high-voltage moving contact 2 and the high-voltage static contact 3, so that the high-voltage moving contact 2 remains stable during operation.

[0076] The permanent magnet 14 is placed inside the yoke 13 and below the electromagnetic coil 12 and the moving iron core 10 , and is used to provide a constant attraction force for the moving iron core 10 after the moving iron core 10 completes the attraction action, thereby ensuring that the moving iron core 10 remains in the attracted position.

[0077] The yoke 13 is used for conducting magnetism and generating electromagnetic attraction, and the raised portion at the upper end thereof is used for limiting the position of the reaction spring 9, thereby ensuring that the reaction spring 9 will not deviate or pop out during movement.

[0078] In this embodiment, if Figure 3 As shown, the high-voltage moving contact 2 and the high-voltage static contact 3 are both made of a good conductive alloy and silver-plated on the surface. The high-voltage static contact 3 is cylindrical in shape, and the high-voltage moving contact 2 is in the shape of a square plate. The epoxy back plate 4, the connecting rod 5, and the fixing table 6 are all made of insulating materials. The coil skeleton 11 is made using 3D printing technology, and the material is a common 3D printing material. The moving iron core 10 and the yoke 13 are both made of silicon steel sheet stacks and are prismatic in shape. The material of the permanent magnet 14 is a common permanent magnet such as neodymium iron boron, and the area is the same as the bottom area of ​​the moving iron core. The permanent magnet 14 is placed directly below the moving iron core 10, and the upper surface height is lower than the lower surface height of the coil skeleton 11.

[0079] Taking the above-mentioned magnetic latching relay to complete the switch state switching as an example, the working steps of the magnetic latching relay control circuit are introduced:

[0080] When the magnetic latching relay is switched from the initial switching state to the first switching state opposite to the initial switching state, the controller in the control circuit performs the following operations:

[0081] S1. Energize each pop-up control switch in the control circuit. Since the pop-up control switch is a normally closed contact, it will be disconnected after being energized.

[0082] S2. Provides a pulse control signal to the DC switch to close it. At this time, the rectifier bridge module outputs DC high voltage and charges the energy storage capacitor.

[0083] S3. Power on each pull-in control switch to close it. At this time, the DC high voltage output by the rectifier bridge module will be directly applied to both ends of the electromagnetic coil. A positive current will flow through the electromagnetic coil, and a magnetic field will be generated inside the coil. The magnetic lines of force will be closed through the iron core and the yoke, and the moving iron core will be attracted downward to complete the pull-in action.

[0084] S4. Disconnect each pull-in control switch. At this time, the moving iron core will be attracted by the permanent magnet below and maintained in the pull-in position, and the electromagnetic coil does not need to be continuously energized.

[0085] When the magnetic latching relay is switched from the first switching state back to the initial switching state, the controller in the control circuit performs the following operations:

[0086] S5. Disconnect the DC switch. At this time, the energy storage capacitor stores the energy required for the subsequent reverse discharge of the coil.

[0087] S6. Disconnect the power supply of each pop-up control switch. Since the pop-up control switch is a normally closed contact, it will return to the closed state after power failure. At this time, the energy storage capacitor discharges the electromagnetic coil, and a reverse current will flow through the electromagnetic coil. A reverse magnetic field will be generated inside the coil. This magnetic field will offset the magnetic field generated by the permanent magnet, thereby weakening the attraction of the permanent magnet to the iron core. Under the action of the reaction spring, the moving iron core will complete the pop-up action.

[0088] When the magnetic latching relay completes the attraction action, since the DC high voltage output by the rectifier bridge module directly discharges to the electromagnetic coil, the amplitude of the forward current flowing through the electromagnetic coil is relatively high, and the magnetic field generated is also relatively strong, and the moving iron core will quickly complete the attraction action.

[0089] When the magnetic latching relay completes the pop-up action, the amplitude of the reverse current flowing through the electromagnetic coil is small due to the existence of the current limiting resistor. This is because the required reverse magnetic field only serves to offset the magnetic field of the permanent magnet. A too strong reverse magnetic field may cause permanent demagnetization of the permanent magnet. At the same time, the current limiting resistor also has the function of realizing over-damping discharge and preventing coil current oscillation.

[0090] It should be noted that the above-mentioned magnetic latching relay is only one implementation method of the magnetic latching relay, and is not the only method. The existing magnetic latching relays can be applied to the control circuit provided by the present invention, which will not be described in detail here.

[0091] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A control circuit of a magnetic latching relay, characterized in that: include: Rectifier bridge module, DC switch, energy storage capacitor, discharge circuit and controller; The rectifier bridge module is connected to both ends of the energy storage capacitor through a DC switch to convert the input AC power into DC power; The discharge circuit includes a first branch and a second branch connected in parallel, and both branches are connected in parallel at both ends of the energy storage capacitor; the first branch and the second branch both include: a pull-in control switch, a pop-up control switch and a current limiting resistor connected in series; one end of the pull-in control switch connected to the pop-up control switch is recorded as the B end, and the other end is recorded as the C end; one end of the current limiting resistor connected to the pop-up control switch is recorded as the D end, and the other end is recorded as the E end; in the first branch, the C end of the pull-in control switch is connected to the positive electrode of the energy storage capacitor, and the E end of the current limiting resistor is connected to the negative electrode of the energy storage capacitor; in the second branch, the C end of the pull-in control switch is connected to the negative electrode of the energy storage capacitor, and the E end of the current limiting resistor is connected to the positive electrode of the energy storage capacitor; The B end of the pull-in control switch in the first branch and the second branch is used as the load output end of the control circuit, and is used to connect the electromagnetic coil of the magnetic latching relay; The DC switch and the pull-in control switch are both normally open switches, and the pop-up control switch is a normally closed switch; The controller is used to control the electromagnetic coil of the magnetic latching relay to perform forward discharge and reverse discharge by controlling the power-on state of the DC switch and each pop-up control switch and each pull-in control switch, thereby controlling the switch state of the magnetic latching relay; Wherein, when the magnetic latching relay is switched from an initial switch state to a first switch state opposite to the initial switch state, the controller is used to energize the DC switch and each pop-up control switch so that the DC switch is closed and each pop-up control switch is disconnected, and the energy storage capacitor is charged; after the charging is completed, each pull-in control switch is energized so that each pull-in control switch is closed to discharge the electromagnetic coil in a forward direction; and during the forward discharge process, when the switch state of the magnetic latching relay changes, the power supply to each pull-in control switch is stopped; When the magnetic latching relay is switched from the first switch state back to the initial switch state, the controller is used to control each pop-up control switch and each pull-in control switch to be in a power-off state, so that each pop-up control switch is closed and each pull-in control switch is disconnected, thereby reversely discharging the electromagnetic coil.

2. The control circuit according to claim 1, characterized in that: The DC switch is a fully controlled switch device.

3. A magnetic latching relay device, characterized in that: include: A magnetic latching relay and a control circuit as claimed in claim 1 or 2.

4. The magnetic latching relay device according to claim 3, characterized in that: The magnetic latching relay comprises: a high-voltage moving contact, a high-voltage static contact, a moving iron core, a linkage component, a magnetic conductive component, an electromagnetic coil and a permanent magnet; The high-voltage moving contact is fixedly connected to the moving iron core through the linkage component; the moving iron core is arranged at a position matching the magnetic conductive component, and moves under the excitation of the electromagnetic coil, and performs an attraction or release action with the magnetic conductive component, thereby driving the linkage component to move, so that the high-voltage moving contact contacts or separates from the high-voltage static contact; The permanent magnet is used to provide a constant attraction force for the moving iron core and keep the moving iron core in the attracted position after the moving iron core completes the attraction action.

5. The magnetic latching relay device according to claim 4, characterized in that: The magnetic latching relay further comprises: a fixing platform, a spring fixing sheet and a reaction spring; The high-voltage static contact, the fixing platform and the magnetic conductive component are fixed on the back plate in sequence from top to bottom; The moving iron core is arranged at a position matching with the magnetic conductive component, and moves up and down along the axis within the aperture of the electromagnetic coil under the excitation of the electromagnetic coil; The spring fixing piece is fixed to one end of the moving iron core close to the high-voltage moving contact; one end of the reaction spring is fixed to the spring fixing piece, and the other end is fixed to the magnetic conductive component, and is used for stretching or compressing with the movement of the moving iron core; The fixing platform is used to limit the moving iron core; The permanent magnet is placed inside the magnetic conductive component and below the electromagnetic coil and the moving iron core; When the electromagnetic coil is discharged in the forward direction, the electromagnetic coil generates a forward magnetic field, the moving iron core moves downward along the axis, performs an attraction action with the magnetic conductive component, and is kept in the attraction position under the attraction of the permanent magnet, and the reaction spring is in a compressed state; When the electromagnetic coil discharges in the reverse direction, the electromagnetic coil generates a reverse magnetic field to offset the magnetic field generated by the permanent magnet, and the moving iron core moves upward under the action of the reaction spring to perform a release action with the magnetic conductive component.

6. The magnetic latching relay device according to claim 4, characterized in that: The permanent magnet is located directly below the moving iron core, and its area is the same as the end area of ​​the moving iron core.

7. The magnetic latching relay device according to claim 4, characterized in that: The high-voltage moving contact is cylindrical in shape, and the high-voltage static contact is square plate-shaped.

8. The magnetic latching relay device according to claim 4, characterized in that: The linkage component is a linkage rod.

9. The magnetic latching relay device according to claim 4, characterized in that: The magnetic conductive component is a magnetic yoke.

10. The magnetic latching relay device according to any one of claims 4 to 9, characterized in that: Also includes: The shock absorbing plate located between the fixing platform and the spring fixing plate provides buffering when the moving iron core bounces and hits the fixing platform.

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