Double-coil relay and control method

Abstract

The invention relates to the technical field of relays, in particular to a double-coil relay and a control method, the performance of the relay is remarkably improved, the charging and discharging of an energy storage element are matched with the double-coil design, the large-current quick action in the pull-in stage and the small-current low-power-consumption maintenance in the holding stage are realized, the response time is shortened, and the reliability of the relay is improved. The power consumption is reduced, the service life of the relay and related elements is prolonged, the application range is widened, the electromagnetic interference is reduced, the stability and reliability of equipment are enhanced, and the circuit is an ideal choice for low-power-consumption and high-reliability application. Therefore, the problem that power consumption is wasted due to the fact that a traditional relay still needs large current to keep the state after actuation is solved.

Description

Technical Field

[0001] This invention relates to the field of relay technology, and in particular to a dual-coil relay and its control method. Background Technology

[0002] A relay is based on the principle of electromagnetic induction, using a smaller current or voltage to control the switching on and off of a circuit with a larger current or voltage. A relay mainly consists of a coil, an iron core, an armature, and contacts. When the control power switch is closed, the coil is energized. Following the right-hand screw rule, the coil generates magnetic lines of force in the iron core, attracting the armature downwards. This causes the normally open contact to close, and the normally closed contact to open, completing the relay's closing process. When the control power switch is opened, the coil is de-energized, the magnetic lines of force disappear, and the return spring pulls the armature back to its original position, causing the normally open contact to open and the normally closed contact to close.

[0003] A relay has two stable operating states: the released state and the holding state. The process of transitioning from the released state to the holding state is called the engaging process, and the process of transitioning from the holding state to the released state is called the releasing process. During the energizing engaging process, a large electromagnetic force is required for the engaging action. In the holding state after engaging, the required electromagnetic force is much smaller, generally less than 1 / 2 of the original force, or even 1 / 10.

[0004] Electromagnetic force is directly proportional to both current and the number of turns. With a fixed number of turns and wire diameter, the coil resistance is also determined. Once the operating voltage is set, the pull-in current is also determined; this current is the crucial pull-in current parameter of the relay. In practical applications, to ensure reliable relay operation, the actual pull-in current is generally designed to be greater than or equal to this value. Of course, the electromagnetic force can be increased by increasing the number of turns (while simultaneously increasing the coil resistance proportionally), thus reducing the pull-in current. However, increasing the number of turns increases the coil inductance, slowing the current rise during pull-in and consequently the electromagnetic force rise, prolonging the pull-in time. This makes the relay unsuitable for applications requiring rapid action. Furthermore, the longer load contact switching time leads to prolonged arcing between contacts, shortening the relay's lifespan. Therefore, a comprehensive consideration of the number of turns and wire diameter is necessary to determine and ensure a suitable pull-in current.

[0005] Although the holding current during the holding phase does not need to reach the same magnitude as the pull-in current, only requiring 1 / 2 to 1 / 10, the holding current is generally still equal to the pull-in current because the relay only has one set of coils. This results in wasted power consumption when the relay is in the holding state, limiting its application in many low-power products. These products often abandon the relay solution altogether or use complex drive circuits to reduce the holding current and achieve energy savings, but this indirectly increases circuit costs, system complexity, and reduces system reliability. Summary of the Invention

[0006] The purpose of this invention is to provide a dual-coil relay and control method, which aims to solve the problem that traditional relays require a large current to maintain the state after being energized, resulting in wasted power consumption.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a control method for a dual-coil relay, comprising the following steps:

[0008] The energy storage element is charged to store driving energy for the coil.

[0009] The energy storage element is controlled to discharge to the coil, so that the current flowing through the coil is greater than the relay's pull-in current threshold, thus driving the contacts to close.

[0010] After the coil discharges, the control contacts are kept closed and the current is switched to be supplied by the holding coil.

[0011] The holding coil is energized to provide a holding current less than the pull-in current threshold to maintain the contact in a closed state.

[0012] In the section "controlling the energy storage element to charge and storing driving energy for the coil to engage", the energy storage element is a capacitor, and the charging step is completed by the power supply charging the capacitor through a current-limiting resistor.

[0013] In the section "controlling the energy storage element to charge and storing driving energy for the pull-in coil", the charging circuit of the capacitor flows through at least the holding coil.

[0014] In the process of “maintaining the closed state of the control contacts after the coil discharges and switching to the current supplied by the holding coil”, the energizing step is achieved by turning on a switching device to discharge the capacitor to the coil.

[0015] In the section "controlling the energization of the holding coil and providing a holding current less than the pull-in current threshold to maintain the closed state of the contacts", the holding coil is directly powered by the power supply.

[0016] In a second aspect, a dual-coil relay is used in the control method for the dual-coil relay described in the first aspect, comprising a relay body, a pull-in coil, a holding coil, and a control circuit, wherein the pull-in coil has N turns and a DC resistance of R1; the holding coil has M turns and a DC resistance of R2, wherein M = m * N, and R2 > R1.

[0017] The pull-in coil and the holding coil are wound on the same iron core and driven independently.

[0018] This invention discloses a control method for a dual-coil relay, comprising the following steps: controlling an energy storage element to charge, storing driving energy for the pull-in coil; controlling the energy storage element to discharge to the pull-in coil, such that the current flowing through the pull-in coil is greater than the relay's pull-in current threshold, driving the contacts to close; after the pull-in coil discharges, controlling the maintenance of the closed contact state and switching to current supplied by a holding coil; controlling the holding coil to energize, providing a holding current less than the pull-in current threshold to maintain the closed contact state. This invention significantly improves relay performance. Through the charging and discharging of the energy storage element combined with a dual-coil design, it achieves high-current rapid action during the pull-in phase and low-current, low-power maintenance during the holding phase. This shortens response time, reduces power consumption, extends the service life of the relay and related components, broadens the application range, reduces electromagnetic interference, and enhances the stability and reliability of the equipment, making it an ideal choice for low-power, high-reliability applications. This solves the problem of traditional relays requiring a large current for the holding state after pull-in, resulting in wasted power. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart of a control method for a dual-coil relay provided by the present invention.

[0021] Figure 2 This is a circuit diagram for a dual-coil relay that uses two independent coils.

[0022] Figure 3 This is a circuit diagram for a dual-coil relay that uses two independent coils.

[0023] Figure 4 This is a schematic diagram of a dual-coil relay provided by the present invention.

[0024] In the diagram: 1-Relay body, 2-Latching coil, 3-Holding coil, 4-Control circuit. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] Please see Figures 1 to 3 In a first aspect, the present invention provides a control method for a dual-coil relay, comprising the following steps:

[0027] S1 controls the energy storage element to charge, storing driving energy for the coil 2 to engage.

[0028] The energy storage element is a capacitor, and the charging step is completed by the power supply charging the capacitor through a current-limiting resistor.

[0029] The charging circuit of the capacitor flows through at least the holding coil 3.

[0030] Specifically, the energy storage element (such as a capacitor) is charged by a power supply through a current-limiting resistor. The charging process is controlled by switching devices (such as transistors and MOSFETs) in control circuit 4 to ensure that the energy storage element can complete charging within a specified time, reserving sufficient energy for the subsequent pull-in action. By precisely controlling the charging process, it is ensured that the energy storage element stores enough energy to meet the high current demand of the pull-in coil 2 at the moment of pull-in, improving the reliability of relay operation. At the same time, the use of a current-limiting resistor can prevent excessive charging current and protect the energy storage element and related circuits from damage.

[0031] S2 controls the energy storage element to discharge to the coil 2, so that the current flowing through the coil 2 is greater than the relay's pull-in current threshold, driving the contacts to close.

[0032] Specifically, when the relay needs to operate, the control circuit 4 triggers the switching device to conduct, and the energy storage element (capacitor) rapidly discharges to the pull-in coil 2. Because the energy storage element has pre-stored sufficient energy, the discharge generates a large instantaneous current far exceeding the relay's pull-in current threshold, producing a powerful electromagnetic force that drives the contacts to close rapidly. Utilizing the large current instantaneously released by the energy storage element ensures rapid and reliable contact closure, significantly shortening the relay's response time and improving operating efficiency. Furthermore, this method enables effective relay driving at lower operating voltages, broadening the relay's application range.

[0033] After the discharge of the coil 2, S3 controls the maintenance of the closed state of the control contacts and switches to the current supplied by the holding coil 3;

[0034] The energizing step is achieved by turning on a switching device, which causes the capacitor to discharge to the energizing coil 2.

[0035] Specifically, after the contacts close, the control circuit 4 promptly cuts off the path between the energy storage element and the pull-in coil 2 to prevent over-discharge of the energy storage element. Simultaneously, the control circuit 4 connects the power supply circuit to the holding coil 3, which then takes over the task of maintaining the closed state of the contacts, ensuring a stable closed state. By switching the power supply circuit in a timely manner, over-discharge of the energy storage element is avoided, extending its service life. Furthermore, the holding coil 3 operates at a lower current, reducing energy consumption, lowering the power consumption of the relay in the holding state, and improving energy utilization efficiency.

[0036] S4 controls the energization of the holding coil 3, providing a holding current less than the pull-in current threshold to maintain the contact closed state.

[0037] The holding coil 3 is directly powered by the power supply.

[0038] Specifically, the current of holding coil 3 is directly supplied by the power supply. Through a current-limiting resistor or other regulating element in control circuit 4, the current is limited to a level below the pull-in current threshold. The electromagnetic force generated by holding coil 3 is sufficient to maintain the closed state of the contacts without causing excessive contact wear or energy waste. Using a lower holding current when maintaining the closed state of the contacts can significantly reduce the power consumption of the relay, extend battery life, and reduce heat generated by prolonged high current flow, thus improving the stability and reliability of the relay. Furthermore, a lower holding current also helps reduce electromagnetic interference and improve the electromagnetic compatibility of the device.

[0039] Example:

[0040] See Figure 2 Method 1: If the dual-coil relay uses two independent coils, and each coil is driven independently, this method corresponds to the standard driving method of the original ordinary relay.

[0041] If the relay electrical structure uses the original relay parameters, and coil 1 still uses the original relay parameters, and the original relay holding current is 1 / m of the pull-in current (where m = 2-10), then if the wire diameter of coil 2 is the same as that of coil 1, and the number of turns of coil 2 is m times that of coil 1, the holding current can be reduced to 1 / m of the original. If the wire diameter of coil 2 is further increased...

[0042] See Figure 3 Method 2: A dual-coil relay uses two coils connected in series to operate, or is equivalent to a single coil with a tap in the middle. This method corresponds to an optimization of the original ordinary relay.

[0043] State 1: When transistor T1 is off, the circuit is the same as before, with no current flowing through relay coils L1 and 2, and the output contacts are open. However, at this time, the power supply Vcc charges capacitor C1 through coil 2, causing the voltage on capacitor C1 to be the same as Vcc.

[0044] State 2: When transistor T1 is first turned on, there is a voltage Vcc on capacitor C1, which supplies power to relay coil L1. The current in relay coil L1 is the same as in the original scheme, causing the output contacts to close quickly. Subsequently, as the charge stored in capacitor C1 is consumed, the voltage on capacitor C1 drops, and the current in the coil eventually becomes IL = Vcc / (RL1 + RL2), where RL1 and RL2 are the DC resistance values ​​of coils L1 and L2, respectively.

[0045] If the relay electrical structure is designed using the original relay parameters, and coil 1 still uses the original relay parameters, the original relay holding current is 1 / m of the pull-in current (where m = 2-10). Then, if the wire diameter of coil 2 is the same as that of coil 1, the number of turns of coil 2 is m-1 times that of coil 1, which can reduce the holding current to 1 / m of the original. If the number of turns of coil 2 is further increased while the wire diameter of coil 2 is reduced, the holding current can be further reduced.

[0046] The advantage of this method is that it allows for rapid operation with a large current at startup, and maintains the state with both coils working simultaneously, reducing the current to 1 / (m+1) or lower than the original value.

[0047] Please see Figure 4 In a second aspect, a dual-coil relay is provided for use in the control method of the dual-coil relay described in the first aspect, comprising a relay body 1, a pull-in coil 2, a holding coil 3, and a control circuit 4, wherein the pull-in coil 2 has N turns and a DC resistance of R1; the holding coil 3 has M turns and a DC resistance of R2, wherein M = m * N, and R2 > R1.

[0048] The attracting coil 2 and the holding coil 3 are wound on the same iron core and are driven independently.

[0049] In this embodiment, the relay body 1 constitutes the basic structure of the relay, supporting and protecting the internal components. The pull-in coil 2 has N turns and a DC resistance of R1, responsible for generating a strong magnetic field to drive the contacts to close. The holding coil 3 has M turns (M = m * N) and a DC resistance of R2 (R2 > R1), maintaining the contacts in a closed state. The control circuit 4 includes capacitors, resistors, and switching devices (such as transistors), responsible for energy storage, current limiting, and circuit switching. During the pull-in phase: the control circuit 4 triggers the switching device, the capacitor discharges to the pull-in coil 2, and the current exceeds the pull-in threshold, driving the contacts to close. During the holding phase: after pull-in, the holding coil 3 maintains the contacts closed with a low current, reducing power consumption.

[0050] The above description is merely a preferred embodiment of a dual-coil relay and control method of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A control method for a dual-coil relay, characterized in that, Includes the following steps: The energy storage element is charged to store driving energy for the coil. The energy storage element is controlled to discharge to the coil, so that the current flowing through the coil is greater than the relay's pull-in current threshold, thus driving the contacts to close. After the coil discharges, the control contacts are kept closed and the current is switched to be supplied by the holding coil. The holding coil is energized to provide a holding current less than the pull-in current threshold to maintain the contact in a closed state.

2. The control method for a dual-coil relay as described in claim 1, characterized in that, In the phrase "controlling the energy storage element to charge and storing driving energy for the coil to engage", the energy storage element is a capacitor, and the charging step is completed by the power supply charging the capacitor through a current-limiting resistor.

3. The control method for a dual-coil relay as described in claim 2, characterized in that, In the phrase "controlling the energy storage element to charge and storing driving energy for the pull-in coil", the charging circuit of the capacitor flows through at least the holding coil.

4. The control method for a dual-coil relay as described in claim 1, characterized in that, The pull-in step in "maintaining the closed state of the control contacts after the pull-in coil has finished discharging and switching to the current supplied by the holding coil" is achieved by turning on a switching device to discharge the capacitor to the pull-in coil.

5. The control method for a dual-coil relay as described in claim 1, characterized in that, In the "controlling the energization of the holding coil and providing a holding current less than the pull-in current threshold to maintain the contact closed state", the holding coil is directly powered by the power supply.

6. A dual-coil relay, used in the control method of the dual-coil relay according to any one of claims 1-5, characterized in that, It includes a relay body, a pull-in coil, a holding coil, and a control circuit. The pull-in coil has N turns and a DC resistance of R1; the holding coil has M turns and a DC resistance of R2, where M = m * N and R2 > R1.

7. The dual-coil relay as described in claim 6, characterized in that, The pull-in coil and the retaining coil are wound on the same iron core and are driven independently.

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