Relay coil energy absorption circuit

Abstract

The utility model provides a relay coil energy absorption circuit, which comprises a relay switch control circuit, an energy absorption loop and an energy discharge diode, and is characterized in that the input end of the relay switch control circuit is connected to a switch control signal input end; the output end of the relay switch control circuit is respectively connected to the first input end of the energy absorption loop, the cathode of the energy discharge diode and one end of the relay coil; the second input end of the energy absorption loop is connected to the power supply, the output end of the energy absorption loop is connected to the other end of the relay coil, the anode of the energy discharge diode is grounded, and the power supply provides working voltage corresponding to the relay coil. The voltage peak when the relay coil cuts off power supply is limited through the energy discharge diode, and the working reliability of the circuit is improved.

Description

Technical Field

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

[0002] Relays are the most commonly used actuators. When the relay is turned on, it only consumes a certain amount of current (about 0.1A-0.2A). When the relay is closed, due to the inductive characteristics of the coil, a reasonable absorption circuit needs to be configured.

[0003] In the traditional absorption circuit, when the relay coil is suddenly powered off, the current in the coil will not suddenly change. Therefore, a large reverse voltage will be generated at the coil end. This reverse voltage will cause the components in the absorption circuit to break down and be damaged, reducing the reliability of the circuit operation. Utility Model Content

[0004] In view of this, the purpose of the present application is to at least provide a relay coil energy absorption circuit, which limits the voltage spike when the relay coil cuts off the power supply through the energy discharge diode, thereby improving the reliability of the circuit operation.

[0005] This application mainly includes the following aspects:

[0006] In a first aspect, an embodiment of the present application provides a relay coil energy absorption circuit, the relay coil energy absorption circuit comprising a relay switch control circuit, an energy absorption loop and an energy discharge diode, wherein the input end of the relay switch control circuit is connected to the switch control signal input end, and the output end of the relay switch control circuit is respectively connected to the first input end of the energy absorption loop, the cathode of the energy discharge diode and one end of the relay coil; the second input end of the energy absorption loop is connected to a power supply, the output end of the energy absorption loop is connected to the other end of the relay coil, the anode of the energy discharge diode is grounded, and the power supply provides a working voltage corresponding to the relay coil.

[0007] In one possible implementation, the relay switch control circuit includes a first resistor, a second resistor and a first control switch, wherein one end of the first resistor is connected to a switch control signal input end, and the other end of the first resistor is respectively connected to one end of the second resistor and a control end of the first control switch; after the first connection end of the first control switch is connected to the other end of the second resistor, it serves as the output end of the relay switch control circuit and is respectively connected to the first input end of the energy absorption loop, the cathode of the energy discharge diode and one end of the relay coil; the second connection end of the first control switch is grounded.

[0008] In one possible implementation, the energy absorption circuit includes an energy absorption control module and an energy absorption module, wherein a first connection end of the energy absorption control module is connected to a power supply, a second connection end of the energy absorption control module is connected to an output end of a relay switch control circuit, and a third connection end of the energy absorption control module is respectively connected to one end of the energy absorption module and the other end of the relay coil; the other end of the energy absorption control module is connected to the other end of the energy absorption module.

[0009] In one possible implementation, the energy absorption control module includes a second control switch and a first diode, wherein the cathode of the first diode is connected to a power supply, the anode of the first diode is connected to a control end of the second control switch, the first connection end of the second control switch is respectively connected to the other end of the relay coil and one end of the energy absorption module, and the second connection end of the second control switch is connected to the other end of the energy absorption module.

[0010] In one possible implementation, the energy absorption control module further includes a second diode, wherein the anode of the second diode is respectively connected to the power supply and the cathode of the first diode, and the cathode of the second diode is respectively connected to one end of the energy absorption module and the other end of the relay coil.

[0011] In one possible implementation, the energy absorption control module also includes a third resistor, wherein one end of the third resistor is respectively connected to the anode of the first diode and the control end of the second control switch, and the other end of the third resistor is respectively connected to the output end of the relay switch control circuit, the cathode of the energy discharge diode and one end of the relay coil.

[0012] In one possible implementation, the energy absorption module includes a first capacitor and a fourth resistor, wherein one end of the first capacitor is respectively connected to the cathode of the second diode and the other end of the relay coil, the other end of the first capacitor is respectively connected to one end of the fourth resistor and the second connection end of the second control switch, and the other end of the fourth resistor is grounded.

[0013] In one possible implementation, the relay coil energy absorption circuit further includes a second capacitor, one end of the second capacitor is respectively connected to the power supply, the cathode of the first diode and the anode of the second diode, and the other end of the second capacitor is grounded.

[0014] In one possible implementation, the first control switch in the relay switch control circuit is an NMOS switch, the control end of the first control switch is the gate of the NMOS switch, the first connection end of the first control switch is the drain of the NMOS switch, and the second connection end of the first control switch is the source of the NMOS switch; the second control switch is a PMOS switch, the control end of the second control switch is the gate of the PMOS switch, the first connection end of the second control switch is the drain of the PMOS switch, and the second connection end of the second control switch is the source of the PMOS switch.

[0015] In a possible implementation manner, a breakdown voltage corresponding to the energy discharge diode is greater than an operating voltage corresponding to the relay coil, and a breakdown voltage corresponding to the energy discharge diode is less than a drain voltage of the first control switch.

[0016] The relay coil energy absorption circuit provided in the embodiment of the present application includes a relay switch control circuit, an energy absorption circuit and an energy discharge diode, wherein the input end of the relay switch control circuit is connected to the switch control signal input end, and the output end of the relay switch control circuit is respectively connected to the first input end of the energy absorption circuit, the cathode of the energy discharge diode and one end of the relay coil; the second input end of the energy absorption circuit is connected to the power supply, the output end of the energy absorption circuit is connected to the other end of the relay coil, the anode of the energy discharge diode is grounded, and the power supply provides the corresponding working voltage of the relay coil. The voltage spike when the relay coil cuts off the power supply is limited by the energy discharge diode, thereby improving the reliability of the circuit operation.

[0017] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 One of the structural schematic diagrams of a relay coil energy absorption circuit provided in an embodiment of the present application is shown;

[0020] Figure 2 A second structural schematic diagram of a relay coil energy absorption circuit provided in an embodiment of the present application is shown;

[0021] Figure 3A third structural schematic diagram of a relay coil energy absorption circuit provided in an embodiment of the present application is shown;

[0022] Figure 4 A schematic diagram of a relay coil energy discharge path provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present application, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0024] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0025] Relays are the most commonly used actuators. When the relay is turned on, it only consumes a certain amount of current (about 0.1A-0.2A). When the relay is closed, due to the inductive characteristics of the coil, a reasonable absorption circuit needs to be configured. In the traditional absorption circuit, when the relay coil is suddenly powered off, the current in the coil will not suddenly change. Therefore, a large reverse voltage will be generated at the coil end. This reverse voltage will cause the device in the absorption circuit to break down and cause damage, reducing the reliability of the circuit operation. Based on this, the embodiment of the present application provides a relay coil energy absorption circuit, which limits the voltage spike when the relay coil cuts off the power supply through an energy discharge diode, thereby improving the reliability of the circuit operation, as follows:

[0026] See also Figure 1 , Figure 1 FIG. 1 shows one of the structural schematic diagrams of a relay coil energy absorption circuit provided in an embodiment of the present application. Figure 1As shown, the relay coil energy absorption circuit provided in the embodiment of the present application includes a relay switch control circuit 1, an energy absorption loop 2 and an energy discharge diode 3, wherein the breakdown voltage of the energy discharge diode 3 is greater than the working voltage corresponding to the relay coil.

[0027] In a preferred embodiment, the input end of the relay switch control circuit 1 is connected to the switch control signal input end Von_off, and the output end of the relay switch control circuit 1 is respectively connected to the first input end of the energy absorption loop 2, the cathode of the energy discharge diode 3 and one end of the relay coil J.

[0028] The second input end of the energy absorption loop 2 is connected to the power supply VCC, the output end of the energy absorption loop 2 is connected to the other end of the relay coil J, the anode of the energy discharge diode 3 is grounded, and the power supply VCC provides a working voltage corresponding to the relay coil J.

[0029] Specifically, the power supply VCC=the working voltage corresponding to the relay coil J=+12V, the energy discharge diode 3 is a TVS diode, and the breakdown voltage of the energy discharge diode 3 is 3V higher than the working voltage +12V of the relay coil J, that is, the breakdown voltage of the energy discharge diode 3=15V.

[0030] In another preferred embodiment, see Figure 2 , Figure 2 FIG2 shows a second structural schematic diagram of a relay coil energy absorption circuit provided in an embodiment of the present application. Figure 2 As shown, the relay switch control circuit 1 includes a first resistor R1, a second resistor R2 and a first control switch Q1.

[0031] like Figure 2 As shown, one end of the first resistor R1 is connected to the switch control signal input terminal Von_off, and the other end of the first resistor R1 is respectively connected to one end of the second resistor R2 and the control end of the first control switch Q1.

[0032] After the first connection end of the first control switch Q1 is connected to the other end of the second resistor R2, it serves as the output end of the relay switch control circuit and is respectively connected to the first input end of the energy absorption loop 2, the cathode of the energy discharge diode 3 and one end of the relay coil, and the second connection end of the first control switch Q1 is grounded.

[0033] Specifically, the first resistor R1 is 51R, the second resistor R2 is 20K, the first control switch Q1 is an NMOS switch, the control end of the first control switch Q1 is the gate of the NMOS switch, the first connection end of the first control switch Q1 is the drain of the NMOS switch, the second connection end of the first control switch Q1 is the source of the NMOS switch, and the corresponding breakdown voltage of the energy discharge diode 3 is less than the drain voltage of the first control switch Q1, so that the first control switch Q1 can be ensured not to be damaged when the relay coil is powered off.

[0034] In another preferred embodiment, the energy absorption circuit 2 includes an energy absorption control module 21 and an energy absorption module 22 .

[0035] like Figure 2 As shown, the first connection end of the energy absorption control module 21 is connected to the power supply VCC, the second connection end of the energy absorption control module 21 is respectively connected to the other end of the second resistor R2, the first connection end of the first control switch Q1, the other end of the relay coil J and the cathode of the energy discharge diode 3, the third connection end of the energy absorption control module 21 is respectively connected to one end of the energy absorption module 22 and the other end of the relay coil J, and the other end of the energy absorption control module 21 is connected to the other end of the energy absorption module 22.

[0036] In a preferred embodiment, see Figure 3 , Figure 3 FIG3 shows a third structural diagram of a relay coil energy absorption circuit provided in an embodiment of the present application. Figure 3 As shown, the energy absorption control module 21 includes a second control switch Q2, a first diode D1, a second diode D2 and a third resistor R3, and the energy absorption module 22 includes a first capacitor C1 and a fourth resistor R4.

[0037] like Figure 3 As shown, the cathode of the first diode D1 is respectively connected to the power supply VCC, the anode of the second diode D2 and the first connection end of the second control switch Q2, and the anode of the first diode D1 is respectively connected to the control end of the second control switch Q2 and one end of the third resistor R3.

[0038] The cathode of the second diode D2 is respectively connected to one end of the first capacitor C1 and the other end of the relay coil J, and the other end of the third resistor R3 is respectively connected to the other end of the second resistor R2, the first connection end of the first control switch Q1, the cathode of the energy discharge diode 3 and one end of the relay coil J.

[0039] The other end of the first capacitor C1 is respectively connected to one end of the fourth resistor R4 and the second connection end of the second control switch Q2, and the other end of the fourth resistor R4 is grounded.

[0040] In a specific embodiment, the third resistor R3 is 5.1K, the fourth resistor R4 is 1.2K, the second control switch is a PMOS switch, the control end of the second control switch is the gate of the PMOS switch, the first connection end of the second control switch is the drain of the PMOS switch, and the second connection end of the second control switch is the source of the PMOS switch.

[0041] In another preferred embodiment, the relay coil energy absorption circuit further includes a second capacitor C2, one end of which is respectively connected to the power supply VCC, the cathode of the first diode D1 and the anode of the second diode D2, and the other end of the second capacitor C2 is grounded.

[0042] like Figure 3 As shown, the power supply VCC = 12V. For the relay coil, when the relay coil is in the normal shutdown state, the switch control signal input terminal Von_off = 0V. At this time, the entire relay coil energy absorption circuit has the following states:

[0043] The voltage across the first resistor R1 is 0V, the control end of the first control switch Q1 is 0V, the first control switch Q1 is disconnected, and the forward applied voltage of the energy discharge diode 3 is 12V, which is lower than the action voltage of the energy discharge diode 3. At this time, the cathode of the energy discharge diode 3, that is, the potential of the VC end is 12V (high potential), the control end (gate) input voltage of the second control switch Q2 is 0V, and the second control switch Q2 is disconnected.

[0044] Let the switch control signal input terminal Von_off = 12V, the relay coil is in the open state, at this time, the entire relay coil energy absorption circuit has the following states:

[0045] ① Von_off passes through the first resistor R1 to the control end of the first control switch Q1, and the first control switch Q1 is turned on;

[0046] ②The potential of the VC terminal drops to 0V, the relay coil is energized, and the relay contacts are closed;

[0047] ③ The VC terminal potential is 0V, the control terminal (gate) input voltage of the second control switch Q2 is negative, and the second control switch Q2 is turned on;

[0048] ④The voltage on the first capacitor C1 is in a fully charged state of 12V.

[0049] Let the switch control signal input terminal Von_off = 0V, the first control switch Q1 is turned off, at this time, the entire relay coil energy absorption circuit has the following state:

[0050] ① The current of the relay coil J1 cannot change suddenly. Under the action of the inductance of the relay coil J1 and the coil current, the voltage at one end of the relay coil J1 rises, that is, the voltage at the VC end rises rapidly, and the coil current flows from one end A of the relay coil J1 to the other end B of the relay coil J1;

[0051] ② As the voltage at the VC terminal rises, the voltage at the control terminal (gate or base) of the second control switch Q2 gradually rises. If the second control switch Q2 is an NPN transistor, when the input voltage at the control terminal of the second control switch Q2 is greater than 0.7V, the second control switch Q2 is ready for conduction.

[0052] The second control switch Q2 is quickly closed and turned on;

[0053] ③ The voltage at the VC terminal continues to rise until it exceeds the clamping voltage of the energy discharge diode 3. The voltage at the VC terminal forms a large discharge current on the energy discharge diode 3, and this discharge current still flows back to the other end of the relay coil.

[0054] See also Figure 4 , Figure 4 FIG. 1 shows a schematic diagram of a relay coil energy discharge path provided by an embodiment of the present application. Figure 4 As shown, after the energy discharge diode 3 is turned on, the ground is connected, as shown in FIG. Figure 4 As shown by the dotted lines, three discharge paths are formed:

[0055] Path 1: one end A of the relay coil---> the broken energy discharge diode 3---> the fourth resistor R4---> the first capacitor C1---> the other end B of the relay coil, through the connection ground, a corresponding discharge path is formed. In this discharge path, a reverse current flows into the first capacitor C1, which is equivalent to the first capacitor C1 being connected in series with the fourth resistor R4, and a voltage of up to -3V is applied instantaneously (15-12=3V), and the energy stored in the first capacitor C1 is partially released.

[0056] Path 2: one end A of the relay coil--->the third resistor R3--->the first diode D1--->the second diode D2--->the other end B of the relay coil, forming a discharge loop. For this loop, since the resistance of the third resistor R3 is large and the pressure difference is small, the discharge capacity of this discharge loop is limited.

[0057] Path three: one end A of the relay coil--->energy discharge diode 3--->fourth resistor R4--->second control switch Q2--->second diode D2--->the other end B of the relay coil, forming a discharge loop.

[0058] In the three discharge loops, since the breakdown voltage of the energy discharge diode 3 is lower than the Vds (between the drain and the source) withstand voltage of the first control switch Q1 , the first control switch Q1 is safe during the entire energy absorption process.

[0059] The present application introduces an energy discharge diode at one end of the relay coil so that the energy discharge diode breaks down when the relay coil is suddenly turned off, thereby forming a corresponding energy discharge loop, preventing other devices from breaking down under the influence of high voltage and improving circuit stability.

[0060] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. In the several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0061] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0062] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0063] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0064] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A relay coil energy absorption circuit, characterized in that: The relay coil energy absorption circuit includes a relay switch control circuit, an energy absorption loop and an energy discharge diode. Wherein, the input end of the relay switch control circuit is connected to the switch control signal input end, and the output end of the relay switch control circuit is respectively connected to the first input end of the energy absorption loop, the cathode of the energy discharge diode and one end of the relay coil; The second input end of the energy absorption loop is connected to the power supply, the output end of the energy absorption loop is connected to the other end of the relay coil, the anode of the energy discharge diode is grounded, and the power supply provides a working voltage corresponding to the relay coil.

2. The relay coil energy absorption circuit according to claim 1, characterized in that: The relay switch control circuit includes a first resistor, a second resistor and a first control switch. Wherein, one end of the first resistor is connected to the switch control signal input end, and the other end of the first resistor is respectively connected to one end of the second resistor and the control end of the first control switch; After the first connection end of the first control switch is connected to the other end of the second resistor, it serves as the output end of the relay switch control circuit and is respectively connected to the first input end of the energy absorption loop, the cathode of the energy discharge diode and one end of the relay coil; The second connection end of the first control switch is grounded.

3. The relay coil energy absorption circuit according to claim 1, characterized in that: The energy absorption circuit includes an energy absorption control module and an energy absorption module. Wherein, the first connection end of the energy absorption control module is connected to the power supply, the second connection end of the energy absorption control module is connected to the output end of the relay switch control circuit, and the third connection end of the energy absorption control module is respectively connected to one end of the energy absorption module and the other end of the relay coil; The other end of the energy absorption control module is connected to the other end of the energy absorption module.

4. The relay coil energy absorption circuit according to claim 3, characterized in that: The energy absorption control module includes a second control switch and a first diode, Among them, the cathode of the first diode is connected to the power supply, the anode of the first diode is connected to the control end of the second control switch, the first connection end of the second control switch is respectively connected to the other end of the relay coil and one end of the energy absorption module, and the second connection end of the second control switch is connected to the other end of the energy absorption module.

5. The relay coil energy absorption circuit according to claim 4, characterized in that: The energy absorption control module further includes a second diode, The anode of the second diode is connected to the power supply and the cathode of the first diode respectively, and the cathode of the second diode is connected to one end of the energy absorption module and the other end of the relay coil respectively.

6. The relay coil energy absorption circuit according to claim 4, characterized in that: The energy absorption control module further includes a third resistor, One end of the third resistor is respectively connected to the anode of the first diode and the control end of the second control switch, and the other end of the third resistor is respectively connected to the output end of the relay switch control circuit, the cathode of the energy discharge diode and one end of the relay coil.

7. The relay coil energy absorption circuit according to claim 5, characterized in that: The energy absorption module includes a first capacitor and a fourth resistor, Among them, one end of the first capacitor is respectively connected to the cathode of the second diode and the other end of the relay coil, the other end of the first capacitor is respectively connected to one end of the fourth resistor and the second connection end of the second control switch, and the other end of the fourth resistor is grounded.

8. The relay coil energy absorption circuit according to claim 5, characterized in that: The relay coil energy absorption circuit also includes a second capacitor, One end of the second capacitor is respectively connected to the power supply, the cathode of the first diode and the anode of the second diode, and the other end of the second capacitor is grounded.

9. The relay coil energy absorption circuit according to claim 4, characterized in that: The first control switch in the relay switch control circuit is an NMOS switch, the control end of the first control switch is a gate of the NMOS switch, the first connection end of the first control switch is a drain of the NMOS switch, and the second connection end of the first control switch is a source of the NMOS switch; The second control switch is a PMOS switch, the control end of the second control switch is the gate of the PMOS switch, the first connection end of the second control switch is the drain of the PMOS switch, and the second connection end of the second control switch is the source of the PMOS switch.

10. The relay coil energy absorption circuit according to claim 9, characterized in that: The breakdown voltage corresponding to the energy discharge diode is greater than the working voltage corresponding to the relay coil, and the breakdown voltage corresponding to the energy discharge diode is less than the drain voltage of the first control switch.

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