Relay feedback contact detection circuit and relay feedback system

Abstract

The application relates to a relay feedback contact detection circuit and a relay feedback system, wherein the relay feedback contact detection circuit comprises a pull-up module and a feedback module; the pull-up module is connected with a power supply end and a feedback contact of a relay respectively; a first end of the feedback module is connected with the pull-up module and the feedback contact respectively; a second end of the feedback module is used for being connected with a controller outside the relay; the feedback module is used for transmitting a contact feedback signal generated by the feedback contact to the controller; the pull-up module is used for generating a transient current at a first end of the feedback contact when a second end of the feedback contact is closed, so as to soften an oxide film on a surface of the feedback contact, and generating a steady-state current at the first end of the feedback contact after the second end of the feedback contact is closed, wherein the steady-state current is smaller than the transient current. The relay feedback contact detection circuit in the application can guarantee the reliability of feedback contact detection while having relatively small power consumption.

Description

Technical Field

[0001] This application relates to the field of relay technology, and in particular to a relay feedback contact detection circuit and a relay feedback system. Background Technology

[0002] Relays with feedback contacts are commonly used electrical switching devices and are widely used in circuits for power management, signal switching, and load control.

[0003] In existing technology, to detect the on / off state of a relay feedback contact, a pull-up resistor is typically placed at one end of the relay feedback contact, causing the feedback contact to output a high level when open and a low level when closed. Considering that an oxide layer is easily formed on the surface of the feedback contact, the resistance value of the pull-up resistor is generally reduced to increase the instantaneous current when the contact closes, thereby improving the reliability of the contact closure.

[0004] However, existing relay feedback contact detection circuits cannot meet the power consumption requirements of low-power devices. Utility Model Content

[0005] Therefore, it is necessary to provide a relay feedback contact detection circuit and relay feedback system that can ensure the reliability of feedback contact detection while having low power consumption, in order to address the above-mentioned technical problems.

[0006] In a first aspect, this application provides a relay feedback contact detection circuit, which includes a pull-up module and a feedback module:

[0007] The first end of the pull-up module is used to connect to the power supply, and the second end of the pull-up module is used to connect to the feedback contact of the relay.

[0008] The first end of the feedback module is connected to the pull-up module and the feedback contact respectively, and the second end of the feedback module is used to connect to the controller outside the relay.

[0009] The feedback module is used to transmit the contact feedback signal generated by the feedback contact to the controller. The pull-up module is used to generate an instantaneous current at the first end of the feedback contact when the first end of the feedback contact is closed with the second end of the feedback contact, so as to soften the oxide film on the surface of the feedback contact. After the first end of the feedback contact is closed with the second end of the feedback contact, a steady-state current is generated at the first end of the feedback contact, and the steady-state current is less than the instantaneous current.

[0010] In one embodiment, the pull-up module includes: a voltage divider circuit and a steady-state control circuit, wherein a first terminal of the voltage divider circuit is connected to a power supply terminal, and a second terminal of the voltage divider circuit is connected to a first terminal of a feedback contact; a first terminal of the steady-state control circuit is connected to the voltage divider circuit, and a second terminal of the steady-state control circuit is connected to a first terminal of the feedback contact.

[0011] The steady-state control circuit is used to generate an instantaneous current at the first end of the feedback contact through a voltage divider circuit when the first end of the feedback contact is closed and the second end of the feedback contact is closed, and to generate a steady-state current at the first end of the feedback contact through a voltage divider circuit after the first end of the feedback contact is closed and the second end of the feedback contact is closed.

[0012] In one embodiment, the voltage divider circuit includes resistors R1 and R2, with a first end of resistor R1 connected to a power supply terminal, a second end of resistor R1 connected to a first end of resistor R2, and a second end of resistor R2 connected to a first end of a feedback contact.

[0013] Resistor R1 is used to generate an instantaneous current at the first end of the feedback contact when the first end of the feedback contact is closed with the second end of the feedback contact;

[0014] Resistors R1 and R2 are used to generate a steady-state current at the first end of the feedback contact after the first end of the feedback contact is closed with the second end of the feedback contact.

[0015] In one embodiment, the steady-state control circuit includes a capacitor C2 connected in parallel with a resistor R2;

[0016] Capacitor C2 is used to short-circuit resistor R2 when the first end of the feedback contact is closed to the second end of the feedback contact, so that the power supply terminal generates an instantaneous current at the first end of the feedback contact through resistor R1; and is used to generate a steady-state current at the first end of the feedback contact through resistors R1 and R2 after the first end of the feedback contact is closed to the second end of the feedback contact.

[0017] In one embodiment, the relay feedback contact detection circuit further includes a discharge circuit connected in parallel with capacitor C2. The discharge circuit is used to discharge capacitor C2 when the first end of the feedback contact is disconnected from the second end of the feedback contact.

[0018] In one embodiment, the instantaneous current ranges from 50mA to 100mA.

[0019] In one embodiment, the resistance of resistor R1 is 47Ω and the resistance of resistor R2 is 220Ω.

[0020] In one embodiment, the feedback module includes a resistor R3, with a first end of the resistor R3 connected to a first end of the feedback contact and a second end of the resistor R3 connected to the controller. The resistor R3 is used to send the contact feedback signal to the controller.

[0021] In one embodiment, the feedback module further includes a capacitor C3, the first end of which is connected to the second end of a resistor R3, and the second end of the capacitor C3 is grounded. The capacitor C3 is used to filter the contact feedback signal.

[0022] Secondly, this application also provides a relay feedback system, which includes a relay feedback contact detection circuit as described in the first aspect.

[0023] The aforementioned relay feedback contact detection circuit and relay feedback system, on the one hand, can provide a large instantaneous current at the moment the first and second ends of the feedback contact close, softening the oxide film on the surface of the feedback contact. This facilitates the removal of the oxide film or contaminant layer on the surface of the feedback contact, reduces contact resistance, and improves the reliability and service life of the feedback contact during initial closure. On the other hand, it can maintain a small steady-state current during circuit steady-state operation, thus maintaining low power consumption and heat generation. Therefore, the relay feedback contact detection circuit in this application can reduce power requirements and device power consumption while ensuring the reliability of feedback contact state detection. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the module structure of a relay feedback contact detection circuit according to one embodiment;

[0026] Figure 2 A schematic diagram of the module structure of a relay feedback contact detection circuit according to another embodiment;

[0027] Figure 3 This is a circuit diagram of a relay feedback contact detection circuit in one embodiment.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100. Relay feedback contact detection circuit; 110. Pull-up module; 111. Voltage divider circuit; 112. Steady-state control circuit; 120. Feedback module; 200. Power supply terminal; 300. Feedback contact; 400. Controller. Detailed Implementation

[0030] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0032] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0033] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0034] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0035] When used herein, the singular forms of “a,” “an,” and “ / the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0036] A relay with feedback contact 300 is a regular relay with an additional set of low-power, follow-up feedback contacts 300, used to output a contact feedback signal indicating the relay's own operating status. The surface of the feedback contact 300 is typically made of alloy or similar materials, which are prone to oxide layer formation, leading to poor contact feedback and inaccurate feedback signals.

[0037] like Figure 1 As shown, in one embodiment of this application, the relay feedback contact detection circuit includes a pull-up module 110 and a feedback module 120. The first end of the pull-up module 110 is used to connect to the power supply terminal 200, and the second end of the pull-up module 110 is used to connect to the feedback contact 300 of the relay. The first end of the feedback module 120 is connected to both the pull-up module 110 and the feedback contact 300, and the second end of the feedback module 120 is used to connect to the controller 400 outside the relay.

[0038] The feedback module 120 is used to transmit the contact feedback signal generated by the feedback contact 300 to the controller 400. The pull-up module 110 is used to generate an instantaneous current at the first end of the feedback contact 300 when the first end of the feedback contact 300 is closed with the second end of the feedback contact 300, so as to soften the oxide film on the surface of the feedback contact 300. After the first end of the feedback contact 300 is closed with the second end of the feedback contact 300, a steady-state current is generated at the first end of the feedback contact 300, and the steady-state current is less than the instantaneous current.

[0039] The second terminal of the feedback contact 300 in the relay is grounded.

[0040] The controller 400 can be an MCU (Micro Controller Unit) or a PLD (Programmable Logic Device). The controller 400 is used to receive the contact feedback signal transmitted by the feedback module 120 and to make logical judgments based on the contact feedback signal in order to monitor the status of the relay.

[0041] The relay feedback contact detection circuit provided in this embodiment can, on the one hand, provide a large instantaneous current at the moment the first and second ends of the feedback contact 300 close, softening the oxide film on the surface of the feedback contact 300. This facilitates the removal of the oxide film or contaminant layer on the surface of the feedback contact 300, reduces contact resistance, and improves the reliability and service life of the feedback contact 300 during initial closure. On the other hand, it can maintain a small steady-state current during circuit steady-state operation, thus maintaining low power consumption and heat generation. Therefore, the relay feedback contact detection circuit in this embodiment can reduce power requirements and device power consumption while ensuring the reliability of the feedback contact 300 status detection.

[0042] In one exemplary embodiment, such as Figure 2 As shown, the pull-up module 110 includes a voltage divider circuit 111 and a steady-state control circuit 112. The first end of the voltage divider circuit 111 is connected to the power supply terminal 200, and the second end of the voltage divider circuit 111 is connected to the first end of the feedback contact 300. The first end of the steady-state control circuit 112 is connected to the voltage divider circuit 111, and the second end of the steady-state control circuit 112 is connected to the first end of the feedback contact 300.

[0043] The steady-state control circuit 112 is used to generate an instantaneous current at the first end of the feedback contact 300 through the voltage divider circuit 111 when the first end of the feedback contact 300 and the second end of the feedback contact 300 are closed, and to generate a steady-state current at the first end of the feedback contact 300 through the voltage divider circuit 111 after the first end of the feedback contact 300 and the second end of the feedback contact 300 are closed.

[0044] In some embodiments, the instantaneous current ranges from 50mA to 100mA, which can soften or break down the oxide film on the surface of the feedback contact 300, ensuring that the feedback contact 300 closes reliably and ensuring the reliability of the contact feedback signal.

[0045] In some embodiments, the steady-state control circuit 112 may employ a combination of current-limiting elements and parallel discharge elements to store charge during the transient phase and provide an additional current path at the moment of closing. Then, the steady-state control circuit 112 enters the steady-state phase and, according to a preset voltage division ratio, enables the power supply terminal 200 to maintain a stable steady-state current at the first end of the feedback contact 300 through the voltage divider circuit 111. The steady-state current is limited to the milliampere level or even the microampere level, which not only ensures the detection accuracy of the conduction state of the feedback contact 300, but also significantly reduces the long-term power consumption and heat generation of the circuit.

[0046] In this embodiment, the pull-up module 110 utilizes the synergistic effect of the voltage divider circuit 111 and the steady-state control circuit 112 to provide a sufficiently large current at the moment of contact closure to improve the reliability of contact closure, while reducing current consumption in the steady-state stage, thus balancing the requirements of reliability and low power consumption. It is particularly suitable for scenarios in low-power electronic devices where relay feedback contacts 300 are detected.

[0047] Figure 3 A circuit diagram of a relay feedback contact detection circuit according to an embodiment of this application is shown. K4-D represents feedback contact 300, label 11 represents the first end of feedback contact 300, and label 12 represents the second end of feedback contact 300; port RLY_FB1 represents the output terminal, used for connection to controller 400.

[0048] In one exemplary embodiment, see [reference] Figure 2 The voltage divider circuit 111 includes resistors R1 and R2. The first end of resistor R1 is connected to the power supply terminal 200, the second end of resistor R1 is connected to the first end of resistor R2, and the second end of resistor R2 is connected to the first end of the feedback contact 300.

[0049] Resistor R1 is used to generate an instantaneous current at the first end of feedback contact 300 when the first end of feedback contact 300 is closed to the second end of feedback contact 300; resistors R1 and R2 are used to generate a steady-state current at the first end of feedback contact 300 after the first end of feedback contact 300 is closed to the second end of feedback contact 300.

[0050] When the contacts are open, no current flows through the feedback contact 300, and the voltage across the steady-state control circuit 112 is 0V. When the first and second terminals of the feedback contact 300 are closed, the steady-state control circuit 112 short-circuits resistor R2, and the power supply terminal 200 generates an instantaneous current at the first terminal of the feedback contact 300 after voltage division by resistor R1. After the first and second terminals of the feedback contact 300 are closed, the steady-state control circuit 112 enters a steady state, and the power supply terminal 200 generates a steady-state current at the first terminal of the feedback contact 300 through voltage divider circuit 111.

[0051] In some embodiments, the resistance of resistor R1 is 47Ω and the resistance of resistor R2 is 220Ω.

[0052] For example, the output voltage Vcc of power supply terminal 200 can be 3.3V. When the first terminal of feedback contact 300 and the second terminal of feedback contact 300 are closed, the steady-state control circuit 112 short-circuits resistor R2. At this time, the equivalent resistance from power supply terminal 200 to feedback contact 300 is approximately resistor R1, and the instantaneous current I1 can be expressed as:

[0053] I1 = Vcc / R1 = 70.2mA.

[0054] It is evident that the instantaneous current I1 can effectively soften or break down the oxide film on the surface of the feedback contact 300.

[0055] As the steady-state control circuit 112 enters a steady state, its influence on the voltage divider circuit 111 becomes negligible. The power supply terminal 200 generates a steady-state current I2 at the first terminal of the feedback contact 300 through the voltage divider circuit 111, which can be expressed as:

[0056] I2 = Vcc / (R1 + R2) = 12.36mA.

[0057] The steady-state power P1 on resistor R1 is about 7.2mW, and the steady-state power P2 on resistor R2 is about 33.6mW, for a total steady-state power consumption of about 40.8mW, which is much smaller than the instantaneous pulse power consumption and can meet the requirements of low heat generation and low power consumption for long-term operation.

[0058] In this embodiment, the voltage divider circuit 111 is composed of resistors R1 and R2 connected in series. At the instant the feedback contact 300 switches from open to closed, due to the small resistance of resistor R1, the power supply terminal 200 can provide a large instantaneous current to the first end of the feedback contact 300 through resistor R1. This instantaneous current can reach tens of milliamperes, sufficient to break down or soften the oxide film on the contact surface, thereby significantly improving the reliability of the contact closure and avoiding unstable detection signals due to excessive contact resistance. As the circuit gradually enters a steady state, resistors R1 and R2 share the voltage. Compared with the prior art using a single pull-up resistor, this embodiment uses a dynamic voltage divider structure formed by the steady-state control circuit 112, resistors R1 and R2 to achieve different current characteristics at the instant of contact closure and in the steady-state phase. This allows a simple circuit structure to meet both the high current requirement at the instant the feedback contact 300 closes and the low current requirement after the feedback contact 300 closes.

[0059] In one possible implementation, the steady-state control circuit 112 includes a capacitor C2 connected in parallel with a resistor R2. The capacitor C2 is used to short-circuit the resistor R2 when the first end of the feedback contact 300 and the second end of the feedback contact 300 are closed, so that the power supply terminal 200 generates an instantaneous current at the first end of the feedback contact 300 through the resistor R1. The capacitor C2 is also used to generate a steady-state current at the first end of the feedback contact 300 through the resistors R1 and R2 after the first end of the feedback contact 300 and the second end of the feedback contact 300 are closed.

[0060] When feedback contact 300 is open, the voltage across capacitor C2 is 0V. When feedback contact 300 switches from open to closed, since the voltage across capacitor C2 cannot change abruptly, power supply 200 rapidly charges capacitor C2 through resistors R1 and R2. Capacitor C2 forms an approximate short circuit with resistor R2, resulting in a momentary current at the first terminal of feedback contact 300. As capacitor C2 gradually charges, its voltage rises from zero to a steady-state voltage. The bypass effect of capacitor C2 on resistor R2 gradually weakens, and the momentary current gradually decreases until capacitor C2 enters a steady-state phase. Capacitor C2 becomes an open circuit, and the current output from power supply 200 flows through resistors R1 and R2, generating a steady-state current at the first terminal of feedback contact 300. The steady-state voltage V of capacitor C2 is... c2 It can be represented as:

[0061] V c2 =3.3*220 / (220+47)=2.72V.

[0062] It is understood that the above-mentioned steady-state control circuit 112 can also take other forms, and is not limited to the forms mentioned in the above embodiments, as long as it can achieve the function of dynamically dividing the voltage divider circuit 111.

[0063] In one possible implementation, the relay feedback contact detection circuit further includes a discharge circuit connected in parallel with capacitor C2. The discharge circuit is used to discharge capacitor C2 when the first end of feedback contact 300 is disconnected from the second end of feedback contact 300.

[0064] For example, the discharge circuit can be a bleeder resistor, which discharges capacitor C2 when the feedback contact 300 is open. Alternatively, the discharge circuit can be an active discharge switch, such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or an NPN transistor, which grounds capacitor C2 when the feedback contact 300 is open and turns off the active discharge switch when the first and second ends of the feedback contact 300 are closed. It is understood that the discharge circuit can also take other forms, not limited to those mentioned in the embodiments above, as long as it can achieve the function of discharging capacitor C2.

[0065] In this embodiment, when the relay feedback contact 300 is in the open state, the discharge circuit provides a charge release path for the capacitor C2, so that the capacitor C2 is quickly discharged to near zero potential, thereby ensuring that the feedback contact 300 can obtain sufficient instantaneous current at the moment of each closure, achieving reliable contact cleaning and conduction effect, and improving the repeatability and stability of the relay feedback contact detection circuit.

[0066] In one exemplary embodiment, see further... Figure 3 The feedback module 120 includes a resistor R3. The first end of the resistor R3 is connected to the first end of the feedback contact 300, and the second end of the resistor R3 is connected to the controller 400. The resistor R3 is used to send the contact feedback signal to the controller 400.

[0067] In one possible implementation, the feedback module 120 further includes a capacitor C3, the first end of which is connected to the second end of the resistor R3, and the second end of the capacitor C3 is grounded. The capacitor C3 is used to filter the contact feedback signal.

[0068] In this circuit, capacitor C3 and resistor R3 together form a low-pass filter circuit to filter the contact feedback signal transmitted to controller 400. Since the feedback contact 300 often exhibits jitter during mechanical closing or opening, the contact feedback signal may contain high-frequency interference or glitches. If directly transmitted to controller 400, this could lead to misjudgment of the state of the feedback contact 300. The RC low-pass filter structure formed by resistor R3 and capacitor C3 effectively filters out high-frequency components in the contact feedback signal, ensuring a stable signal transmitted to controller 400 and preventing malfunctions caused by jitter in the feedback contact 300 or external interference.

[0069] For example, the resistance of resistor R3 can be 1kΩ, capacitor C3 can be 10nF, and the second terminal of capacitor C3 and the second terminal of feedback contact 300 are both grounded.

[0070] In this embodiment, the feedback module 120, composed of resistor R3 and capacitor C3, can effectively suppress the jitter interference during the opening and closing process of the first and second ends of the feedback contact 300 through filtering, and reliably and accurately transmit the contact feedback signal to the controller 400, ensuring the accuracy of the relay feedback detection circuit and the overall stability of the relay feedback system. It is particularly suitable for low-power application scenarios with high requirements for signal integrity and control precision.

[0071] In addition, resistor R3 can also play a role in current limiting protection. When the level of the first terminal of feedback contact 300 changes abruptly, it can limit the current flowing into controller 400 and prevent excessive instantaneous current from damaging the internal circuit of controller 400. Capacitor C3 smooths voltage fluctuations by storing charge, so that the contact feedback signal transmitted to controller 400 has good stability and anti-interference ability.

[0072] See Figures 1 to 3 This application provides a relay feedback contact detection circuit, which includes a pull-up module 110, a feedback module 120, and a discharge circuit. The pull-up module 110 includes a voltage divider circuit 111 and a steady-state control circuit 112.

[0073] The voltage divider circuit 111 includes resistors R1 and R2. The first end of resistor R1 is connected to the power supply terminal 200, the second end of resistor R1 is connected to the first end of resistor R2, and the second end of resistor R2 is connected to the first end of the feedback contact 300.

[0074] The steady-state control circuit 112 includes a capacitor C2 connected in parallel with a resistor R2. Capacitor C2 short-circuits resistor R2 when the first and second terminals of feedback contact 300 are closed, causing a momentary current to be generated at the first terminal of feedback contact 300 through resistor R1, thus softening the oxide film on the surface of feedback contact 300. Furthermore, after the first and second terminals of feedback contact 300 are closed, a steady-state current is generated at the first terminal of feedback contact 300 through resistors R1 and R2, where the steady-state current is less than the momentary current. The momentary current ranges from 50mA to 100mA. The resistance of resistor R1 is 47Ω, and the resistance of resistor R2 is 220Ω.

[0075] The feedback module 120 includes a resistor R3 and a capacitor C3. The first end of resistor R3 is connected to the first end of the feedback contact 300, and the second end of resistor R3 is connected to the controller 400. Resistor R3 is used to send the contact feedback signal to the controller 400. The first end of capacitor C3 is connected to the second end of resistor R3, and the second end of capacitor C3 is grounded. Capacitor C3 is used to filter the contact feedback signal.

[0076] The discharge circuit is connected in parallel with capacitor C2. The discharge circuit is used to discharge capacitor C2 when the first end of feedback contact 300 is disconnected from the second end of feedback contact 300.

[0077] In one exemplary embodiment, a relay feedback system is provided, which includes a relay feedback contact detection circuit as described in the above embodiment. The system may further include a controller 400 connected to the relay feedback contact detection circuit.

[0078] In one embodiment, the relay feedback contact detection circuit includes a pull-up module 110 and a feedback module 120. The first end of the pull-up module 110 is connected to the power supply terminal 200, and the second end of the pull-up module 110 is connected to the feedback contact 300 of the relay. The first end of the feedback module 120 is connected to both the pull-up module 110 and the feedback contact 300, and the second end of the feedback module 120 is connected to a controller 400 external to the relay. The feedback module 120 transmits the contact feedback signal generated by the feedback contact 300 to the controller 400. The pull-up module 110 generates an instantaneous current at the first end of the feedback contact 300 when the first end and the second end of the feedback contact 300 are closed, so as to soften the oxide film on the surface of the feedback contact 300. After the first end and the second end of the feedback contact 300 are closed, a steady-state current is generated at the first end of the feedback contact 300, and the steady-state current is less than the instantaneous current.

[0079] In one embodiment, the pull-up module 110 includes a voltage divider circuit 111 and a steady-state control circuit 112. The first end of the voltage divider circuit 111 is connected to the power supply terminal 200, and the second end of the voltage divider circuit 111 is connected to the first end of the feedback contact 300. The first end of the steady-state control circuit 112 is connected to the voltage divider circuit 111, and the second end of the steady-state control circuit 112 is connected to the first end of the feedback contact 300. The steady-state control circuit 112 is used to generate an instantaneous current at the first end of the feedback contact 300 through the voltage divider circuit 111 when the first end of the feedback contact 300 and the second end of the feedback contact 300 are closed, and is also used to generate a steady-state current at the first end of the feedback contact 300 through the voltage divider circuit 111 after the first end of the feedback contact 300 and the second end of the feedback contact 300 are closed.

[0080] In one embodiment, the voltage divider circuit 111 includes resistors R1 and R2. The first end of resistor R1 is connected to the power supply terminal 200, the second end of resistor R1 is connected to the first end of resistor R2, and the second end of resistor R2 is connected to the first end of feedback contact 300. Resistor R1 is used to generate an instantaneous current at the first end of feedback contact 300 when the first end of feedback contact 300 and the second end of feedback contact 300 are closed. Resistors R1 and R2 are used to generate a steady-state current at the first end of feedback contact 300 after the first end of feedback contact 300 and the second end of feedback contact 300 are closed.

[0081] In one embodiment, the steady-state control circuit 112 includes a capacitor C2 connected in parallel with a resistor R2. The capacitor C2 is used to short-circuit the resistor R2 when the first end of the feedback contact 300 and the second end of the feedback contact 300 are closed, so that the power supply terminal 200 generates an instantaneous current at the first end of the feedback contact 300 through the resistor R1. The capacitor C2 is also used to generate a steady-state current at the first end of the feedback contact 300 through the resistors R1 and R2 after the first end of the feedback contact 300 and the second end of the feedback contact 300 are closed.

[0082] In one embodiment, the relay feedback contact detection circuit further includes a discharge circuit connected in parallel with capacitor C2. The discharge circuit is used to discharge capacitor C2 when the first end of feedback contact 300 is disconnected from the second end of feedback contact 300.

[0083] In one embodiment, the instantaneous current ranges from 50mA to 100mA.

[0084] In one embodiment, the resistance of resistor R1 is 47Ω and the resistance of resistor R2 is 220Ω.

[0085] In one embodiment, the feedback module 120 includes a resistor R3, with a first end of the resistor R3 connected to a first end of the feedback contact 300 and a second end of the resistor R3 connected to the controller 400. The resistor R3 is used to send the contact feedback signal to the controller 400.

[0086] In one embodiment, the feedback module 120 further includes a capacitor C3, the first end of which is connected to the second end of the resistor R3, and the second end of the capacitor C3 is grounded. The capacitor C3 is used to filter the contact feedback signal.

[0087] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0088] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A relay feedback contact detection circuit, characterized in that, The relay feedback contact detection circuit includes a pull-up module and a feedback module. The first end of the pull-up module is used to connect to the power supply end, and the second end of the pull-up module is used to connect to the feedback contact of the relay. The first end of the feedback module is connected to the pull-up module and the feedback contact respectively, and the second end of the feedback module is used to connect to the controller outside the relay; The feedback module is used to transmit the contact feedback signal generated by the feedback contact to the controller. The pull-up module is used to generate an instantaneous current at the first end of the feedback contact when the first end of the feedback contact is closed with the second end of the feedback contact, so as to soften the oxide film on the surface of the feedback contact. After the first end of the feedback contact is closed with the second end of the feedback contact, a steady-state current is generated at the first end of the feedback contact, and the steady-state current is less than the instantaneous current.

2. The relay feedback contact detection circuit according to claim 1, characterized in that, The pull-up module includes a voltage divider circuit and a steady-state control circuit. The first end of the voltage divider circuit is connected to the power supply terminal, and the second end of the voltage divider circuit is connected to the first end of the feedback contact. The first end of the steady-state control circuit is connected to the voltage divider circuit, and the second end of the steady-state control circuit is connected to the first end of the feedback contact. The steady-state control circuit is used to cause the power supply terminal to generate the instantaneous current at the first end of the feedback contact through the voltage divider circuit when the first end of the feedback contact is closed and the second end of the feedback contact is closed, and to cause the power supply terminal to generate the steady-state current at the first end of the feedback contact through the voltage divider circuit after the first end of the feedback contact is closed and the second end of the feedback contact is closed.

3. The relay feedback contact detection circuit according to claim 2, characterized in that, The voltage divider circuit includes resistors R1 and R2. The first end of resistor R1 is connected to the power supply terminal, the second end of resistor R1 is connected to the first end of resistor R2, and the second end of resistor R2 is connected to the first end of the feedback contact. The resistor R1 is used to generate the instantaneous current at the first end of the feedback contact when the first end of the feedback contact is closed with the second end of the feedback contact; The resistors R1 and R2 are used to generate the steady-state current at the first end of the feedback contact after the first end of the feedback contact is closed with the second end of the feedback contact.

4. The relay feedback contact detection circuit according to claim 3, characterized in that, The steady-state control circuit includes a capacitor C2, which is connected in parallel with the resistor R2. The capacitor C2 is used to short-circuit the resistor R2 when the first end of the feedback contact is closed with the second end of the feedback contact, so that the power supply terminal generates the instantaneous current at the first end of the feedback contact through the resistor R1; And it is used to generate the steady-state current at the first end of the feedback contact after the first end of the feedback contact is closed with the second end of the feedback contact, so that the power supply terminal generates the steady-state current at the first end of the feedback contact through the resistor R1 and the resistor R2.

5. The relay feedback contact detection circuit according to claim 4, characterized in that, The relay feedback contact detection circuit further includes a discharge circuit, which is connected in parallel with the capacitor C2. The discharge circuit is used to discharge the capacitor C2 when the first end of the feedback contact is disconnected from the second end of the feedback contact.

6. The relay feedback contact detection circuit according to claim 4, characterized in that, The instantaneous current ranges from 50mA to 100mA.

7. The relay feedback contact detection circuit according to claim 6, characterized in that, The resistance of resistor R1 is 47Ω and the resistance of resistor R2 is 220Ω.

8. The relay feedback contact detection circuit according to any one of claims 1-7, characterized in that, The feedback module includes a resistor R3, the first end of which is connected to the first end of the feedback contact, and the second end of which is connected to the controller. The resistor R3 is used to send the contact feedback signal to the controller.

9. The relay feedback contact detection circuit according to claim 8, characterized in that, The feedback module also includes a capacitor C3, the first end of which is connected to the second end of the resistor R3, and the second end of the capacitor C3 is grounded. The capacitor C3 is used to filter the contact feedback signal.

10. A relay feedback system, characterized in that, The relay feedback system includes the relay feedback contact detection circuit as described in any one of claims 1-9.

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