Auxiliary relay control drive circuit

Abstract

The utility model relates to the field of relay control technology, and provides an auxiliary relay control drive circuit, which includes: resistors RW5, RW6, RW7, RW8; diodes DW1, DW3, DW4; transistors QW3, QW4; reed relay REW3; DC power supply RVDD, which controls large currents through small current or small voltage control signals output by the IO port of a single-chip microcomputer, thereby realizing remote and precise control of power equipment. The circuit design takes electromagnetic compatibility into consideration, and by using diodes to provide reverse voltage protection and prevent leakage current, the stability of the circuit and the safety of the relay during signal switching are ensured. In addition, a voltage regulator diode is used to stabilize the power supply voltage, ensuring that the relay can work stably even when the power supply fluctuates. The circuit design of the utility model is simple, low-cost, and highly sensitive, and has strong adaptability and practicality, and has broad application prospects.

Description

Technical Field

[0001] The utility model relates to the technical field of relay control, in particular to an auxiliary relay control drive circuit. Background Art

[0002] As a basic electronic control device, relays have a long technical background, which can be traced back to the late 19th century. With the development of electromagnetic theory and the popularization of power applications, people have discovered the possibility of using electromagnetic force to control the on and off of circuits. The earliest relay was the electromagnetic relay, whose working principle was based on the electromagnetic induction phenomenon. The current flows through the coil to generate a magnetic field, which in turn drives the mechanical contacts to achieve the purpose of small current controlling large current or long-distance control.

[0003] Relay technology has experienced diversified development in the 20th century, and various types of relays such as time relays, thermal relays, and solid-state relays have emerged, providing solutions for different application scenarios and needs. Solid-state relays are a major breakthrough. They abandon mechanical contacts and use semiconductor devices such as transistors and thyristors as switching elements. They are wear-free, fast in response, and have a long life.

[0004] In modern times, relay technology is still innovating and developing. It not only continues to play an important role in traditional industrial control, power systems, communication equipment and other fields, but also finds new application space in smart home, automotive electronics, aerospace and other industries. With the rise of the Internet of Things and smart grid technology, relays are integrated into highly automated control systems, such as smart meters and remote control equipment, and their intelligence and integration levels are constantly improving.

[0005] Auxiliary relay technology originated from traditional relay control systems and played a vital role in early electrical and electronic control systems. A relay is an electromagnetic device whose action depends on the magnetic field generated by the current to drive the internal mechanical contacts to open and close, thereby controlling the on and off of the circuit. As a member of the relay family, the auxiliary relay was originally designed to enhance and expand the functions of the basic relay.

[0006] Existing auxiliary relay control drive circuits generally have difficulty in achieving precise and remote control of power usage, and generally have problems with safety, stability, and electromagnetic interference. Utility Model Content

[0007] In order to solve the problems existing in the background technology, the utility model utilizes the control signal output by the IO port of the single-chip computer to control the driving circuit through the auxiliary relay, thereby realizing remote and precise control of the power equipment; by using a diode to provide reverse voltage protection and prevent leakage current, the stability of the circuit and the safety of the relay during signal switching are ensured; a voltage regulator diode DW1 is used to stabilize the power supply voltage RVDD to ensure that the relay can work stably even when the power supply fluctuates; the circuit design takes electromagnetic compatibility into consideration, and reduces the influence of electromagnetic interference through reasonable circuit layout and component selection.

[0008] The utility model provides an auxiliary relay control drive circuit, which includes:

[0009] Resistors RW5, RW6, RW7, RW8; diodes DW1, DW3, DW4; transistors QW3, QW4; reed relay REW3; DC power supply RVDD; among which:

[0010] One end of the resistor RW5 is connected to the closing control signal Relay_On_Control, and the other end is connected to RW6 and the base of the transistor QW3;

[0011] One end of the resistor RW6 is connected to the resistor RW5 and the base of the transistor QW3, and the other end is grounded;

[0012] The base of transistor QW3 is connected to resistors RW5 and RW6, the emitter is grounded, and the collector is connected to the closing signal RO1;

[0013] The anode of diode DW1 is connected to the cathodes of diodes DW3 and DW4, and the cathodes are connected to RVDD;

[0014] The anode of the diode DW3 is connected to the closing signal RO1, and the cathode is connected to the anode of the diode DW1;

[0015] The anode of the diode DW4 is connected to the switch-off signal RO2, and the cathode is connected to the anode of the diode DW1;

[0016] One end of the resistor RW7 is connected to the switch-off control signal Relay_Off_Control, and the other end is connected to the resistor RW8 and the base of the transistor QW4;

[0017] One end of the resistor RW8 is connected to the resistor RW7 and the base of the transistor QW4, and the other end is grounded;

[0018] The base of transistor QW4 is connected to resistor RW7, the collector is connected to the switch-off signal RO2, and the emitter is grounded;

[0019] Pin 1 of the reed relay REW3 is connected to the closing signal RO1, pin 2 is connected to the closing signal RO2, pin 3 is connected to the output signal OUT1, pin 4 is connected to the output signal OUT2, and pin 5 is connected to the power supply RVDD.

[0020] In a preferred solution, the relay REW3 is a normally open magnetic latching relay with a standard polarity double coil.

[0021] In a preferred solution, the control signal is connected to the closing control signal Relay_On_Control and the pulling control signal Relay_Off_Control, and the control signal of small current or small voltage is output by the IO port of the single-chip computer to control the large current.

[0022] In a preferred solution, when Relay_On_Control is at a high level, transistor QW3 is turned on, and the signal RO1 at pin 1 of relay REW3 is input at a low level through grounding, triggering the relay to operate.

[0023] When Relay_On_Control is at a low level, transistor QW3 is turned off, and the relay receives a high level signal through diode DW3 and maintains its original state.

[0024] When Relay_Off_Control is at a high level, transistor QW4 is turned on, relay pin 2 is grounded, signal RO2 is at a low level, and the relay is reset.

[0025] When Relay_Off_Control is at a low level, transistor QW4 is turned off, and relay pin 2 receives a high level signal and maintains its original state.

[0026] The beneficial effects achieved by the utility model are:

[0027] The utility model outputs a control signal of a small current or a small voltage through the IO port of the single-chip microcomputer, and the control signal is connected to the closing control signal Relay_On_Control and the pulling control signal Relay_Off_Control. The control signal first passes through the current limiting resistors RW5 and RW7. The function of these resistors is to limit the current flowing to the base of the transistor and protect the IO port of the single-chip microcomputer from damage. After passing through the current limiting resistor, the signal reaches the base of the transistor. In this circuit, the bases of transistors QW3 and QW4 are connected to current limiting resistors RW5 and RW7, respectively. Transistors QW3 and QW4 act as switching elements and are turned on or off according to the signal state (high level or low level) of the IO port of the single-chip microcomputer.

[0028] The on and off states of the transistor determine the level states of the closing signal RO1 and the pulling signal RO2 of the relay REW3. When Relay_On_Control is at a high level, the transistor QW3 is turned on, and the 1st pin of the relay REW3 inputs a low level through the ground, triggering the relay to operate and close the switch. On the contrary, when Relay_Off_Control is at a high level, the transistor QW4 is turned on, the 2nd pin of the reed relay REW3 is grounded, and a low level is input, triggering the relay to pull the switch. Diodes DW1, DW3, and DW4 are also used in the circuit to provide reverse voltage protection and prevent leakage current, ensuring the stability of the circuit and the safety of the relay when the signal is switched. The voltage regulator diode DW1 is used to stabilize the power supply voltage RVDD to ensure that the relay can work stably even when the power supply fluctuates.

[0029] Through the circuit design of the utility model, the small signal of the IO port of the single-chip microcomputer can effectively control the large current in the circuit, realize the remote and precise control of the relay, and can remotely control the switch of the power equipment through software programming, which has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a circuit schematic diagram of the utility model;

[0031] Figure 2 This is the signal control schematic diagram of the reed relay REW3;

[0032] Figure 3 It is a control flow chart of the control drive circuit of the utility model. DETAILED DESCRIPTION

[0033] The technical solution of the utility model will be clearly and completely described below in conjunction with the drawings in the utility model. In addition, the forms of the various structures recorded in the following embodiments are merely illustrative, and the utility model is not limited to the various structures recorded in the following embodiments. All other implementations obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0034] Reference Figure 1-Figure 3 In order to solve the problems existing in the background technology, the utility model provides an auxiliary relay control drive circuit, which includes:

[0035] Resistors RW5, RW6, RW7, RW8; diodes DW1, DW3, DW4; transistors QW3, QW4; reed relay REW3; DC power supply RVDD; among which:

[0036] One end of the resistor RW5 is connected to the closing control signal Relay_On_Control, and the other end is connected to RW6 and the base of the transistor QW3;

[0037] One end of the resistor RW6 is connected to the resistor RW5 and the base of the transistor QW3, and the other end is grounded;

[0038] The base of transistor QW3 is connected to resistors RW5 and RW6, the emitter is grounded, and the collector is connected to the closing signal RO1;

[0039] The anode of diode DW1 is connected to the cathodes of diodes DW3 and DW4, and the cathodes are connected to RVDD;

[0040] The anode of the diode DW3 is connected to the closing signal RO1, and the cathode is connected to the anode of the diode DW1;

[0041] The anode of the diode DW4 is connected to the switch-off signal RO2, and the cathode is connected to the anode of the diode DW1;

[0042] One end of the resistor RW7 is connected to the switch-off control signal Relay_Off_Control, and the other end is connected to the resistor RW8 and the base of the transistor QW4;

[0043] One end of the resistor RW8 is connected to the resistor RW7 and the base of the transistor QW4, and the other end is grounded;

[0044] The base of transistor QW4 is connected to resistor RW7, the collector is connected to the switch-off signal RO2, and the emitter is grounded;

[0045] Pin 1 of the reed relay REW3 is connected to the closing signal RO1, pin 2 is connected to the closing signal RO2, pin 3 is connected to the output signal OUT1, pin 4 is connected to the output signal OUT2, and pin 5 is connected to the power supply RVDD.

[0046] This relay is a normally open magnetic latching relay with standard polarity and double coils. When the smart meter is connected to AC power, the RVDD output by the switching power supply inputs the voltage to the relay pin 5 through the voltage-stabilizing diode DW1. Relay_On_Control is the control signal for controlling the relay closing. When the signal is high, the signal is input to the base of the transistor QW3 through the current-limiting resistor RW5. At this time, the transistor is turned on, and the signal RO1 of the pin 1 of the relay REW3 is grounded, and the input of the pin 1 is low. The relay operates when the input of the pin 1 is low and the input of the pin 5 is high, and the pins 4 and 3 are turned on. When the Relay_On_Control signal is low, the transistor QW3 is in the off state, and the RVDD passes through the voltage-stabilizing diode DW1 and the diode DW3 to the relay pin 1. At this time, the input signal RO1 of the pin 1 is high, and the relay does not operate and maintains the original state.

[0047] Diode DW3 has the function of preventing leakage current, preventing the large current that may be generated in RVDD from entering the relay and causing damage to the relay. Relay_Off_Control is the relay disconnection signal. When the signal is high, the signal passes through the current limiting resistor RW7 to the base of the transistor QW4. At this time, the transistor QW4 is turned on, the relay pin 2 is grounded, the signal RO2 is low, and the pin 5 is a normal high level when powered on. At this time, the relay is reset, and pins 3 and 4 are in a disconnected state. When the signal is low, the transistor QW4 is not turned on, and RVDD passes through the voltage-stabilizing diode DW1 and the diode DW3 to the signal relay pin 2. At this time, the signal RO2 at pin 2 is high, and the relay does not operate and maintains the original state. The details are as follows:

[0048] Closing process: When the closing control signal Relay_On_Control is at a high level, transistor QW3 is turned on.

[0049] The transistor QW3 is turned on, causing the closing signal RO1 connected to its collector to be pulled down to a low level.

[0050] Pin 1 of relay REW3 receives a low-level signal, triggering the relay to operate and close the circuit.

[0051] After the relay is actuated, its pins 3 and 4 are turned on, and the output signals OUT1 and OUT2 become activated.

[0052] Hold state: When the closing control signal Relay_On_Control is at a low level, transistor QW3 is turned off.

[0053] At this time, diode DW3 ensures that pin 1 of relay REW3 receives a high level signal, keeping the relay in the closed state.

[0054] Switch-off process: When the switch-off control signal Relay_Off_Control is at a high level, transistor QW4 is turned on.

[0055] The transistor QW4 is turned on, causing the 2nd foot of the relay REW3 to be grounded, and the switch-off signal RO2 becomes a low level.

[0056] Relay REW3 resets after receiving the switch-off signal, its pins 3 and 4 are disconnected, and the output signals OUT1 and OUT2 become inactive.

[0057] Hold state: when the switch control signal Relay_Off_Control is at a low level, the transistor QW4 is turned off.

[0058] At this time, diode DW4 ensures that pin 2 of relay REW3 receives a high level signal, keeping the relay in the closed state.

[0059] In the circuit, the diode DW1 is used as a voltage-stabilizing diode to stabilize the DC power supply RVDD and protect the circuit.

[0060] In addition to their role in the control process, diodes DW3 and DW4 also provide reverse voltage protection to prevent leakage current in the circuit.

[0061] Through the above working process, the auxiliary relay control drive circuit can accurately control large current through the small current or small voltage control signal output by the IO port of the microcontroller, realize remote control of power equipment, and has broad application prospects.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An auxiliary relay control drive circuit, characterized in that: It includes: Resistors RW5, RW6, RW7, RW8; Diodes DW1, DW3, DW4; Transistors QW3, QW4; Reed relay REW3; DC power supply RVDD; in: One end of the resistor RW5 is connected to the closing control signal Relay_On_Control, and the other end is connected to RW6 and the base of the transistor QW3; One end of the resistor RW6 is connected to the resistor RW5 and the base of the transistor QW3, and the other end is grounded; The base of transistor QW3 is connected to resistors RW5 and RW6, the emitter is grounded, and the collector is connected to the closing signal RO1; The anode of diode DW1 is connected to the cathodes of diodes DW3 and DW4, and the cathodes are connected to RVDD; The anode of the diode DW3 is connected to the closing signal RO1, and the cathode is connected to the anode of the diode DW1; The anode of the diode DW4 is connected to the switch-off signal RO2, and the cathode is connected to the anode of the diode DW1; One end of the resistor RW7 is connected to the switch-off control signal Relay_Off_Control, and the other end is connected to the resistor RW8 and the base of the transistor QW4; One end of the resistor RW8 is connected to the resistor RW7 and the base of the transistor QW4, and the other end is grounded; The base of transistor QW4 is connected to resistor RW7, the collector is connected to the switch-off signal RO2, and the emitter is grounded; Pin 1 of the reed relay REW3 is connected to the closing signal RO1, pin 2 is connected to the closing signal RO2, pin 3 is connected to the output signal OUT1, pin 4 is connected to the output signal OUT2, and pin 5 is connected to the power supply RVDD.

2. The auxiliary relay control drive circuit according to claim 1, characterized in that: The relay REW3 is a normally open magnetic latching relay with double coils of standard polarity.

3. The auxiliary relay control drive circuit according to claim 1, characterized in that: The control signal is connected to the closing control signal Relay_On_Control and the pulling control signal Relay_Off_Control, and the control signal of small current or small voltage is output by the IO port of the microcontroller to control the large current.

4. The auxiliary relay control drive circuit according to claim 1, characterized in that: When Relay_On_Control is high, transistor QW3 is turned on, and the signal RO1 at pin 1 of relay REW3 is input low through ground, triggering the relay to operate; When Relay_On_Control is low, transistor QW3 is turned off, and the relay receives a high-level signal through diode DW3 and maintains its original state; When Relay_Off_Control is high, transistor QW4 is turned on, relay pin 2 is grounded, signal RO2 is low, and the relay is reset; When Relay_Off_Control is at a low level, transistor QW4 is turned off, and relay pin 2 receives a high level signal and maintains its original state.

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