An automatic delayed start or automatic soft start system

Abstract

An automatic delayed start or automatic soft start system includes a single-chip microcomputer, an input module, a current relay, an output module, and a power module. The present invention can directly connect a low-voltage DC brushed motor to a power source. After the system detects that the power cord is connected to the motor, it delays for a certain period of time, automatically connects the circuit or performs a soft start, and runs the motor. After the operator unplugs the connector, the system can repeat the automatic delayed start or PWM duty cycle automatic soft start when testing again. The present invention changes the existing operating method of first connecting the motor power cord and then pressing the start switch when the power is off. This makes power-on testing of motors in factory batch production much simpler and safer, improving production efficiency, especially in large-scale motor production. The control system uses a single-chip microcomputer system, which is compact and low-cost.

Description

Technical Field

[0001] The invention belongs to the field of low-voltage DC brushed motor technology development, and in particular relates to an automatic delayed start or automatic soft start system. Background Art

[0002] At present, in the production process of DC brush motors, it is generally necessary to power on the motor for testing. The conventional practice is to first connect the positive and negative terminals of the motor to the power connector, and then manually press the start switch to power on the motor. When testing again, it is necessary to first connect the power connector and then press the start button. Sometimes, on-site operators will directly connect the live power connector (DC voltage below 36V) to the positive and negative terminals of the motor, which will burn the positive and negative terminals of the motor at the moment of startup.

[0003] In actual production, high efficiency and cycle times are crucial. At the same time, plugging in live motors must be prevented from causing erosion of the positive and negative terminals. Therefore, production sites urgently need a device that automatically turns on the circuit and operates the motor after it has been connected to the power connector for a period of time, without requiring a push of a start switch. This device can also repeat automatic conduction tests and easily connect to various DC power supplies. However, existing DC power supplies or power-on detection equipment on the market require pressing a start switch before the motor can be powered on.

[0004] Therefore, an automatic delayed start or automatic soft start system is designed to solve the above problems. Summary of the Invention

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the present invention aims to provide an automatic delayed start or automatic soft start system.

[0006] To achieve the above-mentioned and other related purposes, the present invention provides a technical solution: an automatic delayed start or automatic soft start system, comprising: a single chip microcomputer for storing an automatic control single chip microcomputer program and receiving an external input signal;

[0007] An input module, used for converting the motor power supply voltage signal into a voltage value input signal allowed by the single chip microcomputer, wherein the sampling point of the input module is placed in the negative pole circuit of the motor power supply;

[0008] A current relay is placed in the positive line of the motor power supply, and is used to detect the current state in the entire circuit and provide a signal to the single chip microcomputer;

[0009] An output module, used to amplify the output signal of the single-chip microcomputer and control the on / off of the motor power supply circuit. The point in the output module that controls the on / off of the motor is placed in the circuit after the sampling point of the input module and before the negative pole of the motor power supply;

[0010] A power supply module, used to supply power to the single chip microcomputer, input module, output module, and current relay;

[0011] The input module and the current relay are both connected to the I / O port of the single chip microcomputer, and the single chip microcomputer is electrically connected to the output module.

[0012] The preferred technical solution is: the input module includes a transistor Q14, a pull-up resistor R33 is set at the collector of the transistor Q14, and the collector of the transistor Q14 is connected to the corresponding I / O port of the single-chip microcomputer; the input module also includes a fourth voltage-stabilizing tube D15, the cathode of the fourth voltage-stabilizing tube D15 is connected to the sampling point test through the first resistor R35, and the cathode of the fourth voltage-stabilizing tube D15 is connected to the base of the transistor Q14 through the second resistor R37.

[0013] The preferred technical solution is: the current relay signal is connected to the middle point of the pull-up resistor connected in series with the third resistor R23 and the fourth resistor R28, and the middle point is connected to the corresponding I / O port of the microcontroller.

[0014] A preferred technical solution is as follows: the output module includes a totem pole driver, which includes several resistors, NPN transistors, and PNP transistors. The corresponding I / O port of the single-chip microcomputer is connected to the totem pole driver input terminal PC1. The totem pole driver output terminal is connected to the gate of the fourth MOS transistor Q21 through a fifth resistor R53. A fast switching diode D21 is connected in parallel to the fifth resistor R53. The point in the output module that controls the on / off of the motor is connected to the drain and source terminals of the fourth MOS transistor Q21.

[0015] A preferred technical solution is as follows: the power module includes a circuit consisting of a resistor, a first MOS transistor Q11, a second MOS transistor Q12, a third MOS transistor Q13, a first voltage regulator transistor D12, a second voltage regulator transistor D13, a third voltage regulator transistor D14, a differential mode inductor L8, a differential mode capacitor C30, a TVS diode D17, and two DC-DC chips; the gate voltages of the first MOS transistor Q11, the second MOS transistor Q12, and the third MOS transistor Q13 are provided by the third voltage regulator transistor D14, the second voltage regulator transistor D13, and the first voltage regulator transistor D12; when the TVS diode D17 is turned on, the first MOS transistor Q11 is in the on state and the third MOS transistor Q13 is in the off state, and the drain and source of the third MOS transistor Q13 are connected to the main loop of the control circuit; the second MOS transistor Q12 and the third MOS transistor Q13 are connected in series, the source of the third MOS transistor Q13 is connected to the source of the second MOS transistor Q12, and the drain of the second MOS transistor Q12 is connected to the negative electrode of the input voltage of the power module.

[0016] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0017] The present invention can directly connect a low-voltage DC brushed motor to a power supply. After the system detects that the power cord is connected to the motor, it delays for a certain period of time, automatically connects the circuit or soft-starts, and runs the motor. After the operator unplugs the connector, the system can repeat the automatic delayed start or PWM duty cycle automatic soft-start when testing again. The present invention changes the original operation mode of having to connect the motor power cord before pressing the start switch when the power is off, making power-on testing in factory motors more convenient and safer, and improving production efficiency, especially in the mass production of motors, the effect is significant. The control system adopts a single-chip microcomputer system with a compact structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a partial structural diagram of the microcontroller.

[0019] Figure 2 Schematic diagram of the input module.

[0020] Figure 3 This is a schematic diagram of the output module.

[0021] Figure 4 Schematic diagram of current relay.

[0022] Figure 5 This is a schematic diagram of the power module. DETAILED DESCRIPTION

[0023] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0024] See also Figures 1 to 5 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship, or adjustment in size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as component models and sizes quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0025] Example: Figure 1 ~ Figure 5 As shown, an automatic delayed start or automatic soft start system includes:

[0026] The single-chip microcomputer is used to store the automatic control single-chip microcomputer program, receive external input signals, execute the pre-programmed program according to the status of the external input signals, and finally output the corresponding signal to turn the motor on and off; the single-chip microcomputer program is used to complete a series of actions according to the predetermined design to achieve the function of automatic control;

[0027] The input module is used to convert the motor power supply voltage signal into a voltage value input signal allowed by the single-chip microcomputer. It has a signal isolation protection function for the single-chip microcomputer. The input module sampling point is placed in the negative pole line of the motor power supply;

[0028] The current relay is placed in the positive line of the motor power supply to detect the current status of the entire circuit and provide a signal to the microcontroller;

[0029] The output module is used to amplify the output signal of the single-chip microcomputer to drive MOS tubes, relays and other actuators to control the on-off of the motor power circuit. The point that controls the on-off of the motor in the output module is placed after the sampling point of the input module and before the negative pole of the motor power supply.

[0030] The power module is used to supply power to the microcontroller, input module, output module, and current relay, and has functions such as power reverse connection protection and overvoltage protection;

[0031] The input module and current relay are respectively connected to the I / O port of the microcontroller. The microcontroller judges the signals of the two input modules and controls the delayed conduction and disconnection of the output module. At the same time, the output module can also output PWM square waves with various duty cycles to achieve the purpose of soft starting of the DC motor. The specific control principle is as follows: If the signal input from the input module to the microcontroller is low, the output module will delay the conduction of the motor power circuit or perform PWM soft start. If the signal input from the current relay to the microcontroller is high, the output module will disconnect the motor power circuit and prepare for the next power-on test.

[0032] Note: In conjunction with the structural diagram of the present invention, the single-chip microcomputer control program can adopt a delayed switch on-off method or a PWM duty cycle soft start method, etc. The software aspect is not described in detail and the present invention does not limit this.

[0033] A preferred embodiment is as follows: the input module includes a transistor Q14, a pull-up resistor R33 is provided at the collector of the transistor Q14, and the collector of the transistor Q14 is connected to the corresponding I / O port of the single-chip microcomputer; the input module also includes a fourth voltage-stabilizing diode D15, the cathode of the fourth voltage-stabilizing diode D15 is connected to the sampling point test via a first resistor R35, and the cathode of the fourth voltage-stabilizing diode D15 is connected to the base of the transistor Q14 via a second resistor R37.

[0034] When the positive and negative poles of the motor are connected to the power supply, the input module sampling point test detects the motor power supply voltage, and the voltage is stabilized at 5V through the circuit composed of the first resistor R35 and the fourth voltage regulator D15. This voltage is connected to the base side of the circuit composed of the second resistor R37 and the transistor Q14. At this time, the transistor Q14 is saturated and turned on, the collector potential of the transistor Q14 is 0V, and the corresponding I / O port of the microcontroller is low. Similarly, when the positive and negative poles of the motor are not connected to the power supply, there is no voltage on the base side of the transistor Q14, the transistor Q14 is cut off, the collector potential of the transistor Q14 is pulled up to 5V, and the corresponding I / O port of the microcontroller is high.

[0035] A preferred embodiment is as follows: a current relay is used to detect the current state in a motor power supply circuit, and the detected wire passes through the detection hole of the current relay. The detected wire can also be wrapped around the detection hole of the current relay multiple times according to actual conditions. When current passes through the wire, the potential of the current relay signal line is 0V. When no current passes through the wire, the current relay signal line is in a floating state. The current relay signal is connected to the middle point of the pull-up resistor connected in series with the third resistor R23 and the fourth resistor R28. At the same time, the middle point is connected to the corresponding I / O port of the single-chip microcomputer. When current passes through the detected wire, the corresponding I / O port of the single-chip microcomputer is at a low level. When no current passes through the detected wire, the corresponding I / O port of the single-chip microcomputer is clamped at a high level by the pull-up resistor.

[0036] The preferred embodiment is as follows: the output module is used to amplify the output signal of the single-chip microcomputer to drive the fourth MOS tube Q21 or an actuator such as a relay to control the on-off of the motor power supply circuit. The point for controlling the on-off of the motor in the output module is placed in the circuit after the sampling point test of the input module and before the negative pole of the motor power supply; the output module includes a totem pole drive, which includes a plurality of resistors, an NPN transistor and a PNP transistor. The corresponding I / O port of the single-chip microcomputer is connected to the totem pole drive input terminal PC1, and the totem pole drive output terminal is connected to the gate of the fourth MOS tube Q21 through the fifth resistor R53. A fast switching diode D21 is connected in parallel to the fifth resistor R53. The fast switching diode D21 cooperates with the totem pole drive circuit to quickly The voltage on the gate of the fourth MOS transistor Q21 caused by the wiring inductance and the junction capacitance of the transistor is quickly released to avoid resonance during rapid switching. In addition to the ordinary low-speed switching function, the output module also has a high-frequency switching function. For a brushed DC motor, the switching frequency can reach 17kHz. PWM duty cycle speed regulation or soft start function can be implemented through the program. When PWM duty cycle speed regulation is used, a freewheeling diode D11 must be connected in parallel at both ends of the DC motor. The point that controls the on-off of the motor in the output module is connected to the drain and source terminals of the fourth MOS transistor Q21. In addition, the drain and source terminals of the fourth MOS transistor Q21 can also be connected to the relay coil to control the attraction and disconnection of the relay. The point that controls the on-off of the motor in the output module is connected to the normally open contact of the relay to switch the motor on and off.

[0037] In a preferred embodiment, the power module includes a circuit consisting of a resistor, a first MOS transistor Q11, a second MOS transistor Q12, a third MOS transistor Q13, a first voltage-stabilizing transistor D12, a second voltage-stabilizing transistor D13, a third voltage-stabilizing transistor D14, a differential-mode inductor L8, a differential-mode capacitor C30, a TVS diode D17, and two DC-DC chips. The differential-mode inductor L8 and the differential-mode capacitor C30 are used to suppress electromagnetic interference.

[0038] MOS transistors are used to turn the circuit on and off; zener diodes are used to provide gate voltage to the MOS transistors, and each zener diode is connected in series with a current-limiting resistor. The gate voltages for the first, second, and third MOS transistors Q11, Q12, and Q13 are provided by the third zener diode D14, the second zener diode D13, and the first zener diode D12. When the TVS diode D17 is turned on, the first MOS transistor Q11 is turned on and the third MOS transistor Q13 is turned off. The drain and source of the third MOS transistor Q13 are connected to the main loop of the control circuit. The second MOS transistor Q12 and the third MOS transistor Q13 are connected in series, with the source of the third MOS transistor Q13 connected to the source of the second MOS transistor Q12, and the drain of the second MOS transistor Q12 connected to the negative input voltage of the power module. When the input voltage of the power module is reversed, the gates of the second and third MOS transistors Q12 and Q13 have no voltage, and the control circuit is disconnected. The second MOS transistor Q12 mainly provides reverse input voltage protection.

[0039] The power module is used to power the microcontroller, input module, output module, and current relay, providing three voltages: 5V, 15V, and 24V. It has functions such as power reverse connection protection and overvoltage protection. Two DC-DC chips are used to convert the input voltage into 15V and 5V, respectively, to power the totem pole drive circuit and microcontroller in the input module and output module.

[0040] The TVS diode D17 is used for overvoltage protection. When the input voltage of the power module exceeds the set value, the TVS diode D17 is turned on, and a voltage is input to the voltage regulator circuit connected after the TVS diode D17. The voltage is clamped at approximately 15V. This 15V provides voltage to the gate of the first MOS transistor Q11. When the first MOS transistor Q11 is turned on, the drain and source of the first MOS transistor Q11 have the same potential of 0V. The drain of the first MOS transistor Q11 is connected to the gate of the third MOS transistor Q13, and the third MOS transistor Q13 is in the off state. At this time, the control circuit is also in the off state, and all subsequent circuits have no voltage input, thereby protecting the control circuit.

[0041] The present invention can directly connect a low-voltage DC brushed motor to a power supply. After the system detects that the power cord is connected to the motor, it delays for a certain period of time, automatically connects the circuit or soft-starts, and runs the motor. After the operator unplugs the connector, the system can repeat the automatic delayed start or PWM duty cycle automatic soft-start when testing again. The present invention changes the original operation mode of having to connect the motor power cord before pressing the start switch when the power is off, making power-on testing in factory motors more convenient and safer, and improving production efficiency, especially in the mass production of motors, the effect is significant. The control system adopts a single-chip microcomputer system with a compact structure and low cost.

[0042] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An automatic delayed start or automatic soft start system, characterized by: include: Single chip microcomputer, used to store automatic control single chip microcomputer program and receive external input signals; An input module, used for converting the motor power supply voltage signal into a voltage value input signal allowed by the single chip microcomputer, wherein the sampling point of the input module is placed in the negative pole circuit of the motor power supply; A current relay is placed in the positive line of the motor power supply, and is used to detect the current state in the entire circuit and provide a signal to the single chip microcomputer; An output module, used to amplify the output signal of the single-chip microcomputer and control the on / off of the motor power supply circuit. The point for controlling the on / off of the motor in the output module is placed between the sampling point of the input module and the negative pole of the motor power supply; A power supply module, used to supply power to the single chip microcomputer, input module, output module, and current relay; The input module and the current relay are both connected to the I / O port of the single chip microcomputer, and the single chip microcomputer is electrically connected to the output module; The input module includes a transistor (Q14), a pull-up resistor (R33) is provided at the collector of the transistor (Q14), and the collector of the transistor (Q14) is connected to the corresponding I / O port of the single-chip microcomputer; the input module also includes a fourth voltage-stabilizing tube (D15), the cathode of the fourth voltage-stabilizing tube (D15) is connected to the sampling point (test) via a first resistor (R35), and the cathode of the fourth voltage-stabilizing tube (D15) is connected to the base of the transistor (Q14) via a second resistor (R37); The current relay signal is connected to the middle point of the pull-up resistor connected in series with the third resistor (R23) and the fourth resistor (R28), and the middle point is connected to the corresponding I / O port of the single chip microcomputer; The output module includes a totem pole driver, which includes a resistor, an NPN transistor, and a PNP transistor. The corresponding I / O port of the single-chip microcomputer is connected to the totem pole driver input terminal (PC1). The totem pole driver output terminal is connected to the gate of the fourth MOS tube (Q21) through a fifth resistor (R53). A fast switching diode (D21) is connected in parallel to the fifth resistor (R53). The point in the output module that controls the on / off of the motor is connected to the drain and source terminals of the fourth MOS tube (Q21). The power supply module comprises a circuit consisting of a resistor, a first MOS tube (Q11), a second MOS tube (Q12), a third MOS tube (Q13), a first voltage regulator tube (D12), a second voltage regulator tube (D13), a third voltage regulator tube (D14), a differential mode inductor (L8), a differential mode capacitor (C30), a TVS diode (D17), and two DC-DC chips. The positive electrode of the power supply module is connected to the first DC-DC chip and the second DC-DC chip in sequence through the differential mode inductor (L8), the negative electrode of the power supply module is connected to the drain of the second MOS tube (Q12) through the differential mode inductor (L8), the source of the second MOS tube (Q12) is connected to the source of the third MOS tube (Q13), and the drain of the third MOS tube (Q13) is connected to the input end of the second DC-DC chip through the inductor and the capacitor. The gate voltages of the first MOS tube (Q11), the second MOS tube (Q12), and the third MOS tube (Q13) are provided by the third voltage regulator tube (D14), the second voltage regulator tube (D13), and the first voltage regulator tube (D12), respectively. The anodes of the third voltage regulator tube (D14), the second voltage regulator tube (D13), and the first voltage regulator tube (D12) are interconnected. The cathode of the third voltage regulator tube (D14) is connected to the gate of the first MOS tube (Q11) and is connected to one end of the TVS diode (D17) through a resistor. The cathode of the first voltage regulator tube (D12) is connected to the gate of the third MOS tube (Q13) and is connected to the other end of the TVS diode (D17) and the positive electrode of the power supply through a resistor. The cathode of the second voltage regulator tube (D13) is connected to the gate of the second MOS tube (Q12) and is connected to the positive electrode of the TVS diode (D17) through a resistor. The other end of the TVS diode (D17) and the positive electrode of the power supply are connected via a resistor; the drain of the first MOS tube (Q11) is connected to the gate of the third MOS tube (Q13); the source of the first MOS tube (Q11) is connected to the anodes of the first voltage-stabilizing tube (D12), the second voltage-stabilizing tube (D13), and the third voltage-stabilizing tube (D14); the source of the first MOS tube (Q11) is also connected to the drain of the second MOS tube (Q12) via a fourth voltage-stabilizing tube (D11); when the TVS diode (D17) is turned on, the first MOS tube (Q11) is in the on state, and the third MOS tube (Q13) is in the off state. At this time, the control circuit is in the off state, and all subsequent circuits have no voltage input, thereby protecting the control circuit.

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