A master drive circuit for an alternating current motor and an elevator arrangement

Abstract

The utility model provides a kind of main control drive circuit and elevator device of alternating current motor, and its main control drive circuit includes: power conversion circuit, for outputting direct-current power supply;Waveform generating circuit is electrically connected with the power conversion circuit, the power conversion circuit is for the waveform generating circuit power supply, the waveform generating circuit is used to generate sine wave signal;Power amplifier circuit is electrically connected with the waveform generating circuit, for amplifying the sine wave signal, for alternating current motor output alternating current power supply;Motor control circuit is electrically connected with the power amplifier circuit, for the alternating current power supply provided to alternating current motor is connected or disconnected.The utility model can effectively solve the safety risk that traditional device uses commercial power direct power supply exists, while solve the problem that elevator device uses the noise of direct current motor is big.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, and in particular to a main control drive circuit for an AC motor and an elevator device. Background Technology

[0002] In current lifting devices (including but not limited to lifting displays and lifting desks), three main power supply and drive methods are typically used:

[0003] The first method is to directly input AC mains power (e.g., 100V-240V AC) to power the device, thereby driving the AC motor. The second method is to use an external power adapter to convert AC mains power (e.g., 100V-240VAC) to DC power, and then power the device to drive the DC motor. The third method is to also input AC mains power (e.g., 100V-240V AC) as the power source, but complete the AC-to-DC conversion internally to drive the DC motor.

[0004] The first and third methods mentioned above directly power the device with mains electricity, which has a high voltage and may pose a safety threat to human health. While the second method uses relatively safe DC power, the DC motors used generate more noise during operation than AC motors, making it unsuitable for applications requiring quiet operation, such as conference rooms, offices, and classrooms. Therefore, achieving low-noise operation while ensuring safety has become a crucial direction for the technological improvement of elevator systems. Utility Model Content

[0005] This utility model provides a main control drive circuit for an AC motor and an elevator device to solve the problems existing in the related technology. The technical solution is as follows:

[0006] In a first aspect, embodiments of the present invention provide a main control drive circuit for an AC motor, comprising:

[0007] Power conversion circuit, used to output DC power;

[0008] The waveform generation circuit is electrically connected to the power conversion circuit. The power conversion circuit supplies power to the waveform generation circuit, which is used to generate a sine wave signal.

[0009] The power amplifier circuit is electrically connected to the waveform generator circuit and is used to amplify the sine wave signal to output AC power to the AC motor.

[0010] The motor control circuit, electrically connected to the power amplifier circuit, is used to connect or disconnect the AC power supply provided to the AC motor.

[0011] In one embodiment, the motor control circuit includes a rectifier and filter circuit; the rectifier and filter circuit includes rectifier bridge RE1, rectifier bridge RE2, filter capacitor C1, filter capacitor C2, and inductor L3; the AC power supply of the power adapter is rectified by rectifier bridge RE1 and rectifier bridge RE2 to convert the AC voltage into a pulsating DC voltage; the rectified pulsating DC voltage is filtered by capacitors C1 and C2 respectively; inductor L3 together with capacitors C1 and C2 forms an LC filter.

[0012] In one embodiment, the motor control circuit further includes a microcontroller U5 and a voltage regulator circuit; the voltage regulator circuit includes a three-terminal regulator U1, a transistor Q1, and a resistor R11; the three-terminal regulator U1 is used to regulate the input voltage to the required stable voltage; the base of the transistor Q1 is connected to the control signal of the microcontroller U5 through the resistor R11, the collector of the transistor Q1 is connected to the enable terminal of the three-terminal regulator U1, and the emitter is grounded.

[0013] In one embodiment, the main control drive circuit further includes a processor and a communication circuit. The processor is connected to the motor control circuit and the communication circuit, and communicates with external devices through the communication circuit.

[0014] In one embodiment, the main control drive circuit further includes a displacement sensor, the detection end of which is connected to the AC motor, and the signal output end of which is connected to the processor.

[0015] In one embodiment, the main control driving circuit further includes a display driving circuit, which is connected to the processor.

[0016] In one embodiment, the main control drive circuit further includes an auxiliary circuit, which includes a button circuit module, a remote control circuit module, and a touch control screen.

[0017] In one embodiment, the power amplifier circuit includes an operational amplifier U102. A sine wave signal is connected to the non-inverting input terminal and the inverting input terminal of the operational amplifier U102 through a filter network composed of resistor R150 and capacitor C130, respectively. The operational amplifier U102 compares the voltages at the non-inverting input terminal and the inverting input terminal and generates an output voltage at the output terminal that is proportional to the difference.

[0018] In one embodiment, the power conversion circuit includes a switching power supply controller U100, a power transistor Q100, and an inductor L100. The OUT pin of the switching power supply controller U100 outputs a PWM signal, which drives the gate of the power transistor Q100 through a resistor R108, causing the power transistor Q100 to periodically turn on and off, and is connected to the load through the inductor L100.

[0019] Secondly, embodiments of this utility model provide an elevator device, comprising:

[0020] A power adapter is used to convert AC power into DC power.

[0021] As mentioned above, the main control drive circuit of the AC motor is connected to the power adapter, and the power adapter provides DC power to the main control drive circuit.

[0022] An AC motor is connected to a main control drive circuit, which is used to drive the AC motor.

[0023] The advantages or beneficial effects of the above technical solutions include at least the following:

[0024] This utility model of a lifting device converts mains power to DC power via a power adapter, and then uses the DC power to drive the lifting device which uses an AC motor. By using safe low-voltage DC to power the lifting device, it can effectively solve the safety risks of traditional devices that use direct mains power. At the same time, the main control drive circuit inside the lifting device converts the DC power to AC power to drive the AC motor of the lifting device, thus solving the problem of high noise when using DC motors in lifting devices. It can meet the application scenarios with low noise requirements (such as meetings, offices, and classrooms).

[0025] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0026] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed according to this utility model and should not be construed as limiting the scope of this utility model.

[0027] Figure 1 This is a schematic diagram showing the connection between the main control drive circuit of this utility model and the power adapter;

[0028] Figure 2 This is a circuit diagram of the boost converter circuit of this utility model;

[0029] Figure 3 This is a circuit diagram of the power amplifier circuit of this utility model;

[0030] Figure 4 This is a circuit diagram of the motor drive section in the motor control circuit of this utility model.

[0031] Figure 5 This is a circuit diagram of the microcontroller U5 of this utility model;

[0032] Figure 6 This is a circuit diagram of the processor of this utility model;

[0033] Figure 7 This is a circuit diagram of the RS-485 communication circuit of this utility model;

[0034] Figure 8 This is a circuit diagram of the antenna communication of this utility model. Detailed Implementation

[0035] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0036] Example 1

[0037] This embodiment provides a main control drive circuit for an AC motor. The main control drive circuit is powered by a DC power supply and is used to drive the AC motor of the elevator device. It can meet the application scenarios with low noise requirements while ensuring electrical safety, and has obvious safety and low noise advantages.

[0038] like Figure 1 As shown, the main control drive circuit mainly includes a power conversion circuit, a waveform generation circuit, a power amplifier circuit, and a motor control circuit.

[0039] The power conversion circuit can be connected to an external power adapter, which is connected to the mains power to convert the mains power (e.g., 100V-240VAC) into safe low-voltage DC power that will not cause harm to the human body. This DC power is output to the main control drive circuit, thereby effectively solving the possible danger of electric shock and improving electrical safety.

[0040] Power conversion circuits provide the necessary power to waveform generation circuits, power amplifier circuits, and other circuits through methods including but not limited to boost, buck, DC-DC conversion, and isolation. Specifically, for example... Figure 2 As shown, the power conversion circuit in this embodiment includes a boost converter circuit. The main function of the boost converter circuit is to boost the lower voltage (such as 12V DC) output by the power adapter to a higher output voltage (30.3V).

[0041] In this embodiment, the boost converter circuit includes an input power supply section, a switching power supply controller U100, a power transistor Q100, an auxiliary transistor Q101, an inductor L100, and an output filter section. The input power supply section includes a DC socket to provide a 12V DC input voltage. A diode D4 is connected to the input power supply section to prevent reverse current from damaging the circuit and, in some cases, to provide freewheeling. The input power supply section is then connected to the switching power supply controller U100 via capacitors CE103, CE104, CE105, and C102. Capacitors CE103, CE104, CE105, and C102 are used for filtering to reduce power supply noise.

[0042] The OUT pin of the switching power supply controller U100 outputs a PWM signal, which drives the gate of power transistor Q100 through resistor R108, causing Q100 to periodically turn on and off. The gate of power transistor Q100 is connected to the OUT pin of U100 through resistor R108, the source of power transistor Q100 is connected to the Isense pin of the switching power supply controller U100 through resistor R109, and is connected to the load through inductor L100. The drain of power transistor Q100 is connected to a 30.3V power supply. The load refers to circuits such as waveform generators and power amplifiers that require power from the power conversion circuit.

[0043] The auxiliary transistor Q101 is an NPN transistor used to assist in switching operation. One end of the inductor L100 is connected to the source of Q100, and the other end is connected to the load. The inductor L100 stores energy and releases it when the switch is open to boost the output voltage. One end of the capacitor C105 is connected to the output of L100, and the other end is grounded for further filtering to ensure the stability of the output voltage.

[0044] The boost process is as follows: When the OUT pin of the switching power supply controller U100 outputs a high level, the power transistor Q100 turns on, and current flows from the 30.3V power supply through the power transistor Q100 and the inductor L100, where the inductor stores energy. When the OUT pin of the switching power supply controller U100 outputs a low level, the power transistor Q100 turns off. Because the inductor attempts to maintain a constant current, it generates a back electromotive force (EMF). This EMF is superimposed on the input voltage, making the output voltage higher than the input voltage. The magnitude of the output voltage can be controlled by adjusting the duty cycle of the OUT pin of U100.

[0045] The waveform generation circuit is electrically connected to the power conversion circuit, which supplies power to the waveform generation circuit. The waveform generation circuit is used to generate sine wave signals. In this embodiment, the waveform generation circuit uses, but is not limited to, MCU, DSP, CPU, etc., to directly generate a sine wave signal of the corresponding frequency (50Hz or 60Hz) according to the required frequency of the AC motor, or to generate a PWM wave signal, which is then filtered and shaped by RC to form a sine wave of the corresponding frequency.

[0046] It should be noted that the working principle of waveform generation circuits that directly generate sine wave signals through MCUs, DSPs, CPUs, etc. is existing technology and will not be described again here.

[0047] The power amplifier circuit is electrically connected to the waveform generator circuit to amplify the sinusoidal signal, providing the necessary AC power to the AC motor. For example... Figure 3 As shown, the power amplifier circuit in this embodiment includes an operational amplifier U102. A sinusoidal signal is connected to the non-inverting and inverting input terminals of operational amplifier U102 via a filter network composed of resistor R150 and capacitor C130. The non-inverting input terminal (pin 3) is grounded through an RC filter network composed of R121 and C114, forming a stable DC bias point. The inverting input terminal (pin 2) is grounded through an RC filter network composed of R118 and C115, also forming a stable DC bias point. Operational amplifier U102 compares the voltages at the non-inverting and inverting input terminals and generates an output voltage proportional to the difference. The output signal of operational amplifier U102 is output from its output terminal (pin 6), further filtered by an RC filter network composed of R122 and C122 to remove high-frequency noise, and finally attenuated or gain-adjusted by a resistor network composed of R124 and R125 before being output through a filter network composed of C117 and C123.

[0048] The output of the power amplifier circuit is electrically connected to the motor control circuit, which is connected to the AC motor of the lifting device and used to connect or disconnect the AC power supply to the AC motor. In this embodiment, as shown... Figure 4 , Figure 5 As shown, the motor control circuit mainly consists of the control section and the motor drive section. The control section includes a microcontroller U5 and motor control switches (MOTOR-SW1 to MOTOR-SW4). These switches are connected to the GPIO ports of the microcontroller and are used to control the operating status of the AC motor.

[0049] The motor drive section includes an AC input terminal, a rectifier and filter circuit (C1, C2, L3, RE1, RE2), a voltage regulator circuit (U1, Q1, R11), transistors, diodes, etc. Specifically, a sine wave signal flows in as AC power from the AC input terminal. The rectifier and filter circuit rectifies the AC voltage into DC voltage and filters it through capacitors and inductors to ensure power stability. The voltage regulator circuit regulates the rectified DC voltage to 12VDC to power the subsequent circuits.

[0050] The rectifier and filter circuit includes rectifier bridge RE1, rectifier bridge RE2, filter capacitor C1, filter capacitor C2, and inductor L3. The AC power supply is rectified by rectifier bridges RE1 and RE2 to convert the AC voltage into a pulsating DC voltage. The rectified pulsating DC voltage is filtered by capacitors C1 and C2 respectively. Inductor L3, together with capacitors C1 and C2, forms an LC filter.

[0051] The voltage regulator circuit includes a three-terminal regulator U1, a transistor Q1, and a resistor R11. The three-terminal regulator U1 is used to regulate the input voltage to the required stable voltage. The base of the transistor Q1 is connected to the control signal of the microcontroller U5 through the resistor R11, the collector of the transistor Q1 is connected to the enable terminal of the three-terminal regulator U1, and the emitter is grounded.

[0052] The motor drive principle in this embodiment is as follows:

[0053] Alternating current (AC) is input through the J15 interface, passing through fuses F1 and F2 before entering rectifier bridges RE1 and RE2. Rectifier bridges RE1 and RE2 convert the AC into pulsating DC. Each rectifier bridge consists of four diodes, forming a full-wave rectifier to ensure the output voltage is always positive. Filter capacitors C1 and C2 smooth the pulsating DC after rectification, reducing voltage fluctuations and providing a relatively stable DC voltage.

[0054] Regulator U1 stabilizes a higher DC voltage (such as 12V DC) to a lower DC voltage (such as 5V DC) to power the microcontroller U5 and other low-voltage devices. Internally, the regulator contains components such as a reference voltage source, an error amplifier, and a regulating transistor, which automatically adjust the output voltage to ensure it remains stable at the set value.

[0055] The microcontroller U5 communicates with external circuits through its digital input / output pins, receiving user commands and processing data. The microcontroller U5 controls the switching states of transistors Q3, Q4, Q5, and Q6 through its output pins, thereby controlling the forward, reverse, and stop of the motor. When the microcontroller U5 issues a forward command, it turns on transistor Q5 through its output pin, allowing current to flow from the positive terminal of the power supply through Q5, the motor coil, and Q6 (which should be in the off state at this time) back to the negative terminal, causing the motor to rotate forward. When the microcontroller U5 issues a reverse command, it turns on transistor Q6 through its output pin, allowing current to flow from the positive terminal of the power supply through Q6, the motor coil, and Q5 (which should be in the off state at this time) back to the negative terminal, causing the motor to rotate in reverse. When the microcontroller U5 issues a stop command, it turns off transistors Q5 and Q6 through its output pins, cutting off the motor power supply and stopping the motor.

[0056] In another embodiment, the main control drive circuit further includes a processor and a communication circuit, such as... Figure 6 As shown, Figure 6 This is a circuit diagram of the processor. The processor is connected to the motor control circuit and to the communication circuit, through which it communicates with external devices, such as RS485, RS232, USB, and CAN. Figure 7 The diagram shows an RS-485 communication circuit, as follows: Figure 8 The diagram shows an antenna communication circuit.

[0057] In another embodiment, the main control drive circuit further includes a displacement sensor. The detection end of the displacement sensor is connected to the AC motor, and the signal output end of the displacement sensor is connected to the processor to provide feedback displacement sensing signals to the main control drive circuit. Specifically, the displacement sensor refers to a rotary encoder or Hall effect sensor, etc., used to detect the motion state of the motor, such as position, speed, and direction. The detection end of the displacement sensor needs to be connected to the rotating part of the AC motor, while its signal output end is connected to the corresponding input port of the processor so that the processor can determine the motion state of the motor based on the information fed back by the sensor. The specific connection method depends on the type of sensor used and its electrical characteristics.

[0058] In another embodiment, the main control driving circuit further includes a display driving circuit, which is connected to the processor. The display driving circuit may be equipped with a display screen, including display input / output interfaces, etc., and provides the necessary driving force for the display screen.

[0059] In another embodiment, the main control drive circuit further includes an auxiliary circuit, which includes a button circuit module, a remote control circuit module, and a touch control screen. The auxiliary circuit is connected to the processor.

[0060] It should be noted that the display driver circuit and auxiliary circuits are existing technologies and will not be described again here. Furthermore, it should be emphasized that the control methods between the processor and each circuit are already disclosed in the prior art, and this embodiment does not protect the control methods themselves, but rather the connection relationships between the circuits.

[0061] Example 2

[0062] This embodiment provides a lifting device, which includes, but is not limited to, a lifting display screen, a lifting table, etc. The lifting device includes:

[0063] A power adapter is used to convert AC power into DC power.

[0064] As described in Embodiment 1, the main control drive circuit of the AC motor is connected to the power adapter, and the power adapter provides DC power to the main control drive circuit.

[0065] An AC motor is connected to a main control drive circuit, which is used to drive the AC motor.

[0066] The functional principle of the main control drive circuit in the elevator device of this embodiment can be found in the corresponding description in the above embodiments, and will not be repeated here.

[0067] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," 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 the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0069] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this utility model, and these should all be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A main control drive circuit for an AC motor, characterized in that, include: Power conversion circuit, used to output DC power; A waveform generating circuit is electrically connected to the power conversion circuit, the power conversion circuit supplies power to the waveform generating circuit, and the waveform generating circuit is used to generate a sine wave signal; A power amplifier circuit, electrically connected to the waveform generator circuit, is used to amplify the sine wave signal and output AC power to the AC motor. The motor control circuit is electrically connected to the power amplifier circuit and is used to connect or disconnect the AC power supply provided to the AC motor.

2. The main control drive circuit for an AC motor according to claim 1, characterized in that, The motor control circuit includes a rectifier and filter circuit; the rectifier and filter circuit includes rectifier bridge RE1, rectifier bridge RE2, filter capacitor C1, filter capacitor C2, and inductor L3; the AC power supply is rectified by the rectifier bridges RE1 and RE2 to convert the AC voltage into a pulsating DC voltage; the rectified pulsating DC voltage is filtered by the capacitors C1 and C2 respectively; the inductor L3 together with the capacitors C1 and C2 forms an LC filter.

3. The main control drive circuit for an AC motor according to claim 2, characterized in that, The motor control circuit also includes a microcontroller U5 and a voltage regulator circuit; the voltage regulator circuit includes a three-terminal regulator U1, a transistor Q1, and a resistor R11; the three-terminal regulator U1 is used to regulate the input voltage to the required stable voltage; the base of the transistor Q1 is connected to the control signal of the microcontroller U5 through the resistor R11, the collector of the transistor Q1 is connected to the enable terminal of the three-terminal regulator U1, and the emitter is grounded.

4. The main control drive circuit for an AC motor according to claim 1, characterized in that, It also includes a processor and a communication circuit. The processor is connected to the motor control circuit and the communication circuit, through which it communicates with external devices.

5. The main control drive circuit for an AC motor according to claim 4, characterized in that, It also includes a displacement sensor, the detection end of which is connected to the AC motor, and the signal output end of which is connected to the processor.

6. The main control drive circuit for an AC motor according to claim 4, characterized in that, It also includes a display driver circuit, which is connected to the processor.

7. The main control drive circuit for an AC motor according to claim 4, characterized in that, It also includes auxiliary circuitry, which includes a button circuit module, a remote control circuit module, and a touch control screen.

8. The main control drive circuit for an AC motor according to claim 1, characterized in that, The power amplifier circuit includes an operational amplifier U102. The sinusoidal signal is connected to the non-inverting input terminal and the inverting input terminal of the operational amplifier U102 through a filter network composed of resistor R150 and capacitor C130, respectively. The operational amplifier U102 compares the voltages of the non-inverting input terminal and the inverting input terminal and generates an output voltage that is proportional to the difference at the output terminal.

9. The main control drive circuit for an AC motor according to claim 1, characterized in that, The power conversion circuit includes a switching power supply controller U100, a power transistor Q100, and an inductor L100. The OUT pin of the switching power supply controller U100 outputs a PWM signal, which drives the gate of the power transistor Q100 through a resistor R108, causing the power transistor Q100 to periodically turn on and off, and is connected to the load through the inductor L100.

10. A lifting device, characterized in that, include: A power adapter is used to convert AC power into DC power. The main control drive circuit of the AC motor as described in any one of claims 1 to 9, wherein the main control drive circuit is connected to the power adapter; An AC motor is connected to the main control drive circuit.

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