Control circuit of alternating-current variable-frequency electric fan

Abstract

The control circuit of the alternating-current variable-frequency electric fan comprises an alternating-current power supply module, a variable-frequency module, a frequency detection module, a controller and a motor, the variable-frequency module achieves accurate control over the rotating speed of the motor through the controller, and the controller is electrically connected with the frequency detection module and used for monitoring input alternating-current voltage frequency. The signal input end of the controller is electrically connected with an external speed regulation module, and when the controller obtains an external speed regulation signal, the frequency conversion module can realize accurate frequency conversion under the control of the controller, so that the motor can realize accurate speed regulation.

Description

Technical Field

[0001] The utility model relates to the field of frequency converters and control circuits, in particular to a control circuit of an AC variable frequency electric fan. Background Art

[0002] Currently, the electric fan industry has widely begun manufacturing variable-frequency fans. Compared to fixed-frequency fans, their superior performance and variable functionality make them more suitable for most home and industrial applications. Common variable-frequency fans include DC and AC fans. The motor rotor of a DC variable-frequency fan is made of rare earth permanent magnet material. The operating principle is that the stator generates a rotating magnetic field, which directly interacts with the rotor's permanent magnet field to achieve motor operation. During operation, the motor speed is changed by varying the DC voltage supplied to the motor. The problem with this model is that the control system is complex, costly, and requires a high power supply, making it impractical in many scenarios. Therefore, AC variable-frequency fans have become a more suitable option for most scenarios.

[0003] However, existing variable frequency AC fans also have certain problems. Most of them are composed of pure circuits such as filtering and rectification, and the speed regulation is not accurate.

[0004] Therefore, there is a need to provide a control circuit for an AC variable frequency electric fan that can achieve precise speed regulation. Utility Model Content

[0005] In order to solve the problems raised in the above background technology, the present invention provides a control circuit for an AC variable frequency electric fan, which solves the problem of low speed regulation accuracy of current variable frequency AC electric fans.

[0006] To achieve the above object, the present invention provides the following technical solution: a control circuit for an AC variable frequency electric fan, comprising:

[0007] An AC power supply module, a frequency conversion module, a frequency detection module, a controller, and a motor, wherein the input end of the frequency detection module is electrically connected to the output end of the AC power supply module, and the output end of the frequency detection module is electrically connected to the controller;

[0008] The signal input end of the controller is electrically connected to an external speed regulation module, the first output end of the controller is electrically connected to the input end of the frequency conversion module, and the output end of the frequency conversion module is electrically connected to the controlled end of the motor.

[0009] Based on the control circuit of the AC variable frequency electric fan described above, in a possible design, the frequency conversion module includes: a bidirectional thyristor, a first transformer, and a first photocoupler;

[0010] The input end of the first optocoupler is electrically connected to the first output end of the controller, and the output end of the first optocoupler is electrically connected to the first input end of the first transformer through the bidirectional thyristor, wherein the second input end of the first transformer is electrically connected to the output end of the AC power supply module, and the output end of the first transformer is electrically connected to the controlled end of the motor.

[0011] Based on the control circuit of the AC variable frequency electric fan described above, in one possible design, the frequency detection module includes: a second photoelectric coupler and a first resistor;

[0012] The first input end of the second photoelectric coupler is electrically connected to the output end of the AC power supply module, the second input end of the second photoelectric coupler is electrically connected to the output end of the AC power supply module through the first resistor, and the output end of the second photoelectric coupler is electrically connected to the input end of the controller.

[0013] Based on the above-mentioned control circuit of the AC variable frequency electric fan, in one possible design, the AC power supply module includes a protector, a first capacitor and a second transformer;

[0014] The first input end and the second input end of the second transformer are electrically connected to an AC power supply, the first capacitor and the protector are connected in parallel between the first input end and the second input end of the second transformer, and the output end of the second transformer is electrically connected to the input end of the frequency detection module.

[0015] The output end of the second transformer is electrically connected to the input end of the frequency detection module.

[0016] Based on the control circuit of the above-mentioned AC variable frequency electric fan, in a possible design, it also includes: a rectifier module, wherein the input end of the rectifier module is electrically connected to the output end of the AC power supply module, and the output end of the rectifier module outputs a DC voltage and is electrically connected to the power supply end of the controller.

[0017] Based on the above-mentioned control circuit of the AC variable frequency electric fan, in one possible design, the rectifier module includes: a rectifier bridge, a power management chip and a filter unit;

[0018] The input end of the rectifier bridge is electrically connected to the output end of the AC power supply module, the voltage output end of the rectifier bridge is electrically connected to the input end of the power management chip, the output end of the power management chip is electrically connected to the input end of the filter unit, and the output end of the filter unit is electrically connected to the controller.

[0019] Based on the above-mentioned control circuit of the AC variable frequency electric fan, in a possible design, the model of the power management chip is LY1203.

[0020] Based on the control circuit of the AC variable frequency electric fan described above, in a possible design, a frequency conversion prompt module is further included, and an input end of the frequency conversion prompt module is electrically connected to the second output end of the controller.

[0021] Based on the control circuit of the AC variable frequency electric fan described above, in one possible design, the variable frequency prompt module includes a passive buzzer, a first diode, a second capacitor, a second resistor and a MOS tube;

[0022] The gate of the MOS transistor is electrically connected to the second input end of the controller, the second resistor is connected in parallel between the gate and source of the MOS transistor, the drain of the MOS transistor is electrically connected to the output end of the passive buzzer, the input end of the passive buzzer is electrically connected to a DC power supply, and the drain of the MOS transistor is electrically connected to one end of the first diode and the second capacitor, and the other end of the first diode and the second capacitor is electrically connected to the DC power supply.

[0023] Based on the above-mentioned control circuit of the AC variable frequency electric fan, in a possible design, the controller adopts the SN8P2711ASG chip and its peripheral circuit

[0024] Beneficial effects:

[0025] The control circuit of the AC variable-frequency electric fan disclosed in the present invention includes an AC power supply module, a frequency conversion module, a frequency detection module, a controller and a motor, wherein the frequency conversion module realizes precise control of the motor speed through the controller, and the controller is electrically connected to the frequency detection module for monitoring the input AC voltage frequency. The signal input end of the controller is electrically connected to the external speed regulation module. When the controller obtains the external speed regulation signal, the frequency conversion module will realize precise frequency conversion under the control of the controller, so that the motor can achieve precise speed regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a functional block diagram of the control circuit of the AC variable frequency electric fan in Example 1 of the present utility model;

[0028] Figure 2 This is a circuit diagram of an AC power supply module in a control circuit of an AC variable frequency electric fan in Example 2 of the present utility model;

[0029] Figure 3 This is a circuit diagram of a frequency conversion module in a control circuit of an AC variable frequency electric fan in Example 2 of the present utility model;

[0030] Figure 4 This is a circuit diagram of a frequency detection module in a control circuit of an AC variable frequency electric fan in Example 2 of the present utility model;

[0031] Figure 5 This is a circuit diagram of a controller and its peripherals in a control circuit of an AC variable frequency electric fan in Example 2 of the present utility model;

[0032] Figure 6 This is a circuit diagram of a rectifier bridge in a control circuit of an AC variable frequency electric fan in Example 2 of the present utility model;

[0033] Figure 7 This is a circuit diagram of a power management chip and a filter circuit in the control circuit of an AC variable frequency electric fan in Example 2 of the present utility model;

[0034] Figure 8 This is a circuit diagram of a frequency conversion prompt module in the control circuit of an AC variable frequency electric fan in Example 2 of the present utility model. DETAILED DESCRIPTION

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention will be briefly introduced below in conjunction with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structures of the drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0036] It should be understood that although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the embodiments of the present invention.

[0037] In the following description, certain details are provided to facilitate a complete understanding of the example embodiments. However, one of ordinary skill in the art will appreciate that the example embodiments can be practiced without these specific details. For example, a system may be shown in a block diagram to avoid obscuring the example with unnecessary detail. In other embodiments, well-known processes, structures, and techniques may be shown without unnecessary detail to avoid obscuring the embodiment.

[0038] Example 1:

[0039] like Figure 1 As shown, this embodiment provides a control circuit for an AC variable frequency electric fan, including an AC power supply module, a frequency conversion module, a frequency detection module, a controller U6 and a motor, wherein the signal input end of the controller is electrically connected to an external speed regulation module, which can obtain an external speed regulation signal and control the frequency conversion module to perform precise frequency regulation to achieve the purpose of accurately controlling the motor speed.

[0040] In this control circuit, the controller's signal input terminal is used to obtain the speed control signal input by the user. The frequency detection module detects the input AC power frequency and processes the speed control signal obtained from the external speed control module to generate a precise frequency conversion signal, which is sent to the frequency conversion module electrically connected to it. The frequency converter completes the regulation of the AC voltage frequency based on the received frequency conversion signal. After receiving the user's speed control signal, the controller will perform real-time control and regulation. The frequency regulation of the controller chip is faster and more accurate than the pure circuit regulation of simple rectification, inversion, and other circuits, thereby achieving precise regulation of the motor speed. Moreover, under the control of the controller, this control circuit can control the frequency conversion control unit according to the target speed input by the user, achieving the ability to automatically adjust the power and speed of the motor to maintain good energy efficiency of the motor operation, thereby achieving energy conservation.

[0041] When applied in actual scenarios, the controller can preferably adopt the SN8P2711ASG type MCU. The SN8P2711ASG type MCU has the characteristics of high performance and low power consumption, which can effectively improve the signal transmission and control capabilities of this control circuit.

[0042] Example 2:

[0043] like Figure 2-8 As shown, this embodiment provides a control circuit for an AC variable frequency electric fan. As a preferred implementation, the frequency conversion module includes: a bidirectional thyristor Q2, a first transformer L59, and a first photocoupler U4;

[0044] The input end of the first optocoupler U4 is electrically connected to the output end of the controller U6, and the output end of the first optocoupler U4 is electrically connected to the first input end of the first transformer L59 through the bidirectional thyristor Q2, wherein the second input end of the first transformer L59 is electrically connected to the output end of the AC power supply module, and the output end of the first transformer L59 is electrically connected to the controlled end of the motor.

[0045] Preferably, the model of the first photoelectric coupler U4 is MOC3022;

[0046] The second pin of the first photocoupler U4 is electrically connected to the first output terminal of the controller, the fourth pin of the first photocoupler U4 is electrically connected to one end of the first resistor R6 and the bidirectional thyristor Q2, and the sixth pin of the first photocoupler U4 is electrically connected to one end of the second resistor R10, wherein the other end of the second resistor R10 is electrically connected to the bidirectional thyristor Q2 and the output terminal of the AC power supply module, and the other end of the first resistor R6 is electrically connected to the bidirectional thyristor Q2 and the first output terminal of the first transformer L59;

[0047] The second input end of the first transformer L59 is electrically connected to the output end of the AC power supply module, and the output end of the first transformer L59 is electrically connected to the controlled end of the motor.

[0048] This embodiment provides a control circuit for an AC variable frequency electric fan. As a preferred implementation, the frequency detection module includes: a second photoelectric coupler U5 and a first resistor R12;

[0049] The first input end of the second photocoupler U5 is electrically connected to the output end of the AC power supply module, the second input end of the second photocoupler U5 is electrically connected to the output end of the AC power supply module through the first resistor R12, and the output end of the second photocoupler U5 is electrically connected to the input end of the controller U6.

[0050] This embodiment provides a control circuit for an AC variable frequency electric fan. As a preferred implementation, the AC power supply module includes an AC power supply, a protector, a first capacitor C1, and a second transformer L58.

[0051] The first output end of the AC power supply is electrically connected to the first input end of the second transformer L58, the second output end of the AC power supply is electrically connected to the second input end of the second transformer L58, and the protector and the first capacitor C1 are connected in parallel between the first input end of the second transformer L58 and the second input end of the second transformer L58;

[0052] The output end of the second transformer L58 is electrically connected to the input end of the frequency detection module.

[0053] The control circuit of an AC variable frequency electric fan provided in this embodiment, as a preferred implementation, further includes: a rectifier module, wherein the input end of the rectifier module is electrically connected to the output end of the AC power supply module, and the output end of the rectifier module is electrically connected to the power supply end of the controller and outputs a DC voltage.

[0054] The rectifier module includes: rectifier bridge, power management chip U3 and filter unit;

[0055] The input end of the rectifier bridge is electrically connected to the output end of the AC power supply module, the positive voltage output end of the rectifier bridge is electrically connected to the input end of the power management chip U3, the output end of the power management chip U3 is electrically connected to the input end of the filter unit, and the output end of the filter unit is electrically connected to the frequency conversion module and the controller U6.

[0056] The model of the power management chip U3 is LY1203;

[0057] The filtering unit includes a third capacitor C5, a third resistor R8, a fourth resistor R9, a fifth resistor R7, a sixth resistor R4, a seventh resistor R11, a fourth capacitor C6, a fifth capacitor C7, a sixth capacitor EC2, a second diode D1, a third diode D2 and a first inductor L60;

[0058] Among them, the first pin of the power management chip U3 is electrically connected to one end of the third resistor R8 and the fourth resistor R9, the other end of the third resistor R8 and the fourth resistor R9 is electrically connected to one end of the first inductor L60, and the other end of the first inductor L60 is connected to a DC power supply; the second pin of the power management chip U3 is electrically connected to one end of the third capacitor C5, and the other end of the third capacitor C5 is electrically connected to the negative end of the second diode D1; the third pin of the power management chip U3 is electrically connected to the negative end of the second diode D1; the fourth pin of the power management chip U3 is electrically connected to the fifth resistor R7, the sixth resistor R4 and the fourth resistor R60. The positive terminal of the third diode D2 is electrically connected to the AN pin of the first photocoupler U4; the positive terminal of the second diode D1 is electrically connected to one end of the sixth capacitor EC2 and one end of the seventh resistor R11, and is grounded, and the other end of the sixth capacitor EC2 and the seventh resistor R11 is electrically connected to the positive terminal of the third diode D2.

[0059] The input terminal of the power management chip U3 is electrically connected to the positive voltage output terminal of the rectifier bridge, the power management chip U3;

[0060] It also includes a frequency conversion prompt module, the input end of the frequency conversion prompt module is electrically connected to the second output end of the controller, and the frequency conversion prompt module is electrically connected to the negative voltage output end of the rectifier bridge.

[0061] The frequency conversion prompt module includes a passive buzzer, a first diode D3, a second capacitor C10, a second resistor R13 and a MOS tube;

[0062] The gate of the MOS transistor is electrically connected to the controller. A second resistor R13 is connected in parallel between the gate and source of the MOS transistor. The drain of the MOS transistor is electrically connected to the output of the passive buzzer. The input of the passive buzzer is electrically connected to the negative voltage output of the rectifier bridge. A first diode D3 and a second capacitor C10 are connected in parallel across the passive buzzer. The frequency conversion prompt module receives a control signal when the controller completes the frequency conversion signal transmission and generates a voice prompt to the user.

[0063] The control circuit of an AC variable frequency electric fan provided in this embodiment, as a preferred embodiment, further includes a touch control circuit, the output of which is electrically connected to the input of the controller. The setting of the touch control circuit can facilitate the user to set the speed.

[0064] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A control circuit for an AC variable frequency electric fan, characterized in that: include: An AC power supply module, a frequency conversion module, a frequency detection module, a controller (U6) and a motor, wherein the input end of the frequency detection module is electrically connected to the output end of the AC power supply module, and the output end of the frequency detection module is electrically connected to the controller (U6); The signal input end of the controller (U6) is electrically connected to an external speed regulation module, the first output end of the controller (U6) is electrically connected to the input end of the frequency conversion module, and the output end of the frequency conversion module is electrically connected to the controlled end of the motor.

2. The control circuit of the AC variable frequency electric fan according to claim 1, characterized in that: The frequency conversion module includes: a bidirectional thyristor (Q2), a first transformer (L59) and a first photoelectric coupler (U4); The input end of the first photoelectric coupler (U4) is electrically connected to the first output end of the controller (U6), and the output end of the first photoelectric coupler (U4) is electrically connected to the first input end of the first transformer (L59) through the bidirectional thyristor (Q2), wherein the second input end of the first transformer (L59) is electrically connected to the output end of the AC power supply module, and the output end of the first transformer (L59) is electrically connected to the controlled end of the motor.

3. The control circuit of the AC variable frequency electric fan according to claim 1, characterized in that: The frequency detection module includes: a second photoelectric coupler (U5) and a first resistor (R12); The first input end of the second photoelectric coupler (U5) is electrically connected to the output end of the AC power supply module, the second input end of the second photoelectric coupler (U5) is electrically connected to the output end of the AC power supply module via the first resistor (R12), and the output end of the second photoelectric coupler (U5) is electrically connected to the input end of the controller (U6).

4. The control circuit of the AC variable frequency electric fan according to claim 1, characterized in that: The AC power supply module includes a protector, a first capacitor (C1) and a second transformer (L58); The first input end and the second input end of the second transformer (L58) are electrically connected to an AC power supply, the first capacitor (C1) and the protector are connected in parallel between the first input end and the second input end of the second transformer (L58), and the output end of the second transformer (L58) is electrically connected to the input end of the frequency detection module; The output end of the second transformer (L58) is electrically connected to the input end of the frequency detection module.

5. The control circuit of the AC variable frequency electric fan according to claim 1, characterized in that: Also includes: A rectifier module, wherein the input end of the rectifier module is electrically connected to the output end of the AC power supply module, and the output end of the rectifier module outputs a DC voltage and is electrically connected to the power supply end of the controller (U6).

6. The control circuit of the AC variable frequency electric fan according to claim 5, characterized in that: The rectifier module includes: a rectifier bridge, a power management chip (U3) and a filter unit; The input end of the rectifier bridge is electrically connected to the output end of the AC power supply module, the voltage output end of the rectifier bridge is electrically connected to the input end of the power management chip (U3), the output end of the power management chip (U3) is electrically connected to the input end of the filter unit, and the output end of the filter unit is electrically connected to the controller (U6).

7. The control circuit of the AC variable frequency electric fan according to claim 6, characterized in that: The model of the power management chip (U3) is LY1203.

8. The control circuit of the AC variable frequency electric fan according to claim 6, characterized in that: It also includes a frequency conversion prompt module, the input end of the frequency conversion prompt module is electrically connected to the second output end of the controller (U6).

9. The control circuit of the AC variable frequency electric fan according to claim 8, characterized in that: The frequency conversion prompt module includes a passive buzzer, a first diode (D3), a second capacitor (C10), a second resistor (R13) and a MOS tube; The gate of the MOS tube is electrically connected to the second input end of the controller (U6), the second resistor (R13) is connected in parallel between the gate and source of the MOS tube, the drain of the MOS tube is electrically connected to the output end of the passive buzzer, the input end of the passive buzzer is electrically connected to a DC power supply, and the drain of the MOS tube is electrically connected to one end of the first diode (D3) and the second capacitor (C10), and the other end of the first diode (D3) and the second capacitor (C10) is electrically connected to the DC power supply.

10. The control circuit of the AC variable frequency electric fan according to claim 1, characterized in that: The controller (U6) adopts a SN8P2711ASG chip and its peripheral circuits.

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