CN212969493U

CN212969493U - Control system for stepless speed regulation of alternating current fan

Info

Publication number: CN212969493U
Application number: CN202022039325.4U
Authority: CN
Inventors: 王玮
Original assignee: Fullwill Technology Co ltd
Current assignee: Fullwill Technology Co ltd
Priority date: 2020-09-17
Filing date: 2020-09-17
Publication date: 2021-04-13
Anticipated expiration: 2030-09-17

Abstract

The utility model belongs to the electronic apparatus field relates to a control system of electrodeless speed governing of alternating current fan, include: the fan motor driving circuit is electrically connected with the fan motor, the fan motor driving circuit is electrically connected with the single chip microcomputer, the AC-DC conversion circuit is electrically connected with the fan motor driving circuit, the zero-crossing detection circuit is electrically connected with the AC-DC conversion circuit, the zero-crossing detection circuit is electrically connected with the single chip microcomputer, and the dial switch circuit is electrically connected with the single chip microcomputer. The control method has the advantages that the single chip microcomputer is controlled to output the PWM waveform, so that different fan speeds can be adjusted according to different duty ratios of the PWM waveform, noise generated by the fan can be effectively reduced on the premise of reducing cost, and the electric fan can be controlled more conveniently.

Description

Control system for stepless speed regulation of alternating current fan

Technical Field

The utility model belongs to the electronic apparatus field relates to a control system of the electrodeless speed governing of alternating current fan.

Background

With the continuous improvement of living standard of people, new requirements on living quality are provided, a plurality of things develop towards automation and intellectualization, a simple electric fan has the characteristics of large air quantity and large speed regulation ratio, the alternating current fan is driven by an alternating current power supply when working, as the power supply voltage can be subjected to positive and negative alternation and is not completely controlled by a circuit, a magnetic field is generated, the power supply frequency is fixed, the magnetic pole change speed generated by silicon steel sheets is determined by the power supply frequency, the switching speed of the magnetic field is faster when the frequency is higher, and the rotating speed is faster theoretically. However, when the power supply frequency is too fast, it causes difficulty in starting the ac fan. At present, an alternating current fan is mainly regulated by the following centralized modes:

1. the series capacitance mode is adopted, but only limited independent gears such as 3 gears, 5 gears and the like exist during alternating current speed regulation, but the body machine of the fan is large;

2. the mode of series inductance is adopted, but the electric fan has limited gears and is large in body size;

3. adopts bidirectional controllable silicon for debugging, but the fan has serious waveform deformation and large noise in the working process

4. The MOS bridge type driving electric fan is used for operation, but the overall cost of the electric fan is high.

Disclosure of Invention

An object of the utility model is to prior art not enough, provide a control system of electrodeless speed governing of alternating current fan, only need control singlechip output PWM waveform for different fan speeds just can be adjusted to the different duty cycle of PWM waveform, under reduce cost's prerequisite, can effectively reduce the noise that the fan produced, and can also make things convenient for more to control the electric fan.

In order to achieve the above purpose, the utility model adopts the following technical scheme: a control system for stepless speed regulation of an alternating current fan comprises: the fan motor, a driving circuit for driving the fan motor to operate, an AC-DC conversion circuit for converting alternating current into direct current, a zero-crossing detection circuit, a dial switch circuit and a single chip microcomputer U1, wherein the fan motor driving circuit is electrically connected with the fan motor, the fan motor driving circuit is electrically connected with the single chip microcomputer U1, the AC-DC conversion circuit is electrically connected with the fan motor driving circuit, the zero-crossing detection circuit is electrically connected with the AC-DC conversion circuit, the zero-crossing detection circuit is electrically connected with the single chip microcomputer U1, and the dial switch circuit is electrically connected with the single chip microcomputer U1.

Further, the driving circuit includes: the driving circuit comprises a rectifier QL, a first diode D1, an IGBT module, a first driving chip U2 and a second diode D2, wherein a first alternating current input end of the rectifier QL is connected with an L end of a mains supply, a positive electricity output end of the rectifier QL is connected with a collector electrode of the IGBT module, an emitter electrode of the IGBT module is grounded, a negative electrode of the first diode D1 is electrically connected with a positive electricity output end of the rectifier QL, an anode of the first diode D1 is connected with an emitter electrode of the IGBT module, a negative electricity output end of the rectifier QL is grounded, a second alternating current input end of the rectifier QL is connected with an N end of the mains supply, a G electrode of the IGBT module is electrically connected with an LO pin of the first driving chip U2 through a first resistor R1, an LIN pin of the first driving chip U2 is connected with the U1 through a second resistor R2, and further comprises a first capacitor C1 and a second diode D2, one end of the first capacitor C1 is connected with the negative pole of the first driving diode D1, the other end of the first capacitor C1 is connected with the positive pole of the first driving diode D1, the positive pole of the second diode D2 is connected with the G pole of the IGBT module, the negative pole of the second diode D2 is electrically connected with the LO pin of the first driving chip U2, and the fan motor is connected between the L end of the commercial power and the N end of the commercial power.

Further, the driving circuit further includes: and one end of the second capacitor C2 is connected to a node at the connection of the first diode D1 and the emitter of the IGBT module, and the other end of the second capacitor C2 is connected to a node at the connection of the second diode D2 and the G pole of the IGBT module.

Further, the single chip microcomputer U1 includes: the PWM pin is connected with the LIN pin of the first driving chip U2, and the ZERO pin is connected with the ZERO-crossing detection circuit.

Further, the zero-cross detection circuit includes: a third diode D3 and a transistor Q1, wherein a cathode of the third diode D3 is connected to a base of the transistor Q1, an anode of the third diode D3 is grounded, an emitter of the transistor Q1 is connected to an anode of the third diode D3, a collector of the transistor Q1 is connected to a third resistor R3, the ZERO pin is connected between a collector of the transistor Q1 and the third resistor R3, and an AC-ZERO terminal of the AC-DC conversion circuit is connected to a node at a connection between the cathode of the third diode D3 and the base of the transistor Q1 through a fourth resistor R4.

Further, the dial switch circuit comprises a dial switch S1 with not less than five bits, and the dial switch circuit comprises: the at least five dial switches S1 are pins with one end grounded, each pin at the other end is connected to a plurality of corresponding pins of the single chip microcomputer U1, a pull-down resistor is connected between each pin of the dial switches S1 and each pin of the single chip microcomputer U1, one end of each pull-down resistor is connected between the pin of the dial switch S1 and the pin of the single chip microcomputer U1, and the other end of each pull-down resistor is grounded.

Furthermore, a fifth resistor R5 is connected between the N-terminal of the utility power and the negative output terminal of the rectifier QL, and two ends of the fifth resistor R5 are connected in parallel with a pressure-sensitive resistor.

Further, the IGBT module comprises an IGBT switch, and the frequency of the IGBT switch in use is more than 20 KHz.

The utility model has the advantages that:

the driving circuit, the AC-DC conversion circuit, the zero-crossing detection circuit, the dial switch circuit and the single chip microcomputer U1 are combined, and the duty ratio of the IGBT switch during switching on or switching off is controlled by outputting a PWM signal through the single chip microcomputer U1, so that the purpose of adjusting the speed of the fan is achieved, the noise generated by the fan can be effectively reduced on the premise of reducing the cost, and the fan can be more conveniently controlled; through setting up first driver chip U2 to be connected first driver chip U2 and singlechip U1, when singlechip U1 transmits PWM signal to drive circuit, can drive the IGBT switch through first driver chip U2, thereby guarantee that the IGBT switch can open or turn-off.

Drawings

Fig. 1 is a schematic diagram of a driving circuit of the present invention;

FIG. 2 is a schematic diagram of the single-chip microcomputer of the present invention;

FIG. 3 is a schematic diagram of the toggle circuit of the present invention;

fig. 4 is a schematic diagram of the zero-crossing detection circuit of the present invention;

FIG. 5 is a schematic diagram of the AC-DC converter circuit of the present invention;

FIG. 6 is a schematic diagram of the present invention;

FIG. 7 is a schematic diagram of the waveform of the grid voltage of the present invention;

fig. 8 is a schematic voltage waveform of the motor of the present invention;

fig. 9 is a schematic waveform diagram of the IGBT switch of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as fixed or detachable connections or as an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Referring to fig. 1-9, a control system for stepless speed regulation of an ac fan includes: the fan motor, the driving circuit for driving the fan motor to operate, the AC-DC conversion circuit for converting alternating current into direct current, the zero-crossing detection circuit, the dial switch circuit and the single chip microcomputer U1, wherein the fan motor driving circuit is electrically connected with the fan motor, the fan motor driving circuit is electrically connected with the single chip microcomputer U1, the AC-DC conversion circuit is electrically connected with the fan motor driving circuit, the zero-crossing detection circuit is used for detecting the zero crossing point of an alternating current power supply signal input by the alternating current input end, the zero-crossing detection circuit is electrically connected with the AC-DC conversion circuit, the zero-crossing detection circuit is electrically connected with the single chip microcomputer U1, the dial switch circuit is electrically connected with the single chip microcomputer U1, and particularly, the AC-DC conversion circuit is connected with the single chip microcomputer U1 through the zero-crossing detection circuit, so that the AC-DC conversion, in this embodiment, the voltage of singlechip during operation is 5V.

In the above embodiment, the driving circuit includes: the driving circuit comprises a rectifier QL, a first diode D1, an IGBT module, a first driving chip U2 and a second diode D2, wherein a first alternating current input end of the rectifier QL is connected with the L end of a mains supply, a positive electricity output end of the rectifier QL is connected with a collector electrode of the IGBT module, an emitter electrode of the IGBT module is grounded, a negative electrode of the first diode D1 is electrically connected with a positive electricity output end of the rectifier QL, a positive electrode of the first diode D1 is connected with an emitter electrode of the IGBT module, a negative electricity output end of the rectifier QL is grounded, a second alternating current input end of the rectifier QL is connected with the N end of the mains supply, a G electrode of the IGBT module is electrically connected with an LO pin of the first driving chip U2 through a first resistor R1, a pin of the first driving chip U2 is connected with a single chip U1 through a second resistor R2, the driving circuit further comprises a first capacitor C1 and a second diode D2, one end of the first capacitor C1 is connected, the other end of the first capacitor C1 is connected with the positive pole of D1, the positive pole of the second diode D2 is connected with the G pole of the IGBT module, the negative pole of the second diode D2 is electrically connected with the LO pin of the first driver chip U2, the fan motor is connected between the L end of the mains supply and the N end of the mains supply, and the driving circuit further includes: and a second capacitor C2, one end of the second capacitor C2 is connected to a node where the first diode D1 is connected to the emitter of the IGBT module, and the other end of the second capacitor C2 is connected to a node where the second diode D2 is connected to the G pole of the IGBT module, in the embodiment, the first capacitor C1 has a capacity of 0.1uF, and the second capacitor C2 has a capacity of 10 nF.

In the above embodiment, the single chip microcomputer U1 includes: PWM pin and ZERO pin, PWM pin and first driver chip U2's LIN pin are connected, and the ZERO pin is connected with ZERO cross detection circuit.

During operation, a PWM waveform output by a PWM pin of the singlechip U1 is firstly transmitted to a G pole of an IGBT switch by an LO pin of the U3 through a first resistor R1 after being amplified and voltage matched by a first driving chip U2, so that the IGBT switch of the IGBT module is controlled to be switched on or switched off.

In the above embodiment, the zero-cross detection circuit includes: a third diode D3 and a triode Q1, a cathode of the third diode D3 is connected to a base of the triode Q1, an anode of the third diode D3 is grounded, an emitter of the triode Q1 is connected to an anode of the third diode D3, a collector of the triode Q1 is connected to a third resistor R3, a ZERO pin is connected between a collector of the triode Q1 and the third resistor R3, and an AC-ZERO end of the AC-DC conversion circuit is connected to a node at a connection between a cathode of the third diode D3 and the base of the triode Q1 through a fourth resistor R4.

In the above embodiment, the dial switch circuit includes the dial switch S1 with not less than five bits, and the circuit of the dial switch circuit is: the at least five dial switches S1 are pins with one end grounded, each pin at the other end is connected to a plurality of corresponding pins of the single chip microcomputer U1, a pull-down resistor is connected between each pin of the dial switches S1 and each pin of the single chip microcomputer U1, one end of each pull-down resistor is connected between the pin of the dial switch S1 and the pin of the single chip microcomputer U1, and the other end of each pull-down resistor is grounded.

In the above embodiment, a fifth resistor R5 is further connected between the N-terminal of the utility power and the negative output terminal of the rectifier QL, and a pressure-dependent resistor VDR is further connected in parallel to two terminals of the fifth resistor R5.

In the above embodiment, the IGBT module includes the IGBT switch, and the frequency of the IGBT switch in use is greater than 20KHz, and the switching frequency of the IGBT switch is controlled to be greater than 20KHz, so that the switching frequency exceeds the audible range of human ears.

The working principle is as follows: AC220V AC is input through L line and N line, the fan motor is connected to the AC loop, the rectifier QL is connected to the circuit and the IGBT switch is connected to the DC part of the circuit, so as to realize the fast switch voltage regulation of the circuit, when the AC is supplied for the positive half cycle, the current passes through the motor, the fourth diode D4 of the rectifier QL, the IGBT switch and the seventh diode D7 of the rectifier QL in sequence to form a current loop, when the AC is supplied for the negative half cycle, the current passes through the fifth diode D5 of the rectifier QL, the IGBT switch, the sixth diode D6 of the rectifier QL and the motor in sequence to form a current loop.

The above embodiments are only one of the preferred embodiments of the present invention, and the ordinary changes and substitutions performed by those skilled in the art within the technical scope of the present invention should be included in the protection scope of the present invention.

Claims

1. A control system for stepless speed regulation of an alternating current fan is characterized by comprising: the fan motor, a driving circuit used for driving the fan motor to operate, an AC-DC conversion circuit used for converting alternating current into direct current, a zero-crossing detection circuit, a dial switch circuit and a single chip microcomputer (U1), wherein the fan motor driving circuit is electrically connected with the fan motor, the fan motor driving circuit is electrically connected with the single chip microcomputer (U1), the AC-DC conversion circuit is electrically connected with the fan motor driving circuit, the zero-crossing detection circuit is electrically connected with the AC-DC conversion circuit, the zero-crossing detection circuit is electrically connected with the single chip microcomputer (U1), and the dial switch circuit is electrically connected with the single chip microcomputer (U1).

2. The control system for stepless speed regulation of the alternating current fan as claimed in claim 1, wherein the driving circuit comprises: a rectifier (QL), a first diode (D1), an IGBT module, a first driving chip (U2) and a second diode (D2), wherein a first alternating current input end of the rectifier (QL) is connected with the L end of the commercial power, a positive output end of the rectifier (QL) is connected with the collector of the IGBT module, the emitter of the IGBT module is grounded, the negative electrode of the first diode (D1) is electrically connected with the positive output end of the rectifier (QL), the positive electrode of the first diode (D1) is connected with the emitter of the IGBT module, the negative output end of the rectifier (QL) is grounded, a second alternating current input end of the rectifier (QL) is connected with the N end of the commercial power, the G electrode of the IGBT module is electrically connected with the pin of the first driving chip (U2) through a first resistor (R1), the LIN pin of the first driving chip (U2) is connected with the single chip microcomputer (U1) through a second resistor (R2), the drive circuit further comprises a first capacitor (C1) and a second diode (D2), one end of the first capacitor (C1) is connected with the negative electrode of the first diode (D1), the other end of the first capacitor (C1) is connected with the positive electrode of the first diode (D1), the positive electrode of the second diode (D2) is connected with the G electrode of the IGBT module, the negative electrode of the second diode (D2) is electrically connected with the LO pin of the first drive chip (U2), and the fan motor is connected between the L end of the mains supply and the N end of the mains supply.

3. The control system for stepless speed regulation of the alternating current fan as claimed in claim 2, wherein the driving circuit further comprises: and a second capacitor (C2), wherein one end of the second capacitor (C2) is connected to the node where the first diode (D1) is connected with the emitter of the IGBT module, and the other end of the second capacitor (C2) is connected to the node where the second diode (D2) is connected with the G pole of the IGBT module.

4. The control system for stepless speed regulation of the alternating current fan as claimed in claim 2 or 3, wherein the single chip microcomputer (U1) comprises: the PWM pin is connected with a LIN pin of the first driving chip (U2), and the ZERO pin is connected with the ZERO-crossing detection circuit.

5. The control system for stepless speed regulation of the alternating current fan as claimed in claim 4, wherein the zero-crossing detection circuit comprises: a third diode (D3) and a transistor (Q1), wherein a cathode of the third diode (D3) is connected to a base of the transistor (Q1), an anode of the third diode (D3) is grounded, an emitter of the transistor is connected to an anode of the third diode (D3), a collector of the transistor (Q1) is connected to a third resistor (R3), and the ZERO pin is connected between a collector of the transistor (Q1) and a third resistor (R3), and an AC-ZERO terminal of the AC-DC conversion circuit is connected to a node at a connection between the cathode of the third diode (D3) and the base of the transistor (Q1) through a fourth resistor (R4).

6. The control system for stepless speed regulation of an alternating current fan as claimed in claim 5, wherein the dial switch circuit comprises a dial switch (S1) with not less than five bits, and the circuit of the dial switch circuit is as follows: the at least five dial switches (S1) are connected to the ground through pins at one end, each pin at the other end is connected to a plurality of corresponding pins of the single chip microcomputer (U1), a pull-down resistor is connected between each pin of the dial switches (S1) and each pin of the single chip microcomputer (U1), one end of each pull-down resistor is connected between the pin of the dial switches and the pin of the single chip microcomputer (U1), and the other end of each pull-down resistor is grounded.

7. The control system for stepless speed regulation of an ac fan according to claim 2, wherein a fifth resistor (R5) is further connected between the N-terminal of the utility power and the negative output terminal of the rectifier (QL), and a pressure Varistor (VDR) is further connected in parallel to the two terminals of the fifth resistor (R5).

8. An AC fan stepless speed regulation control system as claimed in claim 2, characterized in that the IGBT module comprises an IGBT switch (Q2), and the frequency of the IGBT switch (Q2) in use is more than 20 KHz.