Control circuit for fan

The present disclosure provides a control circuit for a fan. The control circuit for a fan including a fan head equipped with a first motor and fan blades connected to the first motor. The control circuit includes an MCU, a stepless regulation circuit and a first driving circuit both connected to the MCU. The stepless regulation circuit includes a stepless regulator for user operation. The first driving circuit is also electrically connected to the first motor, the stepless regulation circuit sends back corresponding electrical signals to the MCU based on user operation of the stepless regulator, and the MCU controls the power output of the first driving circuit to the first motor based on the electrical signal feedback from the stepless regulation circuit, which adjusts the power output to the first motor to adjust the speed of fan blades.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application claims priority of Chinese patent application CN2023230365682, filed on 9 Nov. 2023, which is incorporated herein by reference in its entireties.

TECHNICAL FIELD

The present disclosure relates to the technical field of fans, in particular, to a control circuit for a fan.

BACKGROUND

As is well known, fans are devices used for cooling. Currently, existing fans typically adjust airflow by using button controls with three speed settings: low, medium, and high. With fixed speed levels, this mode of operation does not allow for free adjustment of airflow, which affects the users' experience.

SUMMARY

A main objective of the present disclosure is to provide a control circuit for a fan, in order to solve the problem of existing fans being unable to adjust the speed of the airflow freely.

In order to solve the technical problem, the technical scheme provided by the present disclosure is as follows.

A control circuit for a fan, the fan including a fan head equipped with a first motor and fan blades connected to the first motor, wherein the control circuit includes an MCU, a stepless regulation circuit and a first driving circuit both connected to the MCU; the stepless regulation circuit includes a stepless regulator for user operation, the first driving circuit is also electrically connected to the first motor, the stepless regulation circuit is configured to send back corresponding electrical signals to the MCU based on the user operation provided on the stepless regulator, and the MCU is configured to control a power output of the first driving circuit to the first motor based on the electrical signal from the stepless regulation circuit.

Further, the stepless regulator is a potentiometer or a rotary encoder switch.

Further, the control circuit further includes a power module electrically connected to the MCU, the first driving circuit, and the stepless regulation circuit.

Further, the fan further includes a second motor for controlling a rotation of the fan head, the control circuit including a second driving circuit and a first switch electrically connected to the MCU; the second driving circuit is electrically connected to the power module and the second motor, respectively; the MCU is configured to drive the second motor to work through the second driving circuit based on the electrical signal from the first switch.

Further, the first driving circuit includes a first switching tube and a first interface, the first interface is connected to the first motor; a gate of the first switching tube is connected to the MCU, a source of the first switching tube is grounded; a drain of the first switch is connected to a negative pole of the first motor through the first interface, and an output end of the power module is connected to a positive pole of the first motor through the first interface.

Further, the first driving circuit further includes a first filtering unit, wherein the first filtering unit includes a first inductor, a first diode, and a filtering capacitor; an output end of the power module is sequentially connected to a positive pole of the first motor through the first interface after passing through the first inductor and the first diode; one end of the filtering capacitor is grounded, and the other end is connected to an output terminal of the first diode and the first interface, respectively.

Further, when the stepless regulator is an encoder, the first driving circuit includes a boost chip, a first resistor, a second resistor, a first capacitor, and a regulating resistor; a SW pin of the boost chip is connected to an output end of the first inductor, an enable pin of the boost chip is electrically connected to the MCU; a feedback pin of the boost chip is connected to the output end of the first diode through the first resistor, one end of the second resistor is grounded, and the other end is connected to a feedback pin of the boost chip; an input power pin of the boost chip is grounded through the first capacitor and also electrically connected to the output end of the first diode; the regulating resistor includes multiple parallel third resistors, wherein one end of the third resistor is connected to the feedback pin of the boost chip, and the other end is connected to an output pin of the MCU; the boost chip receives an electrical signal output by the MCU through an enable pin and works according to the electrical signal; the MCU is configured to select several third resistors to be electrically connected to the boost chip based on a feedback signal from the stepless regulator; the boost chip is configured to adjust a voltage output to the first interface based on the electrical signal input from the feedback pin.

Further, the number of the third resistor is 12.

Further, the second driving circuit includes a motor driving chip, a first filtering unit, a second filtering unit, and a second interface; the first filtering unit is electrically connected to an output end of the power circuit and the motor driving chip, and the first filtering unit is configured to filter the voltage output from the power circuit before supplying it to the motor driving chip; the second filtering unit is electrically connected to the motor driving chip and the second interface, and the second interface is connected to the second motor; the second filtering unit is configured to filter the driving voltage output from the motor driving chip before supplying it to the second motor; the sixth and seventh pins of the motor driving chip arc grounded, and SDA and SCK pins of the motor driving chip are electrically connected to the MCU.

Further, the first filtering unit includes a fourth resistor, a second capacitor, and a second diode; an output end of the power circuit is connected to a fourth pin of the motor driving chip through the fourth resistor, and the fourth pin of the motor driving chip is also grounded through the second capacitor; the positive pole of the second diode is grounded, while the negative pole is electrically connected to the fourth pin of the motor driving chip.

Further, the second filtering unit includes a third capacitor, one end of the third capacitor is electrically connected to both a second interface and a eighth pin of the motor driving chip, while its other end is connected to both the second interface and the fifth pin of the motor driving chip.

Further, the encoder is a press switch encoder, and the first switch is the switch on the press switch encoder.

Further, the power module includes a power input interface and a power circuit electrically connected to the power input interface; the power circuit is electrically connected to the MCU, the first driving circuit, the second driving circuit, and the stepless regulation circuit.

Further, the power module further includes a battery electrically connected to the power circuit; the power circuit is a charging and discharging circuit used for charging the battery with a power input from a power interface.

Further, the power module further includes a battery protection circuit electrically connected to both the power circuit and the battery; the battery protection circuit is configured to stop charging the battery during overcharging and prevents the battery from continuing to output voltage during excessive discharge.

Further, the control circuit further includes a power indication circuit electrically connected to the MCU; the power circuit provides a feedback signal to the MCU when the power is connected to the power interface, and the MCU controls the power indication circuit based on the feedback signal from the power circuit.

Further, the power circuit includes a charging and discharging chip, a fifth resistor, a fourth capacitor, and a fifth capacitor; the second pin of the charging and discharging chip is grounded through the fifth resistor, the fourth pin of the charging and discharging chip is grounded through the fourth capacitor, and the fifth pin of the charging and discharging chip is grounded through the fifth capacitor; the positive pole of the battery is electrically connected to the fifth pin of the charging and discharging chip, and the seventh pin of the charging and discharging chip is connected to the MCU for temperature monitoring of MCU.

Further, the battery protection circuit includes a battery protection chip, a sixth capacitor, and a sixth resistor, a first pin of the battery protection chip is connected to the third pin of the battery protection chip through the six resistor, and the third pin of the battery protection chip is connected to the fifth pin of the charging and discharging chip through the sixth resistor; the second pin of the battery protection chip is connected to its first pin, and this second pin is also connected to the negative pole of the battery; the fourth and fifth pins of the battery protection chip are grounded.

Further, the power interface is a Type-C interface.

Further, the control circuit for a fan according to claim 19, wherein the MCU is a model AD156B chip.

Compared with the prior art, the present disclosure has the beneficial effects below: This embodiment can be operated for users by configuring the stepless regulator in the control circuit. When operating the stepless regulator, the stepless regulation circuit provides timely feedback signals to MCU. Based on the feedback signals from the stepless regulation circuit, MCU adjusts the power output to the first interface through the first driving circuit, which adjusts the power output to the first motor to adjust the speed of fan blades. Thus, users can adjust the airflow speed of fan blades according to their needs, solving the problem of existing fans not being able to freely adjust the airflow speed, improving operational performance and users' experience.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The accompanying drawings in the embodiment of the present disclosure are combined, The technical scheme in the embodiment of the present disclosure is clearly and completely described, Obviously, the described embodiment is only a part of the embodiment of the present disclosure, but not all embodiments are based on the embodiment of the present disclosure, and all other embodiments obtained by ordinary technicians in the field on the premise of not doing creative work belong to the protection range of the present disclosure.

Referring toFIGS.1-9, a control circuit for a fan in an embodiment of the present invention.

In this embodiment, the fan includes a fan head8, on which a first motor5and fan blades9connected to the first motor5are located. The control circuit includes an MCU3, a stepless regulation circuit6and a first driving circuit2both electrically connected to the MCU3. The stepless regulation circuit6includes a stepless regulator J8for user operation. The first driving circuit2is also electrically connected to the first motor5. The stepless regulation circuit6provides corresponding electrical signals to the MCU3based on the user's operation of the stepless regulator J8. The MCU3controls the power outputted to the first motor5from the first driving circuit2based on the electrical signals feedback from the stepless regulation circuit6.

This embodiment can be operated for users by configuring the stepless regulator J8in the control circuit. When operating the stepless regulator J8, the stepless regulation circuit6provides timely feedback signals to MCU3. Based on the feedback signals from the stepless regulation circuit6, MCU3adjusts the power output to the first interface J4through the first driving circuit2, which adjusts the power output to the first motor5to adjust the speed of fan blades9. Thus, users can adjust the airflow speed of fan blades9according to their needs, solving the problem of existing fans not being able to freely adjust the airflow speed, improving operational performance and users' experience.

Specifically, the stepless regulator J8is either a potentiometer or a rotary coding switch. When the stepless regulator J8is a potentiometer, the rotating operating component can adjust the resistance of the potentiometer, and the circuit board adjusts the power output to the first motor5based on the change of the resistance. When the stepless regulator J8is a rotary coding switch, the rotating operating component can adjust the rotary coding switch. At this time, the output end of the encoder will provide a phase difference feedback to the circuit board, and the circuit board will adjust the power output to the first motor5based on this phase difference, effectively solving the problem of limited airflow speed range for existing fans and meeting the user's demand for free adjustment of airflow speed.

In the above embodiment, the control circuit also includes a power module1electrically connected to MCU3, the first driving circuit2, and the stepless regulation circuit6, respectively. The power module1supplies power to MCU3, the first driving circuit2, and the stepless regulation circuit6to enable the entire control circuit on power and work.

In one embodiment, the fan further includes a second motor7controlling the rotation of the fan head8, and the control circuit includes a second driving circuit4and a first switch S2both electrically connected to MCU3. The second driving circuit4is electrically connected to the power module1and the second motor7respectively. MCU3drives the second motor7to work through the second driving circuit4based on the electrical signal feedback from the first switch S2to achieve the shaking of fan blades9.

Specifically, in this embodiment, the fan further includes a base10, and the second motor7can be mounted on the base10, with its rotating shaft connected to the fan head8; alternatively, the second motor7can be installed on the fan head8, with its rotating shaft connected to the base10. When the second motor7is in operation, it uses a reaction force to drive the fan head8to shake its head.

Specifically, the power module1includes a power interface14for accessing power and a power circuit13electrically connected to the power interface14. The power circuit13is respectively electrically connected to MCU3, the first driving circuit2, the second driving circuit4, and the stepless regulation circuit6, thus to process the power input from the power interface14and supply power to MCU3, the first driving circuit2, the second driving circuit4, and the stepless regulation circuit6.

In one embodiment, the power module1further includes a battery12electrically connected to the power circuit13, which is a charging and discharging circuit used to charge the battery12through the power input from the power interface14. The charging and discharging of the battery12can be achieved by using power circuit13.

In one embodiment, the power module1further includes a battery protection circuit11that is electrically connected to the power circuit13and the battery12, respectively. The battery protection circuit11stops charging the battery12when the battery12is overcharged and stops the battery12from continuing to output voltage when the battery12is over discharged, thus to protect the battery12from shortening its life span under the circumstances of overcharging or over discharging.

In one embodiment, the control circuit further includes a power indicator circuit31connected to MCU3, and the power circuit13provides feedback signals to MCU3when connected to the power interface14. MCU3controls the power indicator circuit31to give instructions based on the feedback signals from the power circuit13, reminding users that the fan is powered on normally, etc.

Specifically, the power circuit13includes a charging and discharging chip U4, a fifth resistor R1, a fourth capacitor C3, and a fifth capacitor C4. The second pin of the charging and discharging chip U4is grounded through the fifth resistor R1, the fourth pin of the charging and discharging chip U4is grounded through the fourth capacitor C3, the fifth pin of the charging and discharging chip U4is grounded through the fifth capacitor C4, the positive pole of the battery12is electrically connected to the fifth pin of the charging and discharging chip U4, and the seventh pin of the charging and discharging chip U4is electrically connected to MCU3to detect the temperature of MCU3. Among them, the power interface14is a Type-c interface, and the charging and discharging chip U4is a 4056 model chip, specifically TP4056, AXS4056, etc, to realize the charging and discharging of the battery12.

The battery protection circuit11includes a battery protection chip U5, a sixth capacitor C8, and a sixth resistor R6. The first pin of the battery protection chip U5is connected to the third pin of the battery protection chip U5through the sixth capacitor C8. The third pin of the battery protection chip U5is connected to the fifth pin of the charging and discharging chip U4through the sixth resistor R6, and the second pin of the battery protection chip U5is connected to its own first pin, the second pin of the battery protection chip U5is connected to the negative pole of the battery12, and both the fourth and fifth pins of the battery protection chip U5are grounded. Among them, the battery protection chip U5can be a chip of model5352.

The first driving circuit2includes a first switching tube Q1and a first interface J4. The first interface J4is connected to the first motor5. The gate of the first switching tube Q1is connected to MCU3, the source of the first switching tube Q1is grounded, the drain of the first switch is connected to the negative pole of the first motor5through the first interface J4. The output end of the power module1is connected to the positive pole of the first motor5through the first interface J4. When the user turns on the fan through the stepless regulator J8, MCU3sends a conduction signal to the first switching tube Q1based on the feedback signal from the stepless regulator J8, in order to achieve the opening and closing of the first motor5through the first switching tube Q1.

The first driving circuit2also includes a first filtering unit21, which includes a first inductor L2, a first diode D2, and a filtering capacitor C16. The output end of the power circuit13is connected to the positive pole of the first motor5through the first interface J4after sequentially passing through the first inductor L2and the first diode D2. One end of the filtering capacitor C16is grounded, and the other end is respectively connected to the output end of the first diode D2and the first interface J4. Among them, the power output from the power circuit13is stabilized and filtered by the first inductor L2, the first diode D2, and the filtering capacitor C16, and then supplied to the first motor5through the first interface J4.

The stepless regulation circuit6includes a boost chip U3, a first resistor R8, a second resistor R9, a first capacitor C10, and an adjustment resistor22. The SW pin of the boost chip U3is connected to the output end of the first inductor L2, the enable pin of the boost chip U3is electrically connected to MCU3, the feedback pin of the boost chip U3is connected to the output end of the first diode D2through the first resistor R8. One end of the second resistor R9is grounded, and the other end is connected to the feedback pin of the boost chip U3. The input power pin of the boost chip U3is grounded through the first capacitor C10and also electrically connected to the output end of the first diode D2.

The adjustment resistor22includes multiple parallel third resistors R3, with one end of which connected to the feedback pin of the boost chip U3while the other end connected to the output pin of MCU3. The boost chip U3receives the electrical signal output by MCU3through the enable pin and works according to this electrical signal. MCU3selects several third resistors R3to be electrically connected to the boost chip U3based on the feedback signal from the stepless regulator J8. The boost chip U3adjusts the voltage output to the first interface J4based on the electrical signal input from the feedback pin.

It should be noted here that the output pins of each third resistor R3connected to the MCU3are different. When the user operates the stepless regulator J8, MCU3selects several output pins based on the electrical signal input from the stepless regulation circuit6and adjusts the feedback signal output to the boost chip U3through the corresponding third resistor R3. The boost chip U3adjusts the voltage output to the first interface J4based on the feedback signal from the third resistor R3, combined with the first resistor R8and the second resistor R9, to adjust the power output to the first motor5and regulate risk.

Specifically, there are 12 third resistors R3, with each being connected to an output pin of MCU3.

In one embodiment, the second driving circuit4includes a motor driving chip U2, a first filtering unit41, a second filtering unit42, and a second interface J7. The first filtering unit41is electrically connected to the output end of the power circuit13and the motor driving chip U2, respectively. The first filtering unit41is used to filter the voltage output by the power circuit13and supply it to the motor driving chip U2. The second filtering unit42is electrically connected to the motor driving chip U2and the second interface J7, respectively. The second interface J7is electrically connected to the second motor7. The second filtering unit42filters the driving voltage output by the motor driving chip U2and supplies it to the second motor7. The sixth and seventh pins of the motor driving chip U2are grounded, and the SDA and SCK pins on the motor driving chip U2are electrically connected to MCU3. The motor driving chip U2drives the second motor7to work through the signal output by MCU3, enabling the fan head8to shake.

In the above embodiment, the motor driving chip U2can be a chip of model118S, and the MCU3can be a chip of model AD156B.

In one embodiment, the first filtering unit41includes a fourth resistor R12, a second capacitor C14, and a second diode ZD2. The output end of the power circuit13is connected to the fourth pin of the motor driving chip U2through the fourth resistor R12. The fourth pin of the motor driving chip U2is grounded through the second capacitor C14. The positive pole of the second diode ZD2is grounded while its negative pole is electrically connected to the fourth pin of the motor driving chip U2. The output voltage of the power circuit13supplies power to the motor drive chip U2after the voltage drop of the fourth resistor R12and the voltage stabilization of the second diode ZD2. The voltage output from the power circuit13supplies power to the motor driving chip U2after passing through the fourth resistor R12voltage drop and the second diode ZD2voltage stabilization.

In one embodiment, the second filtering unit42includes a third capacitor C15, with one end being electrically connected to the second interface J7and the eighth pin of the motor driving chip U2, while the other end being electrically connected to the second interface J7and the fifth pin of the motor driving chip U2. The voltage output by the motor driving chip U2is filtered by the third capacitor C15and supplies to the second motor7through the second interface J7, preventing noise from affecting the stability of the operation of the second motor7.

In one embodiment, the encoder is a press switch encoder, and the first switch S2is a switch on the press switch encoder, and the switch is electrically connected to MCU3. When the user presses the encoder, the switch on the encoder is about to close. When MCU3detects that the switch is closed, it sends a driving signal to the motor driving chip U2to control the operation of the second motor7.

In the above embodiment, the control circuit can also be applied to handheld fans (as shown inFIG.12), clamp fans (as shown inFIG.10), or in the embodiment without the second motor7, the control circuit can also be applied to neck fans (as shown inFIG.1), etc.

It should be noted that all directional indications (such as up, down, left, right, front, back . . . ) in the embodiments of the present disclosure are only used to explain a relative positional relationship between components, motion situations, etc. at a certain specific attitude (as shown in the figures). If the specific attitude changes, the directional indication also correspondingly changes.

In addition, the descriptions of “first”, “second”, etc. in the present disclosure are only used for descriptive purposes, and cannot be understood as indicating or implying its relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined by “first” and “second” can explicitly instruct or impliedly include at least one feature. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on what can be achieved by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that such a combination of technical solutions does not exist, and is not within the scope of protection claimed by the present disclosure.

The above descriptions are only preferred embodiments of the present disclosure, and are not intended to limit the patent scope of the present disclosure. Any equivalent structural transformation made by using the content of the specification and the drawings of the present disclosure under the invention idea of the present disclosure, directly or indirectly applied to other related technical fields, shall all be included in the scope of patent protection of the present disclosure.