Fan drive circuit without distinguishing positive and negative polarities

Abstract

The utility model relates to the technical field of cooling fans, and discloses a fan driving circuit without distinguishing positive and negative polarities, which comprises a motor, a diode D1, a diode D3, a diode D2 and a diode D4, the diode D1 and the diode D3 are connected to a voltage input end IN1, the diode D2 and the diode D4 are connected to a voltage input end IN2, the diode D1 is connected with the diode D2, the diode D3 is connected with the diode D4, and the diode D4 is connected with the motor. Through the design of a diode D1, a diode D2, a diode D3 and a diode D4, when the voltage input end IN1 is positive voltage and the voltage input end IN2 is 0V, the diode D1 and the diode D4 are conducted, the fan works normally, when the voltage input end IN2 is positive voltage and the voltage input end IN1 is 0V, the diode D2 and the diode D3 are conducted, and the fan works normally, in conclusion, no matter how the voltage input end IN1 and the voltage input end IN2 exchange power supply, no matter how the voltage input end IN1 and the voltage input end IN2 exchange power supply, the fan works normally. The driving of the fan is always kept in the working state from the positive electrode to the negative electrode, namely the fan can work normally without distinguishing the positive electrode and the negative electrode of the wire, so that the potential safety hazard is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of cooling fans, in particular to the wiring field of cooling fans, and specifically relates to a fan drive circuit that can be polarity-independent. Background Technique

[0002] A cooling fan is an electrically driven device used to generate an air flow to achieve a cooling effect in a hot environment.

[0003] The cooling fan utilizes the principle of electromagnetic induction and uses a Hall induction component as a synchronous detection device to control the energization sequence of a set of circuit switching windings, generate a rotating magnetic field, and realize a new type of electromechanical integration fan with electronic commutation. After being powered on, a mutual acting force is generated between the magnetic poles of the stator and the rotor, causing the motor to rotate, thereby driving the fan blades to rotate and generate an air flow.

[0004] After retrieval, a patent with the application number CN201710137664.6 discloses a fan drive circuit. The fan drive circuit includes a processing module and a rotational speed signal providing module. The rotational speed signal providing module includes a first diode, a first impedance element, a first switching element, a second switching element, and a third switching element. The second end of the first switching element receives the fan phase signal; the first end of the second switching element is electrically connected to the first end of the first impedance element, the second end of the second switching element is electrically connected to the second end of the first impedance element and the second end of the first diode, and the third end of the second switching element is electrically connected to the first end of the first switching element; the first end of the third switching element is electrically connected to a DC voltage source, and the third end of the third switching element is electrically connected to the first end of the first diode. In the reverse connection state, the first switching element of the rotational speed signal providing module will not be burned out, effectively reducing the damage caused by incorrect wiring during mass production on the production line, and more effectively improving the use safety.

[0005] Current DC cooling fans have positive and negative polarities. When the positive and negative poles are welded reversely, the fan does not work or even gets damaged. When customers need to use the same color, it is necessary to mark both ends of the wire to avoid mistakes. This method has a high cost and is prone to errors, posing a safety hazard. Therefore, we need to propose a fan drive circuit that can be polarity-independent. Content of the Utility Model

[0006] The purpose of the present utility model is to provide a fan drive circuit that can be polarity-independent. Through the design of diodes D1, D2, D3, and D4, when the voltage input terminal IN1 is at a positive voltage and the voltage input terminal IN2 is at 0V, diodes D1 and D4 conduct, and the fan operates normally. When the voltage input terminal IN2 is at a positive voltage and the voltage input terminal IN1 is at 0V, diodes D2 and D3 conduct, and the fan operates normally. In summary, regardless of how the power supply is switched between the voltage input terminals IN1 and IN2, the drive of the fan always maintains a working state from the positive pole to the negative pole, that is, it is not necessary to distinguish the positive and negative poles of the wire, and the fan can operate normally, reducing potential safety hazards, so as to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present utility model provides the following technical solution: A fan drive circuit that can be polarity-independent, including a motor, diodes D1 and D3 connected to the voltage input terminal IN1, diodes D2 and D4 connected to the voltage input terminal IN2, the diode D1 is connected to the diode D2, the diode D3 is connected to the diode D4, and a capacitor C1 is connected between the connection terminals of the diode D1 and D2 and the connection terminals of the diode D3 and D4, and both ends of the capacitor C1 are respectively connected to the positive and negative poles of the motor.

[0008] Preferably, the output terminal of the diode D1 is connected to the output terminal of the diode D2, the input terminal of the diode D3 is connected to the input terminal of the diode D4, the output terminal of the diode D3 is connected to the input terminal of the diode D2, and the output terminal of the diode D4 is connected to the input terminal of the diode D2.

[0009] Preferably, it further includes a voltage input circuit, and the voltage input circuit includes MOS transistors Q3, Q4, Q7, and Q8 connected to the power supply. A capacitor C6 is connected between the connection terminals of the D poles of the MOS transistor Q3 and the MOS transistor Q8 and the connection terminals of the D poles of the MOS transistor Q4 and the MOS transistor Q7, and both ends of the capacitor C6 are respectively connected to the positive and negative poles of the motor.

[0010] Preferably, a resistor R7 is connected between the G pole and the S pole of the MOS transistor Q3, and a resistor R10 is connected to the G pole of the MOS transistor Q3; a resistor R8 is connected between the G pole and the S pole of the MOS transistor Q4, and a resistor R11 is connected to the G pole of the MOS transistor Q4; a resistor R19 is connected between the G pole and the S pole of the MOS transistor Q7, and a resistor R17 is connected to the G pole of the MOS transistor Q7; a resistor R18 is connected between the G pole and the S pole of the MOS transistor Q8, and a resistor R16 is connected to the G pole of the MOS transistor Q8, the resistor R7 is connected to the resistor R8, and the resistor R18 is connected to the resistor R19.

[0011] Preferably, the voltage input circuit further includes a triode Q5 connected to the resistor R10 and a triode Q6 connected to the resistor R11. A resistor R14 is connected between the base and the collector of the triode Q5. A resistor R12 is connected to the base of the triode Q5, and the resistor R12 is connected to the resistor R17.

[0012] A resistor R15 is connected between the base and the collector of the triode Q6. A resistor R13 is connected to the base of the triode Q6, and the resistor R13 is connected to the resistor R16.

[0013] Preferably, the connection terminals of the diode D1 and the diode D3 are connected to one end of the resistor R12, and one end of the diode D2 and the diode D4 is connected to one end of the resistor R13.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] Through the design of the diodes D1, D2, D3, and D4, when the voltage input terminal IN1 is a positive voltage and the voltage input terminal IN2 is 0V, the diodes D1 and D4 are turned on, and the fan works normally. When the voltage input terminal IN2 is a positive voltage and the voltage input terminal IN1 is 0V, the diodes D2 and D3 are turned on, and the fan works normally. In summary, regardless of how the voltage input terminals IN1 and IN2 are swapped for power supply, the driving of the fan always maintains the working state from the positive pole to the negative pole, that is, it is not necessary to distinguish the positive and negative poles of the wire, and the fan can work normally, reducing the safety hazard. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the circuit diagram for driving the fan of the present invention;

[0017] Figure 2 is the circuit diagram of the voltage input circuit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] Please refer to Figure 1-2, the present utility model provides a technical solution: a fan drive circuit that can be polarity-independent, including a motor, a diode D1 and a diode D3 connected to the voltage input terminal IN1, and a diode D2 and a diode D4 connected to the voltage input terminal IN2. The diode D1 is connected to the diode D2, the diode D3 is connected to the diode D4, and a capacitor C1 is connected between the connection terminals of the diode D1 and the diode D2 and the connection terminals of the diode D3 and the diode D4. One end of the capacitor C1 is grounded, and both ends of the capacitor C1 are respectively connected to the positive and negative poles of the motor.

[0020] During operation: Assume that IN1 is at a positive voltage and IN2 is at 0V. At this time, the diode D3 is cut off, the diode D1 is conducting, the diode D2 is cut off, and the capacitor C1 is used to absorb the back electromotive force, reaching the positive pole of the motor and flowing out from the negative pole. At this time, the diode D4 is in a conducting state, so the fan can operate normally.

[0021] Assume that IN2 is at a positive voltage and IN1 is at 0V. At this time, the diode D4 is cut off, the diode D2 is conducting, the diode D1 is cut off, and the capacitor C1 is used to absorb the back electromotive force, reaching the positive pole of the motor and flowing out from the negative pole. At this time, the diode D3 is in a conducting state, so the fan can operate normally.

[0022] In summary, therefore, regardless of how the power supply of IN1 and IN2 is swapped, the drive of the fan always maintains the operating state from the positive pole to the negative pole.

[0023] The output terminal of the diode D1 is connected to the output terminal of the diode D2, the input terminal of the diode D3 is connected to the input terminal of the diode D4, the output terminal of the diode D3 is connected to the input terminal of the diode D2, and the output terminal of the diode D4 is connected to the input terminal of the diode D2.

[0024] It further includes a voltage input circuit, and the voltage input circuit includes MOS transistors Q3, Q4, Q7, and Q8 connected to the power supply. A capacitor C6 is connected between the connection terminals of the D poles of the MOS transistor Q3 and the MOS transistor Q8 and the connection terminals of the D poles of the MOS transistor Q4 and the MOS transistor Q7. Both ends of the capacitor C6 are respectively connected to the positive and negative poles of the motor.

[0025] The MOS transistors Q3, Q4, Q7, Q8 of the power supply and the capacitor C6 form an H-bridge.

[0026] A resistor R7 is connected between the G pole and the S pole of the MOS transistor Q3, and a resistor R10 is connected to the G pole of the MOS transistor Q3;

[0027] A resistor R8 is connected between the G and S electrodes of the MOS transistor Q4, and a resistor R11 is connected to the G electrode of the MOS transistor Q4;

[0028] A resistor R19 is connected between the G and S electrodes of the MOS transistor Q7, and a resistor R17 is connected to the G electrode of the MOS transistor Q7;

[0029] A resistor R18 is connected between the G and S electrodes of the MOS transistor Q8, a resistor R16 is connected to the G electrode of the MOS transistor Q8, the resistor R7 is connected to the resistor R8, and the resistor R18 is connected to the resistor R19.

[0030] The S electrodes of the MOS transistors Q3 and Q4 are both connected to the power supply, and the S electrodes of the MOS transistors Q7 and Q8, and the connection terminals of the resistors R18 and R19 are grounded.

[0031] The voltage input circuit further includes a triode Q5 connected to the resistor R10 and a triode Q6 connected to the resistor R11. A resistor R14 is connected between the base and collector of the triode Q5, a resistor R12 is connected to the base of the triode Q5, and the resistor R12 is connected to the resistor R17;

[0032] The emitter of the triode Q5 is grounded, and the emitter of the triode Q6 is grounded.

[0033] A resistor R15 is connected between the base and collector of the triode Q6, a resistor R13 is connected to the base of the triode Q6, and the resistor R13 is connected to the resistor R16.

[0034] The connection terminals of the diodes D1 and D3 are connected to one end of the resistor R12, and one ends of the diodes D2 and D4 are connected to one end of the resistor R13.

[0035] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fan driving circuit that can be used regardless of positive or negative polarity, characterized in that: The invention comprises a motor, a diode D1 and a diode D3 connected to a voltage input terminal IN1, and a diode D2 and a diode D4 connected to a voltage input terminal IN2, wherein the diode D1 is connected to the diode D2, the diode D3 is connected to the diode D4, and a capacitor C1 is connected between the connection terminals of the diode D1 and the diode D2 and the connection terminals of the diode D3 and the diode D4, and the two ends of the capacitor C1 are respectively connected to the positive electrode and the negative electrode of the motor.

2. The fan driving circuit that can be used regardless of positive or negative polarity according to claim 1, characterized in that: The output end of the diode D1 is connected to the output end of the diode D2, the input end of the diode D3 is connected to the input end of the diode D4, the output end of the diode D3 is connected to the input end of the diode D2, and the output end of the diode D4 is connected to the input end of the diode D2.

3. The fan driving circuit that can be used regardless of positive or negative polarity according to claim 1, characterized in that: It also includes a voltage input circuit, which includes MOS tubes Q3, Q4, Q7 and Q8 connected to a power supply, and a capacitor C6 is connected between the connection terminals of the D poles of the MOS tube Q3 and the D poles of the MOS tube Q8 and the connection terminals of the D poles of the MOS tube Q4 and the D poles of the MOS tube Q7, and the two ends of the capacitor C6 are respectively connected to the positive pole and the negative pole of the motor.

4. The fan driving circuit that can be used regardless of positive or negative polarity according to claim 3, characterized in that: A resistor R7 is connected between the G pole and the S pole of the MOS tube Q3, and a resistor R10 is connected to the G pole of the MOS tube Q3; a resistor R8 is connected between the G pole and the S pole of the MOS tube Q4, and a resistor R11 is connected to the G pole of the MOS tube Q4; a resistor R19 is connected between the G pole and the S pole of the MOS tube Q7, and a resistor R17 is connected to the G pole of the MOS tube Q7; a resistor R18 is connected between the G pole and the S pole of the MOS tube Q8, and a resistor R16 is connected to the G pole of the MOS tube Q8, the resistor R7 is connected to the resistor R8, and the resistor R18 is connected to the resistor R19.

5. The fan driving circuit that can be used regardless of positive or negative polarity according to claim 4, characterized in that: The voltage input circuit also includes a transistor Q5 connected to a resistor R10 and a transistor Q6 connected to a resistor R11, a resistor R14 is connected between the base and collector of the transistor Q5, a resistor R12 is connected to the base of the transistor Q5, and the resistor R12 is connected to a resistor R17; A resistor R15 is connected between the base and collector of the transistor Q6 , a resistor R13 is connected to the base of the transistor Q6 , and the resistor R13 is connected to a resistor R16 .

6. The fan driving circuit that can be used regardless of positive or negative polarity according to claim 1, characterized in that: The connection ends of the diode D1 and the diode D3 are connected to one end of the resistor R12, and one end of the diode D2 and the diode D4 is connected to one end of the resistor R13.

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