Fan fault switching circuit, heat dissipation device and household appliance

Abstract

The utility model provides a fan fault switching circuit, heat dissipation device and household electrical appliance, the fan fault switching circuit includes power supply input terminal, control circuit, change-over switch, main heat dissipation fan and auxiliary heat dissipation fan, the control circuit includes steering engine, conducting rod, first ground terminal and second ground terminal, change-over switch is electromagnetic control switch, and the control circuit includes the steering engine, conducting rod, first ground terminal and second ground terminal. The electromagnetic control switch is provided with a first magnet exciting coil used for controlling switching of the switch, the first end of the first magnet exciting coil is electrically connected with the power input end, the first end of the first magnet exciting coil is electrically connected with the first end of the conducting rod, and the conducting rod is installed on a driving shaft of the steering engine. The first feedback signal end of the main cooling fan is electrically connected with the control end of the steering engine, and the steering engine is used for driving the second end of the conductive rod to make contact with the first grounding end or the second grounding end according to a feedback signal of the first feedback signal end. By applying the fan fault switching circuit provided by the utility model, pulse feedback type and locked-rotor feedback type fan fault switching control can be met.

Description

Technical Field

[0001] The utility model relates to the technical field of fan fault switching circuits. Specifically, it relates to a fan fault switching circuit, a heat dissipation device applying the fan fault switching circuit, and a household appliance applying the heat dissipation device. Background Art

[0002] In the prior art, fans are widely used as heat dissipation devices in various electronic devices. To ensure the reliability of the fan heat dissipation function, the general method is to use at least two fan devices, including a main fan device and a standby fan device, and usually only start the main fan device to perform the air supply function while leaving the standby fan device idle. When the main fan device malfunctions, the main fan device is immediately turned off and the standby fan device is started to replace the air supply function of the main fan device.

[0003] Common fan feedback types are divided into pulse feedback type and stall feedback type. However, in the existing fan switching control circuits, usually only the control circuit is designed for fans of a single feedback type, and the same switching control circuit cannot meet the switching control of fans of different feedback types, so the versatility and applicability of the switching control circuit are relatively low.

[0004] Therefore, a more optimized fan switching circuit needs to be considered. Summary of the Utility Model

[0005] The first object of the utility model is to provide a fan fault switching circuit that can meet the fan fault switching control of pulse feedback type and stall feedback type.

[0006] The second object of the utility model is to provide a heat dissipation device that can meet the fan fault switching control of pulse feedback type and stall feedback type.

[0007] The third object of the utility model is to provide a household appliance that can meet the fan fault switching control of pulse feedback type and stall feedback type.

[0008] To achieve the above first object, the fan fault switching circuit provided by the present utility model comprises a power input terminal, a control circuit, a switching switch, a main cooling fan and a secondary cooling fan. The power supply terminals of the main cooling fan and the secondary cooling fan are electrically connected to the power input terminal through the switching switch, and the control terminal of the switching switch is electrically connected to the control circuit. The switching switch is used to switch the connection between the main cooling fan or the secondary cooling fan and the power input terminal. The control circuit includes a servo motor, a conductive rod, a first grounding terminal and a second grounding terminal. The switching switch is an electromagnetic control switch, and the electromagnetic control switch is provided with a first excitation coil for controlling the switch to switch. The first end of the first excitation coil is electrically connected to the power input terminal, the first end of the first excitation coil is electrically connected to the first end of the conductive rod, the conductive rod is installed on the driving shaft of the servo motor, and the first feedback signal terminal of the main cooling fan is electrically connected to the control terminal of the servo motor. The servo motor is used to drive the second end of the conductive rod to contact the first grounding terminal or the second grounding terminal according to the feedback signal of the first feedback signal terminal.

[0009] As can be seen from the above solution, the fan fault switching circuit of the present utility model is provided with a servo motor, a conductive rod, a first grounding terminal and a second grounding terminal. The servo motor is used to drive the second end of the conductive rod to contact the first grounding terminal or the second grounding terminal according to the feedback signal of the main cooling fan, thereby conducting the first excitation coil, and then controlling the electromagnetic control switch to switch the connection between the main cooling fan or the secondary cooling fan and the power input terminal. Since the pulse feedback type fan will lock the feedback signal in one of the high level or low level states during a fault, by setting the first grounding terminal or the second grounding terminal, the second end of the first excitation coil can be grounded to conduct the first excitation coil when the pulse feedback type fan has a fault. The stall feedback type fan will lock at a high level during a stall. Therefore, the servo motor can drive the conductive rod to connect to one of the first grounding terminal and the second grounding terminal, thereby conducting the first excitation coil. Therefore, the fan fault switching circuit of the present utility model can meet the switching control of pulse feedback type and stall feedback type fans, and has high versatility and applicability.

[0010] In a further aspect, the electromagnetic control switch is provided with a second excitation coil for locking the switch. The first end of the second excitation coil is electrically connected to the power supply terminal of the secondary cooling fan, and the second end of the second excitation coil is grounded.

[0011] As can be seen from this, the electromagnetic control switch is provided with a second excitation coil for locking the switch, which can conduct the second excitation coil after the secondary cooling fan is powered on, thereby locking the switch by using the second excitation coil to achieve self-locking and improving the stability of the switching control.

[0012] In a further aspect, the electromagnetic control switch is a single-pole double-throw electromagnetic control switch.

[0013] As can be seen from this, using a single-pole double-throw electromagnetic control switch is convenient for switching control.

[0014] In a further embodiment, the first grounding terminal is grounded through a first control switch, and the second grounding terminal is grounded through a second control switch.

[0015] It can be seen that both the first grounding terminal and the second grounding terminal are grounded through control switches, which is convenient for control. The first control switch and the second control switch can be controlled to be in the off state during initial startup to avoid misdetecting faults when the main cooling fan is not operating properly during initial startup.

[0016] In a further embodiment, the control circuit further includes a control chip, and the control terminals of the first control switch and the second control switch are both electrically connected to the control chip.

[0017] It can be seen that by setting the control chip to control the first control switch and the second control switch, automatic control can be achieved.

[0018] In a further embodiment, the second feedback signal terminal of the auxiliary cooling fan is electrically connected to the control chip.

[0019] It can be seen that the second feedback signal terminal of the auxiliary cooling fan is electrically connected to the control chip, which can be used to indicate a fault in the main cooling fan and turn on the auxiliary cooling fan.

[0020] In a further embodiment, the first control switch and / or the second control switch is a relay switch.

[0021] It can be seen that using relay switches for the first control switch and the second control switch can improve the stability of control.

[0022] In a further embodiment, the main cooling fan is a pulse feedback type fan or a stall feedback type fan.

[0023] It can be seen that the fan fault switching circuit of the present invention can be applied to a pulse feedback type fan or a stall feedback type fan, and has high versatility.

[0024] To achieve the above second object, the heat dissipation device provided by the present invention is provided with a fan fault switching circuit, and the fan fault switching circuit adopts the above-mentioned fan fault switching circuit.

[0025] To achieve the above third object, the household appliance provided by the present invention includes a heat dissipation device, and the heat dissipation device adopts the above-mentioned heat dissipation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a circuit principle block diagram of an embodiment of the fan fault switching circuit of the present invention.

[0027] Figure 2 is a circuit schematic diagram of an embodiment of the fan fault switching circuit of the present invention.

[0028] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments. Specific Embodiment

[0029] Embodiment of the fan failure switching circuit:

[0030] In this embodiment, as shown in Figure Figure 1 , the fan failure switching circuit includes a power input terminal VCC, a control circuit 1, a switching switch 2, a main cooling fan 3, and an auxiliary cooling fan 4. The power supply terminals of the main cooling fan 3 and the auxiliary cooling fan 4 are electrically connected to the power input terminal VCC through the switching switch 2. The control terminal of the switching switch 2 is electrically connected to the control circuit 1. The switching switch 2 is used to switch the connection between the main cooling fan 3 or the auxiliary cooling fan 4 and the power input terminal VCC. The main cooling fan 3 is a pulse feedback type fan or a stall feedback type fan.

[0031] Referring to Figure 2 , in this embodiment, the control circuit 1 includes a servo motor 11, a conductive rod 12, a first grounding terminal 13, and a second grounding terminal 14. The switching switch 2 is an electromagnetic control switch. The electromagnetic control switch is provided with a first excitation coil 21 for controlling the switch to switch. The first end of the first excitation coil 21 is electrically connected to the power input terminal VCC. The first end of the first excitation coil 21 is electrically connected to the first end of the conductive rod 12. The conductive rod 12 is installed on the drive shaft (not shown) of the servo motor 11. The first feedback signal terminal of the main cooling fan 3 is electrically connected to the control terminal of the servo motor 11. The servo motor 11 is used to drive the second end of the conductive rod 12 to contact the first grounding terminal 13 or the second grounding terminal 14 according to the feedback signal of the first feedback signal terminal. The working principle of the servo motor 11 is well-known to those skilled in the art and will not be elaborated here. In this embodiment, by using the principle that the drive shaft of the servo motor 11 rotates full circle when obtaining a high level and stops rotating when obtaining a low level, the servo motor 11 drives the second end of the conductive rod 12 to contact the first grounding terminal 13 or the second grounding terminal 14.

[0032] The electromagnetic control switch is further provided with a second excitation coil 22 for locking the switch. The first end of the second excitation coil 22 is electrically connected to the power supply terminal of the auxiliary cooling fan 4, and the second end of the second excitation coil 22 is grounded. The electromagnetic control switch is provided with a second excitation coil 22 for locking the switch, which can conduct the second excitation coil 22 after the auxiliary cooling fan 4 is powered on, thereby using the second excitation coil 22 to lock the switch to achieve self-locking and improve the stability of the switching control.

[0033] In this embodiment, the electromagnetic control switch is a single-pole double-throw electromagnetic control switch. The common terminal of the single-pole double-throw electromagnetic control switch is electrically connected to the power input terminal VCC. The normally closed terminal of the single-pole double-throw electromagnetic control switch is electrically connected to the power supply terminal of the main cooling fan 3. The normally open terminal of the single-pole double-throw electromagnetic control switch is electrically connected to the power supply terminal of the auxiliary cooling fan 4.

[0034] In this embodiment, the first grounding terminal 13 is grounded through the first control switch 15, and the second grounding terminal 14 is grounded through the second control switch 16. Both the first control switch 15 and the second control switch 16 are relay switches. Using relay switches for the first control switch 15 and the second control switch 16 can improve the stability of control. Both the first grounding terminal 13 and the second grounding terminal 14 are grounded through control switches, which is convenient for control. At the initial startup, the first control switch 15 and the second control switch 16 can be controlled to be in the off state to avoid misdetecting faults when the main cooling fan 3 fails to operate normally during the initial startup.

[0035] In addition, the control circuit 1 further includes a control chip 17. The control terminals of the first control switch 15 and the second control switch 16 are both electrically connected to the control chip 17. By setting the control chip 17 to control the first control switch 15 and the second control switch 16, automatic control can be achieved. The second feedback signal terminal of the auxiliary cooling fan 4 is electrically connected to the control chip 17. The electrical connection between the second feedback signal terminal of the auxiliary cooling fan 4 and the control chip 17 can be used to indicate a fault in the main cooling fan 3 and turn on the auxiliary cooling fan 4.

[0036] Furthermore, the control circuit 1 also includes an amplifier circuit 18. The first feedback signal terminal of the main cooling fan 3 is electrically connected to the control terminal of the servo motor 11 through the amplifier circuit 18. Using the amplifier circuit 18 to amplify the feedback signal of the main cooling fan 3 can improve the stability of the control of the servo motor 21.

[0037] When the pulse feedback type fan is operating normally, the feedback signal is a rectangular wave signal with a duty cycle of approximately 50%. When the pulse feedback type fan fails, the feedback signal will lock in one of the high level or low level states. Therefore, when the circuit starts to work, if the main cooling fan 3 is a pulse feedback type fan, the control chip 17 controls the first control switch 15 and the second control switch 16 to close. When the main cooling fan 3 is operating normally, the servo motor 11 controls the conductive rod 12 to be in the middle position, not in contact with the first grounding terminal 13 or the second grounding terminal 14, and the first excitation coil 21 is disconnected; when the main cooling fan 3 fails, since the feedback signal will lock in one of the high level or low level states, the servo motor 11 rotates fully or stops, and the conductive rod 12 contacts one of the first grounding terminal 13 or the second grounding terminal 14. Since both the first control switch 15 and the second control switch 16 are closed, the first excitation coil 21 is connected at this time, and the electromagnetic control switch switches to the auxiliary cooling fan 4 to work.

[0038] When the locked-rotor feedback type fan operates normally, the feedback signal is generally at a low level. When the locked-rotor feedback type fan is locked up, the feedback signal will be locked at a high level. When the circuit starts to work, if the main cooling fan 3 is a locked-rotor feedback type fan, the control chip 17 controls one of the first control switch 15 and the second control switch 16 that corresponds to the servo 11 to conduct when the servo 11 is at a high level and the other to be turned off. When a fault occurs in the main cooling fan 3, the corresponding feedback signal is output to the servo 11 through the amplifier circuit 18. The servo 11 is controlled by the feedback signal of the main cooling fan 3. The servo 11 controls the conductive rod 12 to conduct the first excitation coil 21, and the electromagnetic control switch switches to the operation of the auxiliary cooling fan 4.

[0039] As can be seen from the above solution, the fan fault switching circuit of the present utility model is provided with a servo 11, a conductive rod 12, a first grounding end 13 and a second grounding end 14. The servo 11 is used to drive the second end of the conductive rod 12 to contact the first grounding end 13 or the second grounding end 14 according to the feedback signal of the main cooling fan 3, so as to conduct the first excitation coil 21, and further control the electromagnetic control switch to switch the main cooling fan 3 or the auxiliary cooling fan 4 to be connected to the power input terminal VCC. Since the pulse feedback type fan will lock the feedback signal in one of the high level or the low level state when a fault occurs, therefore, by setting the first grounding end 13 or the second grounding end 14, the pulse feedback type fan can make the second end of the first excitation coil 21 grounded to conduct the first excitation coil 21 when a fault occurs. The locked-rotor feedback type fan will be locked at a high level when locked up. Therefore, the servo 11 can drive the conductive rod 12 to connect to one of the first grounding end 13 and the second grounding end 14, so as to conduct the first excitation coil 21. Therefore, the fan fault switching circuit of the present utility model can meet the switching control of the pulse feedback type and the locked-rotor feedback type fans, and has high versatility and applicability.

[0040] Embodiment of the heat dissipation device:

[0041] In this embodiment, the heat dissipation device is provided with a fan fault switching circuit, and the fan fault switching circuit adopts the fan fault switching circuit in the above embodiment.

[0042] Embodiment of household appliances:

[0043] In this embodiment, the household appliance includes a heat dissipation device, and the heat dissipation device adopts the heat dissipation device in the above embodiment. The household appliances include household appliances such as air conditioners, washing machines, refrigerators, and exhaust fans.

[0044] It should be noted that the above are only the preferred embodiments of the present utility model, but the design concept of the utility model is not limited thereto. Any non-substantive modifications made to the present utility model using this concept also fall within the protection scope of the present utility model.

Claims

1. A fan fault switching circuit, comprising a power input terminal, a control circuit, a switching switch, a main cooling fan, and a secondary cooling fan. The power supply terminals of the main cooling fan and the secondary cooling fan are electrically connected to the power input terminal through the switching switch. The control terminal of the switching switch is electrically connected to the control circuit. The switching switch is used to switch the connection between the main cooling fan or the secondary cooling fan and the power input terminal; Characterized in that: The control circuit includes a servo motor, a conductive rod, a first grounding terminal, and a second grounding terminal. The switching switch is an electromagnetic control switch. The electromagnetic control switch is provided with a first excitation coil for controlling the switch to switch. The first end of the first excitation coil is electrically connected to the power input terminal. The first end of the first excitation coil is electrically connected to the first end of the conductive rod. The conductive rod is installed on the drive shaft of the servo motor. The first feedback signal terminal of the main cooling fan is electrically connected to the control terminal of the servo motor. The servo motor is used to drive the second end of the conductive rod to contact the first grounding terminal or the second grounding terminal according to the feedback signal of the first feedback signal terminal.

2. The fan fault switching circuit according to claim 1, characterized in that: The electromagnetic control switch is provided with a second excitation coil for locking the switch. The first end of the second excitation coil is electrically connected to the power supply terminal of the secondary cooling fan, and the second end of the second excitation coil is grounded.

3. The fan fault switching circuit according to claim 1, characterized in that: The electromagnetic control switch is a single-pole double-throw electromagnetic control switch.

4. The fan fault switching circuit according to any one of claims 1 to 3, characterized in that: The first grounding terminal is grounded through a first control switch, and the second grounding terminal is grounded through a second control switch.

5. The fan fault switching circuit according to claim 4, characterized in that: The control circuit further includes a control chip. The control terminals of the first control switch and the second control switch are both electrically connected to the control chip.

6. The fan fault switching circuit according to claim 5, characterized in that: The second feedback signal terminal of the secondary cooling fan is electrically connected to the control chip.

7. The fan fault switching circuit according to claim 4, characterized in that: The first control switch and / or the second control switch is a relay switch.

8. The fan fault switching circuit according to any one of claims 1 to 3, characterized in that: The main cooling fan is a pulse feedback type fan or a stall feedback type fan.

9. A heat dissipation device provided with a fan fault switching circuit, characterized in that: The fan fault switching circuit adopts the fan fault switching circuit according to any one of claims 1 to 8.

10. A household appliance including a heat dissipation device, characterized in that: The heat dissipation device adopts the heat dissipation device according to claim 9.

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