Fan heater safety control circuit and fan heater

Abstract

The embodiment of the invention relates to a fan heater safety control circuit and a fan heater. The fan heater safety control circuit comprises a switching power supply module, a control module, a fan linkage driving module, a first fan and a second fan, wherein the first fan and the second fan are in linkage control through the fan linkage driving module; the switching power supply module is connected with a power supply, a protector is connected between the power supply and the switching power supply module, and the protector is positioned on the side of the second fan; when the first draught fan rotates abnormally and the second draught fan rotates normally, the first draught fan outputs a second feedback signal to the draught fan linkage driving module to control the second draught fan to stop rotating in a linkage mode, and the protector is disconnected when the environment temperature of the second draught fan side exceeds a safety threshold value; when the second fan rotates abnormally, the environment temperature of the second fan side rises, and the protector is disconnected when the environment temperature of the second fan side exceeds a safety threshold value. According to the fan heater safety control circuit and the fan heater, the cost is controllable, and the problem of local overheating caused by fan abnormity can be effectively solved.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of fan heaters, in particular to a fan heater safety control circuit and a fan heater. BACKGROUND

[0002] In order to increase the air volume and power, the fan heater is generally configured with two fans, and the heat generated by the heating assembly is discharged outside the fan heater through the protector controlling the two fans to work.

[0003] In the prior art, some fan heaters adopt a single-protector scheme, but local overheating caused by fan abnormality often occurs when the single-protector scheme is adopted, thereby causing safety problems; another part of the fan heaters adopts a double-protector scheme, which can improve the local overheating caused by fan abnormality to a certain extent, but the double-protector scheme occupies the space of the fan heater to a certain extent and increases the cost. SUMMARY

[0004] The present application provides a fan heater safety control circuit and a fan heater, which can effectively improve the local overheating caused by fan abnormality and is controllable in cost.

[0005] In a first aspect, the embodiment of the present application provides a fan heater safety control circuit, which comprises:

[0006] a switching power supply module, a control module and a fan linkage driving module electrically connected with the switching power supply module, a first fan and a second fan electrically connected with the fan linkage driving module, and the first fan and the second fan are linkage controlled through the fan linkage driving module.

[0007] The input end of the switching power supply module is connected to a power supply, and a protector is connected between the power supply and the switching power supply module, and the protector is located on the second fan side; wherein,

[0008] When the first fan rotates abnormally and the second fan rotates normally, the first fan outputs a second feedback signal to the fan linkage driving module, and the fan linkage driving module linkage controls the second fan to stop rotating, so that the ambient temperature on the second fan side is increased, and the protector is disconnected when the ambient temperature on the second fan side exceeds a safety threshold.

[0009] When the second fan rotates abnormally, the ambient temperature on the second fan side is increased, and the protector is disconnected when the ambient temperature on the second fan side exceeds a safety threshold.

[0010] Optionally, the power supply comprises a zero line and a live line, and the protector is connected in series on the live line.

[0011] The circuit further comprises a first heating group, one end of the first heating group being connected with the zero line and the other end being connected with the live line through the relay driving module; and a second heating group, one end of the second heating group being connected with the zero line and the other end being connected with the live line through the relay driving module.

[0012] The relay driving module is connected with the control module at the input end and is electrically connected with the first heating group at the side of the first fan and the second heating group at the side of the second fan at the output end, and is used to receive the control signal output by the control module to control the first heating group and the second heating group to work.

[0013] Optionally, the fan linkage driving module comprises:

[0014] The first fan driving unit is connected with the switching power supply module at the power supply end, is connected with the first fan at the output end, and is connected with the control module at the control end, and is used to control the first fan to work or stop working according to the first control signal output by the control module.

[0015] The second fan driving unit is connected with the switching power supply module at the power supply end, is connected with the second fan at the output end, and is connected with the control module at the control end, and is used to receive the second control signal output by the control module.

[0016] The linkage control unit is connected with the feedback end of the first fan at one end and is connected with the second fan driving unit at the other end.

[0017] When the feedback end outputs the first feedback signal, the second fan driving unit is turned on or turned off according to the second control signal, and the second fan works or stops working according to the second control signal.

[0018] When the feedback end outputs the second feedback signal, the output end of the second fan driving unit is disconnected with the second fan, and the second control signal output by the control module cannot control the second fan to work.

[0019] Optionally, when the first fan works, the feedback end outputs the first feedback signal to control the other end of the linkage control unit to be disconnected with the second fan driving unit; at this time, the second fan driving unit is turned on or turned off according to the second control signal, and the second fan works or stops working according to the second control signal.

[0020] When the first fan stops working, the feedback end outputs the second feedback signal to control the other end of the linkage control unit to be connected with the second fan driving unit; at this time, the output end of the second fan driving unit is disconnected with the second fan, and the second control signal output by the control module cannot control the second fan to work.

[0021] Optionally, the fan linkage driving module comprises a first fan driving unit, the first fan driving unit comprises:

[0022] a first transistor, a base of the first transistor being connected to the control module to receive the first control signal, an emitter being grounded, and a collector being connected to a base of a second transistor;

[0023] a second transistor, an emitter of the second transistor being connected to the switching power supply module to receive the first voltage, and a collector being connected to a positive pole of the first fan, a negative pole of the first fan being grounded;

[0024] when the first control signal output by the control module is at a high level, the first transistor and the second transistor are turned on, and the first fan is rotated to work; when the first control signal output by the control module is at a low level, the first transistor and the second transistor are turned off, and the first fan stops working.

[0025] Optionally, the fan linkage driving module comprises a second fan driving unit, the second fan driving unit comprises:

[0026] a fourth MOS transistor, a gate of the fourth MOS transistor being connected to the control module to receive the second control signal, a source being grounded, and a drain being connected to a negative pole of the second fan, a positive pole of the second fan being connected to the switching power supply module to receive the first voltage;

[0027] when the second control signal output by the control module is at a high level, the fourth MOS transistor is turned on, and the second fan is rotated to work according to the second control signal; when the second control signal output by the control module is at a low level, the fourth MOS transistor is turned off, and the second fan stops working according to the second control signal.

[0028] Optionally, the first fan driving unit further comprises a first filter capacitor, one end of the first filter capacitor being connected to the positive pole of the first fan, and the other end being grounded; the second fan driving unit further comprises a second filter capacitor, one end of the second filter capacitor being connected to the positive pole of the second fan, and the other end being connected to the drain of the fourth MOS transistor.

[0029] Optionally, the fan linkage driving module comprises a linkage control unit, the linkage control unit comprises:

[0030] a second capacitor, a first end of the second capacitor being connected to a feedback end of the first fan, the first end of the second capacitor further being connected to the switching power supply module through a fifth resistor to receive the first voltage; a second end of the second capacitor being connected to a third MOS transistor and a fifth MOS transistor; wherein,

[0031] a gate of the third MOS transistor being connected to the second end of the second capacitor, a source being grounded, and a drain receiving the second voltage;

[0032] The gate of the fifth MOS is connected with the drain of the third MOS, the source is grounded, and the drain is connected with the gate of the fourth MOS of the second fan driving unit.

[0033] Optionally, when the first fan rotates, the first feedback signal output by the feedback end of the first fan is a square wave signal, and the square wave signal makes the third MOS conduct and the fifth MOS cut off after passing through the second capacitor, so as to control the linkage control unit and the second fan driving unit to be disconnected; at this time, the second fan driving unit is turned on or turned off according to the second control signal, and the second fan rotates or stops working according to the second control signal.

[0034] When the first fan stops working, the second feedback signal output by the feedback end of the first fan is a fixed level signal, and the fixed level signal is isolated by the second capacitor, so that the third MOS is cut off and the fifth MOS is turned on, so as to control the linkage control unit and the second fan driving unit to be connected; at this time, the fourth MOS of the second fan driving unit is cut off, and the second control signal output by the control module cannot control the second fan to rotate.

[0035] In a second aspect, the embodiments of the present application provide a fan heater, which comprises the fan heater safety control circuit of the first aspect.

[0036] The safety control circuit of the embodiments of the present application is provided with a switching power supply module, a control module and a fan linkage driving module connected with the switching power supply module, a first fan and a second fan connected with the fan linkage driving module, and a protector connected between the power supply and the switching power supply module, and the protector is arranged on the second fan side; when the second fan rotates abnormally, the temperature of the environment on the second fan side rises, and when the temperature exceeds the safety threshold of the protector, the protector on the second fan side is disconnected, cutting off the power supply. When the first fan rotates abnormally, the first fan can output a second feedback signal to the fan linkage driving module, and the second fan is controlled to stop rotating through the linkage of the fan linkage driving module, so that the temperature of the environment on the second fan side rises, and when the temperature exceeds the safety threshold of the protector, the protector on the second fan side is disconnected, cutting off the power supply. The safety control circuit effectively solves the local overheating caused by the abnormal fan in the prior art, and further causes the safety problem without increasing the protector.

[0037] The fan heater using the safety control circuit provided by the present application has controllable cost and effectively improves the safety problem caused by local overheating due to abnormal fan.

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without creative effort. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 A structural schematic diagram of a safety control circuit of a fan heater provided in an example embodiment;

[0040] Figure 2 A structural schematic diagram of a safety control circuit of a fan heater provided in an example embodiment;

[0041] Figure 3 A structural schematic diagram of a safety control circuit of a fan heater provided in an example embodiment. DETAILED DESCRIPTION

[0042] In order to make the purposes, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0043] It should be clear that the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort fall within the scope of protection of the present application.

[0044] The terms used in the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein means and includes any or all possible combinations of one or more associated listed items.

[0045] The following description refers to the accompanying drawings. Unless otherwise noted, same or similar components in different drawings have same or similar reference numerals. The implementations described in the following exemplary embodiments are not meant to represent all implementations consistent with the present disclosure. Rather, they are simply examples of apparatuses and methods consistent with some aspects of the present disclosure as detailed in the appended claims. In the description of the present disclosure, it should be understood that the terms "first", "second", "third", etc., are used merely to distinguish like objects from one another, and are not necessarily meant to denote a particular order or sequence, nor are they necessarily meant to indicate or imply relative importance. The specific meanings of the above terms in the present disclosure can be understood by those of ordinary skill in the art according to the specific circumstances.

[0046] In addition, in the description of the present disclosure, "multiple" means two or more, unless otherwise specified. The association relationship of the associated objects described by "and / or" means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents that the associated objects before and after it are in an "or" relationship.

[0047] In the prior art, in order to increase the air volume and power, a warm air machine generally configures two fans, which are arranged at a certain distance apart to discharge the heat generated by the heating assembly outside the warm air machine. The warm air machine can be a tower type warm air machine, or other warm air machines. The heating assembly can be one, or two or more.

[0048] Taking a tower type warm air machine as an example, it is configured with a fan at the upper end and the lower end of the warm air machine, respectively, to discharge the heat of the heating assembly from the upper end through the upper end fan and to discharge the heat of the heating assembly from the lower end through the lower end fan. In some other embodiments, the tower type warm air machine can be provided with an upper heating assembly corresponding to the upper end fan at the upper end and a lower heating assembly corresponding to the lower end fan at the lower end, respectively.

[0049] If one of the fans is abnormal, the heat at the position corresponding to the fan cannot be discharged, causing local overheating at the position corresponding to the fan, and even causing safety problems.

[0050] To solve this problem, the prior art generally sets a protector between the two fans, which has the function of melting when exceeding a certain temperature, such as a fuse, a fuse, etc. But the problem that follows is that if the protector is set near one of the fan sides, it is inevitable to be far away from the other fan side. When the fan far away from the protector rotates abnormally and the heat on the side of the fan cannot be removed, it will still cause local overheating and cannot trigger the protector to work, thereby causing safety problems. If the protector is set at the middle position of the two fans, the protector is a certain distance away from the two fans. When the protector is triggered to work due to abnormal rotation of the fan, the temperature on the side of the abnormal fan has far exceeded the safety temperature of the protector, and there is also a safety hazard. Therefore, some manufacturers configure protectors on both sides of the two fans, but this scheme increases the cost of the protectors, on the one hand, and on the other hand, the additional protectors further occupy the originally compact internal space of the heater, which brings great challenges to the structural design.

[0051] Therefore, the present application provides a technical solution that can effectively solve the safety problems caused by local overheating due to abnormal rotation of the fan without increasing the protector. The present application will be described in detail below.

[0052] As shown in Figure 1 The heater safety control circuit of the present application includes:

[0053] The switch power supply module 100, the control module 200 electrically connected with the switch power supply module, the fan linkage driving module 300, the first fan 400 and the second fan 500 electrically connected with the fan linkage driving module, the first fan and the second fan are linkage controlled through the fan linkage driving module;

[0054] The input end of the switch power supply module is connected to the power supply, and a protector 600 is connected between the power supply and the switch power supply module, and the protector is located on the side of the second fan; wherein

[0055] When the first fan rotates abnormally and the second fan rotates normally, the first fan outputs a second feedback signal to the fan linkage driving module, and the fan linkage driving module linkage controls the second fan to stop rotating, so that the ambient temperature on the side of the second fan increases, and the protector is disconnected when the ambient temperature on the side of the second fan exceeds the safety threshold;

[0056] When the second fan rotates abnormally, the ambient temperature on the side of the second fan increases, and the protector is disconnected when the ambient temperature on the side of the second fan exceeds the safety threshold.

[0057] The safety control circuit of the embodiment of the present application is provided with a switching power supply module 100, a control module 200 connected with the switching power supply module, a fan linkage driving module 300 connected with the control module, a first fan 400 connected with the fan linkage driving module, a second fan 500, and a protector 600 connected between the power supply and the switching power supply module, and the protector is arranged at the second fan side. When the second fan rotates abnormally, the ambient temperature at the second fan side rises, and when the temperature exceeds the safety threshold of the protector, the protector at the second fan side is disconnected, cutting off the power supply. When the first fan rotates abnormally, the first fan can output a second feedback signal to the fan linkage driving module, and the fan linkage driving module linkage controls the second fan to stop rotating, so that the ambient temperature at the second fan side rises and the protector at the second fan side is disconnected when the temperature exceeds the safety threshold of the protector, cutting off the power supply. The safety control circuit effectively solves the local overheating caused by the fan abnormality in the prior art, thereby effectively improving the safety problem caused by the local overheating due to the fan abnormality.

[0058] The safety control circuit provided by the present application can control the cost of the fan heater and effectively improve the safety problem caused by the local overheating due to the fan abnormality.

[0059] The power supply includes a neutral line ACN and a live line ACL, and the protector 600 is connected in series on the live line.

[0060] The circuit further includes a first heating group 810, one end of the first heating group being connected with the neutral line and the other end being connected with the live line ACL through the relay driving module 700; and a second heating group 820, one end of the second heating group being connected with the neutral line and the other end being connected with the live line ACL through the relay driving module. When the protector is disconnected, the circuit loop of the first heating group 810 and the second heating group 820 is disconnected, so that the first heating group 810 and the second heating group 820 do not work. The first heating group and the second heating group preferably adopt a PTC (Positive Temperature Coefficient) thermistor.

[0061] The relay driving module 700 has an input end connected with the control module 200 and an output end electrically connected with the first heating group 810 at the first fan side and the second heating group 820 at the second fan side. The relay driving module 700 is used to receive the control signal output by the control module to control the first heating group and the second heating group to work. It should be noted that the positional relationship between the first heating group at the first fan side and the second heating group at the second fan side is not embodied in the drawings.

[0062] The fan linkage driving module 300 includes a first fan driving unit 310, a second fan driving unit 320, and a linkage control unit 330.

[0063] The first fan driving unit 310 has a power supply end connected with the switching power supply module, an output end connected with the first fan, and a control end connected with the control module, and is used to control the first fan to work or stop working according to the first control signal output by the control module. As shown in the figure, the power supply end of the first fan driving unit 310 is connected with the switching power supply module 100 to access a working voltage of 12V, the output end is connected with the first fan 400, and the control end is connected with the control module 200 to receive the first control signal FAN1.

[0064] Specifically, the first fan driving unit 310 includes a first triode Q1 and a second triode Q2. The base of the first triode Q1 is connected with the control module 200 to access the first control signal FAN1, the emitter is grounded GND, and the collector is connected with the base of the second triode Q2. The second triode Q2 has an emitter connected with the switching power supply module 100 to access a first voltage of 12V, and a collector connected with the positive electrode of the first fan; the negative electrode of the first fan is grounded GND. When the first control signal FAN1 output by the control module 200 is at a high level, the first triode Q1 and the second triode Q2 are turned on, and the first fan works; when the first control signal FAN1 output by the control module is at a low level, the first triode Q1 and the second triode Q2 are cut off, and the first fan stops working.

[0065] The first control signal FAN1 can be a PWM driving signal. Specifically, the safety control circuit in the embodiment of the present application further includes a temperature sensing module (not shown in the figure without affecting the understanding), which is electrically connected with the control module. The temperature sensing module can detect the temperature on the side of the first fan, and the control module can output the first control signal FAN1 according to the detected temperature to control the first fan to work.

[0066] It should be noted that the above only describes the main electronic circuit elements and connection structure of the first fan driving unit 310, and does not represent a limitation on the first fan driving unit 310. In the specific embodiment, the first fan driving unit 310 can also include other electronic elements. For example, Figure 3As shown, in the embodiment of the present application, the first fan driving unit 310 further comprises a first filter capacitor EC1, one end of which is connected with the positive electrode of the first fan, and the other end is grounded GND. Through the energy storage filtering effect of the first filter capacitor EC1, the stepless speed regulation of the first fan can be realized, and then the PTC heating power of the whole machine can be adjusted. When the fan speed is high, the PTC heating body temperature decreases, the PTC resistance value becomes smaller, and the whole machine heating power increases, thereby realizing the effect of adjusting the heating power of the whole machine by controlling the fan speed. In some specific embodiments, the first fan driving unit 310 further comprises a first resistor R1 connected between the control module 200 and the base of the first triode Q1, a second resistor R2 connected between the base of the first triode Q1 and the ground GND, a third resistor R3 connected between the base of the second triode Q2 and the collector of the first triode Q1, and a fourth resistor R4 connected between the base of the second triode Q2 and the transmitter.

[0067] The second fan driving unit 320 is connected with the switching power supply module at the power supply end, connected with the second fan at the output end, and connected with the control module at the control end, so as to receive the second control signal output by the control module. As shown, the power supply end of the second fan driving unit 320 is connected with the switching power supply module 100 to access a working voltage of 12V, the output end is connected with the second fan 500, and the control end is connected with the control module 200 to receive the second control signal FAN2.

[0068] Specifically, the second fan driving unit comprises a fourth MOS tube Q4, the gate of which is connected with the control module 200 to access the second control signal FAN2, the source is grounded, and the drain is connected with the negative electrode of the second fan. The positive electrode of the second fan is connected with the switching power supply module to access the first voltage 12V.

[0069] When the second control signal FAN2 output by the control module 200 is high, the fourth MOS tube Q4 is turned on, and the second fan rotates according to the second control signal FAN2; when the second control signal FAN2 output by the control module is low, the fourth MOS tube Q4 is cut off, and the second fan stops working according to the second control signal.

[0070] The second control signal FAN2 can be a PWM driving signal. Specifically, the safety control circuit in the embodiment of the present application further comprises a temperature sensing module (not shown in the figure without affecting understanding), which is electrically connected with the control module. The temperature sensing module can detect the temperature on the second fan side, and the control module can output the second control signal FAN2 according to the detected temperature to control the second fan to work.

[0071] It should be noted that the above description only outlines the main electronic circuit components and connection structure of the second fan drive unit 320, and does not represent a limitation on the second fan drive unit 320. In specific embodiments, the second fan drive unit 320 may also include other electronic components. For example... Figure 3 As shown in this embodiment, the second fan drive unit 320 further includes a second filter capacitor EC2, one end of which is connected to the positive terminal of the second fan, and the other end is connected to the drain of the fourth MOSFET Q4. Through the energy storage and filtering function of the second filter capacitor EC2, stepless speed regulation of the second fan can be achieved, thereby adjusting the PTC heating power of the entire unit. When the fan speed increases, the temperature of the PTC heating element decreases, the PTC resistance value decreases, and the overall heating power increases accordingly, achieving the effect of adjusting the overall heating power by controlling the fan speed. In some specific embodiments, the second fan drive unit 320 further includes a tenth resistor R10 connected between the control module 200 and the gate of the fourth MOSFET Q4, and a ninth resistor R9 connected between the gate of the fourth MOSFET Q4 and ground GND.

[0072] The linkage control unit 330 is connected at one end to the 400 feedback terminal of the first fan and at the other end to the second fan drive unit 320.

[0073] When the feedback terminal outputs the first feedback signal, the second fan drive unit 320 is turned on or off according to the second control signal FAN2, and the second fan 500 rotates or stops working according to the second control signal FAN2.

[0074] When the feedback terminal outputs the second feedback signal, the output terminal of the second fan drive unit 320 is disconnected from the second fan 500, and the second control signal FAN2 output by the control module 200 cannot control the second fan 500 to rotate and work.

[0075] In some specific embodiments, when the first fan is rotating, the feedback terminal outputs the first feedback signal to control the other end of the linkage control unit to disconnect from the second fan drive unit; at this time, the second fan drive unit is connected or disconnected according to the second control signal, and the second fan rotates or stops according to the second control signal; when the first fan stops working, the feedback terminal outputs the second feedback signal to control the other end of the linkage control unit to connect to the second fan drive unit; at this time, the output terminal of the second fan drive unit is disconnected from the second fan, and the second control signal output by the control module cannot control the second fan to rotate.

[0076] Specifically, the linkage control unit 330 comprises: a second capacitor C2, a first end of which is connected with the feedback end of the first fan, and the first end of the second capacitor is also connected with the switching power supply module 100 through a fifth resistor R5 to access the first voltage 12V; a second end of the second capacitor C2 is connected with a third MOS tube Q3 and a fifth MOS tube Q5. Wherein, a gate of the third MOS tube Q3 is connected with the second end of the second capacitor C2, a source is grounded GND, and a drain accesses the second voltage 5V; a gate of the fifth MOS tube Q5 is connected with the drain of the third MOS tube Q3, a source is grounded, and a drain is connected with a gate of the fourth MOS tube of the second fan driving unit 320.

[0077] It should be noted that the above only describes the main electronic circuit elements and connection structure of the linkage control unit 330, and does not represent a limitation on the second fan driving unit 320. In the specific embodiment, the linkage control unit 330 can also include other electronic elements. As shown in the figure, in the embodiment of the application, the linkage control unit 330 further comprises a sixth resistor R6 connected between the second end of the second capacitor C2 and the ground GND, which is used for pull-down action. It also includes a seventh resistor R7 connected between the third MOS tube Q3 drain accessing the second voltage 5V, an eighth resistor R8 connected between the third MOS tube Q3 drain and the fifth MOS tube Q5 gate, and a third capacitor C3 connected between the fifth MOS tube Q5 gate and the ground GND. Figure 3

[0078] In the embodiment of the application, when the first fan 400 rotates and works, the first feedback signal output by the feedback end of the first fan 400 is a square wave signal, and the square wave signal makes the third MOS tube Q3 conductive after passing through the second capacitor C2, and further makes the fifth MOS tube Q5 cut off, so as to control the linkage control unit and the second fan driving unit to be disconnected; at this time, the second fan driving unit is in an independent control state, and the second fan driving unit can be turned on or turned off according to the second control signal FAN2, and the second fan rotates and works or stops working according to the second control signal; specifically, the fourth MOS tube is turned on or turned off according to the second control signal FAN2, so as to turn on or turn off the second fan working loop.

[0079] ​When the first fan stops working, the second feedback signal outputted by the feedback end of the first fan 400 is a fixed level signal, the fixed level signal is isolated by the second capacitor C2, the gate of the third MOS tube Q3 cannot be electrified, the third MOS tube Q3 is cut off, the fifth MOS tube Q5 is connected with the second voltage 5V, the fifth MOS tube Q5 is turned on, the linkage control unit 330 and the second fan driving unit 320 are connected; at this time, the gate voltage of the fourth MOS tube Q4 of the second fan driving unit is pulled low, the fourth MOS tube Q4 is cut off, the second control signal FAN2 outputted by the control module 200 cannot control the second fan 500 to work. When the first fan works abnormally, the linkage control unit 330 can be linked to control the second fan to stop working, the heat of the second fan side cannot be discharged, the second fan side is locally overheated, and the protector located on the second fan side is disconnected, the power supply is cut off, and the first and second heat generating groups stop working, so that the safety is effectively ensured.

[0080] The embodiment of the present application provides a fan heater, which comprises the fan heater safety control circuit in the above embodiment. Compared with the prior art fan heater, the safety problem caused by local overheating due to fan abnormality is effectively solved without increasing the protector.

[0081] Those skilled in the art should understand that the embodiments of the present application can be provided as a system or a computer program product. Therefore, the present application can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0082] It should be understood that the embodiments of the present application are not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the embodiments of the present application is only limited by the appended claims.

[0083] The above-described embodiments only express several implementation manners of the embodiments of the present application, the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent. It should be pointed out that, for those skilled in the art, without departing from the concept of the embodiments of the present application, several modifications and improvements can be made, which are all within the protection scope of the embodiments of the present application.

Claims

1. A safety control circuit for a fan heater, characterised in that, The circuit comprises: a switching power module, a control module electrically connected with the switching power module, a fan linkage driving module, a first fan and a second fan electrically connected with the fan linkage driving module, and the first fan and the second fan are linkage controlled through the fan linkage driving module; an input end of the switching power module is connected with a power supply, and a protector is connected between the power supply and the switching power module, and the protector is located at the second fan side; wherein when the first fan rotates abnormally and the second fan rotates normally, the first fan outputs a second feedback signal to the fan linkage driving module, the fan linkage driving module linkage controls the second fan to stop rotating, the environment temperature at the second fan side is increased, and the protector is disconnected when the environment temperature at the second fan side exceeds a safety threshold value; when the second fan rotates abnormally, the environment temperature at the second fan side is increased, and the protector is disconnected when the environment temperature at the second fan side exceeds a safety threshold value.

2. The circuit of claim 1, wherein: the power supply comprises a zero line and a live line, and the protector is connected in series on the live line; the circuit further comprises: a first heating group, one end of the first heating group is connected with the zero line, and the other end is connected with the live line through a relay driving module; a second heating group, one end of the second heating group is connected with the zero line, and the other end is connected with the live line through the relay driving module; a relay driving module, an input end of the relay driving module is connected with the control module, and an output end of the relay driving module is electrically connected with the first heating group located at the first fan side and the second heating group located at the second fan side; the relay driving module is used to receive a control signal output by the control module to control the first heating group and the second heating group to work.

3. The circuit of claim 1, wherein, the fan linkage driving module comprises: a first fan driving unit, a power supply end of the first fan driving unit is connected with the switching power module, an output end of the first fan driving unit is connected with the first fan, and a control end of the first fan driving unit is connected with the control module, so as to control the first fan to rotate and work or stop working according to a first control signal output by the control module; a second fan driving unit, a power supply end of the second fan driving unit is connected with the switching power module, an output end of the second fan driving unit is connected with the second fan, and a control end of the second fan driving unit is connected with the control module, so as to receive a second control signal output by the control module; a linkage control unit, one end of the linkage control unit is connected with a feedback end of the first fan, and the other end of the linkage control unit is connected with the second fan driving unit; when the feedback end outputs a first feedback signal, the second fan driving unit is turned on or turned off according to the second control signal, and the second fan rotates and works or stops working according to the second control signal; when the feedback end outputs a second feedback signal, the output end of the second fan driving unit is disconnected with the second fan, and the second control signal output by the control module cannot control the second fan to rotate and work.

4. The circuit of claim 3, wherein: when the first fan rotates and works, the feedback end outputs a first feedback signal to control the other end of the linkage control unit to be disconnected with the second fan driving unit; at this time, the second fan driving unit is turned on or turned off according to the second control signal, and the second fan rotates and works or stops working according to the second control signal. When the first fan stops working, the feedback end outputs a second feedback signal to control the other end of the linkage control unit to be connected with the second fan driving unit; at this time, the output end of the second fan driving unit is disconnected with the second fan, and the second control signal output by the control module cannot control the second fan to work.

5. The circuit of claim 1, wherein, The fan linkage driving module comprises a first fan driving unit, and the first fan driving unit comprises: a first triode, whose base is connected with the control module to input the first control signal, whose emitter is grounded, and whose collector is connected with the base of a second triode; the second triode, whose emitter is connected with the switching power supply module to input the first voltage, and whose collector is connected with the positive pole of the first fan; the negative pole of the first fan is grounded; When the first control signal output by the control module is at a high level, the first triode and the second triode are turned on, and the first fan works; when the first control signal output by the control module is at a low level, the first triode and the second triode are turned off, and the first fan stops working.

6. The circuit of claim 5, wherein, The fan linkage driving module comprises a second fan driving unit, and the second fan driving unit comprises: a fourth MOS tube, whose gate is connected with the control module to input the second control signal, whose source is grounded, and whose drain is connected with the negative pole of the second fan; the positive pole of the second fan is connected with the switching power supply module to input the first voltage; When the second control signal output by the control module is at a high level, the fourth MOS tube is turned on, and the second fan works according to the second control signal; when the second control signal output by the control module is at a low level, the fourth MOS tube is turned off, and the second fan stops working according to the second control signal.

7. The circuit of claim 6, wherein: The first fan driving unit further comprises a first filter capacitor, one end of which is connected with the positive pole of the first fan, and the other end of which is grounded; the second fan driving unit further comprises a second filter capacitor, one end of which is connected with the positive pole of the second fan, and the other end of which is connected with the drain of the fourth MOS tube.

8. The circuit of claim 6, wherein, The fan linkage driving module comprises a linkage control unit, and the linkage control unit comprises: a second capacitor, whose first end is connected with the feedback end of the first fan, and whose first end is further connected with the switching power supply module through a fifth resistor to input the first voltage; the second end of the second capacitor is connected with a third MOS tube and a fifth MOS tube; wherein, the gate of the third MOS tube is connected with the second end of the second capacitor, the source of the third MOS tube is grounded, and the drain of the third MOS tube inputs the second voltage; the gate of the fifth MOS tube is connected with the drain of the third MOS tube, the source of the fifth MOS tube is grounded, and the drain of the fifth MOS tube is connected with the gate of the fourth MOS tube of the second fan driving unit.

9. The circuit of claim 8, wherein: When the first fan rotates, the first feedback signal outputted by the feedback end of the first fan is a square wave signal, and the square wave signal makes the third MOS tube conduct and the fifth MOS tube cut off after passing through the second capacitor, so as to control the linkage control unit to be disconnected with the second fan driving unit; at this time, the second fan driving unit is turned on or turned off according to the second control signal, and the second fan rotates or stops working according to the second control signal; When the first fan stops working, the second feedback signal outputted by the feedback end of the first fan is a fixed level signal, and the fixed level signal is isolated by the second capacitor, so as to make the third MOS tube cut off and the fifth MOS tube conduct, so as to control the linkage control unit to be connected with the second fan driving unit; at this time, the fourth MOS tube of the second fan driving unit cuts off, and the second control signal outputted by the control module cannot control the second fan to rotate.

10. A fan heater characterised in that The safety control circuit of the fan heater comprises the safety control circuit of the fan heater according to claims 1-9.

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