CN219976556U

CN219976556U - Warm-air drier

Info

Publication number: CN219976556U
Application number: CN202321400153.6U
Authority: CN
Inventors: 郭龙飞; 叶频
Original assignee: Shenzhen Aschip Tech Co ltd
Current assignee: Shenzhen Aschip Tech Co ltd
Priority date: 2023-06-02
Filing date: 2023-06-02
Publication date: 2023-11-07
Anticipated expiration: 2033-06-02

Abstract

The utility model discloses a warm-air drier, wherein the warm-air drier comprises a key circuit, a human body induction sensor, a heating component and a main control circuit; the main control circuit is respectively connected with the key circuit, the human body induction sensor, the heating component and the main control circuit. According to the utility model, the human body is detected by the human body induction sensor and the corresponding human body detection signal is output, and the corresponding trigger signal is output when the key circuit is triggered, the main control circuit switches the triggering mode of the warm air blower according to the trigger signal and controls the heating assembly to work according to the trigger signal and the human body detection signal so as to provide heating, the heating assembly is controlled to work in a human body induction mode, the operation is more convenient and rapid, even if a user forgets to turn off the warm air blower before going out, the warm air blower can automatically stop working when the human body is not detected, the safety is higher, and the electric power is saved.

Description

Warm-air drier

Technical Field

The utility model relates to the technical field of warm air blowers, in particular to a warm air blower.

Background

In order to resist severe cold every time the winter weather is extremely cold, heating devices are necessary in the home to heat, and the heating devices comprise a warm air blower, a small sun or an air conditioner and the like. Because winter weather is dry, if a user forgets to close the warm air blower before going out, the warm air blower can continuously work for a long time, heat is accumulated, the warm air blower can possibly cause failure or even fire, the safety is extremely low, and a large amount of power is consumed.

Disclosure of Invention

The utility model mainly aims to provide a warm air blower, which aims to solve the problem of extremely low safety of the warm air blower.

In order to achieve the above object, the present utility model provides a fan heater, which includes:

the human body induction sensor is used for detecting a human body and outputting corresponding human body detection signals;

the key circuit is used for outputting a corresponding trigger signal when triggered by a user;

the heating assembly is used for providing heating;

the main control circuit, main control circuit's input with human body induction sensor is connected, main control circuit's input still with key circuit connects, main control circuit's control end with heating subassembly is connected, main control circuit is used for according to trigger signal with human body detection signal control heating subassembly work.

In one embodiment, the human body induction sensor includes:

the laser sensor is connected with the main control circuit and is used for transmitting and receiving laser signals;

and/or the PIR human body pyroelectric infrared sensor is connected with the main control circuit and is used for outputting an infrared sensing signal when detecting the human body temperature.

In one embodiment, the fan heater includes:

the output end of the toppling detection circuit is connected with the main control circuit, and the toppling detection circuit is used for outputting a corresponding toppling detection signal when detecting toppling of the warm air blower;

the main control circuit is also used for controlling the heating assembly to stop working when the warm air blower is toppled according to the toppling detection signal.

In an embodiment, the dumping detection circuit includes a plurality of sets of correlation switches, each set of correlation switches includes a photoelectric transmitting tube and a photoelectric receiving tube, and the dumping detection circuit is configured to output the corresponding dumping detection signal according to an output signal of the photoelectric receiving tube in each set of correlation switches.

In one embodiment, the fan heater further comprises:

the controlled end of the alarm circuit is connected with the main control circuit, and the alarm circuit is used for outputting an alarm signal when in operation;

and the main control circuit is used for controlling the alarm circuit to work when detecting the toppling of the warm air blower according to the toppling detection signal.

In one embodiment, the fan heater includes:

the output end of the timing circuit is connected with the main control circuit, and the timing circuit is used for setting the working time of the heating assembly and outputting a corresponding time setting signal;

the main control circuit is also used for controlling the heating assembly to work according to the time setting signal.

In one embodiment, the fan heater further comprises:

the controlled end of the indicating circuit is connected with the main control circuit, and the indicating circuit is used for outputting corresponding indicating signals when working;

the main control circuit also controls the indicating circuit to work according to the time setting signal.

In one embodiment, the fan heater includes:

the output end of the gear adjusting circuit is connected with the input end of the main control circuit, and the gear adjusting circuit is used for setting the heating power of the heating assembly and outputting a gear adjusting signal;

the main control circuit is also used for controlling the heating assembly to work according to the gear adjusting signal so as to control the heating assembly to provide corresponding heating.

In one embodiment, the fan heater includes:

the output end of the mode conversion circuit is connected with the input end of the main control circuit, and the mode conversion circuit is used for outputting a mode conversion signal when triggered;

the main control circuit is also used for controlling the heating assembly to work according to the trigger signal when the voltage value corresponding to the mode conversion signal is smaller than a preset voltage value, and controlling the heating assembly to work according to the human body detection signal when the voltage value corresponding to the mode conversion signal is not smaller than the set voltage value.

In one embodiment, the heating assembly includes:

the controlled end of the heating circuit is connected with the main control circuit, and the heating circuit is used for heating air during working;

the controlled end of the blowing component is connected with the main control circuit, and the blowing component is used for blowing out heated air during working;

the main control circuit is used for outputting a heating control signal and a blowing control signal according to the trigger signal and the human body detection signal, and respectively controlling the heating circuit and the blowing assembly to work.

According to the technical scheme, the human body is detected through the human body induction sensor, the corresponding human body detection signal is output, the corresponding trigger signal is output when the key circuit is triggered, the main control circuit switches the triggering mode of the warm air blower according to the trigger signal, and controls the heating assembly to work according to the trigger signal and the human body detection signal so as to provide heating, the heating assembly is controlled to work in a human body induction mode, the warm air blower is more convenient to operate, even if a user forgets to turn off the warm air blower before going out, the warm air blower can automatically stop working when the human body is not detected, the safety is higher, and the electric power is saved.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is an overall block diagram of an embodiment of the fan heater of the present utility model;

FIG. 2 is a schematic block diagram of another embodiment of the fan heater of the present utility model;

fig. 3 is a circuit diagram of a first switch circuit of the fan heater according to an embodiment of the present utility model.

Reference numerals illustrate:

reference numerals	Name of the name	Reference numerals	Name of the name
				10	Human body induction sensor	80	Alarm circuit
20	Key circuit	90	Indication circuit
				30	Main control circuit	41	Heating circuit
40	Heating assembly	42	Air blowing assembly
				50	Dumping detection circuit	421	First switch circuit
60	Timing circuit	Q1	First switch tube
				71	Gear adjusting circuit	R1	First resistor
72	Mode switching circuit	R2	Second resistor

The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

In order to solve the above problems, the present utility model provides a fan heater.

Referring to fig. 1, in an embodiment of the present utility model, the warm-air blower includes:

a human body sensing sensor 10, wherein the human body sensing sensor 10 is used for detecting human body and outputting corresponding human body detection signals;

a key circuit 20, wherein the key circuit 20 is used for outputting a corresponding trigger signal when triggered;

a heating assembly 40, the heating assembly 40 being configured to provide heating;

the main control circuit 30, the input of main control circuit 30 with human body induction sensor 10 is connected, the input of main control circuit 30 still with key circuit 20 is connected, the control end of main control circuit 30 with heating subassembly 40 is connected, main control circuit 30 is used for according to trigger signal with human body detection signal control heating subassembly 40 work.

In this embodiment, the heating unit 40 may be implemented by any heating unit 40 that can heat, for example, a heating circuit 41 and a blowing unit 42, that is, the blowing unit 42 blows air heated by the heating circuit 41 to implement heating. The key circuit 20 may be implemented by a key circuit 20 such as a mechanical key or a touch key, in this embodiment, the key circuit 20 is preferably a touch key circuit 20, an output end of the touch key circuit 20 is connected to the main control circuit 30, and the touch key circuit 20 is configured to output a touch key signal when triggered by a user; the main control circuit 30 is further configured to control the heating assembly 40 to work according to the touch key signal; the touch key circuit 20 may be a capacitive touch key, which has advantages of beautiful appearance and long service life compared to conventional mechanical keys. It can be appreciated that when the main control circuit 30 receives the trigger signal, the heating assembly 40 can be controlled to work according to the trigger signal, so as to control the fan heater. In addition, the key circuit 20 can be used for a user to select the intensity of the heating component 40 for providing the heating, namely, the user can control the quantity of the heating output by the fan heater through the key circuit 20, and the room temperature can be correspondingly adjusted; the key circuit 20 may also allow the user to select a triggering mode of the warm-air blower, i.e. the user may select to directly control the warm-air blower through the key circuit 20, or select to control the warm-air blower through the human body induction sensor 10, so that the user may select a mode of controlling the warm-air blower by himself.

In this embodiment, the main control circuit 30 may be implemented by a main controller, such as an MCU, a DSP (Digital Signal Process, digital signal processing Chip), an FPGA (Field Programmable Gate Array, programmable gate array Chip), an SOC (System On Chip), or the like;

the human body sensing sensor 10 may be implemented using any human body sensing sensor 10 that can detect a human body, such as a laser sensor or a pyroelectric infrared sensor. In this embodiment, the human body induction sensor 10 is preferably a laser sensor, the laser sensor can emit and receive laser to output a corresponding laser receiving signal, and the main control circuit 30 controls the heating component 40 to work according to the laser receiving signal; compared with the pyroelectric infrared sensor, the laser sensor has the advantages of longer detection distance and higher precision.

It can be understood that, the user can adjust the triggering mode of the fan heater to human body induction mode by triggering the key circuit 20, that is, when the user has inconvenient operation, the heating component 40 can work through the human body induction sensor 10, specifically, when the human body induction sensor 10 detects a human body, a human body detection signal is output to the main control circuit 30, and the main control circuit 30 controls the heating component 40 to work according to the human body detection signal so as to provide heating; similarly, when the human body is not detected by the human body induction sensor 10, the main control circuit 30 controls the heating assembly 40 to stop working so as to control the heating assembly 40 to work in a human body induction mode, so that the operation is more convenient, and even if a user forgets to turn off the warm air blower before going out, the warm air blower stops working when the human body is not detected by the warm air blower, the safety is higher, and the electric power is saved.

According to the technical scheme of the utility model, the human body is detected by the human body induction sensor 10 and the corresponding human body detection signal is output, and the corresponding trigger signal is output when the key circuit 20 is triggered, the main control circuit 30 switches the triggering mode of the warm air blower according to the trigger signal and controls the operation of the heating assembly 40 according to the trigger signal and the human body detection signal so as to provide heating, the operation of the heating assembly 40 is controlled in a human body induction mode, the operation is more convenient, even if a user forgets to turn off the warm air blower before going out, the warm air blower can automatically stop working when the human body is not detected, the safety is higher, and the electric power is saved.

Referring to fig. 2, in one embodiment, the human body induction sensor 10 includes:

a laser sensor connected to the main control circuit 30, the laser sensor being configured to transmit and receive laser signals;

and/or, a PIR human body pyroelectric infrared sensor connected with the main control circuit 30, the PIR human body pyroelectric infrared sensor being configured to output an infrared sensing signal when detecting a human body temperature.

The laser sensor comprises a laser transmitter and a laser receiver, wherein a controlled end of the laser transmitter is connected with the main control circuit 30, and the laser transmitter is used for transmitting laser signals; the laser receiver and the laser emitter are arranged on the same side, the output end of the laser receiver is connected with the main control circuit 30, and the laser receiver is used for receiving and outputting laser signals; it can be understood that the laser transmitter transmits a laser signal under the control of the main control circuit 30, the laser receiver outputs the received laser signal to the main control circuit 30, the main control circuit 30 controls the heating component 40 to operate according to the laser signal, specifically, when the light intensity value corresponding to the laser signal is greater than or equal to the preset light intensity value, the human body is not detected, and the heating component 40 is in a state of stopping operation; when the light intensity value corresponding to the laser signal is smaller than the preset light intensity value, the main control circuit 30 detects the human body and controls the heating component 40 to work for heating, so that the heating is more convenient. When the PIR human body pyroelectric infrared sensor detects the human body temperature, an infrared sensing signal is output to the main control circuit 30, and the main control circuit 30 controls the heating assembly 40 to work according to the infrared sensing signal so as to heat, so that the heating is more convenient. In the embodiment, the laser sensor and/or the PIR human body pyroelectric infrared sensor are used for detecting the human body and outputting the laser signal and/or the infrared signal, and the main control circuit 30 controls the heating assembly 40 to work according to the laser signal and/or the infrared signal, so that the use of a user is more convenient.

Referring to fig. 2, in one embodiment, the warm-air drier includes:

the dumping detection circuit 50, wherein an output end of the dumping detection circuit 50 is connected with the main control circuit 30, the dumping detection circuit 50 comprises a plurality of groups of opposite-shooting switches, each group of opposite-shooting switches comprises a photoelectric transmitting tube and a photoelectric receiving tube, and the dumping detection circuit 50 is used for outputting corresponding dumping detection signals according to output signals of the photoelectric receiving tubes in each group of opposite-shooting switches;

the main control circuit 30 is further configured to control the heating assembly 40 to stop working when the fan heater topples according to the toppling detection signal.

In this embodiment, the plurality of sets of correlation switches may be correspondingly disposed on walls on either side of the room. The number of the correlation switches can be determined according to actual conditions, and in the installation process, the photoelectric transmitting tubes and the photoelectric receiving tubes in each group of correlation switches are required to be arranged in a positive mode, so that the photoelectric receiving tubes can receive optical signals transmitted by the photoelectric transmitting tubes. When the warm air blower is not toppled, one or more photoelectric receiving tubes in the multiple groups of opposite-emission switches cannot receive the light signals emitted by the corresponding photoelectric emitting tubes due to the shielding of the warm air blower, at this time, the toppling detection circuit 50 outputs low-level signals to the main control circuit 30, namely the warm air blower is not toppled, and at this time, the main control circuit 30 normally controls the heating assembly 40 to work; however, when the fan heater is inclined, all the opposite-jet switches in the opposite-jet switches are out of shielding, so that all the photoelectric receiving tubes can receive the light signals emitted by the corresponding photoelectric emitting tubes, namely, the dumping detection circuit 50 outputs high-level signals to the main control circuit 30, the main control circuit 30 detects that the fan heater is dumped, the heating assembly 40 is immediately controlled to stop working, fire disaster caused by dumping of the fan heater is prevented, and safety of a user during heating by using the fan heater is ensured.

In one embodiment, the fan heater further comprises:

the controlled end of the alarm circuit 80 is connected with the main control circuit 30, and the alarm circuit 80 is used for outputting an alarm signal when in operation;

the main control circuit 30 also controls the alarm circuit 80 to operate when detecting that the fan heater is toppled according to the toppling detection signal.

In this embodiment, the alarm circuit 80 may be implemented by any alarm circuit 80 that can output an alarm signal, such as a buzzer or a voice reminder. It will be appreciated that when the fan unit topples over, the main control circuit 30 monitors the fan unit topples over according to the toppling detection signal, and the main control circuit 30 controls the alarm circuit 80 to operate to output an alarm signal so as to inform the user that relevant measures are required to be taken in time, so that other potential safety hazards caused by the toppling over of the fan unit are prevented.

Referring to fig. 2, in one embodiment, the warm-air drier includes:

the output end of the timing circuit 60 is connected with the main control circuit 30, and the timing circuit 60 is used for setting the working time of the heating assembly 40 and outputting a corresponding time setting signal;

the main control circuit 30 is further configured to control the operation of the heating assembly 40 according to the time setting signal.

In this embodiment, the timing circuit 60 may be implemented by a crystal oscillator circuit or a clock chip, etc. of the timing circuit 60. The timing circuit 60 in this example may be implemented using a DS1302 chip, and the DS1302 chip may set the operating time of the heating assembly 40 more precisely than a crystal oscillator circuit. It will be appreciated that the timing circuit 60 may be provided with a button which, when first pressed by the user, i.e. the heating assembly 40 is operated for 2 hours; when the user presses the button a second time, i.e., the operation time of the heating assembly 40 is 5 hours; when the user presses the button for the third time, that is, the working time of the heating assembly 40 is 8 hours, wherein the specific number of times the button is pressed and the working time corresponding to the time when the button is pressed can be set according to the actual situation, so that the timing function of the fan heater is realized, and the fan heater is more convenient.

In one embodiment, the fan heater further comprises:

the controlled end of the indicating circuit 90 is connected with the main control circuit 30, and the indicating circuit 90 is used for outputting corresponding indicating signals when working;

the main control circuit 30 also controls the indicating circuit 90 to operate according to the time setting signal.

In this embodiment, the indication circuit 90 may be implemented by any indication circuit 90 capable of outputting indication signals, for example, LED lamps, and the number and color of the LED lamps may be set according to practical situations. In this embodiment, the main control circuit 30 controls the indication circuit 90 to operate according to the time setting signal output by the timing circuit 60, where the indication circuit 90 includes a green LED lamp, a blue LED lamp, and a red LED lamp, specifically, when the operating duration of the heating component 40 corresponding to the time setting signal is 2 hours, the green LED lamp is controlled to be on, so that the user confirms that the set operating duration of the heating component 40 is 2 hours; when the working time of the heating assembly 40 corresponding to the time setting signal is 5 hours, the blue LED lamp is controlled to be on, so that a user confirms that the set working time of the heating assembly 40 is 5 hours; when the working time of the heating assembly 40 corresponding to the time setting signal is 8 hours, the red LED lamp is controlled to be on, so that a user confirms that the set working time of the heating assembly 40 is 8 hours, the timing time of the current warm air blower is indicated, and the user can easily know the working time of the warm air blower, so that the warm air blower is extremely simple and convenient.

Referring to fig. 2, in one embodiment, the warm-air drier includes:

a gear adjusting circuit 71, wherein an output end of the gear adjusting circuit 71 is connected with an input end of the main control circuit 30, and the gear adjusting circuit 71 is used for setting heating power of the heating assembly 40 and outputting a gear adjusting signal;

the main control circuit 30 is further configured to control the heating assembly 40 to operate according to the gear adjusting signal, so as to control the heating assembly 40 to provide corresponding heating.

In the present embodiment, the gear adjusting circuit 71 may be implemented by using any gear adjusting circuit 71 that can set the heating power of the heating module 40, for example, a touch key or a mechanical key. It can be appreciated that when the fan heater is in operation, a user can set a gear corresponding to the required heating through the gear adjusting circuit 71 so as to enable the room temperature to reach the required temperature; specifically, the gear adjusting circuit 71 may be provided with three gears, namely, a first gear, a second gear and a third gear, wherein when the first gear is pressed, the heating component 40 correspondingly outputs 30% of the heating air, when the second gear is pressed, the heating component 40 correspondingly outputs 60% of the heating air, and when the third gear is pressed, the heating component 40 correspondingly outputs 100% of the heating air, that is, when the user adjusts the gear to the second gear, the main control circuit 30 controls the heating component 40 to output 60% of the heating air when receiving the gear adjusting signal, so as to quickly adjust the required room temperature.

Referring to fig. 2, in one embodiment, the warm-air drier includes:

a mode conversion circuit 72, wherein an output end of the mode conversion circuit 72 is connected with an input end of the main control circuit 30, and the mode conversion circuit 72 is used for outputting a mode conversion signal when triggered;

the main control circuit 30 is further configured to control the heating assembly 40 to operate according to the trigger signal when the voltage value corresponding to the mode conversion signal is less than a preset voltage value, and control the heating assembly 40 to operate according to the human body detection signal when the voltage value corresponding to the mode conversion signal is not less than the preset voltage value.

In this embodiment, the mode conversion circuit 72 may be implemented by any mode conversion circuit 72 that can implement mode conversion, such as a touch key or a mechanical key. It can be understood that when the mode switch circuit 72 is triggered by a user, the mode switch signal is output, the main control circuit 30 selectively controls the heating assembly 40 to operate according to the trigger signal or the human body detection signal according to the mode switch signal, specifically, when the main control circuit 30 detects that the voltage value corresponding to the mode switch signal is lower than the preset voltage value, the heating assembly 40 is controlled to operate according to the trigger signal, that is, the heating assembly 40 is controlled to operate by means of a key; when the main control circuit 30 detects that the voltage value corresponding to the mode conversion signal is higher than or equal to the preset voltage value, the heating assembly 40 is controlled to work according to the human body detection signal, that is, the heating assembly 40 is controlled to work in a human body induction mode, so that the key control or the switching of the human body induction control mode is realized.

Referring to fig. 2 and 3, in one embodiment, the heating assembly 40 includes:

the controlled end of the heating circuit 41 is connected with the main control circuit 30, and the heating circuit 41 is used for heating air during operation;

the air blowing component 42, wherein a controlled end of the air blowing component 42 is connected with the main control circuit 30, and the air blowing component 42 is used for blowing out heated air in operation;

the main control circuit 30 is configured to output a heating control signal and a blowing control signal according to the trigger signal and the human body detection signal, and control the heating circuit 41 and the blowing component 42 to work respectively.

In the present embodiment, the heating circuit 41 may be implemented by an arbitrary heatable heating circuit 41, such as a heating rod or a heating sheet; the air blowing component 42 may be any air blowing component 42 that can blow out heated air, such as a fan, where in the embodiment, the air blowing component 42 may be a fan and the first switch circuit 421, and the fan is used to rotate when working; the first switch circuit 421, the input end of the fan is connected with the power supply, the output end of the fan is connected with the input end of the first switch circuit 421, the output end of the first switch circuit 421 is grounded, the controlled end of the first switch circuit 421 is connected with the main control circuit 30, the first switch circuit 421 is used for being conducted when receiving the blowing control signal to control the fan to work, specifically, when the main control circuit 30 outputs the high-level blowing control signal to the first switch circuit 421, the first switch circuit 421 is conducted to enable the fan to work to rotate; when the main control circuit 30 outputs a low-level blowing control signal to the first switch circuit 421, the first switch circuit 421 is turned off, so that the fan stops operating. The first switch circuit 421 includes a first resistor R1, a second resistor R2, and a first switch tube Q1, and the specific connection relationship refers to fig. 3, where m+ and m+ are connected to the positive pole and the negative pole of the fan, respectively. The first resistor R1 is used for limiting current, the second resistor R2 is used for pulling down, the first switching tube Q1 may be a triode or a MOS tube, and the main control circuit 30 controls the first switching tube Q1 to be turned on or off by outputting a high-low level signal, that is, controls the first switching circuit 421 to be turned on or off, so that the fan works or stops working. It can be understood that the main control circuit 30 controls the heating circuit 41 and the blowing component 42 to work according to the trigger signal and the human body detection signal, specifically, when the main control circuit 30 detects that the heating component 40 needs to be controlled to work according to the trigger signal and the human body detection signal, the main control circuit 30 outputs a heating control signal to control the heating circuit 41 to work so as to generate heat, and heat air; and the main control circuit 30 outputs a blowing control signal to control the blowing assembly 42 to operate, thereby accelerating the flow of air, i.e., blowing out heated air, and thus realizing the supply of heating air.

The foregoing description is only of the optional embodiments of the present utility model, and is not intended to limit the scope of the utility model, and all the equivalent structural changes made by the description of the present utility model and the accompanying drawings or the direct/indirect application in other related technical fields are included in the scope of the utility model.

Claims

1. A fan heater, characterized in that the fan heater comprises:

the heating assembly is used for providing heating;

2. A fan heater as claimed in claim 1, wherein said body sensing sensor comprises:

3. A fan heater as claimed in claim 1, wherein said fan heater comprises:

4. A fan heater as claimed in claim 3, wherein said tip detection circuit comprises a plurality of sets of correlation switches, each set of correlation switches comprising a photo-emitter and a photo-receiver, said tip detection circuit being arranged to output a respective said tip detection signal in dependence on an output signal of the photo-receiver in said each set of correlation switches.

5. A fan heater as claimed in claim 3, wherein said fan heater further comprises:

6. A fan heater as claimed in claim 1, wherein said fan heater comprises:

7. The fan heater of claim 6, further comprising:

8. A fan heater as claimed in claim 1, wherein said fan heater comprises:

9. A fan heater as claimed in claim 1, wherein said fan heater comprises:

10. A fan heater as claimed in claim 1, wherein said heating assembly comprises: