Patent Publication Number: US-2003225480-A1

Title: Electric fan operable in a breeze-simulating mode

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The invention relates to an electric fan, more particularly to an electric fan that is operable in a breeze-simulating mode.  
       [0003] 2. Description of the Related Art  
       [0004] A conventional electric fan, such as a ceiling fan, is usually provided with a manual control unit to control the fan speed. However, because the manual control unit is normally disposed at a fixed location that may be inaccessible to some people, activation of the electric fan and switching of the fan speed may be inconvenient to conduct. It has been proposed heretofore to provide a remote-controlled electric fan to overcome the aforesaid drawbacks that are associated with operation of the manual control unit. It is noted that the known remote-controlled electric fan only permits adjustment of the fan speed to any one of four preset speed settings selected by the user. As a result, after a particular speed setting has been selected, the fan motor will operate continuously at the selected fan speed. During warm nights, a high fan speed might be selected for producing a cooling effect that can help the user to fall asleep easily. However, continued high fan speed operation can eventually result in user discomfort in view of lower ambient temperatures at dawn.  
       SUMMARY OF THE INVENTION  
       [0005] Therefore, the main object of the present invention is to provide an electric fan that is operable in a breeze-simulating mode so as to overcome the aforesaid drawbacks of the prior art.  
       [0006] According to the present invention, an electric fan comprises a fan unit, and a processor unit coupled to the fan unit and operable so as to control the fan unit to rotate at a selected one of preset speed settings. The processor unit is operable in a breeze-simulating mode, wherein the processor unit controls the fan unit to operate in accordance with a programmed sequence of the preset speed settings and corresponding time durations, thereby enabling the fan unit to generate a simulated breeze output. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0007] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:  
     [0008]FIG. 1 is a schematic circuit block diagram illustrating a fan device of the preferred embodiment of an electric fan according to the present invention;  
     [0009]FIG. 2 is a schematic electrical circuit diagram of the fan device of FIG. 1;  
     [0010]FIG. 3 is a schematic electrical circuit diagram of a fan unit of the fan device of FIG. 1;  
     [0011]FIG. 4 is a schematic electrical circuit diagram of another fan device, which is a modification of that shown in FIG. 1;  
     [0012]FIG. 5 is a schematic electrical circuit diagram of a fan unit of the fan device of FIG. 4; and  
     [0013]FIG. 6 is a schematic view showing a remote controller of the preferred embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0014] Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure.  
     [0015] Referring to FIGS.  1  to  6 , the electric fan of the present invention is shown to be embodied in a ceiling fan that includes a remote controller  10  and a fan device  20 . The fan device  20  includes a receiver  21 , a processor unit  22 , a fan unit  23 , a lamp unit  24 , a temperature detector  25 , a wave detector  261 , a direct current (DC) power supplying circuit  262 , and a memory unit  27 .  
     [0016] The receiver  21 , which is coupled to the processor unit  22 , receives remote-control signals transmitted by the remote controller  10 , and provides the same to the processor unit  22 . The processor unit  22  is coupled to the fan unit  23 , the lamp unit  24 , the temperature detector  25 , the wave detector  261 , the DC power supplying circuit  262 , and the memory unit  27 . Each of the fan unit  23 , the lamp unit  24 , the wave detector  261  and the DC power supplying circuit  262  is connected to an alternating current (AC) power source  26 . DC power is supplied to the various electronic components of the fan device by the DC power supplying circuit  262 . The lamp unit  24  includes a plurality of light bulbs and a night lamp. The temperature detector  25  includes a thermistor, and generates a temperature output that varies in accordance with the ambient temperature. In this embodiment, the memory unit  27  is a programmable memory device, such as an electrically erasable programmable read only memory (EEPROM). In response to the remote-control signals received thereby, the processor unit  22  controls fan speed and direction settings of the fan unit  23  and brightness output of the lamp unit  24  in an appropriate manner, which will be described in greater detail in the succeeding paragraphs.  
     [0017] As best shown in FIG. 6, the remote controller  10  includes a fan power switch  11 , a lamp power switch  12 , a fan speed adjustment switch set  13 , a lamp brightness adjustment switch set  14 , a lamp number control switch set  15 , a rotary direction control switch  16 , a fan speed setting select switch set  17 , a breeze-simulating mode control switch  18 , and an automatic reversing mode control switch  19 .  
     [0018] When the fan power switch  11  is operated, the remote controller  10  will generate a remote-control signal for controlling activation and deactivation of the fan unit  23  of the fan device  20  by the processor unit  22  in a conventional manner. Preferably, the fan settings prior to deactivation of the fan unit  23  are recorded by the processor unit  22  in the memory unit  27  so that the processor unit  22  can automatically select the same during subsequent activation of the fan unit  23 .  
     [0019] When the lamp power switch  12  is operated, the remote controller  10  will generate a remote-control signal for controlling activation and deactivation of the lamp unit  24  of the fan device  20  by the processor unit  22  in a conventional manner. Preferably, the lamp settings prior to deactivation of the lamp unit  24  are recorded by the processor unit  22  in the memory unit  27  so that the processor unit  22  can automatically select the same during subsequent activation of the lamp unit  24 . In addition, a 30-second delay is introduced automatically from the time the lamp power switch  12  is operated to the actual deactivation of the lamp unit  24 .  
     [0020] The fan speed adjustment switch set  13  includes a first switch that is operated to enable the remote controller  10  to generate a remote-control signal for increasing the speed of the fan unit  23  through the control of the processor unit  22 , and a second switch that is operated to enable the remote controller  10  to generate a remote-control signal for decreasing the speed of the fan unit  23  through the control of the processor unit  22 . In the preferred embodiment, there are eight preset speed settings for the fan unit  23 , and the switch set  13  is operated to choose any one of the preset speed settings. Preferably, a sound is generated when the highest or lowest preset speed setting is selected to alert the user.  
     [0021] As shown in FIGS. 2 and 3, in one embodiment of the fan device  20 , the fan unit  23  has a speed changing unit  231  which includes a plurality of transistors  232  controlled by the processor unit  22 , and a plurality of thyristors  233  connected to the transistors  232  and a fan motor  30 . The processor unit  22  controls the conduction of the thyristors  233  via the transistors  232  to control in turn the speed of the fan motor  30 .  
     [0022] Referring to FIGS. 4 and 5, in another embodiment of the fan device  20 , the fan unit  23  has a speed changing unit  231  which includes an optically coupled transistor  234  controlled by the processor unit  22 , and a field effect transistor  235  connected to the optically coupled transistor  234  and a fan motor  30 . The processor unit  22  controls the conduction time of the field effect transistor  235  via the optically coupled transistor  234  to control in turn the speed of the fan motor  30 .  
     [0023] The lamp brightness adjustment switch set  14  includes a first switch that is operated to enable the remote controller  10  to generate a remote-control signal for increasing the brightness of the light output from the lamp unit  24  through the control of the processor unit  22 , and a second switch that is operated to enable the remote controller  10  to generate a remote-control signal for dimming the brightness of the light output from the lamp unit  24  through the control of the processor unit  22 . In the preferred embodiment, there are twenty preset brightness settings for the lamp unit  24 , and the switch set  14  is operated to choose any one of the preset brightness settings.  
     [0024] The lamp number control switch set  15  is operated to enable the remote controller  10  to generate a remote-control signal for controlling the number of light bulbs of the lamp unit  24  that are to be activated by the processor unit  22 . For example, operation of a second switch of the switch set  15  indicates that two light bulbs of the lamp unit  24  are to be activated by the processor unit  22 . Operation of a fifth switch of the switch set  15  indicates that five light bulbs of the lamp unit  24  are to be activated by the processor unit  22 . Operation of a night switch of the switch set  15  indicates that the night lamp of the lamp unit  24  is to be activated by the processor unit  22 . Operation of an OFF switch of the switch set  15  indicates that the lamp unit  24  is to be deactivated by the processor unit  22 .  
     [0025] The rotary direction control switch  16  is operated to enable the remote controller  10  to generate a remote-control signal for selecting the direction of rotation of the fan unit  23  under the control of the processor unit  22 . The default direction setting of the fan unit  23  is the positive direction. When the control switch  16  is operated once, the fan motor  30  of the fan unit  23  is controlled by the processor unit  22  via a relay  28  to rotate in the negative direction. When the control switch  16  is operated for the second time, the fan motor  30  of the fan unit  23  is controlled by the processor unit  22  via the relay  28  to once again rotate in the positive direction.  
     [0026] The fan speed setting select switch set  17  is operated to enable the remote controller  10  to generate a remote-control signal for selecting the activation time of the fan unit  23 . For example, operation of a first switch (corresponding to a one-hour setting) of the switch set  17  indicates that the fan unit  23  is to be activated by the processor unit  22  for one hour. Operation of the first switch, followed by operation of a third switch (corresponding to a four-hour setting) of the switch set  17 , indicates that the fan unit  23  is to be activated by the processor unit  22  for five hours. Operation of a fourth switch (corresponding to an eight-hour setting), followed by operation of a fifth switch (corresponding to a twelve-hour setting) of the switch set  17 , indicates that the fan unit  23  is to be activated by the processor unit  22  for twenty hours. The switch set  17  further includes a RESET switch which is operated when it is desired to change the activation time setting of the fan unit  23 .  
     [0027] The breeze-simulating mode control switch  18  is operated to enable the remote controller  10  to generate a remote-control signal to be received by the processor unit  22  via the receiver  21  for enabling the processor unit  22  to operate in a breeze-simulating mode. When operated in the breeze-simulating mode, the processor unit  22  will control the speed changing unit  231  of the fan unit  23  to operate the fan unit  23  in accordance with a programmed sequence of the preset speed settings and corresponding time durations as stored in the memory unit  27 , thereby enabling the fan unit  23  to generate a simulated breeze output. In the preferred embodiment, there are three programmed sequences of the preset speed settings and corresponding time durations stored in the memory unit  27 . The programmed sequences correspond in turn to a mild simulated breeze output, a moderate simulated breeze output, and a strong simulated breeze output. To obtain the mild simulated breeze output, the lower speed settings have longer time durations. To obtain the moderate simulated breeze output, the medium speed settings have longer time durations. Finally, to obtain the strong simulated breeze output, the higher speed settings have longer time durations. The programmed sequences can be selected by the processor unit  22  by operating the fan speed adjustment switch set  13  when the processor unit  22  is operated in the breeze-simulating mode. Preferably, a sound output is generated whenever the switch set  13  is operated to select any of the programmed sequences.  
     [0028] The automatic reversing mode control switch  19  is operated to enable the remote controller  10  to generate a remote-control signal to be received by the processor unit  22  via the receiver  21  for enabling the processor unit  22  to operate in an automatic reversing mode. The automatic reversing mode is selected when the ambient temperature is within a predetermined temperature range, such as 5 to 18° C., where air circulation is normally uneven. In this mode, operation of the automatic reversing mode control switch  19  enables the processor unit  22  to record the temperature output of the temperature detector  25  as a preset reversing reference temperature in the memory unit  27 . Thereafter, when the processor unit  22  determines that the current ambient temperature has dropped below the preset reversing reference temperature with reference to the temperature output of the temperature detector  25 , the processor unit  22  automatically controls the fan motor  30  of the fan unit  23  to rotate in the negative direction via the relay  28 . The effect thereof is to improve circulation of warm air in the vicinity of the fan unit  23  so as to result in a slight increase in the detected ambient temperature. In the automatic reversing mode, the processor unit  22  further controls the fan unit  23  to resume rotation in the positive direction only upon determining that the current ambient temperature has exceeded the preset reversing reference temperature by a preset value, such as when the user activates a heating appliance.  
     [0029] In the preferred embodiment, whenever the processor unit  22  receives a remote-control signal from the remote controller  10  via the receiver unit  21 , the processor unit  22  will activate a buzzer  221  so as to indicate the receipt of the remote-control signal to the user.  
     [0030] While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.