Abstract:
A remote-controlled ventilating system and method. The method can include remotely controlling a ventilation system in a recreational vehicle having a wall and a ceiling. The method can include coupling a fan and a dome to at least one of the wall and the ceiling of the recreational vehicle. The fan and the dome can be connected to a controller. The method can also include transmitting a signal from a remote control to the controller in order to operate the fan and the dome.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Recreational vehicles (RVs) generally include some type of ventilation system. While some RVs have full air-conditioning systems, many use a ventilation system including only a fan and a vent. Conventional fan and vent systems require the occupant to manually operate the fan. Several manual adjustments of the fan may be required until the desired cooling or ventilation effect is achieved.  
       SUMMARY OF THE INVENTION  
       [0002]     Some embodiments of the invention provide a remotely-controlled ventilation system for use in a recreational vehicle having a ceiling and a wall. The system can include a chassis mounted to at least one of the ceiling and the wall of the recreational vehicle, a fan coupled to the chassis, and a dome coupled to the chassis. The system can also include a remote control configured to operate the fan and the dome.  
         [0003]     In some embodiments, the invention provides a method of remotely controlling a ventilation system for use in a recreational vehicle having a wall and a ceiling. The method can include coupling a fan and a dome to at least one of the wall and the ceiling of the recreational vehicle. The fan and the dome can be connected to a controller. The method can also include transmitting a signal from a remote control to the controller in order to operate the fan and the dome.  
         [0004]     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]      FIG. 1  is an exploded perspective view of a remote-controlled ventilation system according to one embodiment of the invention.  
         [0006]      FIG. 2  is an exploded perspective view of a lift arm assembly for use with the remote-controlled ventilation system of  FIG. 1 .  
         [0007]      FIG. 3  is a schematic illustration of a control system for use with the remote controlled ventilation system of  FIG. 1 .  
         [0008]      FIG. 4  is a schematic illustration of a voltage source for use with the control system of  FIG. 3 .  
         [0009]      FIG. 5  is a schematic illustration of an antenna module for use with the control system of  FIG. 3 .  
         [0010]      FIG. 6  is a schematic illustration of a rain sensor module for use with the control system of  FIG. 3 .  
         [0011]      FIG. 7  is a schematic illustration of a temperature sensor module for use with the control system of  FIG. 3 .  
         [0012]      FIG. 8  is a schematic illustration of a dome control module for use with the control system of  FIG. 3 .  
         [0013]      FIG. 9  is a schematic illustration of a fan control module for use with the control system of  FIG. 3 .  
         [0014]      FIG. 10  is a schematic illustration of a current monitoring module for use with the control system of  FIG. 3 .  
         [0015]      FIG. 11  is a schematic illustration of a fan microcontroller for use with the control system of  FIG. 3 .  
         [0016]      FIGS. 12A, 12B , and  12 C are a flow chart illustrating one embodiment of the operation of the system of  FIG. 1 .  
         [0017]      FIG. 13  is a schematic illustration of a remote control for use with the remote-controlled ventilation system of  FIG. 1 .  
         [0018]      FIG. 14  is a schematic illustration of a voltage source for use with the remote-control of  FIG. 13 .  
         [0019]      FIG. 15  is a schematic illustration of an antenna module for use with the remote-control of  FIG. 13 .  
         [0020]      FIG. 16  is a schematic illustration of an indicator module for use with the remote-control of  FIG. 13 .  
         [0021]      FIG. 17  is a schematic illustration of a selector module for use with the remote-control of  FIG. 13 .  
         [0022]      FIG. 18  is a schematic illustration of a microcontroller for use with the remote-control of  FIG. 13 .  
         [0023]      FIGS. 19A and 19B  are a flow chart illustrating one embodiment of the operation of the remote-control of  FIG. 13 .  
         [0024]      FIG. 20  is an exemplary perspective view of a snap-in screen, a panel, and a microswitch of a remote-controlled ventilation system according to one embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.  
         [0026]     In addition, embodiments of the invention include both hardware and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic based aspects of the invention may be implemented in software. As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be utilized to implement the invention. Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the invention and that other alternative mechanical configurations are possible.  
         [0027]      FIG. 1  illustrates a remote-controlled ventilation system  100  according to one embodiment of the invention. The remote-controlled ventilation system  100  can be coupled to the ceiling (and/or roof) or a wall of a RV. The remote-controlled ventilation system  100  is also suitable for other installations where ventilation would be desired, such as houses, boats, sheds, garages, etc.  
         [0028]     The remote-controlled ventilation system  100  can include a chassis  105  configured to mount in an aperture (not shown). The chassis  105  is illustrated as being square in shape but can be other suitable shapes. The chassis  105  can have an outer edge  110 , an inner edge  115 , and a flange  120 . The flange  120  can be positioned circumferentially around a center portion of the chassis  105 . The outer edge  110  can be inserted through the aperture until the flange  120  contacts the edges of the aperture. The flange  120  can be fastened to the aperture by screws or other suitable fasteners, such as rivets, bolts, glue, and double-sided tape. A gasket  125  can fit over the outer edge  110  and mount to the outside of the aperture opposite the flange  120 . A water-tight seal can be formed between the gasket  125  and the chassis  105  and between the gasket  125  and the outside surface of the aperture. A fan motor  130  having an armature  135  can mount to the chassis  105 . The armature  135  can extend through the chassis  105  and can be coupled to a fan  140 .  
         [0029]     A hinge  145  can be coupled to one side of the outer edge  110  of the chassis  105  that extends beyond the aperture. In one embodiment, screws can be used to fasten a first end  150  of the hinge  145  to the chassis  105 . A second end  155  of the hinge  145  can attach to a dome or lid  160 , which can have a generally curved, convex shape, a flat shape, or other suitable shapes. The outer dimensions of the dome  160  can be approximately equal to the outer dimensions of the chassis  105 . The dome  160  can swivel on the hinge  145  to open and/or close access to the aperture. When fully closed, the dome  160  can form a water-tight seal with the gasket  125 , preventing any water from entering the RV through the aperture.  
         [0030]      FIG. 2  illustrates an embodiment of a lift arm assembly  200 . A lift arm  205  having a geared end  206  and a lifting end  207  can be coupled to a worm gear  210  which can be coupled to a worm gear shaft  215 . The end of the worm gear shaft  215  opposite the worm gear  210  can include a gear  220 . The gear end  206  of the lift arm  205  and the worm gear  210  of the worm gear shaft  215  can mount in a housing  222  having a first side  225  and a second side  230 .  
         [0031]     Turning the worm gear shaft  210  in one direction can raise the lifting end  207  of the lift arm  205 , and turning the worm gear shaft  210  in the opposite direction can lower the lifting end  207  of the liftarm  205 . The housing  222  can be mounted to the chassis  105 . The end of the lift arm  205  can be coupled to a bracket  235 , which can be mounted on the dome  160 . As a result, turning the worm gear shaft  215  can raise or lower the dome  160 .  
         [0032]     As shown in  FIG. 1 , a dome motor  240 , with an attached gear head assembly  245 , can be coupled to a panel  250 , which can be coupled to the chassis  105 . When assembled, the gear of the gear head assembly  245  can engage with the gear end  220  of worm gear shaft  215 . The dome motor  240  can open and close the dome  160 . A hand crank  255  can be coupled to the gear head assembly  245  and can have a gear that can allow manual operation of the dome  160 .  
         [0033]     A master controller  260  can be coupled to the chassis  105 . The master controller  260  can be electrically connected to the fan motor  130  and can control the speed and direction of the fan  140 . The master controller  260  can also be electrically connected to the dome motor  240  and can control its speed and direction as well. The master controller  260  can be further coupled to a rain sensor  265  (e.g., model 12-117-01 manufactured by Yantat). A temperature sensor and an antenna can be mounted on or connected to the master controller  260 . The antenna can enable the master controller  260  to receive data from a remote control  270  via a radio frequency (“RF”) signal. Alternative communication methods can be used by the master controller  260  and the remote control  270 , such as infrared (“IR”) or other suitable types of communication.  
         [0034]     As shown in  FIGS. 1 and 20 , a screen assembly  275  can snap into place with the panel  250 . An external flange  280  can be coupled to the chassis  105 .  
         [0035]     In some embodiments, a microswitch  980  having a lever  990 , a first contact  992 , and a second contact  993  can be mounted on the panel  250 . The lever  990  can have a first position in which there can be an electrical open between the first contact  992  and the second contact  993 . The lever  990  can have a second position in which there can be an electrical coupling between the first contact  992  and the second contact  993 . The screen assembly  275  can have a plurality mounting clips  995  which can pass through openings in the panel  250  and can hold the screen assembly  275  in place. An opening in the panel  250  can be positioned such that when the screen assembly  275  is mounted to the panel  250 , a mounting clip  995  can engage the lever  990  and cen move the lever  990  from the first position to the second position and can electrically couple the first contact  992  to the second contact  993 .  
         [0036]      FIG. 3  is a schematic illustration of the master controller  260  according to one embodiment of the invention. The master controller  260  can include a fan microcontroller  305 , a fan battery  310 , a fan voltage source  315 , a fan antenna module  320 , a rain sensor module  325 , a temperature sensor module  330 , a dome controller module  335 , a fan controller module  340 , and a current monitor module  345 .  
         [0037]     In one embodiment, the fan battery  310  can be a standard 12-Volt automotive battery. The fan battery  310  can be connected to the voltage source  315  via a connection  350 . In some embodiments, the +12-Volt contact of the fan battery  310  can connect to the first contact  992  of the microswitch  980 . The second contact  993  of the microswitch  980  can connect to an overcurrent protector F 1 . When the screen assembly  275  is properly mounted, the lever  990  can be forced into its second position and the +12-Volt contact of the fan battery  310  can be electrically coupled to the overcurrent protector F 1 . When the screen assembly  275  is not mounted, or is not properly mounted, to the panel  250 , the lever  990  can be in its first position and the fan battery  310  can be electrically isolated from the overcurrent protector F 1 . Therefore, in potentially unsafe circumstances, where the screen assembly  275  is not mounted correctly, the master controller  260  can be disconnected from the battery  310  and the remote controlled ventilation system  100  can be inoperable.  
         [0038]      FIG. 4  illustrates an embodiment of the fan voltage source  315 . In some embodiments, the +12-Volt contact of the fan battery  310  can connect to the overcurrent protector F 1 . In one embodiment, F 1  can be resettable and can have a trip current of 10 Amps (e.g., part number MF-R500-ND manufactured by Bourns). A transient/surge absorber MOV 1  can be coupled to both the positive and negative leads of the fan battery  310 . The transient/surge absorber MOV 1  can protect the circuits of the master controller  260  should a large current surge (e.g., lightning) occur on the fan battery  310  leads. A filter circuit including two capacitors and a diode, C 1 , C 2 , and D 4 , can filter the 12-Volt signal for the fan battery  310 . An unfiltered +12-Volt signal can be used to drive the fan motor  130  via a connection  355  and the dome motor  240  via a connection  360 . C 1  and C 2 , in some embodiments, have a capacitance of 47 uF and a maximum working voltage of 25 Vdc. Diode D 4 , in some embodiments, has a maximum working voltage of 50 Vdc.  
         [0039]     As shown in  FIGS. 3 and 4 , the fan voltage source  315  can convert the voltage from the fan battery  310  (i.e., +Vb) to a suitable voltage +Vs (e.g., +5 volts) for use by the fan microcontroller  305  via a connection  362 , the antenna module  320  via a connection  364 , the rain sensor module  325  via a connection  366 , the temperature sensor module  330  via a connection  368 , and the current monitor module  345  via a connection  370 . The fan voltage source  315  can include an integrated circuit (e.g., model UA  78  LO  5  CD manufactured by Texas Instruments, among others) for converting the fan battery  310  voltage to +V s .  
         [0040]     As shown in  FIGS. 3 and 5 , the fan antenna module  320  can be coupled to the fan voltage source  315  via a connection  364 , to the fan microcontroller  305  via a connection  372 , and to a fan antenna  373 . In some embodiments, the fan antenna  373  can be implemented as a trace on a printed circuit board. In some embodiments, the fan antenna  373  can be positioned inside the chassis  105 . The antenna  373  can be any antenna capable of receiving the type of signal transmitted by the remote control  270 . The fan antenna module  320  can convert RF signals received by the fan antenna  373  into digital data signals and can supply them to the fan microcontroller  305  via a connection  372 . The fan antenna module  320  can include an integrated circuit  375  (e.g., model RCR-433-RP manufactured by Radiotronix, among others). The fan antenna module  320  can include filtering capacitors C 9  and C 10  (e.g., having a capacitance of 0.1uF and 4.7 uF, respectively) for the +5-Volt from the fan voltage source  315 .  
         [0041]      FIG. 6  illustrates an embodiment of a rain sensor module  325 . The rain sensor module  325  can include the rain sensor  265  (as shown in  FIG. 1 ) mounted remotely from the master controller  260 . As shown in  FIG. 6 , a pull-up resistor R 3  (e.g., 51.0 k Ω) can be connected to one lead  327  of the rain sensor  265 . The other lead  329  of the rain sensor  265  can be connected to ground. A capacitor C 7  (e.g., 0.1 uF, 25 V) can be connected between both leads  327 ,  329  of the rain sensor  265  to filter the signal. The rain sensor  265  and R 3  form a voltage divider. In the absence of rain on the rain sensor  265 , the impedance of the rain sensor can be high, which can result in a low voltage across the rain sensor  265 . In the presence of water on the rain sensor  265 , the impedance of the rain sensor  265  can be low, which can result in a high voltage. The rain sensor signal can be provided to the microcontroller  305  via a connection  374 .  
         [0042]      FIG. 7  illustrates one embodiment of the temperature sensor circuit  330 . A temperature sensor  377  (e.g., part number LM35DZ manufactured by National Semiconductor) can produce an output equal to 10 mV per degree Celcius (i.e., 0.2V at 20° C.). The output of the temperature sensor  377  can be amplified by an amplifier circuit including an op-amp U2B (e.g., part number LM258D manufactured by Texas Instruments, among others), resistors R 4  (e.g., 1.0 kΩ), R 5  (e.g., 10.0 kΩ), and R 6  (e.g., 1.0 kΩ), and capacitor C 8  (e.g., 0.1 uF, maximum working voltage of 25Vdc). The amplified signal corresponding to the temperature detected by the temperature sensor  377  can be provided to the microcontroller  305  via a connection  376 .  
         [0043]      FIG. 8  is a schematic illustration of the dome control module  335  according to one embodiment. The dome control module  335  can perform two functions: driving the dome motor  240 , and determining the direction of operation of the dome motor  240 , and therefore, the dome  160 . Driving the dome motor  240  can be accomplished by providing the +12-Volt unfiltered signal to either terminal W 5  or terminal W 6  and providing a ground potential to the other terminal. A double pole double throw (“DPDT”) relay K 1  (e.g., part number RTE24012F manufactured by Tyco among others) can be configured to control the direction the dome motor  240 .  
         [0044]     The +12-Volt unfiltered signal can be provided to pins  8  and  11  of relay K 1 . A mosfet Q 1  (e.g., part number RFD3055LESM manufactured by Fairchild, among others) can be driven, through resistor R 8  (e.g., 1.0 kΩ), by the microcontroller  305  via a connection  378 . When the microcontroller  305  provides a low signal via the connection  378  to mosfet Q 1 , mosfet Q 1  can maintain an open circuit condition and the +12-Volt unfiltered signal can be provided to pins  6  and  9  of relay K 1  through a diode D 2  (e.g., part number 1N4001 manufactured by Microcomercial, among others). The +12-Volt unfiltered signal can be applied to the four input pins  6 ,  8 ,  9 , and  11  of relay K 1  and to output pins  4  and  13  of relay K 1 . This can apply the +12-Volt unfiltered signal to both terminals W 5  and W 6  of the dome motor  240  to turn the dome motor  240  off.  
         [0045]     To power the dome motor  240 , the fan microcontroller  305  can provide a high signal to the mosfet Q 1 . The mosfet Q 1  can close its circuit to provide a near ground potential (to pins  6  and  9  of relay K 1 ), after the voltage drop of a resistor R 20  (0.47 Ω). Depending on the state of a dome direction signal  380  on the connection from the microcontroller  305 , the ground potential can be passed to the terminal W 5  or W 6  of the dome motor  240  and the +12-Volt unfiltered signal can be passed to the other terminal, resulting in the dome motor  240  being turned on. Diode D 2  can prevent the +12-Volt unfiltered from being shorted to ground in this state.  
         [0046]     The direction of the dome motor  240  can be controlled by the fan microcontroller  305  via a connection  380 . The fan microcontroller  305  can provide a signal to a mosfet Q 3  (e.g., part number 2N7002 manufactured by Fairchild, among others) through resistor R 9  (1.0 kΩ). When the signal is low, the mosfet Q 3  can maintain an open circuit condition. In this state, the +12V signal can be provided to both the inputs  1  and  16  of relay K 1 . The coil in relay K 1  can be deenergized, resulting in input pin  11  being connected to output pin  13  and input pin  6  being connected to output pin  4 . When the dome motor  240  is turned on by the fan microcontroller  305 , the dome motor  240  can run in its forward direction and raise the dome  160 . When the signal provided by the microcontroller  305  via the connection  380  to the mosfet Q 3  is high, the mosfet Q 3  can close its circuit and provide a ground potential to pin  1  of relay K 1 . This can cause the coil to energize and pull the contacts of relay K 1 , such that input pin  9  can be connected to output pin  13  and input pin  8  can be connected to output pin  4 . This can result in reverse operation (lowering) of the dome motor  240  when the dome motor  240  is turned on by the fan microcontroller  305 .  
         [0047]      FIG. 9  is a schematic illustration of an embodiment of the fan control module  340 . The fan control module  340  can perform two functions: driving the fan motor  130 , and determining the direction of operation of the fan motor  130 , and therefore, the fan. Driving the fan motor  130  can be accomplished by providing the +12-Volt unfiltered signal to either terminal W 4  or terminal W 3  and providing a ground potential to the other terminal. A double pole double throw (“DPDT”) relay K 2  (e.g., part number RTE24012F manufactured by Tyco, among others) can control which direction the fan motor  130  will operate.  
         [0048]     As shown in  FIG. 9 , the +12-Volt unfiltered signal can be provided to pins  8  and  11  of relay K 2 . A mosfet Q 2  (e.g., part number HRFZ44N manufactured by Fairchild, among others) can be driven, through resistor R 10  (22 Ω), by the fan microcontroller  305  via a connection  382 . When the fan microcontroller  305  provides a low signal to the mosfet Q 2 , the mosfet Q 2  can maintain an open circuit condition and the +12-Volt unfiltered signal can be provided to pins  6  and  9  of relay K 2  through a diode D 1  (e.g., part number 1N4001 manufactured by Microcomercial, among others). The +12-Volt unfiltered signal can be applied to the four input pins  6 ,  8 ,  9 , and  11  of relay K 2 , and to the output pins  4  and  13  of relay K 2 . This can apply the +12-Volt unfiltered signal to both terminals W 4  and W 3  of the fan motor  130  to turn the fan motor  130  off.  
         [0049]     To power the fan motor  130 , the fan microcontroller  305  can provide a high signal to mosfet Q 2 . The mosfet Q 2  can close its circuit to provide a near ground potential (to pins  6  and  9  of relay K 2 ), after the voltage drop of a resistor R 19  (0.01 Ω). Depending on the state of a fan direction signal  334  from the fan microcontroller  305 , the ground potential can be passed to terminal W 4  or W 3  of the fan motor  130  and the +12-Volt unfiltered signal can be passed to the other terminal, resulting in the fan motor  130  being turned on. Diode D 1  can prevent the +12-Volt unfiltered signal from being shorted to ground in this state. The speed of the fan motor  130  can be controlled by pulse width modulation (“PWM”) of the signal provided to the mosfet Q 2 . In some embodiments, a duty cycle of the signal provided to the mosfet Q 2  can range from 0% (off) to 100% (full speed) in about eight substantially equal increments. In one embodiment, a 50% duty cycle can be equal to 50% fan motor speed.  
         [0050]     The fan motor  130  direction can be controlled by the fan microcontroller  305  via a connection  384 . The fan microcontroller  305  can provide a signal to a mosfet Q 4  (e.g., part number 2N7002 manufactured by Fairchild, among others) through resistor R 17  (0.01 kΩ). When the signal is low, the mosfet Q 4  can maintain an open circuit condition. In this state, the +12-Volt signal can be provided to both inputs  1  and  16  of relay K 2 . The coil in relay K 2  can be deenergized, which can result in input pin  11  being connected to output pin  13  and input pin  6  being connected to output pin  4 . When the fan motor  130  is turned on by the fan microcontroller  305 , the fan motor  130  can run in its forward (intake) direction. When the signal provided by the fan microcontroller  305  via the connection  384  to the mosfet Q 4  is high, the mosfet Q 4  can close its circuit and can provide a ground potential to pin  1  of relay K 2 . This can cause the coil to energize and pull the contacts of relay K 2 , such that input pin  9  can be connected to output pin  13  and input pin  8  can be connected to output pin  4 . This can result in reverse (exhaust) operation of the fan motor  130  when the fan motor  130  is turned on by the fan microcontroller  305 .  
         [0051]     Some embodiments of the current monitor module  345  (as shown in  FIG. 10 ), can monitor current flow in the dome motor  240  windings. An increase in dome motor  240  current can indicate that the dome  160  has reached its fully-open or fully-closed position. When the dome motor  240  is running, current can flow through resistor R 20 . An op-amp U2A (e.g., part number LM258D manufactured by Texas Instruments, among others) can amplify the voltage drop across R 20  and provide the signal to the fan microcontroller  305  via a connection  386 . Resistors R 12  (1.0 k Ω), R 13  (1.0 k Ω), R 14  (1.0 k Ω), R 15  (51.0 k Ω) and R 16  (10 k Ω) along with capacitor C 13  (1.0 uF, 25V) can combine with op-amp U2A to amplify the voltage drop detected across R 20 .  
         [0052]     Some embodiments of the current monitor module  345  (as shown in  FIG. 10 ), can monitor current flow in the fan motor  130  windings. An increase in fan motor  130  current can indicate that the fan  140  is blocked and cannot turn. When the fan motor  130  is running, current can flow through resistor R 19 . The op-amp U2A can amplify the voltage drop across R 19  and provide the signal to the fan microcontroller  305  via a connection  382 . Resistors R 12  (1.0 k Ω), R 13  (1.0 k Ω), R 14  (1.0 k Ω), R 15  (51.0 k Ω) and R 16  (10 k Ω) along with uF, 25V) can combine with op-amp U2A to amplify the voltage drop detected across R 19 .  
         [0053]     As shown in  FIG. 11 , the fan microcontroller  305  can include a microprocessor integrated circuit  390 , which can be programmed to perform various functions. As used herein and in the appended claims, the term “controller” is not limited to just those integrated circuits referred to in the art as microcontrollers, but broadly refers to one or more microcomputers, processors, application-specific integrated circuits, or any other suitable programmable circuit or combination of circuits. In some embodiments, the microprocessor  390  can be a model number MC68HC908JK1CDW manufactured by Freescale Semiconductor, Inc. In some embodiments, the fan microcontroller  305  can be positioned inside the chassis  105 . The microprocessor  390  can include a clocking signal generator including a crystal or oscillator X 1 , resistor R 1  (1.0 mΩ), and loading capacitors C 4  and C 5 . In some embodiments, the crystal X 1  can operate at 8 MHz and the loading capacitors C 4  and C 5  can each have a capacitance value of 12 pF. The clocking signal generator can provide a clock signal input to the microprocessor  390  and can be coupled to pin  3  and to pin  4 .  
         [0054]     The microprocessor  390  (at pin  18 ) can be connected to the fan antenna module  320  via the connection  372 . The microprocessor  390  (at pin  15 ) can be connected to the rain sensor module  325  via the connection  374 . The microprocessor  390  (at pin  13 ) can be connected to the temperature sensor  330  via the connection  376 . The microprocessor  390  (at pins  9  and  16 ) can be connected to the dome control module  335  via the connections  378  and  380 . The microprocessor  390  (at pins  17  and  19 ) can be connected to the fan control module  340  via the connections  382  and  384 . The microprocessor  390  (at pin  14 ) can be connected to the current sensing module  345  via the connection  386 . The microprocessor  390  (at pin  10 ) can be connected to a switch SW 1 , which can be connected to ground.  
         [0055]      FIGS. 12A, 12B , and  12 C illustrate a process the master controller  260  can follow for operation of the remote-controlled ventilator  100 . At step  400 , the microprocessor  390  can determine if a command has been received from the remote control  270  via the fan antenna module  320 . If a new command has not been received, the master controller  260  can check the voltage across the rain sensor  265  (at step  402 ). If the voltage across the rain sensor  265  is greater than a threshold, the rain sensor  265  has not detected any rain and processing continues (at step  404 ). If the voltage across the rain sensor  265  is less than a threshold, the rain sensor  265  has detected rain. The master controller  260  can stop the fan and/or close the dome (at steps  405  and  406 ) to prevent water from entering the RV through the ventilation system  100 . Processing can then continue (at step  404 ).  
         [0056]     If rain was not detected (at step  402 ), the master controller  260  can determine if the system is in automatic mode (step  404 ). If the mode is set to automatic, the microprocessor  390  can read the voltage provided by the temperature sensor module  330 . If the temperature detected is above a first threshold (at step  407 ), the ventilation system can attempt to cool the RV. The microprocessor  390  can output a low signal on pin  16  (connection  380 ) to set the dome direction to open and can output a high signal on pin  9  (connection  378 ) to energize the dome motor  240  opening the dome  160  (step  408 ). When the dome  160  reaches its fully-open position, the dome  160  can stop moving. However, the dome motor  240  can continue running, but because its armature cannot turn, the current the dome motor  240  draws can increase. A signal representative of this increasing current can be sent by the current monitor module  345  via the connection  386  to pin  14  of the microprocessor  390 . Once this signal reaches a threshold, the microprocessor  390  can remove the signal from pin  9 , which can de-energize the dome motor  240 . Processing can continue (at step  410 ), where the fan can be turned on or sped up by incrementing its duty cycle.  
         [0057]     At step  412 , the microprocessor  390  can poll the signal on pin  14  received from the current monitor module  345 . If this signal exceeds a threshold, a high-amps counter can be incremented (step  414 ). If the high-amps counter is less than a threshold, processing can continue (at step  400 .) If the high-amps counter is greater than or equal to the threshold total, a fault condition (e.g., the fan  140  is blocked) can be determined to exist and the fan can be turned off (step  418 ) and the mode can be set to manual (step  420 ).  
         [0058]     If the temperature is below the first threshold (at step  407 ), the temperature can be compared to a second threshold (step  422 ). If the temperature is above the second threshold, processing can continue (at step  412 ) with determining the fan amps. If the temperature is below the second threshold, the master controller  260  can attempt to warm up the RV by turning off the fan (step  424 ) and closing the dome (step  426 ). Processing can continue at step  412  with determining the fan amps. If the mode was set to manual (at step  404 ), processing can continue (at step  412 ) with determining the fan amps.  
         [0059]     In one embodiment, the remote control  270  can have eight functions and a key sequence for changing the synchronization code. For example, the eight functions can include: dome open, dome close, dome stop, toggle exhaust/intake, increase fan speed, decrease fan speed, stop fan, and set temperature range.  
         [0060]     If the remote control  270  transmits a synchronization code change (step  430 ), the master controller  260  can turn off the fan (at step  432 ) and determine if switch SW 1  ( FIG. 11 ) has been pressed (step  434 ). If switch SW 1  is pressed, the connection from common to pin  10  on the microprocessor  390  can open, causing pin  10  to go high. The microprocessor  390  can then save the new synchronization code in its flash memory (step  436 ) and processing can continue (at step  400 ). If switch SW 1  is not pressed, the new synchronization code can be ignored and processing can continue (at step  400 ). If the command received from the remote control  270  is different than changing the synchronization code, the synchronization code sent can be compared to the synchronization code saved in the microprocessor&#39;s  390  flash memory (step  438 ). If the codes do not match, the master controller  260  can ignore the command and continue processing (at step  400 ).  
         [0061]     If the synchronization codes match, processing can continue by determining which command is being sent by the remote control  270 . If the command received is to open the dome  160  (step  440 ), the microprocessor  390  can output a low signal on pin  16  to set the correct direction for the dome motor  240  (step  442 ). If the command received is to close the dome  160  (step  444 ), the microprocessor  390  can output a high signal on pin  16  to set the correct direction for the dome motor  240  (step  446 ). Next the microprocessor  390  can output a high signal on pin  9  to energize the dome motor  240  (step  448 ). At step  450 , the microprocessor  390  can determine the signal on pin  14  received from the current monitor module  345 . If the level of the current signal is above a threshold, the dome has reached the end of its travel path and the microprocessor  390  can turn off the dome motor  240  by removing the signal from pin  9  (step  452 ). Processing then continues (at step  400 ). If the level of the current signal is below a threshold, the microprocessor  390  can determine if an interrupt has occurred (step  454 ). An interrupt can occur when a new command is received by the master controller  260 , while the microprocessor  390  is waiting for the dome  160  to fully open or fully close. When an interrupt occurs, the microprocessor  390  can perform the requested command (step  456 ). Once processing of the command is complete, the microprocessor  390  can return to step  450  to wait for a high current condition.  
         [0062]     If the command received is to stop the dome (step  460 ), the microprocessor  390  can remove power from pin  9 , de-energizing the dome motor  240  (step  462 ). Processing can continue (at step  400 ).  
         [0063]     If the command received is to toggle the fan direction (step  464 ), the microprocessor  390  can turn off the fan at step  466 . The master controller  260  can then determine (at step  468 ), whether the fan is in exhaust mode. If the fan is in exhaust mode, the microprocessor  390  can change the signal on pin  17  from high to low, changing the fan to intake mode (step  470 ). If the fan is in intake mode, the microprocessor  390  can change the signal on pin  17  from low to high, changing the mode to exhaust (step  472 ). At step  474 , the master controller  260  can then set the fan speed to the same level as before it was turned off. Processing can then continue (at step  400 ).  
         [0064]     If the command received is to speed the fan up (step  480 ), the master controller  260  can determine the present speed of the fan  140  (step  482 ). If the speed is less than a maximum, the master controller  260  can increment a PWM duty cycle register, which can increase the duty cycle, and thus the speed of the fan, for example, ⅛ th  of full speed (step  484 ). The duty cycle can be increased, and thus the fan  140  can run, regardless of the position of the dome  160 , including when the dome  160  is fully closed. If the speed of the fan  140  is at a maximum, processing can continue (at step  400 ).  
         [0065]     If the command received is to slow the fan down (step  486 ), the master controller  260  can determine the present speed of the fan  140  (step  488 ). If the fan  140  is not off, the master controller  260  can decrement the PWM duty cycle register, which can lower the duty cycle, and thus the speed of the fan, for example,⅛ th  of full speed (step  490 ). If the fan is off, processing can continue (at step  400 ). If the command received is to stop the fan (step  492 ), the master controller  260  can turn the fan  140  off (step  494 ). Processing can then continue (at step  400 ).  
         [0066]     If the command received is to set the temperature range (step  496 ), the master controller  260  can determine if the range is set to zero (step  498 ). If the range is set to zero, the mode can be manual and the temperature control can be disabled (step  500 ). If the range is not set to zero, the range can be saved and control can be set to automatic (step  502 ). Processing can then continue (at step  400 ).  
         [0067]      FIG. 13  is a schematic illustration of an embodiment of a remote control  270 . The remote control  270  can include a battery  605 , a voltage source  610 , an antenna  615 , a microcontroller  620 , an indicator group  625 , and a selector group  630 . The components of the remote control  270  can be constructed with one or more integrated circuits mounted on a circuit board (not shown) that can be mounted in a housing.  
         [0068]     In one embodiment, the battery  605  can be a standard 9-Volt battery. However, a direct current (“DC”) voltage source providing between about 7-Volts and about 20-Volts can be used. The battery  605  can be connected to the voltage source  610  via a connection  635 . As shown in  FIG. 14 , the voltage source  610  can convert the voltage from the battery (i.e., +V b ) to a suitable voltage +V s , (e.g., +5 Volts) for use by the microcontroller  620  via a connection  640  and +V a  (e.g., +3 Volts) for use by the antenna  615  via a connection  645 . The voltage source  610  can include an integrated circuit  650  (e.g., model UA78L05CD manufactured by Texas Instruments, among others) for converting the battery voltage to +V s . The integrated circuit  650  can be coupled to a capacitor C 1 . The capacitance of C 1  can be designed to provide a constant, suitable voltage output for use with the microcontroller  620 . In some embodiments, the capacitance value can be 0.10 uF for C 1 . In addition, the maximum working-voltage rating of capacitor C 1  can be 25 Vdc. In addition, the voltage source  610  can include an integrated circuit  655  (e.g., model REG101NA-3/250 manufactured by Texas Instruments, among others) for converting +V s  voltage to +V a . The integrated circuit  655  can be coupled to a capacitor C 2 . The capacitance of C 2  can be designed to provide a constant, suitable voltage output for use with the antenna module  615 . In some embodiments, the capacitance value can be 0.10 uF for C 2 . In addition, the maximum working-voltage rating of capacitor C 2  can be 25 Vdc.  
         [0069]     As shown in  FIG. 15 , the antenna module  615  can be coupled to the voltage source  610  via a connection  645 , to the microcontroller  620  via a connection  660 , and to the antenna  665 . The antenna module  615  can convert data signals, received from the microcontroller  620  via connection  660 , into RF signals and transmit the signals to the antenna  665 . The antenna  665  then can transmit the RF waves. The antenna module  615  can include an integrated circuit  670  (e.g., model RCT-433-AS manufactured by Radiotronix, among others). The antenna module  615  can include filtering capacitors C 5  and C 6  (e.g., capacitance values of 6.0 pF), which can connect the output (at pin  1 ) of the integrated circuit  670  to the antenna  665 . In some embodiments, the antenna  665  can be implemented as a trace on a printed circuit board.  
         [0070]     As shown in  FIG. 16 , the indicators  625  can be coupled to the microcontroller  620  via a connection  675 . The indicators  625  can include green light emitting diodes (“LED”)  680 - 684  (e.g., MV5474C manufactured by Fairchild, among others), yellow LEDs  686 - 688  (e.g., MV5374C manufactured by Fairchild, among others), and red LEDs  690 - 694  (e.g., MV5075C manufactured by Fairchild, among others). The indicators  625  can include a current-sinking resistor R 1  (e.g., 1.0 kΩ).  
         [0071]     As shown in  FIG. 17 , the selectors  630  can be coupled to the microcontroller  620  via a connection  700 . The selectors  630  can include diode arrays  710 - 723  (e.g., BAV170E6327 manufactured by Infineon, among others). The selectors  630  can include switches  731 - 739  (e.g., B3F-1000 manufactured by Omron, among others). In one embodiment, the functions shown in Table 1 can be applied to the switches  731 - 739 .  
                         TABLE 1                           Switch Functions            Switch   Function               731   Speed Up/Synchronization       732   Speed Down/Synchronization       733   Fan Stop/Implement           Synchronization Code Change       734   Dome Open       735   Dome Close       736   Dome Stop       737   Cool       738   Warm       739   Exhaust/Intake                  
 
         [0072]     As shown in  FIG. 18 , the microcontroller  620  can include a microprocessor integrated circuit  750 , which can an be programmed to perform various functions. In some embodiments, the microprocessor  750  can be a model number MC68HC908JK1CDW manufactured by Freescale Semiconductor, Inc. The microcontroller  620  can include pull-up resistors R 5  (e.g., 10 kΩ) and R 6  (e.g,10 kΩ) The microprocessor  750  can include a clocking signal generator  755  including a crystal or oscillator X 1  and loading capacitors C 3  and C 4 . In some embodiments, the crystal X 1  can operate at 8 MHz and the loading capacitors C 3  and C 4  can each have a capacitance value of 12 pF. The clocking signal generator  755  can provide a clock signal input to the microprocessor  750  and can be coupled to pin  3  and pin  4 . The microprocessor  750  (at pins  6 - 8  and  11 - 15 ) can be connected to the indicators  625  via a connection  675 . The microprocessor  750  (at pins  9 ,  10 ,  16 , and  17 ) can be connected to the selectors  630  via a connection  700 .  
         [0073]     The microprocessor  750  can be programmed to operate the remote control  270  as shown in  FIGS. 19A and 19B . As shown in  FIG. 19A , the microprocessor can be initialized (at step  800 ) by setting various registers, inputs/outputs, and variables. The microprocessor  750  can wait until a switch has been engaged (at step  810 ). When a switch  731 - 739  in the selector  630  is engaged, the microprocessor  750  can determine which switch  731 - 739  in the selector  630  was engaged. The microprocessor  750  can determine this by monitoring the states of its pins ( 9 ,  10 ,  16 , and  17 ). The combination of states for each pin ( 9 ,  10 ,  16 , and  17 ) can signify which switch  731 - 739  is engaged. One embodiment of state combinations is shown in Table 2.  
                                                   TABLE 2                           Switch State Combinations                State of                Switch engaged   Pin 9   Pin 10   Pin 16   Pin 17               731   Off   On   On   On       732   On   Off   On   On       733   On   On   Off   On       734   On   On   On   Off       735   Off   Off   On   On       736   Off   On   Off   On       737   Off   On   On   Off       738   On   Off   Off   On       739   On   Off   On   Off                  
 
         [0074]     Once the microprocessor  750  determines which switch  731 - 739  has been engaged, the microprocessor  750  can determine if the engaged switch is the warm switch  738  or the cool switch  737  (at steps  820  and  830 ). If the engaged switch is the warm switch  738 , the microprocessor  750  can determine whether the temperature setting is at a maximum (at step  840 ). If the temperature is not at the maximum, the microprocessor  750  can increment a temperature register (at step  850 ) and an LED count (at step  860 ). The microprocessor  750  can apply power to the proper number of LEDs  680 - 694  in the indicator  625  (at step  870 ).  
         [0075]     At step  880 , the microprocessor  750  can send a digital signal to the antenna module  615  representative of the temperature setting. The antenna module  615  can convert this digital signal into an RF signal and transmit the RF signal via the antenna  665 .  
         [0076]     If the engaged switch is the cool switch  737 , the microprocessor  750  can determine whether the temperature setting is at a minimum (at step  890 ). If the temperature is not at the minimum, the microprocessor  750  can decrement the temperature register (at step  900 ) and the LED count (at step  905 ). The microprocessor  750  can then apply power to the proper number of LEDs  680 - 694  in the indicator  625  (at step  870 ).  
         [0077]     At step  880 , the microprocessor  750  can send a digital signal to the antenna module  615  representative of the temperature setting. The antenna module  615  can convert this digital signal into an RF signal and transmit the RF signal via the antenna  665 .  
         [0078]     If the engaged switch is not the warm switch  738  or the cool switch  737 , the microprocessor  750  can send a digital signal to the antenna module  615  representative of the switch pressed (at step  880 ). The antenna module  615  can convert this digital signal into an RF signal and transmit the RF signal via the antenna  665 .  
         [0079]     If the temperature setting was at the maximum setting (at step  840 ), or the temperature setting was at the minimum setting (at step  890 ), or following transmission of the digital signal to the antenna module  615  (at step  880 ), processing can continue (at step  910 ) with sequences for modifying the synchronization code (as shown in  FIG. 19B ). The microprocessor  750  can determine if the switch pressed is the speed down switch  731  or the speed up switch  732 . If the switch pressed is the speed down switch  731  or the speed up switch  732 , the microprocessor  750  can determine if a timer is running (step  915 ). If the timer is not running, the microprocessor  750  can start the timer (at step  920 ) and processing can continue (at step  810 ).  
         [0080]     If the timer is running (at step  915 ), the microprocessor  750  can determine if the timer has been running for a predetermined time (e.g., fifteen seconds) (at step  925 ). If the timer has been running for the predetermined time, a random number generator can be started (at step  930 ) and processing can continue (at step  810 ). If the predetermined time has not been reached (at step  925 ), processing can continue (at step  810 ).  
         [0081]     If the switch selected is not the speed down switch  731  or the speed up switch  732  (at step  910 ), the microprocessor  750  can determine if the switch selected is the fan stop switch  733  (step  935 ). If the fan stop switch  733  is not selected, the timer can be stopped and reset (at step  940 ) and processing can continue (at step  810 ). If the switch selected is the fan stop switch  733 , the microprocessor  750  can determine if the timer has been running for a predetermined time (e.g., fifteen seconds) (step  945 ). If the timer has been running for less than the predetermined time, processing can continue (at step  810 ). If the timer has been running for the predetermined time, the random number from the random number generator can be saved by the microprocessor  750  in its flash memory (at step  950 ). The microprocessor  750  can then transmit this code via the antenna module  615  (at step  955 ). The microprocessor  750  can then determine if the speed up switch  732  is still selected (at step  960 ). If the fan stop switch  733  is still selected, processing can continue (at step  955 ) with retransmission of the code. If the fan stop switch  733  is not selected any longer, processing can continue (at step  810 ).  
         [0082]     The resistance, capacitance, and voltage values used herein are used as examples only. Various features and advantages of the invention are set forth in the following claims.