Abstract:
A wireless remote control system for extending the control functions of the electrically actuated control systems of a boat including a plurality of transmitters and receivers, each transmitter capable of generating a signal on two channels and receiver control responsive to each of the two signals and capable of synthesizing a third control signal from the combination of the two signals.

Description:
TECHNICAL FIELD 
     The present invention relates generally to the remote control of the functions of a boat&#39;s trim/tilt adjustments, engine lift, engine starter, audio system, and more particularly, to the wireless control of the these systems from a plurality of transmitters and receivers. 
     BACKGROUND OF THE INVENTION 
     Boats are provided with electrically actuated systems that allow the operator of the boat to control numerous functions of the boat and propulsion system. Due to design constraints, these controls are often placed in areas that are less than ideal ergonomically. The boat owner frequently adds additional systems after the boat is purchased and the controls for these systems are typically located in even less desirable locations. 
     My prior invention, U.S. Pat. No. 5,725,402 that issued on Mar. 10, 1998, discloses a wireless control system for boats. The present invention is an improvement over my prior invention. 
     In general, boats are provided with an electrically actuated means to adjust the angle at which the boat&#39;s hull rides in the water. These adjustments are commonly known as “trim” adjustments. Changes in water condition, passenger weight distribution, and boat speed require the operator to make these adjustments frequently to maintain optimum hull attitude for maximum efficiency, safety, and performance. Trim adjustments are accomplished by any of the following methods: moving the propulsion unit about an axis within a range of approximately −5 degrees to +20 degrees referenced to the boats transom; moving the jet pump&#39;s discharge nozzle about an axis; moving about an axis external hydrodynamic control surfaces affixed to the stem known as “trim tabs”; varying the depth of the propulsion unit in the water by moving it vertically. 
     The term “tilt” is used to describe the movement of the propulsion unit from the fully lowered position (−5 degrees) to the fully raised position of approximately +45 degrees. Tilt is used for raising and lowering the propulsion unit when the boat is entering or leaving the water, flushing the cooling system on land, transporting the boat on a trailer, and storing the boat. 
     A boat&#39;s engine is typically started by turning a key switch located on the dashboard. The key switch completes the electrical circuit that energizes the engine&#39;s ignition and starter motor. The wires and connection terminals to the key switch are usually exposed. 
     The audio systems used in boats typically consist of a stereo sound source connected to a separate audio power amplifier. The sound source is frequently an in-dash radio/cassette/audio disc player. The controls for the sound source are usually located some distance from the operator, normally on the dashboard in front of the passenger seat. 
     There are numerous problems with the type of controls taught by the prior art. The first problem is that the trim and tilt controls are located inside of the boat and are connected by wires to control electronics. These controls are usually push buttons. They are typically integrated into the throttle arm, attached to the steering wheel, or mounted on the dashboard. All of these locations are in the front of the boat. When the boat is sitting on its trailer and the operator uses the trim/tilt switches to lower the propulsion unit, it is necessary to stop frequently to walk back to the stem to see how far away from the ground the propulsion unit&#39;s skeg is. Misjudging the distance and tilting the unit into the ground will damage the skeg and propeller. 
     The second problem is that prior art makes it inconvenient and time consuming for the operator to remove the boat&#39;s cover after transporting to gain access to the trim and tilt controls to lower the propulsion unit prior to storage. Manufacturers of boats and propulsion units require the unit be stored in the fully lowered position to eliminate stress on the boat&#39;s transom and the hydraulic system of the propulsion unit&#39;s trim/tilt cylinders. 
     The third problem is that the prior art makes it difficult to attach any control switches (trim, tilt, trim tabs, jet discharge nozzle, engine lift, and audio control) to the boat&#39;s steering wheel where they can be safely and conveniently accessed by the operator&#39;s fingertips while the boat is underway. This is due to the requirement for a heavy water proof, usually coiled; wire that connects the control switches to the boat&#39;s dashboard. Such wire can become tangled during turns, especially at high speeds, and impair hand and steering wheel movement. 
     The fourth problem is the exposed terminals and wires on the boat&#39;s key switch are easily accessible under the dashboard. The easy access offers no deterrent to theft. Unauthorized persons can bypass the switch in a matter or seconds with a jumper wire and enable the ignition and activate the engine&#39;s starter. 
     The fifth problem is prior art makes it difficult for the boat operator to adjust the volume of the boat&#39;s audio system due to the distance between the location of the audio controls and the driver&#39;s position, and the inherent rough and unstable driving conditions experienced while underway. 
     The sixth problem is that when the boat is stationary in the water and the occupants are outside, prior art makes it difficult for them to control the volume of the boat&#39;s audio system due to control means utilizing signals that propagate line-of-sight. Additionally, the control device can not withstand exposure to water. 
     SUMMARY OF THE INVENTION 
     The present invention is a wireless remote control system using multiple waterproof transmitters that are mounted on the boat&#39;s steering wheel for use while the boat is underway and multiple waterproof transmitters that are carried by the boat operator to activate the boat&#39;s control systems from outside of the boat while the boat is stationary in the water or on land. The transmitter signals are received by multiple receivers located in the control unit that provides an electrical interface to the boat&#39;s control electronics responsive to push-button inputs to the transmitters. 
     The transmitters that are carried by the operator are a battery powered key fob design with two push-button switches. The enclosures are waterproof and are sealed by a gasket that incorporates the push-button actuators for the switches. Each transmitter output is encoded with a unique digital address and is capable of simultaneous transmission on two channels in response to inputs from the switches. 
     The transmitters that are mounted on the steering wheel are battery powered and designed to mount on the spoke of the wheel, placing the control switch at the thumb of the operator. The transmitter enclosures are mirror image pairs allowing multiple transmitters to be used on both sides of the steering wheel. The enclosures are waterproof and incorporate a momentary waterproof rocker switch. The back of the enclosure is gasketed and removable to allow access to the battery. Each transmitter output is encoded with a unique digital address and is capable of non-simultaneous transmission on two channels in response to inputs from the rocker switch. 
     ADVANTAGES OF THE INVENTION 
     One advantage of the present invention is that it allows the functions of the boat&#39;s control systems to extend to ergonomically correct locations on the steering wheel and controlled simultaneously, while keeping both hands on the wheel, without the requirement and inconvenience of wires. 
     Yet another advantage of the invention is that it provides a wireless means to control the functions of the boat&#39;s control systems from a location outside of the boat while the boat is stationary in the water or on dry land sitting on its trailer. 
     Another advantage of the present invention allows the propulsion unit&#39;s trim and tilt functions to be controlled by the boat&#39;s operator from the steering wheel while the boat is underway. 
     Yet another advantage of the present invention allows the propulsion unit to be raised and lowered without removing the boat&#39;s cover to access switch controls inside the boat by an operator standing at the stem where he may observe the propulsion unit&#39;s position to ensure that it does not strike the ground or other obstacles. 
     Another advantage of the present invention provides a wireless remote control means from the boat&#39;s steering wheel and from outside of the boat to control any marine propulsion unit that utilizes an electrically actuated jet pump discharge nozzle. 
     Another advantage of the present invention provides a wireless remote control means from the steering wheel and from outside of the boat to operate an electrically controlled outboard engine lifting device known as a “stem lift”. The stem lift elevates the propulsion unit vertically and works in conjunction with trim to minimize drag without employing a high trim angle that will cause instability. 
     Yet another advantage of the present invention provides a wireless remote control means from the steering wheel and from outside of the boat to operate electrically controlled stem mounted “trim tabs”. 
     Another advantage of the present invention provides a wireless remote control means from the steering wheel and from outside of the boat to control the volume of the boat&#39;s audio system. 
     Another advantage of the present invention provides a remote control means from outside of the boat to disable the boat&#39;s electrical system to deter theft. 
     Yet another advantage of the present invention provides a remote control means to control the supply of electrical current to any device onboard, typically a security alarm system, security illumination, or audio system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a  shows the steering wheel transmitters of the preferred embodiment of the present invention in right and left hand applications mounted on the steering wheel. 
     FIG. 1 b  is a perspective view of a steering wheel transmitter. 
     FIGS. 1 c - 1   f  are front views of the right hand application of the steering wheel mounted transmitters. 
     FIGS. 1 g - 1   j  are front views of the left hand application of the steering wheel mounted transmitters. 
     FIG. 1 k  is a perspective view of a key fob hand held transmitter. 
     FIGS. 1 l - 1   p  are front views of the key fob hand held transmitters. 
     FIGS. 2 a - 2   d  are block diagrams showing the functional elements of the steering wheel mounted transmitters. 
     FIGS. 2 c - 2   h  are block diagrams showing the functional elements of the hand held key fob transmitters. 
     FIG. 3 is a block diagram showing the functional elements of the wireless remote receivers and control system taught by the present invention. 
     FIG. 4 is an exploded perspective view of the receivers and control system, the waterproof enclosure, and the electrical outputs of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In FIG. 1 a , remote transmitter  302  is attached to steering wheel  316  with screws  320  and  318  in a position convenient to allow the operation of rocker switch  304  while the operator of the boat is holding wheel  316  with the right hand. Likewise, remote transmitter  306  is attached to steering wheel  316  with screws  321  and  319  in a position convenient to allow the operation of rocker switch  308  by the operator&#39;s left hand. 
     FIG. 1 b  shows a perspective view of remote transmitter  302 . Waterproof rocker switch  304  is mounted in the case of  302 . Mounting screws  318  and  320  pass through holes  321  and  323  respectively. Nuts  322  and  324  attach to screws  318  and  320 . 
     FIGS. 1 c - 1   f  are front views of the steering wheel mounted transmitters shaped for right-handed operation. Transmitter  302  and switch  304  are adapted electrically to control the “Trim” function of a boat&#39;s propulsion unit. Transmitter  326  and switch  340  are adapted electrically to control the “Tabs” function of a boat. Transmitter  328  and switch  342  are adapted electrically to control the “Audio” volume of the stereo system of a boat. Transmitter  330  and switch  344  being adapted electrically to control the “Lift” of an elevation device of a boat&#39;s propulsion system. 
     FIGS. 1 g - 1   j  are front views of the wheel-mounted transmitters shaped for left-handed operation. Transmitter  332  and switch  346  are adapted electrically to control the “Trim” function of a boat&#39;s propulsion unit. Transmitter  306  and switch  352  are adapted electrically to control the “Tabs” function of a boat. Transmitter  336  and switch  348  are adapted electrically to control the “Audio” volume of the stereo system of a boat. Transmitter  338  and switch  350  are adapted electrically to control the “Lift” of the elevation device of a boat&#39;s propulsion system. 
     FIG. 1 k  shows a perspective view of remote handheld key fob transmitter  308 . Switch actuator  311  covers switch  310  (not visible) and forms a seal with the plastic case of transmitter  308  preventing water from entering. Likewise, switch actuator  313  covers switch  312  (not visible). Switch actuators  311  and  312  are part of the gasket (not visible) that forms a seal between the top and bottom case halves at  315 . Keychain  314  is connected to transmitter  308 . 
     FIG. 11 shows a front view of remote hand held key fob transmitter  308 , switches  310  and  312  (not visible) and the attachment of keychain  314 . FIG. 1 m  shows a front view of remote hand held key fob transmitter  390 , switches  402  and  404  (not visible) and the attachment of keychain  314 . FIG. 1 n  shows a front view of remote hand held key fob transmitter  474 , switches  504  and  506  (not visible) and the attachment of keychain  314 . FIG. 1 p  shows a front view of remote hand held key fob transmitter  444 , switches  470  and  472  (not visible) and the attachment of keychain  314 . 
     In FIG. 2 a , block  302  contains the elements of waterproof steering wheel transmitter  302 . Block  302  is designated to control the “Trim” functions of a marine propulsion unit. Momentary waterproof rocker switch  304  is connected to block  364  with wires  355 ,  359 , and  357 . Block  364  contains steering diodes responsive to contact closures on switch  304  that produce an enable signal on wire  368  connected to block  360  and a direction signal on wire  366  connected to block  358 . Block  356  contains a digital address that is unique to block  302  in FIG. 2 a , block  308  in FIG. 2 e , and block  50  in FIG.  3 . Block  356  provides the digital address on wire  354  which is connected to block  358 . Block  358  encodes the digital address from block  356  and the direction signal from block  364 . The encoded output of block  358  is connected by wire  362  to block  360 . Block  360  is a wireless transmitter operating on frequency #1. Battery  370  provides +12 volts to the electrical elements of block  302 . 
     In FIG. 2 b , block  306  contains the elements of waterproof steering wheel transmitter  306 . Block  306  is designated to control the “TABS” functions of a boat. Momentary waterproof rocker switch  352  is connected to block  450  with wires  353 ,  361 , and  363 . Block  450  contains steering diodes responsive contact closures on switch  352  that produce an enable signal on wire  424  connected to block  420  and a direction signal on wire  422  connected to block  416 . Block  412  contains a digital address that is unique to block  306  in FIG. 2 b , block  390  in FIG. 2 f , and block  61  in FIG.  3 . Block  412  provides the digital address on wire  414  which is connected to block  416 . Block  416  encodes the digital address from block  412  and the direction signal from block  450 . The encoded output of block  416  is connected by wire  418  to block  420 . Block  420  is a wireless transmitter operating on frequency #2. Battery  426  provides 12 volts to the electrical elements of block  306 . 
     In FIG. 2 c , block  330  contains the elements of waterproof steering wheel transmitter  330 . Block  330  is designated to control the “Lift” functions of a marine propulsion unit. Momentary waterproof rocker switch  344  is connected to block  446  with wires  345 ,  347 , and  349 . Block  446  contains steering diodes responsive to contact closures on switch  344  that produce an enable signal on wire  440  connected to block  436  and a direction signal on wire  438  connected to block  432 . Block  428  contains a digital address that is unique to block  330  in FIG. 2 c , block  444  in FIG. 2 g , and block  55  in FIG.  3 . Block  428  provides the digital address on wire  430  which is connected to block  432 . Block  432  encodes the digital address from block  428  and the direction signal from block  446 . The encoded output of block  432  is connected by wire  434  to block  436 . Block  436  is a wireless transmitter operating on frequency #1. Battery  442  provides +12 volts to the electrical elements of block  330 . 
     In FIG. 2 d , block  328  contains the elements of waterproof steering wheel transmitter  328 . Block  328  is designated to control the “Audio” volume functions of a boat&#39;s audio system. Momentary waterproof rocker switch  342  is connected to block  482  with wires  343 ,  341 , and  339 . Block  482  contains steering diodes responsive to contact closures on switch  342  that produce an enable signal on wire  488  connected to block  490  and a direction signal on wire  486  connected to block  480 . Block  476  contains a digital address that is unique to block  328  in FIG. 2 d , block  474  in FIG. 2 h , and block  11  in FIG.  3 . Block  476  provides the digital address on wire  478  which is connected to block  480 . Block  480  encodes the digital address from block  476  and the direction signal from block  482 . The encoded output of block  480  is connected by wire  484  to block  490 . Block  490  is a wireless transmitter operating on frequency #2. Battery  492  provides +12 volts to the electrical elements of block  328 . 
     In FIG. 2 e , block  308  contains the elements of waterproof handheld key fob transmitter  308 . Block  308  is designated to control the “Trim” functions of a boat&#39;s propulsion unit. Momentary switch  310  is connected to block  388  with wires  315  and  317 . Momentary switch  312  is connected to block  388  with wires  319  and  321 . Block  388  contains steering diodes responsive to contact closures on switches  310  and  312  that produce an enable signal on wire  384  connected to block  380  and a direction signal on wire  382  connected to block  376 . Block  372  contains a digital address that is unique to block  308  in FIG. 2 e , block  302  in FIG. 2 a , and block  50  in FIG.  3 . Block  372  provides the digital address on wire  374  which is connected to block  376 . Block  376  encodes the digital address from block  372  and the direction signal from block  388 . The encoded output of block  376  is connected by wire  378  to block  380 . Block  380  is a wireless transmitter operating on frequency #1. Battery  386  provides +12 volts to the electrical elements of block  308 . 
     In FIG. 2 f , block  390  contains the elements of waterproof handheld key fob transmitter  390 . Block  390  is designated to control the “TABS” functions of a boat. Momentary switch  402  is connected to block  452  with wires  403  and  405 . Momentary switch  404  is connected to block  452  with wires  407  and  409 . Block  452  contains steering diodes responsive to contact closures on switches  402  and  404  that produce an enable signal on wire  408  connected to block  400  and a direction signal on wire  406  connected to block  396 . Block  392  contains a digital address that is unique to block  390  in FIG. 2 f , block  306  in FIG. 2 b , and block  61  in FIG.  3 . Block  392  provides the digital address on wire  394  which is connected to block  396 . Block  396  encodes the digital address from block  392  and the direction signal from block  452 . The encoded output of block  396  is connected by wire  398  to block  400 . Block  400  is a wireless transmitter operating on frequency #2. Battery  410  provides +12 volts to the electrical elements of block  390 . 
     In FIG. 2 g , block  444  contains the elements of waterproof handheld key fob transmitter  444 . Block  444  is designated to control the “Lift” functions a marine propulsion unit. Momentary switch  470  is connected to block  448  with wires  471  and  473 . Momentary switch  472  is connected to block  448  with wires  475  and  477 . Block  448  contains steering diodes responsive to contact closures on switches  470  and  472  that produce an enable signal on wire  466  connected to block  462  and a direction signal on wire  464  connected to block  458 . Block  454  contains a digital address that is unique to block  444  in FIG. 2 g , block  330  in FIG. 2 c , and block  55  in FIG.  3 . Block  454  provides the digital address on wire  456 , which is connected to block  458 . Block  458  encodes the digital address from block  454  and the direction signal from block  448 . The encoded output of block  458  is connected by wire  460  to block  462 . Block  462  is a wireless transmitter operating on frequency #1. Battery  468  provides +12 volts to the electrical elements of block  440 . 
     In FIG. 2 h , block  474  contains the elements of waterproof handheld key fob transmitter  474 . Block  474  is designated to control the “Audio” volume functions of a boat&#39;s audio system. Momentary switch  504  is connected to block  516  with wires  505  and  507 . Momentary switch  506  is connected to block  516  with wires  509  and  511 . Block  516  contains steering diodes responsive to contact closures on switches  504  and  506  that produce an enable signal on wire  512  connected to block  500  and a direction signal on wire  510  connected to block  498 . Block  494  contains a digital address that is unique to block  474  in FIG. 2 h , block  328  in FIG. 2 d , and block  11  in FIG.  3 . Block  494  provides the digital address on wire  496  that is connected to block  498 . Block  498  encodes the digital address from block  494  and the direction signal from block  516 . The encoded output of block  498  is connected by wire  502  to block  500 . Block  500  is a wireless transmitter operating on frequency #2. Battery  514  provides +12 volts to the electrical elements of block  474 . 
     In FIG. 3, block  10  is an electrical block diagram of the wireless remote control system taught by the preferred embodiment of the present invention. It should be noticed that block  12  is functionally identical to my prior invention, U.S. Pat. Ser. No, 5,725,402 issued Mar. 10, 1998, except for the addition of blocks  26  and  22 . 
     Block  14  contains a wireless receiver tuned to frequency #1. The output of block  14  is serial data and is connected by wire  1  to serial data bus  18 . Block  112  contains a wireless receiver tuned to frequency #2. The output of block  112  is serial data and is connected by wire  2  to serial data bus  18 . Serial data bus  18  connects to blocks  28 ,  59 ,  53 , and  9  which are each serial data decoders. Block  28  connects to block  54  with wire  44 ,  42 , and  40 . Wire  44  is the UP output command of block  28 . Wire  42  is the DOWN output command of block  28 . Wire  40  is the VALIDATION output command of block  28 . Block  54  contains digital AND, NAND, and OR logic that produces outputs on wires  52 ,  56 ,  38 ,  60 , and  62 . Wire  52  carries the VALIDATION command and is connected to block  22 . Wire  56  carries the ENABLE/DISABLE command and is connected to block  65 . Wires  60  and  62  are connected to block  48  and carry the DOWN and UP commands, respectively. Block  50  contains a digital address that is unique to block  12 , block  308  in FIG. 2 e , and block  302  in FIG. 2 a . Block  50  is connected by wire  30  to block  28 . 
     Block  34  contains a flip-flop with its output connected by wire  32  to block  26 , wire  36  to block  48 , and wire  3  to block  54 . Block  34  toggles its output each time it receives and UP AND DOWN command on wire  38 . Block  48  contains part of a ULN2003 relay driver integrated circuit that provides current gain. Block  48  is connected by wires  68  and  72  to block  97 , and by wires  64  and  66  to block  99 . Wires  68  and  72  both carry the SECURITY RELAY command. Wire  66  carries the TRIM RELAY UP command and wire  64  carries the TRIM RELAY DOWN command. Block  97  contains one SPST relay switch and one SPDT relay switch. Block  97  is connected by wires  80 ,  82 , and  84  to block  114 , and by wires  86  and  88  to block  116 . Wires  80 ,  82 , and  84  are respectively the normally closed, common, and normally open SPDT relay switch contacts of block  97 . Wires  86 , and  88  are respectively the common, and normally open SPST relay switch contacts of block  97 . Block  114  represents an electrically actuated device onboard the boat, i.e., security alarm system, security illumination, engine ignition circuit. Block  116  represents the electrically actuated starting relay solenoid of a boat&#39;s engine. Block  99  contains two SPST relay switches and is connected by wires  90 ,  92 , and  94  to block  118 . Wires  90  carries the TRIM DOWN command. Wire  92  carries the TRIM COMMON command. Wire  94  carries the TRIM UP command. Block  118  represents the electrically actuated trim/tilt relay solenoid of a boat&#39;s propulsion unit. 
     Block  59  connects to block  65  with wire  75 ,  73 , and  71 . Wire  71  carries the UP output command from block  59 . Wire  73  carries the DOWN output command from block  59 . Wire  75  is the VALIDATION output command from block  59 . Block  65  contains digital AND, NAND, and OR logic that produces outputs on wires  58 ,  69 ,  79 , and  77 . Wire  58  carries the VALIDATION command and is connected to block  54 . Wire  69  carries the ENABLE/DISABLE command and is connected to block  5 . Wire  79  carries the DOWN command and is connected to block  108 . Wire  77  carries the UP command and is connected to block  108 . Block  61  contains a digital address that is unique to block  50 , block  306  in FIG. 2 b , and block  390  in FIG. 2 f . Block  61  is connected by wire  63  to block  59 . Block  108  contains part of a ULN2003 relay driver integrated circuit that provides current gain. Block  108  is connected by wires  83  and  81  to block  110 . Wire  81  carries the TABS RELAY UP command and wire  83  carries the TABS RELAY DOWN command. Block  110  contains two SPST relay switches and is connected by wires  95 ,  93 , and  91  to block  122 . Wire  95  carries the TABS DOWN command. Wire  93  carries the TABS COMMON command. Wire  91  carries the TABS UP command. Block  122  represents the electrically actuated trim tabs relay solenoid of a boat. 
     Block  53  connects to block  5  with wires  51 ,  49 , and  47 . Wire  47  carries the UP output command from block  53 . Wire  49  carries the DOWN output command from block  53 . Wire  51  is the VALIDATION output command from block  53 . Block  5  contains digital AND, NAND, and OR logic that produces outputs on wires  67 ,  45 ,  41 , and  39 . Wire  67  carries the VALIDATION command and is connected to block  65 . Wire  45  carries the ENABLE/DISABLE command and is connected to block  7 . Wire  41  carries the DOWN command and is connected to block  102 . Wire  39  carries the UP command and is connected to block  102 . Block  55  contains a digital address that is unique to block  55 , block  330  in FIG. 2 c , and block  444  in FIG. 2 g . Block  55  is connected by wire  57  to block  53 . Block  102  contains part of a ULN2003 relay driver integrated circuit that provides current gain. Block  102  is connected by wires  37  and  35  to block  104 . Wire  35  carries the LIFT RELAY UP command and wire  37  carries the LIFT RELAY DOWN command. Block  104  contains two SPST relay switches and is connected by wires  89 ,  87 , and  85  to block  124 . Wire  89  carries the LIFT DOWN command. Wire  87  carries the LIFT COMMON command. Wire  85  carries the LIFT UP command. Block  124  represents the electrically actuated elevation relay solenoid of the lifting device of a boat&#39;s propulsion unit. 
     Block  9  connects to block  7  with wires  33 ,  31 , and  29 . Wire  29  carries the UP output command from block  9 . Wire  31  carries the DOWN output command from block  9 . Wire  33  is the VALIDATION output command from block  9 . Block  7  contains digital AND, NAND, and OR logic that produces outputs on wires  43 ,  27 , and  25 . Wire  43  carries the VALIDATION command and is connected to block  5 . Wire  27  carries the DOWN command and is connected to block  3 . Wire  25  carries the UP command and is connected to block  3 . Block  11  contains a digital address that is unique to block  11 , block  328  in FIG. 2 d , and block  474  in FIG. 2 h . Block  11  is connected by wire  13  to block  9 . Block  3  contains part of a ULN2003 relay driver integrated circuit that provides current gain. Block  3  is connected by wires  23  and  21  to block  106 . Wire  21  carries the LIFT RELAY UP command and wire  23  carries the LIFT RELAY DOWN command. Block  106  contains two SPST relay switches and is connected by wires  19 ,  17 , and  15  to block  126 . Wire  19  carries the AUDIO DOWN command. Wire  17  carries the AUDIO COMMON command. Wire  15  carries the AUDIO UP command. Block  126  represents the electrically actuated multi-channel audio attenuator of a boat&#39;s audio system. 
     Block  78  contains a 5 volt DC regulator integrated circuit and a filter circuit for 13.8 volts DC. Block  78  is connected by wires  96  and  98  to block  120 . Wire  96  is electrical ground, and wire  98  is 13.8 volts DC. Block  120  represents the storage battery of the boat. Block  78  supplies 5 volts DC and 13.8 volts DC to wires  74  and  76 , respectively. Wires  74  and  76  supply 5 volts DC and 13.8 volts DC to the electrical elements contained within block  10 . 
     In FIG. 3, receiver  14  is tuned to frequency #1 and responds to transmitters  302 ,  330 ,  332 ,  338 , in FIG. 1, and transmitters  308  and  444  in FIG.  2 . Receiver  112  is tuned to frequency #2 and responds to transmitters  306 ,  326 ,  328 ,  336 , in FIG. 1, and transmitters  390  and  474  in FIG.  2 . The serial data output of receivers  14  and  112  is supplied by wire  18  simultaneously to decoders  28 ,  59 ,  53 , and  9 . Address block  50  provides decoder  28  with the same digital address (address #1) as transmitters  302 ,  332 , and  308  in FIG.  1 . Therefore, decoder  28  only produces outputs responsive to switch closures on transmitters  302 ,  332  and  308  which are designated as “TRIM” transmitters. Address block  61  provides decoder  59  with the same digital address (address #2) as transmitters  306 ,  326 , and  390  in FIG.  1 . Therefore, decoder  59  only produces outputs responsive to switch closures on transmitters  306 ,  326  and  390  which are designated as “TABS” transmitters. Address block  55  provides decoder  53  with the same digital address (address #3) as transmitters  330 ,  338 , and  444  in FIG.  1 . Therefore, decoder  53  only produces outputs responsive to switch closures on transmitters  330 ,  338  and  444  which are designated as “LIFT” transmitters. Address block  11  provides decoder  9  with the same digital address (address #4) as transmitters  328 ,  336 , and  474  in FIG.  1 . Therefore, decoder  9  only produces outputs responsive to switch closures on transmitters  328 ,  336  and  474  which are designated as “AUDIO” transmitters. 
     The outputs produced by decoder  28  are UP, DOWN, and VALIDATION on wires  44 ,  42 , and  40 , respectively. These commands are supplied to block  54  wherein logic gates process the UP, DOWN, and VALIDATION commands and synthesize another command, UP AND DOWN. The synthesis of the UP AND DOWN command by control logic block  54  occurs exclusively as a result of the simultaneous activation of momentary push button switches  310  and  312  on key fob “Trim” transmitter  308 . Even though transmitters  302  and  332  operate on the same frequency as transmitter  308  and contain identical digital addressing, rocker switches  304  and  346  prohibit simultaneous UP and DOWN commands. Block  54  supplies the UP AND DOWN command to block  34  on wire  38 . Block  34  contains a flip-flop integrated circuit that toggles its output state each time it receives the UP AND DOWN command from block  54  and produces the command ENABLE/DISABLE. The ENABLE/DISABLE command output of block  34  is connected to block  54  by wire  3  and serves to place the control logic of block  54  in an enabled state when wire  3  is at a logic-1 level and a disabled state when wire  3  is at a logic-0 level. The ENABLE/DISABLE command state is outputted from block  54  by wire  56  to the control logic block  65 , from block  65  by wire  69  to block  5 , and from block  5  by wire  45  to block  7 . This configuration allows block  34  to enable all of the control logic blocks contained in block  10  of FIG. 1 when the ENABLE/DISABLE command is set to logic-1 level, and disable all of the control logic blocks when the command is set to a logic-0 level. When control logic block  54  is enabled, it outputs the UP and DOWN commands on wires  62  and  60  respectively, responsive to switch closures on “TRIM” transmitters  308 ,  302 , and  332 . When block  65  is disabled, its only output responsive to switch closures on the “TABS” transmitters, is the VALIDATATION command on wire  52 . Wire  52  connects to block  22  where a drive signal responsive to the logic-1 level of the VALIDATION command produces a dive signal for piezo transducer  16 . Wires  62  and  60  are connected to relay driver block  48  which provides the outputs on wires  66  and  64  to block  99 . Block  99  contains 2 SPST relay switches. One SPST relay switch connects to wire  66  and activates when an UP switch is pressed on a “Trim” transmitter. The remaining SPST relay switch is connected to wire  64  and activates when a DOWN switch is pressed on a “Trim” transmitter. The common poles of both SPST relay switches are joined and connect to wire  92 , the TRIM COMMON command wire. The normally open contact of the relay switch connected to wire  66  is connected to wire  94  and provides the TRIM RELAY UP command wire. The normally open contact of the relay switch connected to wire  64  is connected to wire  90  and provides the TRIM RELAY DOWN command wire. Wires  90 ,  92  and  94 , are connected to the boat&#39;s trim/tilt solenoids represented by block  118 . 
     Block  34  outputs the ENABLE/DISABLE command on wire  36  to block  48 . Block  48  contains relay drivers that output the SECURITY RELAY command on wires  68  and  72 . Wires  68  and  72  connect to block  97  which contains a SPST and a SPDT relay switch. When the ENABLE/DISABLE command is set to a logic level-1, the SPDT relay in block  97  activates and provides a circuit path between wires  82  and  84 . When the ENABLE/DISABLE command is set to a logic-0 level, the SPDT relay deactivates and provides a circuit path between wires  82  and  80 . Likewise, when the ENABLE/DISABLE command is set to a logic-1 level, the SPST relay in block  97  activates and provides a circuit path between wires  86  and  88 . When the ENABLE/DISABLE command is set to a logic-0 level, the SPDT relay deactivates and opens a circuit path between wires  86  and  88 . Wires  80 ,  82 , and  84  are connected to block  114  which represents any device onboard a boat requiring remote control, i.e., security system, security illumination, engine ignition, audio system. Wires  86  and  88  connect to block  116  which represents the starting solenoid of a marine propulsion unit. 
     The output of block  34  connects by wire  32  to block  26 . Block  26  contains a one second duration one-shot circuit and a 6 Htz square wave generator. Each time wire  32  transitions from a logic-0 to a logic-1 level, block  26  produces a 6 pulse square wave output on wire  24 . Wire  24  connects to block  22 , a piezo driver that provides a drive signal to block  16  on wire  20 . The piezo transducer provides audio annunciation of the state of operation of the present invention. 
     The outputs produced by decoder  59  are UP, DOWN, and VALIDATION on wires  71 ,  73 , and  75 , respectively. These commands are supplied to block  65  wherein logic gates process the UP, DOWN, and VALIDATION commands. The ENABLE/DISABLE command output of block  54  is connected to block  65  by wire  56  and serves to place the control logic of block  65  in an enabled state when wire  56  is at a logic-1 level and a disabled state when wire  56  is at a logic-0 level. When control logic block  65  is enabled, it outputs the UP and DOWN commands on wires  77  and  79  respectively, responsive to switch closures on “TABS” transmitters  326 ,  306 , and  390 . When block  65  is disabled, its only output responsive to switch closures on the “TABS” transmitters, is the VALIDATATION command on wire  58 . Wire  58  connects to block  54  wherein the VALIDATION command produced by block  56  it is combined (logical OR) with the VALIDATION command produced by block  54 . Wires  77  and  79  are connected to relay driver block  108  which provides outputs on wires  81  and  83  to block  110 . Block  110  contains 2 SPST relay switches. One SPST relay switch connects to wire  81  and activates when an UP switch is pressed on a “TABS” transmitter. The remaining SPST relay switch is connected to wire  83  and activates when a DOWN switch is pressed on a “TABS” transmitter. The common poles of both SPST relay switches are joined and connect to wire  93 , the TABS RELAY COMMON command wire. The normally open contact of the relay switch connected to wire  81  is connected to wire  91  and provides the TABS RELAY UP command wire. The normally open contact of the relay switch connected to wire  83  is connected to wire  95  and provides the TABS RELAY DOWN command wire. Wires  95 ,  93  and  91 , are connected to the boat&#39;s trim tabs solenoids represented by block  122 . 
     The outputs produced by decoder  53  are UP, DOWN, and VALIDATION on wires  47 ,  49 , and  51 , respectively. These commands are supplied to block  5  wherein logic gates process the UP, DOWN, and VALIDATION commands. The ENABLE/DISABLE command output of block  65  is connected to block  5  by wire  69  and serves to place the control logic of block  5  in an enabled state when wire  69  is at a logic-1 level and a disabled state when wire  69  is at a logic-0 level. When control logic block  5  is enabled, it outputs the UP and DOWN commands on wires  39  and  41  respectively, responsive to switch closures on “LIFT” transmitters  330 ,  338 , and  444 . When block  5  is disabled, its only output responsive to switch closures on the “LIFT” transmitters, is the VALIDATATION command on wire  67 . Wire  67  connects to block  65  wherein The VALIDATION command produced by block  5  it is combined (logical OR) with the VALIDATION command produced by block  65 . Wires  39  and  41  are connected to relay driver block  102  which provides outputs on wires  35  and  37  to block  104 . Block  104  contains 2 SPST relay switches. One SPST relay switch connects to wire  35  and activates when an UP switch is pressed on a “LIFT” transmitter. The remaining SPST relay switch is connected to wire  37  and activates when a DOWN switch is pressed on a “LIFT” transmitter. The common poles of both SPST relay switches are joined and connect to wire  87 , the LIFT RELAY COMMON command wire. The normally open contact of the relay switch connected to wire  35  is connected to wire  85  and provides the LIFT RELAY UP command wire. The normally open contact of the relay switch connected to wire  37  is connected to wire  89  and provides the LIFT RELAY DOWN command wire. Wires  89 ,  87  and  85 , are connected to the boat&#39;s engine lift solenoids represented by block  124 . 
     The outputs produced by decoder  9  are UP, DOWN, and VALIDATION on wires  29 ,  31 , and  33 , respectively. These commands are supplied to block  7  wherein logic gates process the UP, DOWN, and VALIDATION commands. The ENABLE/DISABLE command output of block  7  is connected to block  5  by wire  43  and serves to place the control logic of block  7  in an enabled state when wire  43  is at a logic-1 level and a disabled state when wire  45  is at a logic-0 level. When control logic block  7  is enabled, it outputs the UP and DOWN commands on wires  25  and  27  respectively, responsive to switch closures on “AUDIO” transmitters  328 ,  336 , and  474 . When block  7  is disabled, its only output responsive to switch closures on the “AUDIO” transmitters, is the VALIDATATION command on wire  43 . Wire  43  connects to block  5  wherein The VALIDATION command produced by block  7  it is combined (logical OR) with the VALIDATION command produced by block  5 . Wires  25  and  27  are connected to relay driver block  3  which provides outputs on wires  21  and  23  to block  106 . Block  106  contains two SPST relay switches. One SPST relay switch connects to wire  21  and activates when an UP switch is pressed on an “AUDIO” transmitter. The remaining SPST relay switch is connected to wire  23  and activates when a DOWN switch is pressed on an “AUDIO” transmitter. The common poles of both SPST relay switches are joined and connect to wire  17 , the AUDIO RELAY COMMON command wire. The normally open contact of the relay switch connected to wire  21  is connected to wire  15  and provides the AUDIO RELAY UP command wire. The normally open contact of the relay switch connected to wire  23  is connected to wire  19  and provides the AUDIO RELAY DOWN command wire. Wires  19 ,  17  and  15 , are connected to the boat&#39;s multi-channel audio attenuator represented by block  126 . 
     In FIG. 4, functional block  10  is disposed inside a waterproof plastic case  700 , with output cable bundles  710  and  712  exiting the case through hermetic seals  714  and  706 , respectively. The individual input and output wires are labeled for identification. 
     The system control unit shown in FIGS. 3 and 4 is mounted in any convenient place inside the boat such as under the dashboard, or engine compartment. The wiring harness is connected as shown in FIG.  4 . The transmitters are then attached to the steering wheel of the boat. The handheld key fob transmitters are complete as supplied and require no installation. 
     To operate the invention, enable the system control unit by simultaneously pressing both the UP and DOWN switches on the handheld “Trim” key fob transmitter. This will cause six “beeps” to be omitted from the system control unit, both security relays will activate and devices connected through the security relays will be active. To move the propulsion unit, push the UP or DOWN switch on any “Trim” transmitter. To operate the other control system functions, i.e., “Tabs” , Lift”, “Audio”, simply push the UP or DOWN switch on the corresponding steering wheel or handheld key fob transmitter. To disable the invention, simultaneously press both the UP and DOWN switches on the handheld “Trim” key fob transmitter. This will cause a single “beep” to be omitted, both security relays will deactivate, and all UP and DOWN control functions will disable. Subsequent pressing of the UP or DOWN switches on any transmitters will produce “beeps” from the system control unit responsive to the switch closures on the transmitters but all UP and DOWN relay switch activation is disabled. 
     Although this specification has disclosed the best embodiment known to the inventor of practicing the present invention, it should not be read as limiting the invention. The invention should be limited only by the appended claims and their equivalents.