Abstract:
There is provided an electrical enabling device that comprises a transmitter for transmitting a control signal, a receiver for receiving the control signal, and a switching apparatus for selectively closing an electrical circuit for a time window to initiate operation of an electrical apparatus in response to the control signal and for opening the electrical circuit after the time window. The switching apparatus is unresponsive to the control signal during the operation of the electrical apparatus.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an electrical enabling device for enabling an electrical circuit to operate, and is useful in particular, but not exclusively, to allow electrical circuits in vehicles to operate in order to start the vehicle. The device of the present invention can thus be used as an anti-theft system for vehicles.  
         [0003]     2. Description of the Related Art  
         [0004]     A conventional electrical enabling device for a vehicle is triggered by an RF signal to enable a vehicle to be started. If, however, the vehicle is not started, the electrical enabling device does not automatically disable the vehicle from being started.  
         [0005]     In U.S. Pat. No. 6,265,787 issued on Jul. 24, 2001 to Richard T. Downey, an anti-theft system for a vehicle is disclosed which responds to a remote control to selectively provide power to an ignition coil. Each time the remote control is actuated, the anti-theft system toggles a switch from a previous state to either open or close the switch.  
         [0006]     It is a disadvantage of this prior art electrical enabling device that, after the electrical enabling device has enabled the vehicle to be started and the vehicle has not been started, the electrical enabling device does not automatically disable the vehicle from being started after a time period.  
         [0007]     It is a further disadvantage of previous electrical enabling devices that, after a vehicle has been started and the vehicle is being operated, the electrical enabling device can toggle the state of a switch, thereby turning off the vehicle. This is potentially hazardous when the vehicle is being driven and the electrical enabling device is disabled by a rogue RF signal.  
       BRIEF SUMMARY OF THE INVENTION  
       [0008]     It is accordingly an object of the present invention to provide a novel electrical enabling device that enables a vehicle to be started and once started the electrical enabling device can not turn off the vehicle, but rather the vehicle must be turned off in the normal manner to activate the electrical enabling device again.  
         [0009]     According to one aspect of the present invention, there is provided an electrical enabling device that comprises a transmitter for transmitting a control signal, a receiver for receiving the control signal, and a switching apparatus for selectively closing an electrical circuit for a time window to initiate operation of an electrical apparatus in response to the control signal and for opening the electrical circuit after the time window. The switching apparatus is unresponsive to the control signal during the operation of the electrical apparatus.  
         [0010]     According to a second aspect of the invention, there is provided a combination of a vehicle and an electrical enabling device. The electrical enabling device comprises a transmitter for transmitting a control signal, a receiver for receiving the control signal, and a switching apparatus for selectively closing an electrical circuit for a time window to initiate operation of an electrical apparatus in response to the control signal and for opening the electrical circuit after the time window. The switching apparatus is unresponsive to the control signal during the operation of the electrical apparatus.  
         [0011]     According to a third aspect of the present invention, there is provided a method of protecting a vehicle from theft comprising the steps of opening a segment of an electrical circuit in the vehicle, thereby disabling the vehicle from being started, transmitting a control signal to close the segment of the electrical circuit for a time window, thereby enabling the vehicle to be started during the time window, and opening the segment of the electrical circuit if the car is not started during the time window and thereby disabling the vehicle from being started.  
         [0012]     According to a fourth aspect of the present invention, there is provided in combination, an electrically enabling device, an electrically operable apparatus and an electrical power source. The electrically enabling device comprises a control signal transmitter, a control signal receiver, a switch between the power source and the electrically operable apparatus a timing circuit between the control signal receiver and the switch, and a latching circuit between the electrically operable apparatus and the switch.  
         [0013]     It is an advantage of this invention that, when used with an insured motor vehicle, you can obtain a discount on the motor vehicle insurance. The device of the present invention can be used as an anti-theft deterrent device in motor vehicles.  
         [0014]     It is another advantage of this invention to prevent unintentional switch state transitions by disabling the device from responding to rogue RF signals once the electrical apparatus is started. It is yet another advantage of the present invention to provide only a time window in which to initiate operation of the electrical apparatus, thereby preventing unintentional enabling of the electrical apparatus.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     The present invention will be more readily understood from the following description of preferred embodiments thereof given, by way of example, with reference to the accompanying drawings, in which:  
         [0016]      FIG. 1  shows a view in perspective of a vehicle and an electrical enabling device according to an embodiment of the present invention;  
         [0017]      FIG. 2  shows a block diagram of the electrical enabling device and an electrical circuit of the vehicle of  FIG. 1 ;  
         [0018]      FIG. 3  shows a block diagram view of an electrical enabling device and an electrical circuit of a vehicle according to another embodiment of the present invention;  
         [0019]      FIG. 4  shows a block diagram view of an RF transmitter of the electrical enabling device of  FIG. 3 ;  
         [0020]      FIG. 5  shows a block diagram view of an electrical enabling device and an electrical circuit of a vehicle according to another embodiment of the present invention; and  
         [0021]      FIG. 6  shows a block diagram view of an RF transceiver of the electrical enabling device of  FIG. 5 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]     In  FIG. 1 , there is shown a vehicle indicated generally by reference numeral  10  having a battery  12 , an electrical enabling device indicated generally by reference numeral  14 , an ignition coil  16  and an ignition coil driver  17 . An electrical circuit indicated generally by reference numeral  18  is formed by the battery  12 , the electrical enabling device  14 , the ignition coil  16 , the ignition coil driver  17  and associated electrical connections therebetween. The electrical enabling device  14  forms a segment of the electrical circuit  18 .  
         [0023]     The electrical enabling device  14  opens the segment of the electrical circuit  18  to disable the ignition coil  16  and ignition coil driver  17  from operating. The electrical enabling device  14  closes the segment of the electrical circuit  18  to enable the ignition coil  16  and ignition coil driver  17  to operate.  
         [0024]     In other embodiments of the present invention, the electrical enabling device can enable and disable other electrical circuits in the vehicle  10  from operating, for example, an electronic fuel injection system or an electrical fuel pump.  
         [0025]     Referring to  FIGS. 1 and 2 , the electrical enabling device  14  comprises an RF transmitter  20  and an apparatus  22  installed within the vehicle  10 . The RF transmitter  20  comprises a button  15  that, when pressed, actuates the transmitter to emit an RF control signal  35 . The apparatus  22  comprises an RF receiver  24 , a switch  26 , a timing circuit  28 , a latching circuit  30  and a switch driver  32 .  
         [0026]     The RF receiver  24  has an input  34  and an output  36 . The input  34  receives the RF control signal  35  from the RF transmitter  20 . The output  36  is connected to the timing circuit  28 . The RF receiver  24  is responsive to the RF control signal  35  and provides an electrical control signal  38  at the output  36 .  
         [0027]     The RF receiver  24  is programmed to operate with one or more of the RF transmitters  20 . The RF receiver  24  is only responsive to the RF transmitters  20  that have been programmed to operate with the particular RF receiver  24 . If one of the RF transmitters  20  is lost or stolen, the RF receiver can be programmed to no longer operate with that particular RF transmitter  20 .  
         [0028]     The RF receiver  24  is placed into program mode by actuating a button (not shown) on the RF receiver, and stays in program mode for a set time period. During the program mode time period, any RF transmitter  20  that is actuated within range of the RF receiver  24  will be programmed to operate with the RF receiver. During normal operation, the RF receiver  24  makes a clicking noise when an RF transmitter  20  that has programmed for that RF receiver is actuated.  
         [0029]     The timing circuit  28  has an input  40 , and an output  42 . The input  40  is connected to the output  36  of the receiver  24  and receives the control signal  38 . The output  42  is connected to the switch driver circuit  32 . The timing circuit  28  is responsive to the control signal  38  and provides a one-shot switch signal  44  at the output  42 .  
         [0030]     The switch driver circuit  32  has a first input  46 , a second input  48  and an output  50 . The first input  46  is connected to the output  42  of the timing circuit  28  and receives the one-shot switch signal  44 . The output  50  is connected to the switch  26 . The switch driver circuit  32  is responsive to the one-shot switch signal  44  and provides a switch control signal  58  at the output  50 .  
         [0031]     The switch  26  comprises an electromechanical relay (not shown) in this example. In other embodiments, the switch  26  can comprise, for example and without limitation, a solid state relay, a solid state switch or a self-latching relay. The switch  26  has a first switch terminal  52 , a second switch terminal  54  and a switch control input  56 . The switch control input  56  is connected to the output  50  of the switch driver circuit  32  and receives the switch control signal  58 .  
         [0032]     Normally, the switch  26 , between the first and second switch terminals  52  and  54 , is open and no electrical energy can flow between these terminals. When the switch control signal  58  is applied to the switch control input  56 , the switch  26  closes allowing electrical energy to flow between the terminals  52  and  54 .  
         [0033]     The first switch terminal  52  is connected to a negative terminal on the ignition coil driver  17  by electrical connection  60 . The second switch terminal  54  is connected to a first terminal  70  on the ignition coil  16  by electrical connection  62 . A positive terminal on the ignition coil driver  17  is connected to a positive terminal on the battery  12  by electrical connection  66 . A terminal  72  on the ignition coil  16  is connected to a negative terminal on the battery  12  by electrical connection  64 . The battery  12 , the ignition coil driver  17 , the switch  26 , the ignition coil  16  and the electrical connections  60 ,  62 ,  64  and  66  form the electrical circuit  18 .  
         [0034]     The latching circuit  30  comprises an input  68  and an output  69 . The input  68  is connected to the second switch terminal  54  and the output  69  is connected to the second input  48  of the switch driver circuit  32 . The latching circuit  30  is responsive to electrical energy at input  68  and provides a latching signal  31  to the second input  48  of the switch driver circuit  32 . The switch driver circuit  32  is further responsive to the latching signal  31 , in addition to the one-shot signal  44 , to provide the switch control signal  58 .  
         [0035]     In operation the vehicle  10  is initially inoperative and the switch  26  is open. A vehicle operator actuates the transmitter  20  by pressing the button  15  and the transmitter  20  emits the control signal  35 . The receiver  24  receives the control signal  35  and provides the electrical signal  38  to the timing circuit  28 . The timing circuit  28  in response provides the one-shot signal  44  to the switch driver  32 . The switch driver  32  in response provides the switch control signal  58  which enables the switch  26  by closing the circuit between the first and second switch terminals  52  and  54 .  
         [0036]     The switch control signal  58  is applied to the switch  26  as long as the one-shot signal  44  or the latching signal  31  is applied to the switch driver  32 . The one-shot signal  44  is a pulse that has a pulse width determined by the timing circuit  28 . In this example, the pulse width of the one-shot signal  44  is  60  seconds, but in other examples the pulse width can be set for other time periods. The one-shot signal  44  therefore provides a time window for the vehicle operator to start the vehicle.  
         [0037]     During the time window when the circuit between the first and second switch terminals  52  and  54  is closed, the switch  26  is enabled and the vehicle operator can turn an ignition key and the vehicle  10  will start. If the vehicle is not started during the time window, the switch driver circuit  32  disables the switch  26  by removing the switch control signal  58 . In this situation, the vehicle operator must press the button  15  on the RF transmitter  20  to enable the switch  26  again.  
         [0038]     If the ignition key is turned on during the time window ofthe pulse, the ignition coil driver  17  will provide electrical energy through the switch  26  to the ignition coil  16 , which then provides the electrical energy to a distributor (not shown) in order to start the vehicle. The latching circuit  30  senses the electrical energy at input  68  and provides the latching signal  31  to the switch driver  32 . In this situation, after the time window is over, and the one-shot signal  44  is removed from the switch driver circuit  32 , the latching signal  31  is still present and the switch driver circuit  32  still provides the switch control signal  58  to the switch  26 .  
         [0039]     Once the vehicle is started, pressing the button  15  on the transmitter  20  has no further effect on the operation of the vehicle since the latching signal  31  maintains the switch  26  closed. Only when the vehicle is turned off by turning off the ignition key will the electrical energy stop flowing through the switch  26 , at which point the latching circuit  30  no longer senses the electrical energy and removes the latching signal  31  from the switch driver circuit  26  thereby opening the switch  26 . At this point the electrical enabling device  14  prevents the vehicle from starting without the button  15  on the transmitter  20  firstly being pressed by the operator.  
         [0040]     It is understood that in other embodiments of the present invention, the switch  26  of the electrical enabling device  14  can form a segment of the connection  64  or a segment of the connection  66 , and the latching circuit  30  would accordingly sense electrical energy through the switch  26 , e.g. by sensing an electrical current.  
         [0041]     Referring now to  FIGS. 3 and 4 , in another embodiment of the present invention, wherein like parts to the previous embodiment have like reference numerals with an additional suffix “ 0 . 3 ”, there is an electrical enabling device indicated generally by reference numeral  14 . 3  comprising an RF transmitter  20 . 3  and an apparatus  22 . 3 .  
         [0042]     The RF transmitter  20 . 3  is similar to the previous RF transmitter  20  and further includes a button  81  that when actuated generates RF signal  83 . Button  15 . 3  of the RF transmitter  20 . 3  when actuated generates RF signal  35 . 3   
         [0043]     The apparatus  22 . 3  includes an RF receiver  24 . 3  similar to the RF receiver  24 , and which further includes an output  80 . Input  34 . 3  of the RF receiver  24 . 3  is responsive to both RF signals  35 . 3  and  83 . When the input  34 . 3  receives the RF signal  35 . 3  the RF receiver  24 . 3  produces signal  38 . 3  at output  36 . 3 . When the input  34 . 3  receives the RF signal  83  the RF receiver  24 . 3  produces control signal  84  at the output  80 .  
         [0044]     The apparatus  22 . 3  is similar to the apparatus  22  and further includes a switch driver circuit  85  and a switch  87 . The switch driver circuit  85  comprises an input  82  and an output  86 . The input  82  is connected to the output  80  of the RF receiver  24 . 3  and receives the control signal  84 . The output  86  is connected to the switch  87 . The switch driver circuit  85  is responsive to the control signal  84  and provides a switch control signal  90  at the output  86 .  
         [0045]     The switch  87  comprises an electromechanical relay (not shown) in this example and has a first switch terminal  92 , a second switch terminal  94  and a switch control input  88 . The switch control input  88  is connected to the output  86  of the switch driver circuit  85  and receives the switch control signal  90 .  
         [0046]     Normally, the switch  87 , between the first and second switch terminals  92  and  94 , is open and no electrical energy can flow between these terminals. When the switch control signal  90  is applied to the switch control input  88 , the switch  87  closes allowing electrical energy to flow between the terminals  92  and  94 .  
         [0047]     The first switch terminal  92  is connected to a terminal  96  on a car horn  99  by connection  100 . The second switch terminal  94  is connected to a negative terminal on battery  12  by connection  102 . A terminal  98  on the car horn  99  is connected to a positive terminal on the battery  12  by connection  104 . The battery  12 , the car horn  99 , the switch  87  and the electrical connections  100 ,  102 , and  104  form an electrical circuit indicated generally by reference numeral  106 .  
         [0048]     In operation, when a user actuates button  81  the electrical circuit  106  closes and the car horn sounds. The car horn sounds as long as the button  81  is actuated.  
         [0049]     The ability to sound the car horn is advantageous to scare intruders away from your vehicle without having to approach the vehicle itself. In another situation, if a vehicle operator is confronted outside their vehicle and is in fear, they can simply actuate the button  81  to sound the car horn in order to attract attention. In another useful application, if the vehicle operator can not locate their vehicle, e.g. within a parking lot, they can simple actuate button  81  on the RF transmitter  20 . 3  to sound the car horn in order to give them an indication of where the vehicle is located.  
         [0050]     Referring now to  FIGS. 5 and 6 , in another embodiment of the present invention, wherein like parts to the previous embodiments have like reference numerals with an additional suffix “ 0 . 5 ”, there is an electrical enabling device indicated generally by reference numeral  14 . 5  comprising an RF transceiver  20 . 5  and an apparatus  22 . 5 .  
         [0051]     The RF transceiver  20 . 5  comprises an RF receiver (not shown), an RF transmitter (not shown) and a bidirectional RF port  120 . The RF transceiver  20 . 5  receives an RF signal  122  at the port  120  and transmits an RF signal  124  therefrom.  
         [0052]     The apparatus  22 . 5  is similar to the apparatuses  22  and  22 . 3  and instead of the RF receivers  24  and  24 . 5  the apparatus  22 . 5  includes an RF transceiver  24 . 5  having a bi-directional RF port  126 , an output port  36 . 5  and a power port  128 . The RF transceiver  24 . 5  transmits the RF signal  122  from the RF port  126  and receives the RF signal  124  at the RF port  126 . The power port  128  is connected to a negative terminal on an ignition coil driver  17 . 5  by connection  130 . The output port  36 . 5  operates substantially the same as the outputs  36  and  36 . 3 .  
         [0053]     In operation, the electrical enabling device  14 . 5  is used to enable and disable the operation of an ignition circuit in a vehicle. In order for an operator to initiate operation of the vehicle they insert a key into the ignition and turn the key to start as is normally done. Turning the key enables the ignition coil driver  17 . 5  which then provides electrical energy to the RF transceiver  24 . 5 .  
         [0054]     Upon being energized, the RF transceiver  24 . 5  transmits the RF signal  122 , which is encoded, to the RF transceiver  20 . 5 , which receives and decodes the signal  122 . Normally the RF transceiver  20 . 5  is attached to the key and is therefore within range. The RF transceiver  20 . 5  must be in the range of the RF transceiver  24 . 5  and vice versa.  
         [0055]     If the decoded signal  122  is correct then the RF transceiver  20 . 5  transmits the RF signal  124 , which is also encoded, to the RF transceiver  24 . 5 , which then receives and decodes the signal  124 . If the decoded signal  124  is correct then the RF transceiver outputs an electrical control signal  38 . 5 . The operation of apparatus  22 . 5  following the output of the electrical control signal  38 . 5  is similar to that described in previous embodiments.  
         [0056]     When the key is removed from the ignition the ignition coil driver  17 . 5  is disabled and the electrical energy is removed from latching circuit  30 . 5  and the RF transceiver  24 . 5  and the vehicle therefore turns off. In order to start the vehicle again the above procedure must be repeated.  
         [0057]     As will be apparent to those skilled in the art, various other modifications may be made to the above described invention within the scope of the appended claims.