Abstract:
An apparatus and method for controlling a plurality of lighting fixtures. A start controller provides power to the plurality of lighting fixtures. A control power timer connected to the start controller provides a first time period for illumination of the plurality of lighting fixtures, wherein the start controller is operable to interrupt power to the plurality of lighting fixtures when the first time period expires. A control timer connected to the control power timer provides a second time period for illumination of the plurality of lighting fixtures, wherein the second time period commences and then elapses before the end of the first time period. A control flasher connected to the control timer alternates the plurality of lighting fixtures between a high power state and a low power state during the second time period for illumination. An end user is alerted to the termination of the illumination of the plurality of lighting fixtures before termination occurs.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a method and apparatus for controlling lighting fixtures and, more particularly, to a method and apparatus for alerting occupants in a lighted area that the timing cycle of the lighting fixtures is due to expire.  
         BACKGROUND OF THE INVENTION  
         [0002]    Many recreational facilities require a significant number of lighting fixtures for adequate illumination and, therefore, use a significant amount of power to operate the fixtures. To reduce power consumed to light these facilities, a number of facilities use lighting control systems which control when the lighting fixtures are energized. For example, a step-dimming system, such as the two-level lighting control system disclosed in U.S. Pat. No. 5,216,333 to Nuckolls, can be used to switch facility fixtures between energy saving, low-level or reduced wattage operation, and full-level or normal wattage operation in accordance with output signals from a motion sensor. Step-dimming systems can respond to other conditions besides occupancy levels such as ambient light level, time and manual switching. U.S. Pat. No. 4,713,598 to Smith discloses another device for controllably switching an AC line to energize a load. The device uses a passive infrared (PIR) detector to sense motion.  
           [0003]    However, PIR sensors do not work well in outdoor conditions. Temperature and sun light can affect the sensing ability of these types of sensors. Additionally, timing devices can be used; however, it can be difficult to set a suitable time out (TO) period. For example, it is difficult to anticipate the amount of time period an occupant needs a facility and preprogram a corresponding time out period. This problem is particularly apparent with respect to recreational facilities because the time a user requires a recreational facility can vary depending on the users, and the game or event.  
           [0004]    Another problem with existing lighting control devices is that the end user does not know when illumination of lighting fixtures, which are subject to time out operation, will end. For instance, if an end user reserves a facility for two hours and does not monitor the amount of time that has elapsed, the illumination of the facility may terminate unexpectedly, creating sufficient darkness in the facility to make it difficult for the end user to find the lighting control and reset the timer.  
           [0005]    Another problem with existing lighting control devices is that they only interface with a low voltage two-wire lighting fixture. There presently is no lighting control device that interfaces with a high voltage two-wire lighting fixture.  
           [0006]    Therefore, a lighting control system is needed to provide time out periods that can be used outdoors, as well as indoors, that is not subject to temperature or extraneous lighting conditions, that can be reset by an end user before a facility goes dark and that is easy to operate by the end user. It would also be useful to have a lighting control system that can interface with fixtures in either of an industrial or commercial power system (e.g. 480 VAC) and a residential power system (e.g., 120 VAC).  
         SUMMARY OF THE INVENTION  
         [0007]    An apparatus and method for controlling a plurality of lighting fixtures are provided. The apparatus comprises a start controller for providing power to the plurality of lighting fixtures. A control power timer is connected to the start controller for providing a first time period for illumination of the plurality of lighting fixtures, wherein the start controller is operable to interrupt power to the plurality of lighting fixtures when the first time period expires. A control timer is connected to the control power timer for providing a second time period for illumination of the plurality of lighting fixtures, wherein the second time period commences and then elapses before the end of the first time period. A control flasher is connected to the control timer for alternating the plurality of lighting fixtures between a high power state and a low power state during the second time period for illumination. An end user is alerted to the termination of the illumination of the plurality of lighting fixtures before termination occurs.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    The details of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:  
         [0009]    [0009]FIG. 1 is a schematic diagram of a switched level activity monitor (SLAM) constructed in accordance with an embodiment of the present invention;  
         [0010]    [0010]FIG. 2 is a front view of an exemplary face panel box for the SLAM depicted in FIG. 1;  
         [0011]    [0011]FIG. 3 depicts an exemplary configuration for circuit components of the SLAM within the panel box;  
         [0012]    [0012]FIG. 4 is a schematic diagram of the SLAM of FIG. 1 and its components in FIG. 3; and  
         [0013]    [0013]FIG. 5 is a schematic diagram of a SLAM constructed in accordance with another embodiment of the present invention. 
     
    
       [0014]    To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0015]    Although the present invention is described for use in recreational facilities, the present invention can be used in other types of facilities and still fall within the scope of this invention. It will be appreciated by those skilled in the art that the term recreational facilities includes, but is not limited to, tennis courts, batting ranges, golf driving ranges, and the like. In addition, the present invention can be practiced at indoor and/or outdoor facilities.  
         [0016]    [0016]FIG. 1 depicts a circuit schematic diagram of a switched level activity monitor (SLAM) circuit in accordance with a first embodiment of the present invention. The SLAM  100  comprises a power source  102 , a power switch  104 , a start controller  106 , a first relay  108  operable in conjunction with the start controller  106 , a keylock power switch  110 , a light emitting diode (LED)  112 , a control power timer  114 , an override switch  116  operable in conjunction with the control power timer  114 , a control timer  118 , a resistor  120 , a control flasher  122 , a second relay  124  operable in conjunction with the control flasher  122 , a hot line  126 , a neutral line  128 , a contactor control hot line  130 , a contactor control neutral line  132 , a fixture control hot line  134  and a fixture control neutral line  136 .  
         [0017]    The operation of the SLAM  100  will now be described. The power source  102  is connected to the neutral line  128  and to the hot line  26  via the power switch  104 . Thus, when power is supplied to the circuit via power source  102 , the SLAM  100  receives power when the power switch  104  is closed.  
         [0018]    In one embodiment, the SLAM  100  can interface with a commercial or industrial power system (e.g., 480 VAC) voltage line and control a plurality of lights (not shown). SLAM  100  can be used in a high intensity discharge (HID) dimming system. However, those skilled in the art will appreciate that the present invention may be used in other types of lighting systems.  
         [0019]    In still another embodiment of the invention, SLAM  100  can interface with a low voltage line and control a plurality of lights. SLAM  100  controls the plurality of lights directly in both the high voltage and low voltage applications. No intermediate device is required.  
         [0020]    In addition to being the main power switch for SLAM  100 , the power switch  104  is also the main power switch for the lighting fixtures (not shown) being controlled by the SLAM  100 . By closing power switch  104 , power is supplied to contactor control hot line  130  and contactor control neutral line  132  which are respectively connected to hot line  126  and neutral line  128 . The two contactor control lines  130 ,  132 , in turn, are connected to a control coil (not shown) of lighting contactors that are attached to the lights being powered. Specifically, closing power switch  104  causes power to be supplied to the lights.  
         [0021]    Start controller  106  is connected to neutral line  128  via pin  3 , to hot line  126  via pin  3 , and to keylock power switch  110  and first relay  108  via pin  1 . When power switch  104  is closed, the start controller causes the first relay  108  to close which, in turn, causes power to be delivered to the fixture control hot line  134  and fixture control neutral line  136 . The two fixture control lines  134 ,  136  are connected to a bi-level relay (not shown) which is in each one of the plurality of lights. Accordingly, the SLAM  100  controls the bi-level relays in the plurality of lights.  
         [0022]    The start controller  106  is preferably a 15 minute “start-at-high” controller. Light manufacturers require an initial 15 minute interval before full power is applied to the plurality of lights for warranty reasons. Start controller  106  is only reset if there is an interruption in power to the SLAM  100 . For example, if there is an electrical outage, start controller  106  will be reset, and the plurality of lights will be allowed to warm up for 15 minutes when power is restored. After the initial, timed warm-up period, the lights can return to the low power state, and the main control function is enabled.  
         [0023]    The keylock power switch  110  serves as a manual override. Closing the contacts of keylock power switch  110  closes first relay  108 . Thus, there is no ability to use the timing features of the SLAM  100  since power is applied directly to first relay  108  and not via the start controller  106 . Therefore, the plurality of lights remain at full power until keylock power switch  110  is turned off. Keylock power switch  110  can be useful for maintenance purposes, special events or for the initial burn-in of new lights, among other uses.  
         [0024]    In the present embodiment of the invention, first relay  108  and second relay  124  are in parallel. Either relay being powered can cause the fixture control lines  134 ,  136  to go high. The two relays operate as a logical “or” gate. Therefore, the closing of either or both of the relays results in the fixture control lines  134 ,  136  going high.  
         [0025]    The closing of either power switch  104  and/or keylock power switch  110  applies power to LED  112 , which is bridged across hot line  126  and neutral line  128  and provides a visual indication that the SLAM  100  is receiving power.  
         [0026]    The control power timer  114  is connected to the hot line  126  via pin  1 , and pin  3  is connected to the neutral line  128 . Pin  4  is connected to over-ride switch  116  which is, in turn, connected to neutral line  128 . Pin  2  is connected to pin  1  of control timer  118 . Pin  2  of control power timer  114  is also connected to second relay  124  which is, in turn, connected to pin  1  of control flasher  122 . Pin  3  of control timer  118  is connected to the neutral line  128  and to resistor  120  which is also connected to pin  2  of control timer  118  and to pin  3  of control flasher  122 . Pin  2  of control flasher  122  is connected to the neutral line  128 .  
         [0027]    Resistor  120  can be a power resistor. The resistor  120  drains excess charge which may build up when solid state devices such as control timer  118  and control flasher  122  are connected together. Specifically, resistor  120  maintains the proper operation of the two devices and prevents faults such as residual charge build up from occurring and turning on the two devices improperly.  
         [0028]    When power is applied to SLAM  100  and power switch  104  is closed, power is supplied to the contactor control lines  130 ,  132 . After a 15 minute warm up period, start controller  106  closes first relay  108 . The control power timer  114  operates the main timing for the SLAM  100 . Its timing is adjustable to provide the desired duration of a lighting cycle. Timing adjustment can be implemented via manual initiation by a user using, for example, a push button switch (not shown) connected to the timer  114  or the override switch  116 . Accordingly, the plurality of lights are operated for a variable amount of time based on the setting of the control timer  114 . The time setting or “lighting cycle” may vary from 15 minutes to 100 minutes. More specifically, the plurality of lights can operate at full power or “high” during the lighting cycle and then go to a no power or low light setting condition when the lighting cycle has elapsed. However, those skilled in the art will appreciate that a timer having a length of time different from the above mentioned timer may be substituted and still fall within the scope of the present invention.  
         [0029]    The power timer  114  also serves to operate control timer  118  directly and control flasher  122  indirectly. Prior to the lighting cycle expiring, the power timer  114  commences a delay period corresponding to a period of time before the expiration of the lighting cycle during which the lights are flashed to indicate to a user that the lighting cycle is about to expire. Power timer  114  activates control timer  118  at the beginning of the delay period via pin  1  of control timer  118 . Control timer  118  is a delay-on-make-interval type relay and delays closing its relay for some pre-set time, then closes for a pre-set interval, then reopens again. The control timer  118  activates the control flasher  122  for the delay period whereby the control flasher  122  applies power to second relay  124  closing the second relay  124  which, as previously discussed above, brings the plurality of lights to full power. During normal operation, the plurality of lights operate at full power during the lighting cycle. However, in accordance with an aspect of the present invention, one of the pins of the control flasher  122  is switched to neutral via control timer  118 . Control flasher  122  being a dual mode relay, acts a flasher oscillating its output from high to low. Second relay  124 , in turn, oscillates from high to low via pin  1  of control flasher  122 . The plurality of lights, in response to second relay  122  oscillating from high to low, also oscillate from high to low during the delay period. The oscillation from high to low during the delay period alerts the user of the recreational facility that the period for illumination of the recreational facility is about to expire. The user, therefore, has until the delay period expires to reset the power timer  114  via the push button switch.  
         [0030]    In a first embodiment of the present invention, an end user may press over ride switch  116  during the delay period which will cause power timer  114  to begin a new period of illumination once the delay period ends, that is, the original period of illumination will expire based on power timer  114  finishing its time period. A new period of illumination cannot begin until the original period of illumination comes to an end based on power timer  114  finishing its timing cycle to completion.  
         [0031]    In another embodiment of the present invention, an end user presses override switch  116  during the delay period, which causes power timer  114  to begin a new period of illumination instantly before the delay period expires. Specifically, the power timer  114  resets its timer during the delay period initiating a new period of illumination.  
         [0032]    It will be appreciated by those skilled in the art that according to the teachings of the present invention, the end user has control over the period of illumination. The end user may use the facility for the initial period of illumination or may seek to extend the period of illumination. The end user is alerted to the need to extend the period of illumination via the flashing of lights as opposed to being in a facility and finding oneself to be in the dark once the period of illumination has expired.  
         [0033]    The SLAM  100  circuit preferably includes the components listed in the following table:  
                                   DEVICE   COMPONENT                   104   Power Switch       106   15 Minute Solid State Timer       108   120 Volt Relay       110   Key Switch       112   125 Volt Light Emitting Diode       114   Adjustable Delay-On-Make Timer       116   Push Button Switch       118   Adjustable Delay-On-Make Timer       120   10K Ohm 20 Watt Resistor       122   Adjustable Dual Mode           Timer/Flasher       124   120 Volt Relay                  
 
         [0034]    Turning now to FIG. 2, an exemplary layout for a face panel box  200  for the SLAM  100  is depicted. The buttons, switches and LED are structured and arranged to allow an end user and/or facility ower or maintenance person easy access to the switches, buttons and LED. It will be appreciated by those skilled in the art that the buttons, switch and LED can be arranged in a different arrangement and still fall within the scope of the invention. For instance, power switch  104  is displayed on the face of the box  200 . However, the invention may be practiced where access to power switch  104  may require opening the box  200  with a key. This may prevent end users who do not have legal access to the facility from turning on the lights of the facility without having a key to box  200 .  
         [0035]    [0035]FIG. 3 depicts a diagram showing an exemplary layout for the SLAM  100  within the panel box  200 . FIG. 3 includes all of the components of FIG. 1 in addition to power terminal block  138 , power bus block  140  and contact terminal block  142 . The main power source is connected to power terminal block  138 . In turn power terminal block  138  is connected to contact terminal block  142 , power bus block  140 , contactor control neutral line  132 , contactor control hot line  130  and fixture control hot line  134  (see FIG. 4). The components for the SLAM  100  circuit are supplied power via the power bus terminal  140  and contact terminal block  142 .  
         [0036]    Turning to FIG. 5, an alternative embodiment for SLAM  100  is depicted. Specifically, FIG. 5 depicts a programmable processor  300  suitable for use in the SLAM  100  circuit. The programmable processor  300  comprises a microprocessor  302 , as well as memory  304  for storing programs for various timing functions. The microprocessor  302  cooperates with conventional support circuitry  306  such as power supplies, clock circuits and the like, as well as circuits that assist in executing the timer functions of the present invention. A user interface device  310  such as a keypad is provided to enter selected time out periods.  
         [0037]    The programmable processor  300  also comprises input/output circuitry  308  that forms an interface between the microprocessor  302 , first relay  108 , second relay  124 , contactor control hot line  130 , contactor control neutral line  132 , fixture control hotline  134 , fixture control neutral line  136  and override switch  116 . The input/output circuitry  308  can interface with lines  130 ,  132 ,  134  and  136  extending to different groups of light fixtures such that these groups can be programmed to operated independently of each other and in accordance with different lighting cycles and delay periods that are programmed from a single, convenient control point (e.g., via the user interface  310 ).  
         [0038]    Although the programmable processor  300  is depicted as a general purpose computer that is programmed to perform the timer functions of start controller  106 , control power timer  114 , control timer  118  and control flasher  122  in accordance with the present invention, the invention can be implemented in hardware, in software, or a combination of hardware and software. As such, the timer functions described above with respect to the various figures are intended to be broadly interpreted as being equivalently performed by software, hardware, or a combination thereof.  
         [0039]    Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention can be described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification and the following claims.