Abstract:
A modular self-diagnostic assembly for controlling diagnostic, charge and transfer functions necessary to operation of fluorescent emergency lighting packs also referred to as inverters or fluorescent battery packs used particularly in emergency lighting systems such as are configured for operation with fluorescent lighting fixtures and the like. Self-test/self-diagnostic circuitry contained within a module separate from an emergency lighting pack functions as an add-on accessory to existing emergency lighting packs without need for modification of structure or circuitry of the lighting pack. The self-diagnostic module of the invention connects electrically and mechanically to the lighting pack through appropriate leads terminated by an appropriate header and further connects mechanically and electrically to a test switch module through appropriate leads terminated by an appropriate header. The resulting physical assembly is modular in concept with a first housing containing the conventional emergency lighting pack, or inverter, a second housing separate from the first housing and containing circuitry for controlling diagnostic, charging and transfer functions, the self-diagnostic module contained by the second housing connecting to the test switch module. Particular circuitry which can be incorporated into the self-diagnostic module provides control and self-test functions although other circuitry capable of appropriate function can be contained within the self-diagnostic module.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to self-test and/or self-diagnostic systems used with emergency battery packs which provide emergency functions for lighting fixtures including fluorescent lighting fixtures, the invention particularly relating to a modular self-diagnostic assembly configured as an add-on accessory for existing emergency lighting packs without the need for modification of such packs. 
     2. Description of the Prior Art 
     Standard lighting fixtures such as fluorescent lighting fixtures are commonly provided with an emergency lighting capability by installation of appropriate inverter circuitry in the form of “battery pack” systems as are described inter alia in U.S. Pat. No. 5,202,608 and 5,814,971 to Johnson, these patents being subject to assignment to the present assignee, Acuity Brands, Inc., of Atlanta, Ga., doing business in the lighting industry under the name of Lithonia Lighting. The patents to Johnson describe circuitry embodied in fluorescent emergency battery packs known in the industry under the trademark “Power Sentry”, the present invention being configured to provide a self-test or self-diagnostic function to the emergency battery packs of the Power Sentry series as well as to emergency battery packs generally as are known in the art. The ability to test and perform diagnosis of failures in such battery packs has become a desirable practice in the industry. Previously available self-test or self-diagnostic capability has taken the form of circuitry incorporated into the emergency lighting pack itself, this prior circuitry typically acting to test proper function of inverter circuitry including charging circuitry as well as battery and lamp status. Such circuitry typically functions through use of a test switch electrically connected to the circuitry which is to be tested so that a test button or the like can be manually operated to accomplish the testing function. Timing circuitry of conventional configuration is also known in the art for automatically performing testing and diagnostic functions at specified intervals, such circuitry typically being integrated into the emergency pack and being configured within a common housing containing inverter and other circuitry comprising the emergency pack. Integration of testing and/or diagnostic circuitry directly into that circuitry comprising the inverter function and housed by a single housing has required modification to such emergency battery packs both structurally and electrically. Retrofitting of existing packs with self-diagnostic circuitry has been difficult at best in prior art practice in view of the necessity for modification of existing packs to accommodate such circuitry. A need has thus existed in the industry for an advance that allows an emergency capability to be provided to a standard lighting fixture through installation of an emergency pack to which a self-diagnostic function can be incorporated without the need for modification of the pack. This need exists in newly installed lighting systems as well as in retrofit situations where lighting fixtures are already in place having emergency packs operable with such fixtures. 
     Conventional fluorescent emergency lighting packs ordinarily provide for manual testing of such packs by means of an externally connected test switch and indicator lamp electrically connected to a high voltage AC power input of the pack. Operation of such a test switch simulates a power failure so that a user can test and confirm operation of the pack under the simulated conditions of an emergency, that is, the loss of mains power. Such conventional indicators verify that a battery of a conventional pack is in a charging state. Indicators of this type are located within the emergency pack housing except for at least a portion of the indicator lamp which extends from the pack at a location convenient for viewing by a user who is manually testing the pack. As described in U.S. patent application Ser. No. 09/865,913, filed May 24, 2001, the patent application being subject to an assignment to Acuity Brands, Inc., a test switch and indicator is provided with a separate housing externally of the pack housing and is connected electrically and mechanically through insulated leads and a suitable connector to an emergency pack, the switch and indicator being electrically connected to a low voltage portion of the emergency pack as dictated in the pending patent application identified above, the test switch and indicator being mounted on a printed circuit board and contained by an appropriate housing which is preferably formed of a plastic material. The connector described in the patent application also acts to enable inverter circuitry of the emergency pack for emergency operation and further to prevent the pack when the connector is not connected to the pack from operating in the event AC power is not present. The invention of the patent application reduces product cost and simplifies external wiring. 
     A prior emergency lighting system embodying the teachings of U.S. Pat. No. 5,416,384 to Bavaro incorporates a battery module and a power module, the power module acting to operate a lamp when AC mains power is available to the lighting system while the battery module drives lamping when AC mains power is absent such as occurs during emergency conditions. This prior lighting system does not provide the advantages occasioned by the present invention in that a self-test and/or self-diagnostic module is not provided by the prior system. The prior system does not therefore provide the capability of incorporating a self-test and/or self-diagnostic function into an existing emergency lighting pack without modification to the pack whether in a new installation or in a retrofit situation. 
     Accordingly, the present invention provides utility not found in existing emergency lighting systems by providing teachings including dense multi-board assembly, large product packaging, dedicated product formats and the ability to upgrade previously installed packs with self-test and/or self-diagnostic capabilities. The present invention provides advantages not previously available in the art through embodiment of a modular system concept wherein self-test and/or self-diagnostic circuitry is contained within a module housing and connected through a lead and connector assembly to a low voltage portion of an existing emergency pack, the self-test/self-diagnostic module being further connected by a lead and connector assembly to a test switch and indicator module contained by a housing separate from the module housing containing the self-test and/or self-diagnostic circuitry. While the modular concept of the invention can include various self-test and/or self-diagnostic circuitry including known circuitry, the invention is preferably provided with circuitry particular to the invention for control and other functions including power conversion, boost enable and automatic self-configuration on determination of the nature of a battery forming a portion of an emergency pack. 
     SUMMARY OF THE INVENTION 
     The invention provides in a modular form self-test and/or self-diagnostic circuitry contained within a housing and forming a portion of an emergency lighting system and having the ability to impart self-test/self-diagnostic function to emergency lighting packs used to incorporate emergency capability into standard lighting systems. According to the invention, a housing containing the self-test and/or self-diagnostic circuitry is separate from structure housing circuitry and components of an emergency lighting pack to which the self-test and/or self-diagnostic circuitry adds the testing and/or diagnostic function. Functions including charging and transfer functions are also provided by circuitry housed within the diagnostic module, the diagnostic module being an add-on accessory to existing emergency lighting packs without the need for modification of such lighting packs. 
     The diagnostic module of the invention further provides particular circuitry contained within the diagnostic module for accomplishment of diagnostic and control functions although it is to be recognized that conventional or other circuitry capable of providing necessary diagnostic, control and other functions can be utilized as the circuitry contained in the diagnostic module of the invention. Functions produced by circuitry contained within the diagnostic module of the invention include performance of manual or scheduled tests such as by means of low voltage operation, cooperation with a test switch and indicator lamp located externally of the diagnostic module, conversion of battery voltage levels present in battery structures housed within an emergency lighting pack to a regulated DC voltage of a predetermined level, detection of the on and off state of lamping of the lighting system for postponement of scheduled tests, and automatic self-reconfiguration for operation with battery structures of differing voltages. 
     The diagnostic module of the invention operates in concert with a separately contained test switch and indicator lamp external of the module and connected to the module by conventional leads and a connector. The test switch and indicator lamp permit manual testing of the emergency lighting pack through connection with the diagnostic module to produce a visual indication of the operational worthiness of the pack. 
     Accordingly, it is an object of the invention to provide a self-contained module capable of accomplishment of self-test and/or self-diagnostic and other functions indicative of an acceptable potential for operation of an emergency lighting pack or emergency battery pack which imparts an emergency capability to standard lighting fixtures and particularly to ballasted fluorescent lighting fixtures, the module being separate from the pack and connectable to the pack without modification of the pack, thereby permitting incorporation of the test and diagnostic functions to packs installed as original equipment or as retrofitting to a previously installed pack. 
     It is another object of the invention to provide a modular system incorporating the functions of an emergency battery pack within a first module, self-test and/or self-diagnostic as well as control and other functions within a second module, and a test switch and indicator lamp module, the modules being interconnected by appropriate leads and connectors and functioning to impart an emergency capability to standard lighting fixtures. 
     It is a further object of the invention to provide control functions within a diagnostic module which are provided through the agency of one or more microprocessors to convert battery voltage levels within a given range to a regulated DC voltage of a predetermined level. 
     It is yet another object of the invention to provide a diagnostic module with the ability to automatically reconfigure itself to operate with emergency lighting packs having differing battery voltages. 
     It is a still further object of the invention to provide a self-contained module capable of accomplishment of self-test/self-diagnostic and other functions indicative of an acceptable potential for operation of an emergency lighting pack, the module containing particular circuitry capable of test, diagnostic, control and other functions necessary and desirable to operation of the emergency pack and the lighting fixture to which the pack imparts emergency capability. 
     It is another object of the invention to provide a self-contained module capable of accomplishment of self-test/self-diagnostic and other functions indicative of an acceptable potential for operation of an emergency lighting pack which comprises any useful circuitry capable of necessary and desirable functioning of the pack and the lighting fixture to which the pack imparts emergency capability. 
     Further objects and advantages of the invention will become more readily apparent in light of the following detailed description of the preferred embodiments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an idealized perspective view of a diagnostic module of the invention operatively associated with an emergency lighting pack and a test switch and indicator lamp as a portion of a system capable of installation with standard lighting fixtures either as original equipment or retrofitted to impart an emergency capability to the standard lighting fixture; 
     FIG. 2 is a block diagram illustrating components of the diagnostic module and emergency lighting pack and test switch of FIG. 1 in an operational interrelationship; 
     FIGS. 3A,  3 B and  3 C each form portions of a schematic of the system shown generally in FIG. 2; and, 
     FIG. 4 is a circuit diagram illustrating electrical connection of the diagnostic module and test switch to inverter circuitry with which the invention finds utility. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIG. 1, a system capable of providing an emergency lighting function to a standard lighting fixture (not shown) is seen at  10  to comprise an emergency lighting pack  12 , often referred to in the art as an emergency battery pack, a diagnostic module  14  and a test switch and pilot light indicator  16 . The emergency lighting pack  12  can take the form of the circuitry described inter alia in U.S. Pat. Nos. 5,202,608 and 5,814,971, the disclosures of these patents being incorporated hereinto by reference. Emergency lighting packs such as the pack  12  are conventionally used to provide an emergency lighting function to standard lighting fixtures and particularly to fluorescent lighting fixtures operable with either magnetic or electronic ballasts (not shown). The lighting pack  12  conventionally comprises a pack housing  18  which contains inter alia inverter circuitry and at least one battery and is conventionally mounted to or in association with a conventional lighting fixture operated in a known fashion through a ballast device by AC mains power. On discontinuation of normal power to the fixture, the pack  12  functions to recognize the absence of AC power and to convert operation of the fixture from normal AC power to DC typically provided by a battery (not shown) contained within the pack housing  18 . 
     The emergency lighting pack  12  is provided conventionally with a four-wire insulated lead  20  which extends from the pack housing  18  and terminates in a conventional connector  22 . The lead  20  contains four wires (not seen in FIG. 1) that connect to circuitry located internally of the pack housing  18  as will be described hereinafter. The diagnostic module  14  is provided with a first four-wire insulated lead  24  which extends from module housing  26  and terminates in a conventional connector  28 , the connector  28  mating in a conventional manner with the connector  22  terminating the lead  20  of the lighting pack  12 . The diagnostic module  14 , even though referred to only as the “diagnostic” module for simplification of reference, should be understood to include functions including but not limited to self-test functions, self-diagnostic functions, control functions and other functions as well as combinations thereof as will be apparent from the context and particular description herein provided. The diagnostic module  14  contains circuitry and components thereof within the module housing  26  that provide the aforesaid functions to the lighting pack  12  without the need for modification of the lighting pack. Cost reduction, inventory reduction and standardization are thus accomplished through modular configuration of the diagnostic module  14  and of the system as described herein. The existence in the present system of the diagnostic module  14  having the functional capabilities described herein negates the requirement for modification of existing lighting packs such as the pack  12  as has been necessary in practices of the prior art for incorporation of circuitry and the like necessary to produce such functions into the pack  12  itself. In essence, the testing, diagnostic, control and other functions provided by the circuitry contained within the diagnostic module and associated therewith can be accomplished through use of an add-on accessory which takes the form of the diagnostic module  14 . 
     The diagnostic module  14  is further provided with a two-wire insulated lead  30  which extends from the module housing  26  and terminates in the test switch and pilot light assembly  16  which is of modular conformation by virtue of containment essentially within indicator housing  32 . The test switch and pilot light indicator  16  preferably takes the form of one of the structures described in copending U.S. patent application Ser. No. 09/865,913, filed May 24, 2001 and entitled “LED Test Switch and Mounting Assembly”, and subject to an assignment to Acuity Brands, Inc., the disclosure of Ser. No. 09/865,913 being incorporated hereinto by reference. Prior art indicator assemblies such as are described in Ser. No. 09/865,913 as well as other indicator structure suitable for function in the manner intended for cooperation with the diagnostic module  14  and the lighting pack  12  can be used as the indicator  16 . Further description of the indicator  16  is not necessary herein due to the disclosure provided by the aforesaid copending patent application. In use with the system  10  of this invention, the indicator  16  when utilized as intended provides a visual indication of the operational worthiness of the lighting pack  12  inter alia. In the aforesaid copending patent application, indicators which can function as the indicator  16  are provided for direct connection to a lighting pack such as the pack  12  to provide a manual test function as described in said patent application, such function being absent a self-test or self-diagnostic capability as is provided by the system  10  of this invention. In the system  10  of the present invention, the indicator  16  is capable of low voltage operation from low voltage provided to the indicator  16  through the diagnostic module  14  which in turn is powered by connection through the lead  20  to a low voltage portion of the pack as will be described hereinafter. 
     Circuitry of particular configuration which can be advantageously contained within the diagnostic module  14  is shown generally in FIGS. 3A,  3 B and  3 C, the circuitry being too extensive to be shown on a single pace, the circuitry being referred to as circuitry  34  and encompassing the circuitry of FIGS. 3A,  3 B and  3 C as continuously operable circuitry. The circuitry  34  is located on a divided circuit board represented by a board perforation line at  36 , the circuit board being illustrated by the line  36  to represent separation of the circuit board into two essentially equal parts allowing stacking of said parts to provide volumetric efficiency within the confines of the module housing  26 . The circuitry  34  of FIGS. 3A,  3 B and  3 C is described generally in relation to FIG. 2 as a part of the system  10  comprising the pack  12  and the indicator  16 . Particular description of the circuitry  34  of FIGS. 3A,  3 B and  3 C will be provided hereinafter following description of the system  10  as functionally seen in the diagram of FIG.  2 . 
     The system  10  of the invention is generally shown in FIG. 2 absent a representation of the lighting pack  12  which is conventional. FIG. 2 generally illustrates the circuitry  34  contained within the diagnostic module  14  as well as the indicator  16  as seen in the illustration. With the exception of the indicator  16  and beeper  38 , the remaining representational blocks of the diagram of FIG. 2 are circuits, circuitry components or representations of function incorporated into the circuitry  34  contained within the diagnostic module  14 . Low voltage DC seen at  40  by the module  14  is provided for operation of said module  14  by connection of the module to the lighting pack  10  (not shown in FIG.  2 ). Circuitry is provided at  42  for sensing power supply and charging current applied to a battery (not shown in FIG. 2) located in the lighting pack  12 , the lighting pack  12  as aforesaid not being shown in FIG.  2 . Input from the sensing circuitry  42  is provided to microprocessor  44  which controls circuitry seen at  46 , the circuitry  46  functioning as a power supply clamp and for sensing of brown-out conditions. A boost converter and regulator circuit  48  provide input to the microprocessor  44  which utilizes input thereto to control the circuit  48  in part in order to provide a regulated DC voltage, such as 5 volts, even though battery voltage levels can vary within a range such as from 2 to 8 volts. The circuit  48  is capable of a power converting function which provides regulated DC voltage. The circuit  48  functions with input from battery voltage sensing circuitry  50  for connection to a battery (not shown in FIG. 2) contained within the lighting pack  16 , the circuitry  50  sensing the voltage of such a battery and supplying input also to the microprocessor  44 . An enabling function is provided by FEBP inverter control circuitry seen at  52 , the circuitry  52  connecting to the lighting pack for control of inverter circuitry (not shown in FIG. 2) contained within the lighting pack  12 . The circuitry  52  is controlled in turn by the microprocessor  44 . Control of EEPROM  54  is also provided by the microprocessor  44 , the EEPROM  54  being a memory device capable of storing configuration variables necessary for decision formulation, the logging of stored variables for providing records of brown out and other events, low voltage disconnection, failures, etc. The EEPROM  54  maintains a library of information even in the absence of battery or AC power. The circuitry  34  embodies the capability of detecting the on or off state of lamping (not shown) of a lighting fixture (not shown) with which the system  10  functions to provide an emergency lighting capability, detection of the state of such tamping enabling postponement of scheduled testing. The circuitry  34  further enables reconfiguration of itself automatically to operate with particular lighting packs represented by the lighting pack  12 , such packs having batteries of differing voltages and configurations as represented by 3.6, 4.8, 6.0 battery models as well as higher voltage battery models. 
     Referring now again to FIGS. 3A,  3 B and  3 C, the circuitry  34  which is preferably contained within the diagnostic module  14  is seen in detail. It is to be understood that diagnostic circuitry of differing description can be utilized as circuitry contained within the module  14 , said circuitry being capable of various testing, diagnostic, control and other functions as are necessary and desirable for operating and being operational with a lighting pack such as the lighting pack  12  and such as can find utility within the concept of the system  10 . 
     That portion of the circuitry  34  carried on one-half of the circuit board represented by the board perforation line  36  is conveniently referred to as circuit  56  while that portion of the circuitry  34  carried by the other half of the circuit board and providing control functions is conveniently referred to as circuit  58 . The circuits  56  and  58  are electrically interconnected through board-to-board ribbon cables  60  and  62 , each conductor of each of the ribbon cables  60  and  62  being respectively numbered for connection to like-numbered pin locations of microprocessors  64  and  66  the microprocessor  66  provides a timing function and is set for astable operation with control pin  5  thereof having a portion of the DC voltage regulated to a constant voltage such as 5 volts. The microprocessor  66  thus comprises a portion of a fixed frequency unregulated pulse width modulator which comprises a power converter wherein the modulator is configured for boost operation with linear low voltage dropout regulator  68 . The boost conversion function is provided by inductor  70 , transistor switch  72 , diode  74  and filter capacitor  76 . The boost converter so configured is enabled through astable operation of the timer function of the microprocessor  64  to vary boost ratio by a function of two to three. Linear regulation provided by the microprocessor  64  provides for the desired 5 volt DC output for microprocessor and support circuitry. Resistor  78  and zener diode  80  form an active load to limit boost voltage under no-load conditions. Reset pin  4  of the microprocessor  64  is used to enable boost conversion function depending on battery voltage level as sensed by the microprocessor  66  by means of resistor  82 , capacitor  84  and resistor  86 , thereby allowing shutdowns of the boost conversion function when adequate battery voltage is detected and a default boost operation during initial power is realized. The on or off state of lamping (not shown) of a lighting fixture (not shown) to which emergency function is provided by the system  10  of the invention is accomplished through the ability of the microprocessor  64  to detect internal body diode temperature which is a function of the temperature rise of the lamping. The temperature detection thus provided is processed by software to determine whether the lamping is in an on or off condition. Sensing of battery voltage is processed through software programmed conventionally into the microprocessor  64  so that the microprocessor  64  after a predetermined time and testing schedule can determine the type of battery according to voltage which is present in the lighting pack  12 . 
     Referring now to FIG. 4, it is to be seen at 81 that an inverter circuit identical to the circuit shown in FIG. 1 of U.S. Pat. No. 5,814,971 is reproduced with the exception that the numerals of the Figure of U.S. Pat. No. 5,814,971 are each modified by inserting the numeral “1” before each of the numerals as seen in 5,814,971. As an example, the numeral “60” of 5,814,971 is thus converted to numeral “160” in FIG.  4 . The inverter circuitry of FIG. 4 is provided herein to indicate the locations of the circuitry to which the wires of the lead  20  are electrically connected. As is indicated in FIG. 4, wires  194  and  196  of inverter circuitry  181  connect through the lead  20  of FIG. 1 with the two-wire lead  30  via the diagnostic module  14  to the indicator  16 . The other two wires of the four-wire lead  20  connect to the “RED” wires of FIG.  4  and electrically connect through the connectors  22 ,  28  with the circuitry  34  of the diagnostic module  14 . Connection of red wire  152  is to battery enable line  65  of the circuit  34  while connection of the red wire  154  from the pack  12  is to line  63  of the circuit  34 , the line  63  carrying positive battery voltage. Sensing of AC line voltage is accomplished through the relay coils  155 ,  157  and  159  of a relay formed by said coils. Inference of AC line voltage and charge current is the differential between V BATT  and V ENABLE  as indicated in FIG.  4 . The inferred voltage and characteristics of the relay formed by the coils  155 ,  157  and  159  infers charge current. Control function is thus accomplished and a steady voltage is provided to the microprocessors  64  and  66  of the circuit  34 . 
     It is to be understood that the invention can be practiced other than as explicitly shown and described herein without departing from the scope of the invention as intended and as recited in the appended claims.