Patent Abstract:
A low-power illumination apparatus may be used in areas where conventional incandescent illumination would be unsafe, especially to children or small pets. The apparatus may be configured to appear as a window candle and can be safely installed in windows which are easily accessible to children. Safe application is accomplished by supplying a low-wattage bulb with a low voltage, providing a resettably-fused bulb supply within the apparatus to prohibit the use of high-wattage bulbs and an interlocking base attached to the window frame which prevents the apparatus from being inadvertently removed or tipped over.

Full Description:
FIELD OF THE INVENTION  
         [0001]    This invention generally relates to decorative illumination systems. More specifically, this invention relates to illumination systems for use in home or commercial edifices. More particularly, this invention relates to a low-power illumination apparatus that may be safely deployed in areas regularly occupied by or accessible to children or pets due to the low heat production by the apparatus. The subject invention is particularly adapted in certain embodiments to be mounted in the window sills of edifices to provide a decorative and safe illumination system. Additionally, the subject invention is directed to a decorative illumination system which may be built into a building&#39;s frame at the time of construction which permits most, if not all, of the necessary wiring to be hidden from the occupants&#39; view.  
         BACKGROUND OF THE INVENTION  
         [0002]    A persistent challenge in the field of illumination is the safe location of the illumination source in avoidance of the heat produced by the source. It has been established that the onset of pain due to excess heat corresponds with the temperature at which tissue damage occurs, 40° to 45° C., a temperature range far exceeded by traditional illumination systems. Thus, many desired illumination applications have been precluded for use in establishments where children have access to illumination systems due to hazardous levels of heat dissipated by the light source.  
           [0003]    Illumination safety is of particular concern in areas where children or pets have direct access to the illumination source. As children, and to a lesser degree pets, are drawn to and have a fascination with light, especially decorative lamps, great care must be taken to protect the child from injury by contact with a heated lamp. Generally, preventative measures in the past have involved placing the illumination source high above the floor or by surrounding the hot bulb with a screen or a shade. However, these measures are not available in such lighting applications as electric window candles, which utilize a bare bulb in openly accessible windows.  
           [0004]    As demonstrated by the foregoing discussion, there exists a need for a decorative illumination device that may be safely placed in low lying areas without the requirement of screen, shade, or other extraneous protective measures. Additionally, there exists a need for an illumination system wherein the required wiring and other system elements remain inaccessible to and hidden from view, such that the possibility of electrical accidents and injury is diminished.  
         SUMMARY OF THE INVENTION  
         [0005]    The low-power illumination apparatus of the present invention provides decorative illumination while dissipating heat at a temperature below the hazardous temperatures discussed above. Thus, the present invention can be utilized in low lying areas wherein children and pets may have access.  
           [0006]    In a preferred embodiment of the instant invention, the low-power illumination apparatus is configured to appear as an electric candle placed on the sill of a window. In actuality, the window candle is fixedly secured to the window sill by means of a base mounting plate, which is electrically coupled to low voltage house wiring, e.g., 24 VAC.  
           [0007]    An illumination housing forming the candle portion of the illumination apparatus is slidably received into the base mounting plate and is electrically and mechanically coupled thereto. The illumination housing encloses a power conversion circuit which reduces and regulates the low voltage house wiring to a final lamp voltage, e.g., 12 VDC. Electrically interposed between the power conversion circuit and the lamp of the illumination housing is a resettable fuse, which opens if the power consumption of the bulb installed exceeds the safety threshold imposed by the invention.  
           [0008]    The low-power illumination apparatus of the present invention includes a decorative base collar configured to appear as the candle holder portion of the window candle. The lower surface of the decorative base collar has formed thereon a recess corresponding in shape and size to the base mounting plate.  
           [0009]    When the decorative base collar is in place, the illumination housing is prevented from being slidably removed from the base mounting plate as lateral motion is prohibited by the recess of the base collar being in contact with the base mounting plate. However, when it is desired to remove the illumination housing from the base mounting plate, one simply removes the base collar first and the sliding removal of the illumination housing is easily performed. With the illumination housing removed, the base mounting plate may be protected by the application of a cover. The cover also prevents children and pets from having access to the low voltage electrodes installed on the base mounting plate.  
           [0010]    The low-power illumination of the present invention affords a variety of decorative effects by providing interchangeable components of the low-power illumination apparatus. The invention includes interchangeable decorative base collars as well as interchangeable decorative sleeves for changing the appearance of the illumination housing. Furthermore, a variety of different shaped lamps or bulbs may be used, provided they do not exceed the predetermined wattage safety level.  
           [0011]    Still further, all operating components and connections may be formed in the frame of the edifice and/or hidden from external view to lessen the possibility of accidents occurring where an individual may be injured.  
           [0012]    A further object of the present invention is to provide an auxiliary circuit in the illumination housing of the low-power illumination apparatus. The auxiliary circuit may embody an intruder alarm sensor, e.g., a shock vibration detector, an IR detector or a continuity loss detector, which can be deployed in each window opening where the low-power illumination apparatus is installed.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a perspective view of the subject system mounted in the window sill of an edifice;  
         [0014]    [0014]FIG. 2 is a perspective view of the present invention with decorative elements removed to show structural elements;  
         [0015]    [0015]FIG. 3 is a perspective exploded view of the present invention showing operative elements;  
         [0016]    [0016]FIG. 4 is a perspective exploded view of the details of the coupling mechanism between the illumination housing and the base mounting plate of the present invention;  
         [0017]    [0017]FIG. 5 is a perspective exploded view of the base mounting plate of the present invention showing wiring features;  
         [0018]    [0018]FIG. 6A, FIG. 6B, and FIG. 6C are illustrations of the decorative base collar of the present invention;  
         [0019]    [0019]FIG. 7 is an exploded view illustration of the illumination housing of the present invention;  
         [0020]    [0020]FIG. 8 is a schematic diagram of the voltage converter circuit of the present invention;  
         [0021]    [0021]FIG. 9 is a perspective exploded view of the coupling mechanism between the illumination housing and the base mounting plate of a three-contact embodiment of the present invention; and, FIG. 10A and 10B are block circuit diagrams showing the connection of an auxiliary circuit to the power conversion circuit of the three-contact embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    Referring to FIG. 1, the low-power illumination apparatus of the present invention, generally indicated at  10 , is shown in a configuration having the appearance of a window candle. The window candle is designed to appear as though it is set upon a window sill  100  where, in fact, as will be shown in paragraphs that follow, the window candle is fixedly attached to window sill  100 . The details of the electrical and mechanical attachment of the low-power illumination apparatus are hidden by a decorative base collar  40 .  
         [0023]    The window candle illustrated in FIG. 1 includes an illumination housing  30  having coupled thereto a low-power electric lamp  20 . Illumination housing  30 , and therethrough low-power lamp  20 , is supplied electrical power via low voltage wiring  110 . The low-voltage wiring  110  may be coupled to a low-voltage power source (not shown) such as a 24 VAC supply found in typical modern homes.  
         [0024]    Low-power lamp  20  is preferably a low-wattage incandescent bulb, and may be formed in the shape of a candle flame or any other desired configuration. The bulb is threadably inserted into a lamp socket (shown in FIG. 6) and may thereby be interchanged with bulbs of different shapes. However, the power consumption or heat dissipation must be held to safe levels to prevent injury to overly curious persons or pets. In a preferred embodiment of the invention, low-power lamp  20  is a 2 W incandescent bulb driven by 12 VDC. Preferably, low-power lamp  20  produces heat at a temperature less than 45° C.  
         [0025]    Several such window candles may be wired in parallel to achieve a desired decorative effect. As shown in FIG. 1, a low-voltage source is coupled to an individual window candle through low-voltage wiring  110  and is further coupled to low-voltage wiring  120 . Low-voltage wiring  120  is then routed to provide electrical power to another low-power illumination apparatus  10  in the parallel chain of window candles.  
         [0026]    Referring to FIG. 2, the low-power illumination apparatus  10  is shown with decorative base collar  40  removed from the lower portion of illumination housing  30 . Beneath decorative base collar  40  and fixedly attached to window sill  100  is base mounting plate  60 , to which illumination housing  30  is mechanically coupled to securely maintain its upright orientation. Electrical coupling is concurrently effected by this mechanical coupling of base mounting plate  60  to illumination housing  30 , such that electrical power is provided to low-power lamp  20  via lamp driving circuitry as discussed in paragraphs that follow.  
         [0027]    As is illustrated in FIG. 2, illumination housing  30  may be optionally fitted with a decorative sleeve  50  to alter the appearance of the window candle in some way. Decorative sleeve  50  may be of a different color or may carry an aesthetically pleasing design thereon. Decorative sleeve  50  is sized to fit snugly over illumination housing  30 , i.e., decorative sleeve  50  is equivalent in length to illumination housing  30  and has an inner cross-sectional diameter substantially equivalent to the exterior cross-sectional diameter of illumination housing  30 . When used, decorative sleeve  50  is placed over illumination housing  30  and decorative base collar  40  is placed over decorative sleeve  50  to complete the appearance of a free-standing window candle.  
         [0028]    As is illustrated in FIG. 3, illumination housing  30  is removable from base mounting plate  60  to provide flexibility in decorating using the low-power illumination apparatus  10  of the present invention. Illumination housing  30  may be removed completely, or may be replaced by an illumination housing of a different size or shape. The removal and replacement of illumination housing  30  are easily performed without the use of tools.  
         [0029]    In a preferred embodiment of the invention, base mounting plate  60  has formed thereon a stopped groove  65  for slidable receipt of mating extension  70  disposed on illumination housing  30 . Mating extension  70  and stopped groove  65  engage in an interlocking arrangement that prevents illumination housing  30  from being inadvertently tipped over or lifted up away from base mounting plate  60 .  
         [0030]    Referring to FIG. 4, there is shown in detail the coupling arrangement between illumination housing  30  and base mounting plate  60 . As is shown, base mounting plate  60  is electrically coupled to low-voltage wiring  110  at electrodes  63   a ,  63   b  for providing low-power to illumination housing  30 . Electrodes  63   a ,  63   b  and low-voltage wiring  110  are also electrically coupled to low-voltage wiring  120  for providing low power to a separate window candle or other low-power electrical device. In the preferred embodiment, low-voltage wiring  110 ,  120  are routed within the wall framing about the given window sill  100  to emerge from hole  150  formed in window sill  100  so as to allow coupling to base mounting plate  60 . With the electrical connection in place, base mounting plate  60  is fixedly attached to window sill  100  by screws  61   a ,  61   b  or other suitable fastening means.  
         [0031]    Base mounting plate  60  is preferably molded from flame retardant, UV-stabilized, polymeric thermoplastic material such as acrylonitrile butadiene styrene (ABS) and, as previously stated, has formed thereon stopped groove  65  for slidably receiving mating extension  70  of illumination housing  30 . Stopped groove  65  preferably formed with one open end at groove opening  67 . The end of stopped groove  65  opposite groove opening  67  is closed so as to prevent the illumination housing  30  from being slid past a position of optimum alignment of electrical contacts.  
         [0032]    The surface forming the bottom of stopped groove  65  is installed with two elongated electrodes  63   a ,  63   b . Electrodes  63   a ,  63   b  are accessibly disposed within elongated electrode openings  64   a ,  64   b  to be recessed relative to the bottom surface of stopped groove  65 , situated for alignment with the illumination housing electrodes  73   a ,  73   b . Each electrode  63   a ,  63   b  is electrically coupled to a corresponding conductor of either or both of low-voltage wiring  110 ,  120 . Moreover, electrodes  63   a ,  63   b  are preferably plated with a metal such as gold to prevent corrosion due to humidity, condensation, and other environmental conditions typically encountered around windows.  
         [0033]    Extending laterally into stopped groove  65  from upper portions of opposing walls formed thereabout are protuberances  66   a ,  66   b . The protuberances  66   a ,  66   b  retentively engage with mating extension  70  to prevent illumination housing  30  from being decoupled from base mounting plate  60  by a longitudinally directed force.  
         [0034]    As stated hereinabove, illumination housing  30  has coupled thereto a mating extension  70  for sliding receipt in stopped groove  65  of base mounting plate  60 . Mating extension  70  has formed on opposing walls thereof elongated grooves  76   a ,  76   b  (elongated groove  76   b  not visible in the view shown) for slidably engaging with protuberances  66   a ,  66   b  of base mounting plate  60 . Elongated grooves  76   a ,  76   b  are formed in mating extension  70  so that the lower lip of grooves  76   a ,  76   b  are thinner than protuberances  66   a ,  66   b  of base mounting plate  60 . Thus, an excessive lateral force applied to the upper portion of illumination housing  30  will result in the breaking of mating extension  70  and not in the breaking of base mounting plate  60 . In this regard, mating extension  70  incorporates a selected point of failure, given that it is normally less difficult to replace a broken illumination housing  30  than it is to replace a broken base mounting plate  60 .  
         [0035]    Mating extension  70  has further formed on an end thereof a pair of slotted openings  75   a ,  75   b  through which a pair of illumination housing electrodes  73   a ,  73   b  emerge for electrical coupling to electrodes  63   a ,  63   b  of base mounting plate  60 . Illumination housing electrodes  73   a ,  73   b  are preferably constructed from thin wire to form resilient wiper springs  73   a ,  73   b  and are, like electrodes  63   a ,  63   b , preferably plated with gold. As will be discussed in further paragraphs, wiper springs  73   a ,  73   b  are electrically coupled to voltage conversion circuitry for supplying power to low-power lamp  20 .  
         [0036]    To engage illumination housing  30  in base mounting plate  60 , illumination housing  30  is held in an upright orientation so that elongated grooves  76   a ,  76   b  are aligned with protuberances  66   a ,  66   b  of base mounting plate  60  at groove opening  67 . Illumination housing  30  is then slid into stopped groove  65  until mating extension  70  is fully inserted and stopped within stopped groove  65 . In this position, wiper springs  73   a ,  73   b  will be in contact with electrodes  63   a ,  63   b  and electrical coupling between illumination housing  30  and base mounting plate  60  will be established. Further, as wiper springs  73   a ,  73   b  are formed from a resilient material, wiper springs  73   a ,  73   b  will bias the bottom walls of elongated grooves  76   a ,  76   b  against protuberances  66   a ,  66   b  thereby preventing illumination housing  30  from wobbling or leaning within stopped groove  65 . Once illumination housing  30  has been fully seated in base mounting plate  60 , one or both of the optional decorative sleeve  50  and decorative base collar  40  may be slid over illumination housing  30 , as previously discussed.  
         [0037]    When illumination housing  30  is removed from base mounting plate  60 , base mounting plate  60  may be protected by a cover plate  80  as shown in FIG. 4. Cover plate  80  may be manufactured from an elastic material, such as rubber, and may be optionally fitted with means for attachment to window sill  100  so as to prevent its unintentional or unauthorized removal.  
         [0038]    The internal structure of the wiring mechanism of the low-power illumination apparatus is shown in FIG. 5. As is illustrated, base mounting plate  60  is assembled from a mounting clip  610 , a pair of electrodes  63   a ,  63   b  and a wire lock mechanism  620 . The combination of elements that form base mounting plate  60  provides a compact, fool-proof wiring mechanism for interconnecting a plurality of window candles.  
         [0039]    The wiring mechanism is made compact by the configuration of electrodes  63   a ,  63   b , each of which serve three main functions. First, the planar electrode bodies  635   a ,  635   b  of electrodes  63   a ,  63   b  are positioned beneath the surface of stopped groove  65  to be at least partially revealed through elongated electrode opening  64   a ,  64   b . The revealed portions of electrodes  63   a ,  63   b  are accessible for contact by wiper springs  73   a ,  73   b  of the illumination housing&#39;s mating extension  70 , as discussed hereinabove.  
         [0040]    The second function performed by electrodes  63   a ,  63   b  is providing electrical continuity between low-voltage supply wiring  110  and low-voltage branch wiring  120 . In other words, a leg of low-voltage wire set  110  is electrically coupled to a leg of wire set  120  by one electrode  63   a , and the other leg of wire set  110  is electrically coupled to that of wire set  120  by electrode  63   b.    
         [0041]    Finally, the third function performed by the electrodes  63   a ,  63   b  is providing the mechanical means for making the electrical connection between low-voltage wiring  110 ,  120 . Each electrode  63   a ,  63   b  has formed thereon a pair of insulation displacement spurs  632 . When base mounting plate  60  is fully assembled, insulation displacement spur  632  pierces the insulation of one leg of low voltage wiring  110 ,  120  at each end of electrodes  63   a ,  63   b  and is embedded in the conducting region sheathed therein.  
         [0042]    A mounting clip  610  provides both mounting means for the base mounting plate  60  as well as an enclosure for safely encasing the wiring mechanism. Mounting flange  615  extending outward from mounting clip  610  provides a structure by which base mounting plate  60  may be firmly fastened to window sill  100 . On the underside of mounting flange  615 , there is formed a cylindrical shell  611  which serves as the wiring mechanism housing. Cylindrical shell  611  has formed thereon a plurality of longitudinal ribs  616 . When base mounting plate  60  is inserted into a properly sized hole  150  in window sill  100 , longitudinal ribs  616  engage the walls of hole  150  to prevent rotation of base mounting plate  60  when screws  61   a ,  61   b  have not been installed.  
         [0043]    The interior walls of cylindrical shell  611  have formed thereon a pair of longitudinally oriented alignment keys  612   a ,  612   b . The alignment keys  612   a ,  612   b  are complementary features to a plurality of keyways  622   a ,  622   b  formed in wire lock  620 . Alignment keys  612   a ,  612   b  ensure the correct orientation of the wire lock  620  with respect to electrodes  63   a ,  63   b  so that base mounting plate  60  is properly wired.  
         [0044]    Wire lock  620  serves to ensure the correct wiring of base mounting plate  60 , providing a plurality of wire guides  624   a - 624   d  and a wire pairing channel  625 . Wire pairing channel  625  is centrally located on wire lock  620  and comprises a substantially square hole having formed on two opposing walls thereof an inwardly protruding cable separator  627   a ,  627   b . Low voltage wiring pair  110  is inserted through wire pairing channel  625  on one side of cable separator  627   a ,  627   b  and low voltage wiring pair  120  is threaded through wire pairing channel  625  on the other side of cable separator  627   a ,  627   b . In so doing, each conductor of low voltage wiring pairs  110 ,  120  is in its proper position in wire lock  620  so as to facilitate the correct interconnection of conductors by electrodes  63   a ,  63   b  during full assembly of base mounting plate  60 .  
         [0045]    After low voltage wiring  110 ,  120  has been threaded through wire pairing channel  625 , the individual conductors thereof are separated and laid into the wire guides  624   a - 624   d . Wire pairing channel  625  is oriented so that the separate conductors of low voltage wiring pairs  110 ,  120  emerge adjacent to one of the wire guides  624   a - 624   d . The individual conductors of low voltage wiring pairs  110 ,  120  and may then be coupled by electrodes  63   a ,  63   b  in the manner described above.  
         [0046]    To assemble base mounting plate  60 , electrodes  63   a ,  63   b  are positioned over a corresponding one of electrode mounting studs  614   a ,  614   b  such that insulation displacement spurs  632  are in close proximity to the interior wall of cylindrical shell  611 . Each of the electrodes  63   a ,  63   b  are then pushed onto electrode mounting stud  614   a ,  614   b  and held in place by a plurality of prongs projecting inward on stud receiving aperture  634 . Thereafter, with low voltage wiring  110 ,  120  positioned in wire lock  620  as described above, keyways  622   a ,  622   b  formed in circumferential wall  628  are aligned with alignment keys  612   a ,  612   b  of mounting clip  610 , and wire lock  620  is pressed into the interior of cylindrical shell  611 . In this manner, insulation displacement spurs  632  are pressed into the individual conductors of low voltage wiring  110 ,  120  in the manner described above, and base mounting plate  60  is then electrically coupled to the low voltage wiring system. Wire lock  620  is retained within the cylindrical shell  611  of mounting clip  610  by screws  626   a ,  626   b.    
         [0047]    Decorative base collar  40  of the low-power illumination apparatus  10  serves not only an aesthetic function, but also serves to prevent illumination housing  30  from being inadvertently removed from base mounting plate  60 . As illustrated in FIG. 6A, the underside of decorative base collar  40  has formed thereon a recess  45  corresponding in shape and size to base mounting plate  60 . Thus, when illumination housing  30  is placed in longitudinal bore  43 , and decorative base collar  40  is allowed to slide to the bottom of illumination housing  30 , recess  45  of decorative base collar  40  will envelop base mounting plate  60  so that lower rim  47  of decorative base collar  40  is placed in direct contact with the surface of window sill  100 . As illumination housing  30  may only be removed from base mounting plate  60  by the sliding action described above, illumination housing  30  may not be removed with decorative base collar  40  fully in place. Illumination housing  30  is prevented from lateral motion by recess  45  engaging with the edges of base mounting plate  60 .  
         [0048]    [0048]FIGS. 6B and 6C illustrate two alternative candle holder styles. In accordance with the present invention, decorative base collar  40  may embody any candle holder style but should incorporate longitudinal bore  43  and recess  45  to provide the safety feature described in the previous paragraph.  
         [0049]    Referring to FIG. 7, the construction of illumination housing  30  is illustrated in detail. Illumination housing  30  includes a cylindrical housing tube  35  having coupled at one end thereof mating extension  70 . Housing tube  35  and mating extension  70  are preferably molded from flame-retardant, ultraviolet-stabilized ABS. In the preferred embodiment, mating extension  70  is formed from two identical complementary half-cylindrical sections  71   a ,  71   b  which, when mated together along a longitudinally bisecting plane, form the cylindrical mating extension  70 . The mated sections of mating extension  70  are inserted into one end of housing tube  35  and are held therein by a snap-fit mechanism of known type. When housing extension member  70  is in its fully seated position, circumferential ridge  77  contacts the periphery of the end of housing tube  35 .  
         [0050]    In the end of housing tube  35  opposite the mating extension  70 , a circuit board  200 , having constructed thereon a voltage conversion circuit  1100 , is inserted so that wiper springs  73   a ,  73   b  are positioned in slotted openings  75 . With the end of circuit board  200  extending past the end of housing tube  35  opposite to that in which it was inserted, the two halves of housing extension member  70  are mated to enclose the end of circuit board  200  in circuit board retaining slot  72  such that wiper springs  73   a ,  73   b  protrude from slotted openings  75   a ,  75   b  and circuit board notch  210  is engaged with boss  74 . In this arrangement, circuit board  200  is prohibited from moving longitudinally within housing tube  35 . Thus, the force of wiper springs  73  against electrode  63  of base mounting plate  60  is transferred to the entire illumination housing  30  so as to promote even contact between elongated grooves  76   a ,  76   b  of mating extension  70  and protuberances  66   a ,  66   b  of base mounting plate  60 .  
         [0051]    With circuit board  200  placed in circuit board retaining slot  72  and notches  210  engaged with bosses  74 , the assembled housing extension member  70  containing circuit board  200  is inserted into housing tube  35 . At the opposite end of housing tube  35 , lamp socket  90  is inserted and is held in place by friction fit engagement. Lamp socket  90  and housing tube  35  may contain relative motion prevention means so as to prevent lamp socket  90  from spinning within the end of housing tube  35  when low-power lamp  20  is threaded into lamp socket  90 .  
         [0052]    Referring to FIG. 8, a voltage conversion circuit  1100  is schematically depicted. The voltage converter circuit  1100 , constructed on circuit board  200 , is used to decrease the voltage level for supplying power to low-power lamp  20 . In the preferred embodiment, the voltage supplied to power converter circuit  1100  is 24 VAC and the voltage level supplied by power converter circuit  1100  is 12 VDC. In FIG. 8, 24 VAC is provided at J 1  which is electrically coupled to wiper springs  73   a ,  73   b  of circuit board  200 . The 24 VAC is rectified by full-wave rectifier U 1  and filtered to a DC level by capacitor C 1 . Breakdown diode D 1  is provided as transient voltage relief.  
         [0053]    The rectified DC voltage is coupled to the input of voltage converter chip U 2 , which is preferably an LM2575 step-down voltage regulator manufactured by National Semiconductor Corporation or an equivalent integrated circuit. Voltage converter chip U 2 , in conjunction with Schottky diode D 2  and energy storage inductor L 1 , form the basis of a step-down regulator for producing 12 VDC. Output filter capacitor C 2  performs the final filtering of the DC voltage.  
         [0054]    The load voltage of the power converter circuit taken at output filter capacitor C 2  is protected by resettable fuse F 1 . In the preferred embodiment, resettable fuse F 1  is a polymeric positive temperature coefficient device whose input impedance increases dramatically, i.e., to essentially an open circuit, at a predetermined threshold temperature. The threshold temperature is reached when an over-current condition exists and, once the over-current condition is removed and the device has cooled, the polymeric positive temperature coefficient device will return to a low impedance state.  
         [0055]    The protected output voltage is supplied to J 2  which is electrically coupled to lamp socket  90 . Thus, when a lamp having a higher than specified power consumption level or heat dissipation temperature is threaded into lamp socket  90 , resettable fuse F 1  will “trip” and will remain in a high impedance state until a lower wattage bulb is threaded into lamp socket  90 .  
         [0056]    In an alternate embodiment of the present invention, the window candle&#39;s proximity to and positioning within the boundaries of a window opening are advantageously exploited. One or more window candles in a decorative illumination system is equipped with an auxiliary circuit such as an alarm sensor which when disturbed by a would-be intruder, activates an alarm. The auxiliary circuit or alarm sensor may be a shock/vibration sensitive circuit, infrared detector, or may be as simple as an electrical continuity type sensor which would trigger an alarm if an illumination housing  30  is removed from base plate  60  without authorization such as being upset by an intruder entering through the window.  
         [0057]    [0057]FIG. 9 illustrates an exemplary electrical contact configuration which could be used to provide means for transmitting a signal from an auxiliary circuit. As is shown in the Figure, mating extension  70  has formed thereon three slotted openings  75   a ,  75   b ,  75   c  through which three illumination housing electrodes  73   a ,  73   b ,  73   c  extend. Correspondingly, base mounting plate  60  includes three electrodes  63   a ,  63   b ,  63   c  which are revealed in elongated electrode openings  64   a ,  64   b ,  64   c . As in the previous embodiment, electrodes  63   a ,  63   b  and corresponding wiper springs  73   a ,  73   b  are used to supply power to the circuitry within illumination housing  30 . The third electrode  63   c , and corresponding wiper spring  73   c , can be used to carry an alarm indication or any other appropriate signal from an auxiliary circuit also located in illumination housing  30 . The auxiliary circuit may be constructed on the same circuit board  200  on which the voltage conversion circuit previously described is constructed.  
         [0058]    [0058]FIGS. 10A and 10B illustrate possible wiring configurations of auxiliary circuit  1200  to voltage conversion circuit  1100 . In the circuit of FIG. 10A, power to auxiliary circuit  1200  is derived directly from the external power source and would be directly coupled to wiper springs  73   a ,  73   b . The output of auxiliary circuit  1200  would be carried over wiper spring  73   c  and would be electrically coupled to a remote receiver such as centrol alarm system. FIG. 10B illustrates a similar circuit where power to auxiliary circuit  1200  is derived from the output of voltage conversion circuit  1100  as, in the preferred embodiment, voltage conversion circuit  1100  supplies DC power.  
         [0059]    Although the invention has been described herein in conjunction with specific embodiments thereof, many alternatives, modifications and variations will be apparent to those skilled in the art. The present invention is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended Claims.

Technology Classification (CPC): 5