Abstract:
An anti-flicker and anti-glow switchable load apparatus to be installed in the light socket of a commonly powered electronic switching device, such as a motion activated light switch. An energy efficient light bulb or lamp, such as a cathode fluorescent lamp or light emitting diode is then screwed into the apparatus. A first embodiment of the present invention includes a switchable light source, a switchable load, a controller, and a voltage sensor. When the present invention in the first embodiment detects a higher voltage, thus indicating the lamp has been switched from the “off” state to the on state, the switchable load is disconnected, and the current is re-routed to pass through the energy efficient lamp.

Description:
REFERENCE TO RELATED APPLICATION 
     This patent application claims priority to U.S. provisional patent application entitled “CFL Anti Flicker Device,” having Ser. No. 61/562,425 filed on Nov. 21, 2011, the entirety of which is hereby incorporated by reference into the present patent application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to lighting circuitry, and more particularly, to lighting circuitry for stabilizing operation of a high efficiency lighting element activated by an automated switching apparatus, such as a light switch motion detector. 
     2. Description of Related Art 
     Higher efficiency lighting elements, such as Cold Cathode Fluorescent Lamp (CCFL), are becoming extremely popular due to the current “Green” movement. Current government mandates are requiring incandescent bulbs to be phased out of production in favor high efficiency fluorescent light bulbs, such as CCFLs and Light Emitting Diodes (LEDs). Within the next few years incandescent light bulbs are not expected to be available in the marketplace of the United States. 
     While fluorescent light bulbs provide higher power efficiency and longer life expectancy, fluorescent light bulbs had several negative factors. For instance, it has been discovered that fluorescent light bulbs do not function properly when connected to commonly powered electronic switching devices such as motion detectors, electronic timers, and other devices requiring a low current to pass through the lighting element to provide power to the electronic switching device while the lighting element is in the “off” state. This is typically required due to the wiring limitations of residential homes and other building structures, wherein a small current is required to pass through the lighting element in order to provide current to the electronic switching device. 
     While the phenomena of current leakage in the off state has existed for quite some time, it has not typically been a problem with incandescent light bulbs. The filament used in incandescent light bulbs allows small currents to pass through the incandescent light bulbs without lighting the bulb because the small current does not experience enough resistance to cause the filament to heat up and glow or light. 
     High efficiency lighting element, however, such as CCFLs and Light Emitting Diodes (LEDs) are very sensitive to low currents, thus causing LEDs to emit a soft glow and CCFLs to flicker when a low current passes through theses lighting elements. Low currents cause the ballasts in CCFLs to false start which results in the lamp flickering on and off. The false start of the ballast discharges capacitors in CCFL ballast, and since there is not a significant line voltage present in the off state, the CCFL will flicker on and off. This flickering can become quite bothersome and annoying to individuals in the area. Furthermore, the flickering is damaging to the overall life of the CCFL. 
     Accordingly, there exists a need to provide a convenient and easily installed apparatus by consumers that can eliminate the flicker and glow from high efficiency lighting elements using commonly power electronic switching devices. 
     ASPECTS AND SUMMARY OF THE PRESENT INVENTION 
     In order to achieve these goals, an aspect of the present invention is to provide an inexpensive and energy efficient apparatus that can be easily installed by consumers between a light socket and an energy efficiency lighting element for light sockets controlled by commonly powered electronic switching devices to prevent flickering and glowing of the energy efficient lighting element during the off state. 
     In order to achieve these aspects, the present invention provides an anti-flicker and anti-glow apparatus to be installed in the light socket of a commonly powered electronic switching device, such as a motion activated light switch. An energy efficient light bulb or lamp, such as a CCFL, a Cathode Fluorescent Lamp (CFL), or an LED is then screwed into the apparatus. The present invention does not require any additional wiring or installation procedures. The present invention is simply screwed into the source light socket, and the energy efficient lamp is screwed into a second socket within the present invention. 
     A first embodiment of the present invention includes a switchable light source, a switchable load, a controller, and a voltage sensor. A second embodiment of the present invention includes a switchable load, a controller, a local power supply, and a voltage sensor. Both embodiments of the present invention are designed to provide a minimal load for the minor current to pass through in the “off” state. When the present invention in the first embodiment detects a higher current passing through the minimal load, and therefore a higher voltage, thus indicating the lamp has been switched from the “off” state to the on state, the switchable load is disconnected, and the current is re-routed to pass through the energy efficient lamp. Thus, no power is wasted passing current through the switchable load in the “on” state. In the second embodiment, when the present invention detects a higher current passing through the minimal load, and therefore a higher voltage, thus indicating the lamp has been switched from the “off” state to the on state, current through the switchable load is turned off, and the power current is directed to pass through the energy efficient lamp. In the second embodiment, the load resistor is used to hold the voltage low across the hot and neutral line, thus keeping the CCFL from firing. 
     The foregoing has outlined, rather broadly, the preferred features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed invention and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention, and that such other structures do not depart from the spirit and scope of the invention in its broadest form. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a circuit diagram showing the insertion of an anti-flicker apparatus configured in accordance with the present invention into a conventional residential light socket wiring diagram; 
         FIG. 2  is a block diagram of an anti-flicker apparatus configured in accordance with a first embodiment of the present invention; 
         FIG. 3  is a circuit diagram of the block diagram shown in  FIG. 2 ; 
         FIG. 4  is a block diagram of an anti-flicker apparatus configured in accordance with a second embodiment of the present invention; and 
         FIG. 5  is a circuit diagram of the block diagram shown in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings,  FIG. 1  illustrates a circuit diagram  100  of a conventional light socket wiring diagram of a residential home and internal wall  102 , wherein a wall mounted, motion activated light switch  104  controlling an energy efficient light  106  is connected to a light socket  105  having a standard switched hot wire  107  and a standard neutral wire  109 . As the diagram illustrates, a complete circuit must be established between hot node  111  and neutral node  113  of the light switch socket  108  in order to power the auto switch, here a motion detector  104 , while the energy efficient lamp  106  is in the “off” state. While this is conventionally accomplished by passing a small current through the lamp  106  to complete the circuit and power the motion detector  104 , this results in flickering or a soft glow in energy efficient lamps, as discussed above in the background of the invention section. In order to overcome this deficiency in the prior art, the present invention provides an anti-flicker or anti-glow switchable load apparatus  110  to carry the current during the “off” state, thus by-passing the energy efficient lamp  106  in the first embodiment of the invention, and minimizing current to the energy efficient lamp in the second embodiment of the present invention, thereby both first and second embodiments of the present invention preventing flickering or glowing of the energy efficient lamp  106 . When the motion detector detects movement, and switches from an “off” state to an “on” state, thus providing increased voltage to the socket  105 , the anti-flicker switchable load apparatus  110  detects the increased voltage, and re-directs or increases current flow, depending upon the embodiment of the invention, to the lamp  106  instead of a switchable load contained within the anti-flicker switchable load apparatus. 
       FIG. 2  illustrates a block diagram of anti-flicker or anti-glow apparatus  10  configured in accordance with a first embodiment of the present invention. The apparatus  10  preferably is configured to be easily screwed into the original socket  12  of an electronically activated light source, such as an internal wall-mounted motion activated light switch using an energy efficient lamp  14 , such as a CCFL or a CFL. The energy efficient lamp is simply screwed into the light socket  18  of the anti-flicker apparatus  10 . 
     Block diagram  16  illustrates the internal electrical components of the anti-flicker apparatus  10  configured in accordance with a first embodiment of the present invention. Included in the anti-flicker apparatus  10  are a switchable load  20 , a controller  22 , a voltage sensor  24 , and a switchable light source  23 . In the illustrated embodiment, the switchable light source  25  is a Single-Pull Double-Through (SPDT) switch. The anti-flicker apparatus  10  is electrically connected between the light socket  12  and the energy efficient lamp  14 . During the “off” state, a minimal current passes though the switchable load  20 , thus preventing enough current to pass through the energy efficient lamp  14  to cause flicker or a soft glow. The voltage sensor  24  monitors the level of voltage between lines Hot (In) and Neutral. When the voltage level between lines Hot (In) and Neutral increases to a level to indicate the electronic switch, such as a motion sensor, has switched from an “off” state to an “on” state, the controller  22  will disconnect the Hot (In) line from switchable load  20 , and connect it to Hot (Out) line, thus re-directing all the current to the lamp  14 . 
       FIG. 3  is a circuit diagram corresponding to the block diagram shown in  FIG. 2 . The energy efficient lamp  14  is shown to be connected to the anti-flicker switchable load apparatus  16 . The anti-flicker switchable load apparatus  16  includes a normally open relay  26  and a low-load resistor  28 . The normally open relay  26  functions as the controller  22  and the voltage sensor  20 . The resistor  28  functions as the switchable load  20 . In the “off” state, the normal open relay  26  allows the small current, which provides power to the motion detector, to flow through line  27 , which is connected to open position “O” of relay  26 . The current passes through low-load resistor  28  to provide a complete circuit back to Neutral connection B  13 . While the relay  28  is in the normal open position “O”, no current flows to the lamp  14  via line  29  because it is an open circuit. While resistor  28  is illustrated as being 17 ohms, resistor  28  can be various low ohms values and still function properly. 
     When the motion detector detects movement and switches to the “on” state, the voltage level across nodes Hot (A) and Neutral (B) increases significantly, which is detected by the normally open “make before brake” relay  26 . Sensing the increased voltage, the relay  26  switches to the closed position “C,” thus allowing current to flow through line  29  to the lamp  14 , and then line  27  changes to an open connection. This design eliminates power loss across the resistor  28  during the “on” state. 
       FIG. 4  is a block diagram of an anti-flicker or anti-glow switchable load apparatus  50  configured in accordance with a second embodiment of the present invention. Illustrated is a motion detector  52  including a light socket  54  that is activated by the motion detector. The motion detector security light  52  is designed to be electrically connected and mounted to an electrical switch box for a light fixture having a “hot” wire connection  53  and a “neutral” wire connection  55 . The components of the anti-flicker switchable load apparatus  50  are illustrated in the block diagram  60  shown in  FIG. 4 . The anti-flicker switchable load apparatus  50  includes a socket  58  for receiving an energy efficient lamp  56 . 
     The block diagram  60  of the anti-flicker switchable load apparatus  50  include a switchable load  62 , a controller and local power supply  64 , and a voltage sensor  66 . Similar to the first embodiment, the switchable load  62  provides a path for the small current providing power to the motion detector during the “off” state. The voltage sensor  66  monitors the voltage level between the hot lead  53  and the neutral lead  55 . When the voltage level increases indicating that the motion detector  52  has detected an object and switched from the “off” state to the “on” state, the voltage sensor  66  detects the increase in voltage and signals the controller and local power supply  64 . The controller and local power supply  64  then opens the switchable load  62 , turning off current flow through the switchable load  62 , and maximizing the current flow through the energy efficient lamp  56 . When a decrease in voltage is detected by the voltage sensor  66 , thus signaling the motion detector  52  has switched back to an “off” state, the controller and local power supply  64  detects the voltage drop from the voltage sensor  66  and closes the switchable load  62  to re-direct current through the switchable load. This reduces the voltage to the CCFL, thus keeping it from falsely firing. 
       FIG. 5  is a circuit diagram of the block diagram  60  shown in  FIG. 4 . Resistors R 4  and R 5  function as the voltage sensor  66 , and micro-processor based control functions as the controller  64 . One suitable micro-processor that may be utilized in the illustrated circuit is a Texas Instrument micro-processor, part number MSP430F2001. Resistors R 2  and R 3  and mosfet Q 1  function as the switchable load. Diode bridge B 1 , diode D 1 , resistor R 1 , capacitor C 2 , and zener diode D 2  function as a power supply that is biased on. 
     The diode bridge B 1  converts 120 volts RMS to a full wave The first component is a diode bridge. It converts the 120V RMS to a full wave  180  VDC. The resistor R 1 , capacitor C 2 , and zener diode D 2  create a 3.3 v power supply to power the micro-processor  70 . The microprocessor  70  monitors the voltage across nodes E and F via sense line  72 , which is located between the resistor bridge R 4  and R 5 . The microprocessor is programmed to control the switchable load  62  to provide power for the motion detector  52  if the “off” state. 
     The switchable load  62  includes the mosfet Q 1  and the resistive load R 2 . The mosfet Q 1  has a shunt resistor R 3  on the gate to ensure the mosfet Q 1  is off during power up. The microprocessor  70  activates the mosfet Q 1  when current flow is necessary to provide power to the motion detector  52  and shuts it off when the motion detector  52  has turned on the light  56  so it does not waste power. This is accomplished though the gate control line  71  In this embodiment a microprocessor  70  was selected because of its price and ability to implement an intelligent switching load. 
     It should also be understood that the present invention is not limited to the specifically illustrated package designs. For example, the present invention also can be located within light socket fixture box, typically located within the ceiling of a home. Further, the present invention can be incorporated into various types of electronics switches, in addition to electronic switches such as motion detectors and electronic timers.