Abstract:
A ballast to power a lamp includes two switches, each to selectively connect the ballast to respective high voltage terminals, each having two states (ON and OFF). The ballast also includes a converter circuit that provides a voltage to energize the lamp, and a detector circuit. The detector circuit includes two inputs, each coupled to a respective switch; two resistors, each coupled to a respective input; two outputs, each connected to the converter circuit; a transistor network; and a capacitor. One output provides the converter circuit with power, and is connected to the input via the resistors. The other provides the converter circuit with a control signal, indicating a voltage level so as to power the lamp to a particular light level, depending on the switches&#39; states. The transistor network detects a differential voltage between the inputs, generating the control signal as a result. The capacitor smoothes the control signal.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to lighting, and more specifically, to control circuits for electronic lighting ballasts. 
       BACKGROUND 
       [0002]    Multiple level lighting systems allow a user to set the level of light the user desires to receive from the lamp or lamps within the lighting system. For example, a two level lighting systems allows the user to select between two different levels of light: full on, such that the lamp or lamps in the lighting system is/are at their maximum output setting, and half on, such that the lamp or lamps in the lighting system is/are at half of their maximum output setting. As a result, multiple level lighting systems are typically used in overhead lighting applications, to give the user a choice between levels of light. 
         [0003]    A typical implementation of a two level lighting system includes two power switches and two ballasts. Each power switch in the lighting system controls only one of the ballasts in the lighting system. Turning on both of the switches at the same time powers both ballasts, thus producing full light output from the lighting system. Turning on only one of the switches applies power to only one of the ballasts in the lighting system and thus results in a reduced light level and a corresponding reduction in power consumed. 
       SUMMARY 
       [0004]    The conventional two level lighting system described above suffers from a variety of deficiencies, most notably in economy. It is more economical to use only a single ballast instead of the two ballasts typically found in the conventional two level lighting system. For compatibility purposes, the single ballast would be required to operate from the same two power switches used in the two ballast system. When both switches are closed, the ballast would operate in a full light mode. Conversely, when only one of the two power switches is closed, the ballast would operate in a reduced light mode. 
         [0005]    Embodiments of the present invention provide a multiple level lighting system using a single ballast that overcomes the deficiencies of the conventional two level lighting systems. In particular, embodiments are directed to a ballast having a first switch and a second switch that selectively connect the ballast, respectively, to a first power line and to a second power line. The ballast includes a lighting system converter circuit that provides voltage to energize one or more lamps connected to the ballast, and a detector circuit that controls the lighting system converter circuit based on the states of the first and second switches. The detector circuit is self-powered via the first power line and the second power line. 
         [0006]    The magnitude of the voltage provided by the lighting system converter circuit varies so that the one or more lamps operate at multiple lighting levels. In some embodiments, the one or more lamps are operated at either full output or half output based on the states of the first and second switches. The detector circuit includes a transistor network to detect the states of the first and second switches and generates a direct current (DC) control signal that controls the magnitude of the voltage provided to the one or more lamps by the lighting system converter circuit. 
         [0007]    In an embodiment, there is provided a ballast to power at least one lamp from an alternating current (AC) voltage supply. The ballast includes: a first switch adapted to selectively connect the ballast to a first high voltage terminal of the AC voltage supply, the first switch having an on state and an off state; a second switch adapted to selectively connect the ballast to a second high voltage terminal of the AC voltage supply, the second switch having an on state and an off state; a lighting system converter circuit to provide voltage suitable to energize the at least one lamp; and a detector circuit. The detector circuit includes: a first input terminal coupled to the first switch; a second input terminal coupled to the second switch; a first resistor R 1  connected to the first input terminal; a second resistor R 2  connected to the second input terminal; a first output terminal connected to the lighting system converter circuit, wherein the first output terminal provides a supply current to the lighting system converter circuit to power components of the lighting system converter circuit, and wherein the first output terminal is connected to first input terminal via the first resistor R 1  and to the second input terminal via the second resistor R 2 ; a second output terminal connected to the lighting system converter circuit, wherein the second output terminal provides a control signal to the lighting system converter circuit, the control signal indicating one of a plurality voltage levels for providing to the at least one lamp to energize the at least one lamp as a function of the states of the first and second switches, wherein each voltage level corresponds to a different lighting level generated by the at least one lamp; a transistor network to detect a differential voltage between the first input terminal and the second input terminal and to generate a control signal as a function thereof; and a capacitor connected to the transistor network to smooth the control signal from the transistor network to provide a substantially direct current (DC) control signal. The lighting system converter circuit receives the DC control signal via the second output terminal of the detector circuit and provides voltage to the at least one lamp as a function of the DC control signal. 
         [0008]    In a related embodiment, the transistor network may include a first transistor and a second transistor, each having a base, an emitter, and a collector, wherein the emitter of the second transistor and the base of the first transistor may be connected to the first switch via the first resistor, and wherein the emitter of the first transistor and the base of the second transistor may be connected to the second switch via the second resistor. 
         [0009]    In another related embodiment, the detector circuit may further include an overvoltage protection circuit. In a further related embodiment, the overvoltage protection circuit may include a first diode having an anode and a cathode, a second diode having an anode and a cathode, and a resistor, wherein the anode of the first diode may be connected to the second switch via the second resistor and the anode of the second diode may be connected to the first switch via the first resistor, and wherein the cathode of the first diode and the cathode of the second diode may be connected to the first output via the resistor. 
         [0010]    In yet another related embodiment, the ballast may further include a diode and an other resistor, wherein the diode and the other resistor may each be connected in parallel with the capacitor. In still another related embodiment, the ballast may further include an inverting stage circuit to invert the logic levels of the DC control signal. In a further related embodiment, the inverting stage circuit may include a transistor connected between the capacitor and the second output terminal of the detector circuit. In still yet another related embodiment, the ballast may further include a full wave rectifier connected between the first and second switches and the lighting system converter circuit. 
         [0011]    In another embodiment, there is provided a ballast to power at least one lamp from an alternating current (AC) voltage supply. The ballast includes: a first switch adapted to selectively connect the ballast to a first high voltage terminal of the AC voltage supply, the first switch having an on state and an off state; a second switch adapted to selectively connect the ballast to a second high voltage terminal of the AC voltage supply, the second switch having an on state and an off state; a lighting system converter circuit to provide voltage suitable to energize the at least one lamp; and a detector circuit. The detector circuit includes: a first input terminal coupled to the first switch; a second input terminal coupled to the second switch; a first resistor connected to the first input terminal; a second resistor connected to the second input terminal; an output terminal connected to the lighting system converter circuit to provide a control signal to the lighting system converter circuit, the control signal indicating one of a plurality voltage levels for providing to the at least one lamp to energize the at least one lamp as a function of the states of the first and second switches, wherein each voltage level corresponds to a different lighting level generated by the at least one lamp; a first transistor having a base, an emitter, and a collector; a second transistor having a base, an emitter, and a collector, wherein the emitter of the second transistor and the base of the first transistor are connected to the first switch via the first resistor, wherein the emitter of the first transistor and the base of the second transistor are connected to the second switch via the second resistor; and a capacitor having a first node connected to the collector of the first transistor, the collector of the second transistor, and the output terminal, the capacitor having a second node connected to ground potential, wherein the capacitor smoothes current from the collectors of the first and second transistors to provide a substantially direct current (DC) control signal. The lighting system converter circuit receives the DC control signal via the second output of the detector circuit and provides voltage to the at least one lamp as a function of the DC control signal. 
         [0012]    In a related embodiment, the detector circuit may further include an other output terminal connected to the lighting system converter circuit to provide a supply current to the lighting system converter circuit to power components of the lighting system converter circuit, wherein the other output terminal may be connected to the first input terminal via the first resistor and to the second input terminal via the second resistor. In another related embodiment, the detector circuit may further include an overvoltage protection circuit, including: a first diode having an anode and a cathode; a second diode having an anode and a cathode; and a resistor; wherein the anode of the first diode may be connected to the second switch via the second resistor and the anode of the second diode may be connected to the first switch via the first resistor, and wherein the cathode of the first diode and the cathode of the second diode may be connected to the first output via the resistor. 
         [0013]    In still another related embodiment, the ballast may further include a diode and an other resistor, wherein the diode and the other resistor may each be connected in parallel with the capacitor. In yet another related embodiment, the ballast may further include an inverting stage circuit to invert the logic levels of the control signal. In still yet another related embodiment, the inverting stage circuit may include a transistor connected between the capacitor and the second output terminal of the detector circuit. In yet still another related embodiment, the ballast may further include a full wave rectifier connected between the first and second switches and the lighting system converter circuit. 
         [0014]    In another embodiment, there is provided a ballast to power at least one lamp from an alternating current (AC) voltage supply. The ballast includes: a first switch adapted to selectively connect the ballast to a first high voltage terminal of the AC voltage supply, the first switch having an on state and an off state; a second switch adapted to selectively connect the ballast to a second high voltage terminal of the AC voltage supply, the second switch having an on state and an off state; a lighting system converter circuit to provide voltage suitable to energize the at least one lamp; and a detector circuit. The detector circuit includes: a first input terminal coupled to the first switch; a second input terminal coupled to the second switch; a first resistor connected to the first input terminal; a second resistor connected to the second input terminal; a first output terminal connected to the lighting system converter circuit to provide a supply current to the lighting system converter circuit to power components of the lighting system converter circuit, wherein the first output terminal is connected to the first input terminal via the first resistor and to the second input terminal via the second resistor; a second output terminal connected to the lighting system converter circuit to provide a control signal to the lighting system converter circuit, the control signal indicating one of a plurality voltage levels for providing to the at least one lamp to energize the at least one lamp as a function of the states of the first and second switches, wherein each voltage level corresponds to a different lighting level generated by the at least one lamp; a first transistor having a base, an emitter, and a collector; a second transistor having a base, an emitter, and a collector, wherein the emitter of the second transistor and the base of the first transistor are connected to the first switch via the first resistor, wherein the emitter of the first transistor and the base of the second transistor are connected to the second switch via the second resistor; and a capacitor connected to the collector of the first transistor and the collector of the second transistor and connected to the second output terminal to smooth current from the collectors of the first and second transistors to provide a substantially direct current (DC) control signal. The lighting system converter circuit receives the DC control signal via the second output terminal of the detector circuit and provides voltage to the at least one lamp as a function of the DC control signal. 
         [0015]    In a related embodiment, the detector circuit may further include an overvoltage protection circuit, the overvoltage protection circuit including a first diode having an anode and a cathode, a second diode having an anode and a cathode, and a resistor, wherein the anode of the first diode may be connected to the second switch via the second resistor and the anode of the second diode may be connected to the first switch via the first resistor, and wherein the cathode of the first diode and the cathode of the second diode may be connected to the first output terminal via the resistor. 
         [0016]    In another related embodiment, the ballast may further include a diode and an other resistor, wherein the diode and the other resistor may each be connected in parallel with the capacitor. In still another related embodiment, the ballast may further include an inverting stage circuit to invert the logic levels of the control signal, the inverting stage circuit including a transistor connected between the capacitor and the second output terminal of the detector circuit. In yet another related embodiment, the ballast may further include a full wave rectifier connected between the first and second switches and the lighting system converter circuit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The foregoing and other objects, features and advantages disclosed herein will be apparent from the following description of particular embodiments disclosed herein, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles disclosed herein. 
           [0018]      FIG. 1  is a schematic diagram, partially in block form, of a lamp system according to embodiments disclosed herein. 
           [0019]      FIG. 2  is a schematic diagram of a detector circuit of a ballast according to embodiments disclosed herein. 
           [0020]      FIG. 3  is a schematic diagram of a detector circuit of a ballast according to embodiments disclosed herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]      FIG. 1  illustrates a lamp system  100  according to an embodiment of the invention. The lamp system  100  includes an input power source, such as but not limited to an alternating current (AC) power supply  102 . The lamp system  100  also includes an electronic ballast  104  (hereinafter ballast  104 ) and a lamp  106 . Although the lamp  106  is illustrated as a single lamp, the lamp  106  may be one lamp or a plurality of lamps connected together in series or in parallel. In some embodiments, the lamp  106  is an electrodeless gas discharge lamp, such as but not limited to the ICETRON® lamp available from OSRAM SYLVANIA, the QL induction lamp available from Philips, the GENURA lamp available from General Electric, and the EVERLIGHT lamp available from Matsushita. In other embodiments, the lamp  106  may be a lamp that includes solid state light sources, such as but not limited to one or more light emitting diode(s) (LED). The lamp system  100  may be used to energize other types of lamps not specifically mentioned herein without departing from the scope of the invention. 
         [0022]    The ballast  104  includes a first high voltage input terminal  108  (i.e., line voltage input terminal, hot input terminal) to connect to a first high voltage terminal (e.g., hot wire) of the AC power supply  102 , (e.g., standard 120V or 240V AC household power), and a second high voltage input terminal  110  (i.e., line voltage input terminal) to connect to a second high voltage terminal of the AC power supply  102 . The ballast  104  also includes a neutral input terminal  112  to connect to a neutral wire of the AC power supply  102 , and a ground terminal (not shown) connectable to ground potential. A first switch  51  is connected to the first high voltage input terminal  108 . Accordingly, the first switch  51  is adapted to selectively connect the ballast  104  to the first high voltage terminal of the AC voltage source  102 . A second switch S 2  is connected to the second high voltage input terminal  110 . As such, the second switch S 2  is adapted to selectively connect the ballast  104  to the second high voltage terminal of the AC voltage source  102 . The first switch S 1  and the second switch S 2  may be implemented by, but are not limited to, conventional wall switches having an on state and an off state. 
         [0023]    A rectifier circuit  120  is coupled to the first high voltage input terminal  108 , the second high voltage input terminal  110 , and the neutral terminal  112 . In particular, the rectifier circuit  120  is coupled to the first high voltage input terminal  108  via the first switch S 1  and a first electromagnetic interference (EMI) inductor L 1 . The rectifier circuit  120  is coupled to the second high voltage input terminal  110  via the second switch S 2  and a second EMI inductor L 2 . The rectifier circuit  120  is coupled to the neutral terminal  112  via a third EMI inductor L 3 . In  FIG. 1 , the rectifier circuit  120  is a full-wave rectifier implemented by an arrangement comprising six diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6 . The first diode D 1  has an anode coupled to a first node  122  and a cathode coupled to a second node  124 . The first node  122  is coupled to the second high voltage input terminal  110  via the second EMI inductor L 2 . The second diode D 2  has an anode coupled to ground potential and a cathode coupled to first node  122 . The third diode D 3  has an anode coupled to a third node  126  and a cathode coupled to the second node  124 . The third node  126  is coupled to first high voltage input terminal  108  via the first EMI inductor L 1 . The fourth diode D 4  has an anode coupled to the ground potential and a cathode coupled to third node  126 . The fifth diode D 5  has an anode coupled to a fourth node  128  and a cathode coupled to second node  124 . The fourth node  128  is coupled to the neutral input terminal  112  via the third EMI inductor L 3 . The sixth diode D 6  has an anode coupled to ground potential and a cathode coupled to the fourth node  128 . 
         [0024]    A first EMI capacitor Cx 1  is connected between the first high voltage input terminal  108  and the neutral terminal  112 . A second EMI capacitor Cx 2  is connected between the second high voltage input terminal  1  and the neutral terminal  112 . Specifically, the first EMI capacitor Cx 1  is connected between the third node  126  and the fourth node  128 . The second EMI capacitor Cx 2  is connected between the first node  122  and the fourth node  128 . As shown in  FIG. 1 , a high frequency bypass capacitor C 3  may be connected between the fourth node  128  and the ground potential. 
         [0025]    In operation, the ballast  104  selectively receives a sinusoidal AC voltage signal from the AC power supply  102  via the first switch S 1  and/or the second switch S 2 . The EMI inductors (L 1 , L 2 , and L 3 ), and the EMI capacitors (Cx 1  and Cx 2 ) reduce high frequency noise generated by the ballast  104 . The rectifier circuit  120  receives the AC voltage signal and generates a rectified voltage signal therefrom. The high frequency bypass capacitor C 3  reduces high frequency noise in the rectified voltage signal. A lighting system converter circuit  130  is coupled to the rectifier circuit  120  via the high frequency bypass capacitor C 3 . The lighting system converter circuit  130  receives the rectified voltage signal and provides a voltage and current suitable to energize the lamp  106 . For example, in some embodiments, the lighting system converter circuit  130  may include a power factor correction circuit and an inverter circuit. 
         [0026]    The ballast  104  includes a detector circuit  132 . The detector circuit  132  provides a control signal to the lighting system converter circuit  130  as a function of the states of the first switch S 1  and the second switch S 2 . In some embodiments, the control signal is a voltage signal having a magnitude (e.g., voltage level) that is dependent on the states of the first switch S 1  and the second switch S 2 . In turn, the lighting system converter circuit  130  provides a voltage signal to the lamp  106  as a function of the control signal. The lamp  106  generates a particular amount of light (e.g., lumens, lighting level) as a function of the voltage signal (e.g., voltage level, voltage magnitude) provided to the lamp  106  by the lighting system converter circuit  130 . For example, in  FIG. 1 , when both the first switch S 1  and the second switch S 2  are in the ON state, the magnitude of the control signal is at a first level (e.g., low level, 0 volts) causing the lighting system converter circuit  130  to operate the lamp  106  at a first lighting level (e.g., 100% of full light output). When only one of the first switch S 1  and the second switch S 2  is in the ON state, the magnitude of the control signal is at a second level (e.g., high level, defined by a breakdown voltage of a Zener diode D 10 , for instance 15 volts), causing the lighting system converter circuit  130  to operate the lamp  106  at a second lighting level (e.g., 50% of full light output). 
         [0027]    In some embodiments, the detector circuit  132  includes a first input terminal  134  coupled to the first switch S 1  via the first inductor L 1 , and a second input terminal  136  coupled to the second switch via the second inductor L 2 . The first input terminal  134  receives an AC current signal when the first switch S 1  is connected to the AC power supply  102  (e.g., when the first switch S 1  is ON). The second input terminal  136  receives an AC current signal when the second switch S 2  is connected to the AC power supply  102  (e.g., when the second switch S 2  is ON). The detector circuit  132  includes a transistor network configured to detect a differential current and/or differential voltage between the first input terminal  134  and the second input terminal  136 . The transistor network provides a control signal output indicative of whether one of the first and second switches (S 1 , S 2 ) or both the first and the second switch (S 1  and S 2 ) are connected to the AC power supply (e.g., operating in the ON state). A capacitor C 4  is connected to the transistor network to smooth the control signal from the transistor network. Thus, the capacitor C 4  provides a substantially direct current (DC) control signal. The detector circuit  132  includes an output terminal  140  connected to the lighting system converter circuit  130 . The lighting system converter circuit  139  receives the DC control signal via the output terminal  140  of the detector circuit  132  and provides voltage to the lamp as a function of the DC control signal. 
         [0028]    In  FIG. 1  as shown, the transistor network is implemented via a first current limiting resistor R 1 , a second current limiting resistor R 2 , a first transistor Q 1 , and a second transistor Q 2 . For example, the first transistor Q 1  and the second transistor Q 2  may each be, but are not limited to, a bipolar PNP transistor available from Fairchild Semiconductor. The first transistor Q 1  and the second transistor Q 2  each have a base, an emitter, and a collector. The emitter of the second transistor Q 2  and the base of the first transistor Q 1  are connected to the first switch  51  and to the first input terminal  134  via the first current limiting resistor R 1 . The emitter of the first transistor Q 1  and the base of the second transistor Q 2  are connected to the second switch S 2  and to the second input terminal  136  via the second current limiting resistor R 2 . The capacitor C 4  has a first node  142  and a second node  144 . The first node  142  of the capacitor C 4  is connected to the collector of the first transistor Q 1 , the collector of the second transistor Q 2 , and the output terminal  140  of the detector circuit  132 . The second node  144  of the capacitor C 4  is connected to ground potential. A diode, such as the Zener diode D 10 , is connected in parallel with the capacitor C 4  to limit the amount of voltage provided at the output terminal  140  of the detector circuit so that it is suitable for controlling the lighting system converter circuit  130 . In particular, the Zener diode D 10  has an anode connected to the second node  144  of the capacitor C 4  and a cathode connected to the first node  142  of the capacitor C 4 . A resistor R 6  is connected in parallel with the capacitor C 4  and with the Zener diode D 10  to discharge the capacitor C 4 , providing a fast transition between voltage levels of the DC control signal. 
         [0029]      FIG. 2  illustrates a detector circuit  232  which, in addition to the components described above in connection with the detector circuit  132 , also includes an overvoltage protection circuit  252  connected between the first and second resistors, R 1  and R 2 , and the output terminal  250 . The overvoltage protection circuit  252  limits maximum voltage applied to the transistors Q 1 , Q 2  in order to protect them from damage by overvoltage and allows the transistors Q 1  and Q 2  to be low voltage rated and thereby less expensive. As an additional benefit, the overvoltage protection circuit  252  provides a supply current to a common-collector voltage (VCC bus) signal in the lighting system converter circuit  130 . The detector circuit  232  itself does not require a VCC signal for operation. The detector circuit  232  is self-powered via the resistors R 1  and R 2  from the first high voltage input terminal  108  and the second high voltage input terminal  110 . The VCC signal (e.g., 15 Volts) is used to power the components of the lighting system converter circuit  130 . In  FIG. 2  as shown, the detector circuit  232  includes an output terminal  250  that is connected to the lighting system converter circuit  130 , for voltage limiting across the transistors Q 1 , Q 2  and, also for providing supply current to the lighting system converter circuit  130 . The output terminal  250  is connected to a first input terminal  234  (analogous to the first input terminal  134  of  FIG. 1 ) via the first resistor R 1 , and to a second input terminal  236  (analogous to the second input terminal  136  of  FIG. 1 ) via the second resistor R 2 . The overvoltage protection circuit  252  also includes a first diode D 7 , a second diode D 8 , and a resistor R 3 . The first diode D 7  has an anode connected to the second input terminal  236  via the second resistor R 2 . The second diode D 8  has an anode connected to the first input terminal  234  via the first resistor R 1 . The first diode D 7  and the second diode D 8  each have a cathode connected to the resistor R 3  which is also connected to the output terminal  250 . 
         [0030]      FIG. 3  illustrates a detector circuit  332 , which includes an inverting stage circuit  354  connected between a capacitor C 4  and an output terminal  340 . The inverting stage circuit  354  inverts the logic levels of the DC signal output from the capacitor C 4 . Thus, the DC control signal that is provided to the lighting system converter circuit  130  via the output terminal  340  has inverted logic levels. Accordingly, the inverting stage circuit  354  allows the detector circuit  332  to be used with ballasts that have a lighting system converter circuit  130  configured to operate the lamp  106  at the first lighting level (e.g., 100% of full light output) when the control signal has a high voltage logic level (e.g., 15 volts or other value defined by the components of the lighting system converter circuit  130 ) and to operate the lamp  106  at the second lighting level (e.g., 50% of full light output) when the control signal has a low voltage logic level (e.g., 0 volts). In  FIG. 3 , the detector circuit  332  includes a first resistor R 4 , a second resistor R 5 , and a transistor Q 3  having a collector, a base, an emitter. For example, the transistor Q 3  may be, but is not limited to, an NPN bipolar junction transistor. The first resistor R 4  is connected between a first node  342  of the capacitor C 4  and the base of the transistor Q 3 . Thus, the base of the transistor Q 3  is connected to the first node  342  of the capacitor C 4  via the first resistor R 4 . The second resistor R 5  is connected across the base and the emitter of the transistor Q 3 . The emitter of the transistor Q 3  is connected to a second node  344  of the capacitor C 4 , which is at ground potential. The collector of the transistor Q 3  is connected to the output terminal  340 . 
         [0031]    Unless otherwise stated, use of the word “substantially” may be construed to include a precise relationship, condition, arrangement, orientation, and/or other characteristic, and deviations thereof as understood by one of ordinary skill in the art, to the extent that such deviations do not materially affect the disclosed methods and systems. 
         [0032]    Throughout the entirety of the present disclosure, use of the articles “a” and/or “an” and/or “the” to modify a noun may be understood to be used for convenience and to include one, or more than one, of the modified noun, unless otherwise specifically stated. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
         [0033]    Elements, components, modules, and/or parts thereof that are described and/or otherwise portrayed through the figures to communicate with, be associated with, and/or be based on, something else, may be understood to so communicate, be associated with, and or be based on in a direct and/or indirect manner, unless otherwise stipulated herein. 
         [0034]    Although the methods and systems have been described relative to a specific embodiment thereof, they are not so limited. Obviously many modifications and variations may become apparent in light of the above teachings. Many additional changes in the details, materials, and arrangement of parts, herein described and illustrated, may be made by those skilled in the art.