Abstract:
A system and method are described in which power is inductively supplied to a product or a package containing a product. This power is received via a coil and used by a light source to further enhance the presentation of the product or packaging. The illuminated light draws more attention to the product or package and thereby increases the probability that a prospective buyer till buy the product. Power is supplied to the package via a coil mounted to a shelf system. The frequency of the power supplied to the shelf coil may be changed to change the frequency at which the light source in the product or package illuminates.

Description:
RELATED APPLICATION  
       [0001]     This application is related to U.S. application Ser. No. ______ [Attorney Docket No. BCS03923] entitled “System and Method for Providing Inductive Power to Improve Product Marking and Advertising” filed on the same day herewith. 
     
    
     FIELD OF THE INVENTION  
       [0002]     A system and method are described that provide power to a product package and/or the product itself through inductive coupling. This power is then used to light-up a portion of the package or product or a screen mounted into the package and draw the attention of prospective buyers.  
       BACKGROUND OF THE INVENTION  
       [0003]     Advertisers and marketers are always searching for ways to get prospective buyers to buy their products. Tremendous amounts of money and ingenuity go into developing product advertisements and colorful product packaging. All to hopefully increase sales.  
         [0004]     One method that may be used is to provide a light source on a product or product package. Such a light would distinguish that particular product from competitor&#39;s products. One problem with this form of packaging is providing power to turn the light on.  
         [0005]     In one proposed system a battery is installed in the packaging to provide the necessary power for the light. However, there are several drawbacks to this approach.  
         [0006]     First, the battery adds some significant costs to the packaging itself. In low margin products, this added cost may be unacceptable. Second, batteries have a limited lifetime. If a product remains in transit to the store and then on the shelf for many months, it is possible the power from the battery would be drained before a potential buyer would ever see it. Third, the light is not really needed once the prospective buyer has purchased the product. There is therefore no need to grab the user&#39;s attention with a light once the user has purchased the product and taken it home. What is needed is a form of powering a light on the product or packaging that can overcome these shortfalls. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  shows an illustrative package that includes a light element;  
         [0008]      FIG. 2  shows an illustrative circuit used to provide power to a light element on a package;  
         [0009]      FIG. 3  shows another illustrative circuit used to provide power to a light element on a package;  
         [0010]      FIG. 4  shows another illustrative circuit used to provide power to a light element on a package;  
         [0011]      FIG. 5  shows another illustrative package that includes a screen;  
         [0012]      FIG. 6  shows an illustrative circuit for powering and driving a screen;  
         [0013]      FIG. 7  shows an illustrative shelf used to provide power to a product or package;  
         [0014]      FIG. 8  shows another illustrative shelf used to provide power to a product or package;  
         [0015]      FIG. 9  shows another illustrative shelf system used to provide power to a product or package;  
         [0016]      FIG. 10  shows another illustrative shelf system used to provide power to a product or package;  
         [0017]      FIG. 11  shows another illustrative shelf system used to provide power to a product or package.  
         [0018]      FIG. 12  shows an illustrative product that includes a light element and/or a screen;  
         [0019]      FIG. 13  shows another illustrative circuit for powering at least two light elements on a product or package; and  
         [0020]      FIG. 14  shows another illustrative circuit for powering at least two light elements on a product or package. 
     
    
       [0021]     Like numbers in different figures denote similar elements among the figures.  
       DETAILED DESCRIPTION  
       [0022]      FIG. 1  shows a package  100 . A package is something that encapsulates or surrounds, partially or wholly, a particular product. The package usually protects the product during shipping to and display at a store and it may provide a medium for product identification, advertising and marketing. Package  100  includes a housing  102  typically made of paperboard or plastic and may be shaped in any of a variety of structures such as a bottle or a box. Inside housing  102  is a food product, drug or other item (not shown). Package  100  typically also includes writing  110  that identifies the trade name of the consumable item or product, the manufacturer&#39;s name, uses for the product, directions for consuming or using the product, chemical or physical composition of the product and potential warnings. Package  100  also includes a display element, such as light source  105 , mounted onto housing  102 .  10023 ] Package  100  rests on shelf  115 . Shelf  115 , in addition to supporting package  100  off of the floor in a horizontal manner, provides power to package  100  to turn on light source  105 . Power is provided to package  100  via coil  120  inside shelf  115 .  
         [0023]      FIG. 2  shows an illustrative circuit  200  that is used to drive a light source. Circuit  200  resides on a surface of housing  102 . Typically circuit  200  is coupled to housing  102  on an inside surface. Circuit  200  includes coil  205 . Coil  205  is inductively coupled to coil  120  in a shelf. Coil  205  supplies power to full bridge rectifier  210 . The output of full bridge rectifier  210  is coupled to capacitor  215 . Coupled in parallel to capacitor  215  is light-emitting diode (LED)  220  and resistor  225 . In this circuit, LED  220  is light source  105  from  FIG. 1 .  
         [0024]     Circuit  200  operates as follows. Coil  120  receives an alternating source of electricity. In one implementation coil  120  receives a sine wave operating at  60  Hz. Coil  205  captures power from coil  120  due to their mutual inductance. Coil  205  then supplies power to the remaining portions of circuit  200 .  
         [0025]     The power generated by coil  205  will have the same frequency as the frequency of the power supplied to coil  120 . If the power to coil  120  has both positive and negative polarities, coil  205  will produce power with both positive and negative polarities.  
         [0026]     Full bridge rectifier  210  converts the negative polarity portions of the power generated by coil  205  into positive polarity power. Capacitor  215  acts as a storage device and stores the positive polarity power it receives from full bridge rectifier  210 . The result, in an ideal system, is the voltage at node A remains at a DC, positive value. The voltage at node A is used to drive LED  220  and resistor  225 . It should be noted that LED  220  and resistor  225  dissipate power from node A so that the voltage at node A will have a ripple. The size of this ripple can be quite small depending on the characteristics of capacitor  215 , LED  220 , resistor  225  and frequency of the power supplied by coil  205   
         [0027]     In one implementation of circuit  200 , LED  220  remains on as long as coil  205  is sufficiently coupled to coil  120 . In other words, the voltage at node A does not drop to a point at which LED  220  turns off. Instead the voltage at node A ripples between two values that are both sufficient to drive current through LED  220  and resistor  225  and keep LED  220  continuously on.  
         [0028]      FIG. 3  shows an illustrative circuit  300  used to power a light source. Circuit  300  is coupled to a surface, such as an inside surface, of housing  102 . Circuit  300  includes a coil  305  that is coupled to LED  310  and resistor  315 .  
         [0029]     Coil  305  is inductively coupled to coil  120  in shelf  115 . Like the circuit of  FIG. 2 , coil  305  receives power from coil  120  due to their mutual inductance. Coil  305  therefore outputs a signal having the same frequency as applied to coil  120 .  
         [0030]     When coil  305  supplies a sufficient positive voltage across nodes A and B, LED  310  turns on and conducts current to resistor  315 . When LED  310  is on, it emits light. However, when the voltage across nodes A and B is a small positive voltage or a negative voltage, LED  310  does not turn on and does not emit any light nor does it conduct current to resistor  315 . Thus, LED  310  turns on and off at the same frequency as the voltage oscillating in both coils  120  and  305 . As an example, if the voltage across coil  120  oscillates at  60  Hz, the voltage generated by coil  305  will also oscillate at  60  Hz. LED  310  will therefore turn on and off 60 times a second. The human eye cannot detect a flashing light at this frequency so it appears to the prospective buyers as a constant source of light.  
         [0031]      FIG. 4  shows another illustrative circuit  400  used to power a light source. Circuit  400  is coupled to a surface, such as an inside surface, of housing  102 . Circuit  400  includes coil  405  that is inductively coupled to coil  120  in shelf  115  (not shown). Coil  405  provides power to rectifier  410 . Rectifier  410  may be a full bridge rectifier, a half bridge rectifier or a single diode.  
         [0032]     Circuit  400  also includes another coil  415 . Like coil  405 , coil  415  is inductively coupled to coil  120 . Coil  415  is also coupled to a frequency divider  420 . It should be noted that any frequency divider known to those of ordinary skill in the art may be used in circuit  400 . The output of frequency divider  420  is coupled to LED  425  and resistor  430 .  
         [0033]     Circuit  400  operates as follows. Coil  405  generates power in response to the oscillating power provided through coil  120 . Typically the power generated by coil  405  includes both positive and negative polarity components. Rectifier  410  receives this oscillating power from coil  405  and produces a positive, relatively stable DC power output. An example of a rectifier circuit includes the full bridge rectifier  210  and capacitor  215  shown in  FIG. 2 . The DC power generated by rectifier  410  is provided to divider  420 .  
         [0034]     Divider  420  also receives an oscillating signal from coil  415 . Divider  420  divides the frequency of that signal and outputs it to LED  425  and resistor  430 . Divider  420  provides a different frequency signal to LED  425  and resistor  430  than that provided to coil  120  and generated by coils  405  and  415 . As an example, if coil  120  receives power at 60 Hz, and frequency divider  420  divides by 60, LED  425  will turn on once a second. The human eye can perceive an LED turning on and off once a second. If circuit  400  is implemented in package  100  as such, prospective buyers will observe light source  105  turning on and off once a second.  
         [0035]      FIG. 5  shows another illustrative package  500  that includes a screen. Like the package  100  shown in  FIG. 1 , package  500  includes a housing  102 . Package  500  also includes writing  110  that identifies the trade name of the consumable item or product, the manufacturer name, uses for the product, directions for using or consuming the product and potential warnings. Unlike package  100 , the display element coupled to package  500  is a screen  505  mounted onto housing  102  instead of a light source.  
         [0036]     Screen  505  may be any size screen with any resolution. An example of screen  505  is an LCD screen with a 1 inch diameter. Screen  505  allows for a more dynamic display in that the image displayed on screen  505  can vary over time. For example, a leg can be shown flexing back and forth at the knee with an indication that there is pain in the knee. Screen  505  can also display other images such as text describing special offers or pricing.  
         [0037]      FIG. 6  shows a circuit  600  for powering and driving a screen. Circuit  600  is coupled to a surface, such as an inside surface, of housing  102 . Circuit  600  includes coil  605  that is inductively coupled to coil  120  in shelf  115  (not shown). Coil  605  provides power to rectifier  610 . Rectifier  610  may be a full bridge rectifier or other suitable circuit. Rectifier  610  in turn provides power to memory  615 , processor  620 , display driver  625  and screen  505 .  
         [0038]     Circuit  600  operates by receiving power from coil  120  via the mutual inductance between coils  120  and  605 . Typically the output power from coil  605  will be alternating between positive and negative polarities. Rectifier  610  converts the negative polarity portions of the power it receives into positive polarity power and provides a substantially stable DC power output to memory  615 , processor  620 , display driver  625  and screen  505 .  
         [0039]     Memory  615  stores pixel data. In one illustrative system the pixel data is stored into memory  615  before or at the time circuit  600  is mounted onto package  102 . Processor  620  retrieves that pixel data from memory  620 . In some implementations processor  620  may process the data received from memory  615 . That process may include a decoding and/or a decryption process. Processor  620  outputs data to display driver  625 . Display driver  625  formats the data it receives from processor  620  so it can be properly displayed by screen  505  and outputs the formatted data to screen  505 . Screen  505  generates visual images based upon the data it receives from display driver  625 .  
         [0040]     Processor  620  controls the rate at which pixel data is retrieved from memory  615  which in turn relates to how often the image displayed on screen  505  changes. In some cases the image displayed is constant, from the perspective of the viewer, while in other cases the image changes (e.g. a leg bending back and forth at the knee).  
         [0041]     The rate at which the images change may be dependent or independent of the frequency and amplitude of the signal generated by coil  605 . In an implementation where the images displayed on screen  505  vary dependent in frequency based upon the frequency or amplitude of the signal generated by coil  605 , processor  620  detects those changes and retrieves pixel data from memory  615  accordingly. This allows the operator of the shelf containing coil  120  to change the amplitude or frequency of the current passing through coil  120  and cause screen  505  to display a different image.  
         [0042]     It should also be noted that while memory  615 , processor  620  and display driver  625  are shown as separate elements in circuit  600 , one of ordinary skill in the art could combine some or all of them into one circuit as an ASIC or programmed into a programmable circuit. Processor  620  may also be omitted if display driver  625  has the capability to retrieve pixel data  615  on its own and lesser control of the image being displayed on screen  505  is desired.  
         [0043]      FIG. 7  shows a cross-sectional view of an illustrative shelf  700 . Shelf  700  includes a housing  705 . Housing  705  will typically be made of an insulative material such as plastic. Housing  705  may also contain a shield of conductive material to prevent the flux lines from emanating in directions other than up into packages  100 . In addition, housing  705  may not be a completely closed object with a hollow interior.  
         [0044]     Coil  710  is placed inside housing  705  and is coupled to an AC power source  715 . In one implementation, AC power source  715  is variable in frequency. Coil  710  wraps back in forth in housing  705  in a serpentine fashion. By wrapping coil  710  in this manner, all of the packages placed on top of shelf  700  will be in close proximity to a portion of coil  710 . In this way, as packages are removed from the front edge  730  of shelf  700 , the additional packages behind those will receive power and have powered light sources  105 .  
         [0045]     Coupled in series with AC power source  715  is a resistor  720 . Resistor  720  is used to limit the amount of current drawn by coil  710 . In one implementation, resistor  720  is variable. In this way the user can adjust the resistance of resistor  720  to increase or decrease the amount of current flowing through coil  710 . By allowing for adjustable current flow, the user can control how much power is dissipated to the packages resting on shelf  700  while keeping the amount of current flowing through coil  710  at a safe amount.  
         [0046]     For added safety, protection circuit  725  may also be added in series to the AC power source  715  and coil  710 . Protection circuit  725  will create an open circuit or high impedance condition to prevent excess current from flowing through coil  710 . Examples of protection circuit  725  include fuses, circuit breakers, thermistors or thermal switches.  
         [0047]     Operation of shelf  700  in conjunction with package  100  is as follows. A store clerk places packages  100  on shelf  700 . The coils inside packages  100  are then in close proximity to coil  710  so as to be coupled via mutual induction. The clerk then adjusts the frequency and amount of the power supplied to coil  710  by turning a knob on AC power source  715  and a knob on resistor  720 . As power oscillates through coil  710 , power is generated by the coil in package  100  as described previously in conjunction with  FIGS. 2-6  so that the light source  105  is illuminated or screen  505  displays images. When a prospective purchaser picks the package  100  off of shelf  700 , the mutual inductance between package  100  and shelf  700  is broken, due to the increased distance between the coils, and the light source  105  stops illuminating or screen  505  turns off.  
         [0048]     As noted earlier, light sources  105  in circuits  200  and  300  illuminate at the same frequency as the frequency of the power supplied to coil  120  in some cases. In many typical implementations, the frequency of power supplied to coil  120  will be so high that the human eye may not perceive LED  220  or  310  flashing. By using a variable AC power source  515 , circuits  200  and  300  can receive power at different frequencies and in turn LED  220  or  310  on and off at a frequency perceptible to the human eye.  
         [0049]     Similarly, variable AC power supply  515  could be used with circuit  400  of  FIG. 4  and allow for greater flexibility in setting the frequency at which LED  425  turns on and off. As an example, if divider  420  divides by 60 and the frequency of the power generated by coil  415  is 30 Hz, LED  425  will turn on and off once every 2 seconds. Similarly if AC power source  515  provides power to coil  510  at 120 Hz, and divider  420  divides by 60, LED  425  will turn on and off twice every second.  
         [0050]      FIG. 8  shows another shelf  800 . Shelf  800  contains many of the same elements as shelf  700  that are similarly numbered. One difference between shelf  700  and shelf  800  is the manner in which coil  810  is wrapped inside housing  705 . In shelf  800 , coil  810  is wrapped in a spiral fashion inside housing  705 . Again, coil  810  provides power through inductive coupling to all packages  100  placed on shelf  800 .  
         [0051]     It should be noted that shelves  700  and  800  provide power to all packages or products resting upon them. Thus, light sources  105  will be illuminated and screens  505  will be operational even on packages or products that are not visible to prospective buyers. This is because some will be blocked from view by other packages  100  being placed in front of them. A lot of power is therefore wasted.  
         [0052]     Shelf system  900  shown in  FIG. 9  solves this problem. Shelf system  900  includes housing  905 . Inside housing  905  is a coil  910  located near the front edge. Placed on top of housing  905  are packages  100  or products that include a light source  105  or a screen  505 .  
         [0053]     Housing  905  also includes a lip or stop  915  at the front edge of housing  905 . Lip or stop  915  may be an integrated part of housing  905  or it may be a separate piece attached to housing  905 . Behind packages  100  is ram  920 . Ram  920  is coupled to spring  925  that is in turn coupled to surface  930 .  
         [0054]     Shelf system  900  operates as follows. A clerk pushes ram  920  towards surface  930  and thereby compresses spring  925 . The clerk then inserts packages  100  between ram  920  and lip or stop  915 . The clerk releases ram  920  and it pushes against packages  100  because of the force exerted by spring  925 . Packages  100  are in turned pushed up against lip or stop  915 .  
         [0055]     In this arrangement only the first one, two or three or so packages  100  are near enough to coil  910  so as to be coupled to coil  910  via mutual inductance. The actual number of packages  100  coupled to coil  910  will depend on the size of coil  910 , the size of packages  100 , the size of the coils inside packages  100  and the amount of current flowing through coil  910 , among other things. Of the plurality of packages resting on housing  905  between lip or stop  915  and surface  930 , only one or a few near the front edge and coil  910  will receive enough power to have their respective light source  105  illuminated or screens  505  operative.  
         [0056]     When a prospective buyer decides to purchase a package  100 , he/she selects the first or second one pressed up against lip or stop  915 . Ram  920  will then be pushed toward lip or stop  915  by spring  925  which in turn causes the remaining packages  100  to move towards lip or stop  915 . Ram  920  and packages  100  stop moving when the next package  100  is resting against lip or stop  915 . In this way a new subset of packages is close enough to coil  910  to receive power and have their respective light sources  105  illuminated.  
         [0057]      FIG. 10  shows an alternative shelf system  1000 . Shelf system  1000  includes a housing  1005  that includes coil  910  near its front edge. Housing  1005  also includes a lip or stop  915 . Housing  1005  is also mounted onto a surface  930 , such as a wall. Resting on the top surface  1015  of housing  1005  are packages  100  or products and weight  1010 . Top surface  1015  is curved as shown in  FIG. 8 .  
         [0058]     Operation of shelf system  1000  is as follows. Weight  1010  pushes against packages  100  due to the curve of top surface  1015  and gravity. Packages  100  in turn push against lip or stop  915 . Like shelf system  900 , only one or a few of the packages  100  are close enough to the front edge and coil  910  to be inductively coupled to coil  910 . Therefore only one or a few of the packages  100  receive sufficient power from coil  910  to illuminate light sources  105  or operate screen  505 .  
         [0059]     When a prospective buyer selects package  100  next to or near lip or stop  915 , weight  1010  slides down the curved top surface  1015  and pushes the remaining packages  100  against lip or stop  915 . In this way a new subset of packages is close enough to coil  910  to receive power and have their respective light sources  105  illuminated or screens  505  operational. Meanwhile, the package  100  selected by the prospective buyer is moved far enough away from coil  910  so as to render any mutual inductance insignificant and thereby stop supplying power to package  100  and stop illuminating light source  105  or operating screen  505 . In an alternative system, weight  1010  is not needed if the weight of packages  100  is sufficient to overcome the friction between top surface  1015  and packages  100  so that packages  100  can slide down top surface  1015  and rest on lip or stop  915  by themselves.  
         [0060]      FIG. 11  shows yet another shelf system  1100 . Shelf system  1100  includes a shelf  1105  that holds package  100  or products off of the ground. Mounted onto or adjacent to shelf  1105  is a divider  1110 . Divider  1110  can be used to separate different products or similar products from different manufacturers on shelf  1105 . In a typical application divider  1110  is substantially vertical.  
         [0061]     Inside divider  1110  is one or more coils  1115  and  1120 . Coil  1115  is oriented into the page while coil  1120  is oriented along the height of divider  1110 . Using divider  1110  allows manufacturers of package  100  to place the internal coil  205 ,  305 ,  405 ,  415  or  605  along any of the sides or surfaces of package  100 . As shown in  FIG. 11 , package  100  may have an internal coil  1125  located along a left-side of the package oriented along the height of package  100 . Alternatively, package  100  may have an internal coil  1130  located at the bottom-left corner of package  100  oriented along the depth of package  100 . Coil  1120  is best oriented to supply power to coil  1125  while coil  1115  is best oriented to supply power to coil  1130 . Shelf system  1100  allows the package manufacturer to place coils inside package  100  on other surfaces besides the bottom surface that rests on shelf  1105 .  
         [0062]      FIG. 12  shows a product  1200  that includes light elements and/or a screen. Product  1200  is distinguishable from package  100  in that it is the item desired by the buyer or end user as opposed to a structure that is used to convey the-desired product to the buyer or end user. In the example shown in  FIG. 12 , the product is a small Christmas tree that can be placed on a person&#39;s shelf for decoration. Of course other products such as picture frames, Halloween decorations, Hanukkah decorations or other item may incorporate the systems described above.  
         [0063]     Product  1200  includes one or more light elements  1205 . In some implementations product  1200  includes a screen  1210  in addition to or instead of light elements  1205 . Product  1200  rests on shelf  105 . As shown in  FIG. 12 , shelf  105  includes a coil  120 . Inside product  1200  is an inductive power source  1215 , a switch  1220  and a battery or outlet power source  1225 .  
         [0064]     Operation of product  1200  is as follows. Product  1200  is placed on shelf  105 . Shelf  105  may be in a store or at the end user&#39;s home or office. In a typical store setting, shelf  105  will include coil  120 . Inductive power source  1215  includes any of the circuits shown in  FIGS. 2, 3 ,  4  or  6  or their equivalents and generates power from the mutual inductance between itself and coil  120  as previously described. Switch  1220  couples inductive power source  1215  to light elements  1205  and/or screen  1210 . In this way, product  1200  operates in the store so that the prospective buyer can determine if it is something he/she feels is appropriate for his/her home. If the prospective buyer selects product  1200  off of shelf  105 , the mutual inductance between coil  120  and inductive power source  1215  decreases so that light elements  1205  and/or screen  1210  cease to operate.  
         [0065]     Once the prospective buyer takes product  1200  home, the prospective buyer switches switch  1220  and either inserts a battery or plugs product  1200  into an electrical outlet. The battery or connection to the electrical outlet provides power to battery/outlet power source  1225  that is then coupled to light elements  1205  or screen  1210  via switch  1220 . Of course if the prospective buyer has a shelf like shelf  105  with a coil inside of it, the prospective buyer may use inductive power source  1215  to supply power to light elements  1205  and/or screen  1210  at his or her home or office. Details of the circuitry within second power source  1225  are well-known and can be found in many household items such as in a clock, electric razor or other appliance.  
         [0066]     While the above systems and methods have been described using specific elements, it is possible to use alternative elements without departing from the scope of the invention. For example, instead of using LEDs in circuits  200 ,  300  and  400 , an incandescent light bulb or other light source could be used. In addition, rectifier circuits other than full bridge rectifier  210  may be used in circuits  200  and  400 . In addition, coil  415  and divider  420  may be replaced with an oscillator or timing circuit that receives power from rectifier  410 . In yet other alternative systems, curved surface  1015  could be replaced with a triangular top surface. Finally, it is understood that any arrangement of coils may be used in the packaging, product or shelf. For example, a shelf may have a coil inside of it that extends beyond the front edge as shown in  FIGS. 9 and 10  but does not extend throughout the entire shelf as shown in  FIGS. 7 and 8  (e.g., it may extend through only have of the shelf&#39;s depth).  
         [0067]     In addition, other combinations of the described systems may also be employed. For example, spring  925  could be mounted to the front edge of housing  905  and to ram  920  through the top surface of housing  905 . In this arrangement, spring  925  is pulled, not pushed, to make room for stocking packages  100  onto housing  905 . In this alternative arrangement, spring  925  pulls ram towards lip or stop  915  when one package  100  is removed.  
         [0068]     In addition, a shelf system could be developed that uses combinations of spring  925  and ram  920  along with a curved top surface  1015 . Finally, multiple coils may be employed both inside package  100  or product  1200  and in shelf systems  900 ,  1000  and  1100 . This would allow for multiple light sources  105 , screens  505  or combinations of the two to be mounted onto package  100 . The multiple coils in shelf systems  900 ,  1000  and  1100  may be located in the shelf housings or in the dividers. These multiple coils may also receive power at different frequencies that in turn allow the plurality of lights mounted onto package  100  to illuminate at different frequencies. This can be extended to include using different color light sources  105  to further enhance the displaying of packages and products.  
         [0069]     In yet another configuration shown in  FIG. 13 , circuit  1300  provides power to two different light sources. Circuit  1300  includes a coil  1305  that generates power when mutually inductively coupled to coil  120 . The power generated by coil  1305  is rectified by rectifier  1310  to provide a substantially stable DC power output. The DC power output by rectifier  1310  is provided to a first sub-circuit that includes amplitude switch  1315  and LED  1320 . DC power is also supplied to a second sub-circuit that includes amplitude switch  1325  and LED  1330 .  
         [0070]     Operation of circuit  1300  is as follows. A certain amount of current is passed through coil  120  which in turn causes the output of coil  1305  to output DC power at certain amplitude at node A. Amplitude switch  1315  turns on when a certain voltage range is applied to it and turns off when a voltage outside of that range is applied to it. Mathematically, amplitude switch turns on when the voltage at node A (V A ) is: 
 
V LT1 ≦V A ≦V UT1  
 
 where V LT1  is the lower voltage threshold and V UT1  is the upper voltage threshold of amplitude switch  1315 . If voltage V A  is less than V LT1  or above V UT1 , amplitude switch  1315  turns off and thereby turns off light source  1320 . 
 
         [0071]     Amplitude switch  1325  operates differently. It turns on when V A  exceeds a lower threshold or: 
 
V LT2 ≦V A  
 
 where V LT2  is the lower voltage threshold of amplitude switch  1325 . The values of V LT1 , V UT1  and V LT2  can be adjusted by a dial (not shown) before placing the package or product on a shelf. Typically, however, these values will be set when the package or product is manufactured. In one implementation, values are set such that: 
 
V UT1 ≦V LT2  
 
 This allows for light sources  1320  and  1330  to be turned on and off substantially independently of each other by varying the amplitude of the current passing through coil  120 . By passing a certain amount of current through coil  120 , the voltage V A  will be between V LT1  and V UT1  but less than V LT2 . This causes amplitude switch  1315  to turn on and amplitude switch  1325  to turn off. This in turn causes light source  1320  to turn on and light source  1330  to turn off. By increasing the current through coil  120  the voltage V A  will increase so it is greater than both V UT1  and V LT2 . This causes amplitude switch  1315  to turn off and amplitude switch  1325  to turn on. This in turn causes light source  1320  to turn off and light source  1330  to turn on. 
 
         [0072]      FIG. 14  shows a circuit  1400  that provides power to two different light sources. Circuit  1400  includes coil  1405  that provides power to rectifier  1410 . Circuit  1400  also includes a second coil  1415  that is coupled to two sub-circuits. The first sub-circuit includes filter  1420 , switch  1425  and light source  1430  (shown as an LED in  FIG. 14 ). The second sub-circuit includes filter  1435 , switch  1440  and light source  1445  (also shown as an LED in  FIG. 14 ).  
         [0073]     Operation of circuit  1400  is as follows. Coil  1405  and rectifier  1410  produce a substantially stable DC power output as previously described. Coil  1415  produces a signal due to its being mutual inductively coupled to coil  120 . The frequency of the signal generated by coil  1415  is substantially similar to the frequency of the current passing through coil  120 . Filters  1420  and  1435  are frequency dependent. Examples of filters that may be used include low pass, high pass and band pass. The frequency responses of filters  1420  and  1435 , in conjunction with the frequency of the current in coils  1415  and  120 , determine how much of the signal generated by coil  1415  is passed to switches  1425  and  1440 . This in turn determines whether switches  1425  and  1440  turn on to turn on light sources  1430  and  1445  or turn off to turn off light sources  1430  and  1445 .  
         [0074]     As an example, assume filter  1420  is a low pass filter that passes signals at 30 Hz and below and assume filter  1435  is a high pass filter that passes signals at 45 Hz and above. If the current passes through coil  120  at a frequency of 20 Hz, coil  1415  will output a signal at 20 Hz. Filter  1420  passes this signal through, which in turn turns on switch  1425  and light source  1430 . Filter  1435 , however, blocks the signal output from coil  1415 , which in turn turns off switch  1440  and light source  1445 .  
         [0075]     If the frequency of the current through coil  120  is then changed to 60 Hz, coil  1415  will similarly produce a signal at 60 Hz. Filter  1420  blocks the signal from coil  1415  to switch  1425 , which turns off switch  1425  and light source  1430 . Filter  1435 , however, passes the signal from coil  1415  to switch  1440  which, turns on switch  1440  and light source  1445 .  
         [0076]     In circuit  1400 , it is assumed that filters  1420  and  1435  and switches  1425  and  1440 , or a subset thereof, contain active elements that require DC power. This DC power is supplied by coil  1405  and rectifier  1410 . If filters  1420  and  1435  and switches  1425  and  1440  only contain passive elements then coil  1405  and rectifier  1410  are not needed. It should be noted that one of ordinary skill in the art could combine circuits and features of circuit  400  and circuits  1300  and  1400  to provide even greater flexibility in how to provide a variety of changing displays.  
         [0077]     Circuits  1300 ,  1400  and  600  (when processor  620  senses the output of coil  605 ) change which light source is illuminated or which image is displayed on screen  505  when the frequency and/or amplitude of the current passing through coil  120  changes. This allows for dynamic advertising to the potential buyers. Suppose it is known that one group (group A) shop at a particular store primarily during one part of the day or week and another group (group B) shop at that same store but primarily at a different time of day or week. Suppose each group also responds differently to differently stimulus. For example, if group A tends to buy more products when a light source is red or a particular image is presented on a screen while group B tends to buy more products when a light source is blue or a different image is presented on the screen. The store owner can adjust the frequency, amplitude or both of the current passing through coil  120  and change the appearance of packages  100  depending on the time of day or week. This in turn will target group A or group B accordingly so as to maximize the amount of products purchased from the store. The same can be done for changing the frequency of a flashing light as was described in conjunction with  FIG. 4  to target groups A and B accordingly.  
         [0078]     Finally, it should be noted that while the figures show package  100  and product  1200  being in contact with the various shelf systems, this is not a requirement. In one example, package  100  or product  1200  may be placed a relatively small distance from divider  1110  and still operate properly.