Abstract:
Disclosed is a portable charger adapted for use with wireless devices. Integrated circuitry controls the amount of current charge delivered to the primary power source of a wireless device through an adaptor. The current charge is delivered by a power source located within an attractive housing. A light emitting diode coupled to the integrated circuit indicates whether the wireless device is actively being charged.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates generally to the field of battery chargers. More specifically, the current invention is directed to portable battery chargers for portable media devices.  
       BACKGROUND OF THE INVENTION  
       [0002]     Today&#39;s fast-paced, global marketplace requires constant communication between parties. Indeed, the ability to communicate with potential clients, vendors, or manufacturers is vital to an entity&#39;s success. As a result, entities and individuals require wireless communication devices capable of being utilized at any geographical location at any time. While many such devices are known, the most common of these is the portable telephone, also known as a cellular telephone.  
         [0003]     All cellular telephones and portable personal entertainment units (i.e., MP3 players) are electronic devices. As such, they require a power source. For example, most cellular telephones utilize a battery. During operation, the battery provides electrical energy to both a transmitter and a receiver of the cellular telephone. As the cellular telephone is utilized, the energy stored in the battery energy is consumed. Over time, this will drain the battery of all of its electrical energy. As a result, the power source of the cellular telephone must be replaced or replenished.  
         [0004]     Replacing batteries is often cost-prohibitive due to the expense associated with wireless device batteries. A cheaper alternative utilizes a rechargeable battery scheme which allows a user to more frequently utilize the cellular telephone. However, conventional rechargeable batteries require bulky chargers which require conventional power sources such as an electrical outlet to recharge the battery. Therefore, a user must remain in close proximity to a conventional power source which hampers the portability of wireless devices utilizing such batteries.  
         [0005]     In addition, the battery charger is usually only adapted for use with a single type of battery because the input jack of each rechargeable battery is different. As a result, a user of multiple communication devices must carry several of these bulky, inconvenient chargers.  
         [0006]     To overcome some of the problems associated with conventional battery chargers alternatives have been developed. For instance, there are portable chargers that utilize a secondary battery source (e.g., a single or multitude of “AA” battery(s)) to charge the primary cellular telephone battery. These chargers often come with adapters which allow a user to utilize the charger with a plurality of mobile devices. In operation, some of these chargers utilize a circuit to boost their electrical output to match the requirements of the primary cellular telephone battery.  
         [0007]     Importantly, however, a number of these chargers do not have a means to regulate the amount of energy delivered nor do they limit the maximum rate at which energy is supplied to the primary cellular telephone battery. Instead with a number of prior art/existing systems, a user must manually disconnect the charging device to regulate the amount of energy distributed to the battery. If a user forgets to disconnect the portable charger, it will continue to supply a charge to the primary battery. If the primary battery receives an excessive amount of energy it may overload and become damaged. If the primary battery becomes damaged, its usable capacity typically becomes degraded and a user must purchase a costly replacement battery in order to maintain maximum usage time.  
         [0008]     In light of the foregoing, there exists a clear need in the art for an adaptable, portable wireless device charger which is capable of regulating the amount of energy distributed to the primary battery of a portable wireless device.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention discloses a portable charger adapted for use with wireless devices. Importantly, the portable charger does not require an AC connection. At least one integrated circuit located within the housing of the battery charger controls the amount of current charge delivered to the primary power source of a wireless device and the maximum rate at which it is delivered. The current charge is delivered by a power source located within the housing of the battery charger and is electrically coupled to the integrated circuit. A means for attaching the battery charger to a wireless device is electrically coupled to the integrated circuit. Advantageously, the attachment means is one of a plurality of adaptors. This allows a user of the device to charge the battery of a plurality of wireless devices with a single battery charger. A light emitting diode coupled to the integrated circuit indicates whether the wireless device is actively being charged.  
         [0010]     The integrated circuitry (which may be implemented with a single custom ASIC or a plurality of “off the shelf” IC&#39;s) comprises a novel combination of well known components including a differential op amp, a boost converter, and a comparator.  
         [0011]     While battery chargers for portable devices are well known, the present invention is an improvement over the prior art in that it utilizes a sensor located within the integrated circuit topology that monitors current flow into the wireless device. This prevents the battery charger from high rate overcharging the primary battery of the device and preserves the life of the primary battery. This also protects the charger&#39;s circuitry against accidental short circuit connection.  
         [0012]     Also disclosed is a method of charging the primary power source of a wireless device or other primary battery powered consumer product. The method comprises the steps of providing a battery charger in accordance with the present invention, attaching the battery charger to a wireless device, and charging the power source of a wireless device. The present invention advantageously utilizes an interchangeable interconnect system in the form of a plurality of adaptors. These adaptors directly attach to the battery charger and the wireless device. As a result, the battery charger of the present invention can be used to recharge the power supply of a variety of different wireless devices or primary battery powered portable consumer products, eliminating confusing conventional chargers.  
         [0013]     In addition, the current invention is portable and does not require a conventional power source requiring an AC connection. Instead, it utilizes secondary batteries which are disposed in its housing. This eliminates the need for a user to remain in close proximity to a static power source (such as an AC line connection), which provides greater flexibility in using the wireless device.  
         [0014]     In accordance with the foregoing, it is an object of the invention to create a portable wireless device charger.  
         [0015]     Still another object of the current invention is to provide a portable cellular telephone charger.  
         [0016]     Further, it is an object of the present invention to provide a portable wireless device charger which will not damage the primary rechargeable battery and will inherently protect itself against damage from short circuit connection.  
         [0017]     Yet another object of the present invention is to utilize a method of charging a rechargeable battery without damaging the rechargeable battery.  
         [0018]     Still another object of the present invention is to provide a portable, wireless device charger which can be used with a plurality of communications devices. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     A further understanding of the present invention can be obtained by reference to a preferred embodiment set forth in the illustrations of the accompanying drawings. Although the illustrated embodiment is merely exemplary of systems for carrying out the present invention, both the organization and method of operation of the invention, in general, together with further objectives and advantages thereof, may be more easily understood by reference to the drawings and the following description. The drawings are not intended to limit the scope of this invention, which is set forth with particularity in the claims as appended or as subsequently amended, but merely to clarify and exemplify the invention. Reference is now made of the drawings in which:  
         [0020]      FIG. 1  is a diagram of a portable charging system in accordance with the present invention  
         [0021]      FIG. 2  is a diagram of the constituent parts of a disassembled portable charger in accordance with the present invention  
         [0022]      FIG. 3  is a sectional view of a battery charger in accordance with the present invention  
         [0023]      FIG. 4  depicts various adaptors which can be used in conjunction with the portable charger in accordance with the present invention  
         [0024]      FIG. 5  is a circuit diagram of an over-current protected and regulated DC-DC converter and charge delivery sense circuitry in accordance with the present invention  
         [0025]      FIG. 6  is a flow diagram of a method of utilizing a portable charger in accordance with the present invention 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]     A detailed illustrative embodiment of the present invention is disclosed herein. However, techniques, systems and operating structures in accordance with the present invention may be embodied in a wide variety of forms and modes, some of which may be quite different from those in the disclosed embodiment. Consequently, the specific structural and functional details disclosed herein are merely representative, yet in that regard, they are deemed to afford the best embodiment for purposes of disclosure and to provide a basis for the claims herein that define the scope of the present invention.  
         [0027]     Initially, the use of the terms “cellular telephone,” “cell phone,” “wireless device,” “media device,” and the like are not meant to limit the scope of the present invention. Rather, the terms are used interchangeably and are meant to be merely illustrative in nature of certain aspects of the present invention.  
         [0028]     In addition, the terms “charger,” “portable charger,” “device charger,” and the like are not meant to limit the scope of the present invention. These terms are also used interchangeably and are meant to be merely illustrative in nature of certain aspects of the present invention.  
         [0029]     Moreover, well known methods, procedures, and substances for both carrying out the objectives of the present invention and illustrating the preferred embodiment are incorporated herein but have not been described in detail as not to unnecessarily obscure aspects of the present invention.  
         [0030]     Finally, while the foregoing description describes the preferred embodiment only in relation to a cellular telephone, it will be appreciated by those of skill in the art that the invention described herein can be used with other portable media devices. Non-limiting examples include: MP3 players, Blackberry® devices manufactured by Research In Motion, Inc., iPod® music players, and the like. The following presents a detailed description of a preferred embodiment of the present invention.  
         [0031]     Referring now to  FIG. 1 , disclosed is the general system of the present invention. Battery charger  100  and wireless device  300  are electrically coupled to each other by attachment means  200 . Wireless device is any well known wireless device that utilizes a rechargeable power source. Examples include a cellular telephone, a portable digital assistant, a digital media storage device, a digital media playback device, a digital media transmitting device, a digital media receiving device, an iPod®, and a blackberry®. Of course, any wireless device can be used in accordance with the preferred embodiment without departing from the spirit of the invention.  
         [0032]     Wireless device  300  is powered by rechargeable primary battery source with an input  301 . Attachment means  200  has a terminus  202  that attaches to wireless device  300  at input  301 . Attachment means  200  also has a second terminus  201  which is electrically coupled to battery charger  100  on integrated circuit  107  as depicted in  FIG. 3 .  
         [0033]     Turning now to  FIGS. 2-3 , shown are the components of battery charger  100 . Battery charger  100  is comprised of hollow housing  101  with base  105  and top  109 . Base  105  and top  109  are attached to housing  101  by any conventional well known means. For example, base  105  and top  109  can be permanently attached to housing  101  via adhesive, via a snap-on means, or via a clip-on means. In a preferred embodiment, base  105 , top  109 , and housing  101  are all threaded so that the components are removably attached.  
         [0034]     In a preferred embodiment, housing  101  and base  105  is comprised of a lightweight, inexpensive metal. Of course, any material can be used without departing from the spirit of the present invention. Preferably top  109  is made of a clear plastic material so a user can see a light emitting diode (not shown) disposed within the housing. However, top  109  can be made of any material.  
         [0035]     While housing  101  can be any shape, preferably the shape is cylindrical to accommodate power source  111 . Power source  111  can be any well known electrical power source, however, it is preferred that power source  111  is a battery. Power source  111  can be a disposable, alkaline or lithium primary battery or a rechargeable secondary battery such as a nickel/cadmium battery. Preferably, the battery is a standard “AA” sized alkaline battery. Of course, any other well known size or type of battery can be used without departing from the spirit of the invention.  
         [0036]     Spring  103  is oriented in housing  101  such that it remains in contact with a terminus of power source  111 . Preferably, spring  103  is located within base  105  and is comprised of metal. Of course, spring  103  can be oriented at the other terminus of power source  111 . Integrated circuit  107  (discussed in detail below) is disposed within housing  101  such that it is in contact with power source  111 . In a preferred embodiment, integrated circuit  107  and spring  103  contact power source at opposing ends of power source  111 .  
         [0037]      FIG. 3  is a sectional view of the assembled components of battery charger  100 . As depicted, power source  111  is in contact with spring  103  and integrated circuit  107 . A charge current is derived from between points  303  and  305  and travels through integrated circuit  107 . The charge energy/power passes through terminus  201  of attachment means  200  because terminus  201  is in electrical contact with integrated circuit  107 .  
         [0038]     Attachment means  200  is any well known means of connecting two power sources. For example, attachment means  200  can be an electrically conductive wire. Of course, any other well known attachment means can be used without departing from the spirit of the present invention.  
         [0039]     Attachment means  200  further comprises second terminus  202 . Advantageously, second terminus  202  can have several different configurations, examples of which are depicted in  FIG. 4 . For example, second terminus  202 A is designed to attach to an input of a primary power source of a Samsung® cellular telephone. Similarly, second terminus  202 B is designed to attach to an input of a primary power source for a Nextel® cellular telephone, second terminus  202 C is designed to attach to an input for a primary power source of a Motorola® cellular telephone, and second terminus  202 D is designed to attach to an input for a primary power source of a Nokia® cellular telephone. By providing a plurality of varying attachment means, a user can utilize the battery charger of the present invention with a plurality of wireless devices. Of course, any other type of terminus is can be used without departing from the spirit of the present invention.  
         [0040]     Referring now to  FIG. 5 , depicted is a schematic of integrated circuit  107  according to the preferred embodiment of battery charger  100 . The schematic depicts connection  502  to the positive terminal of power supply  111  and second connection  504  to the negative terminal of power supply  111 . Integrated circuit  107  then employs MAX1675 High-Efficiency, Low-Supply-Current, Compact, Step-Up DC-DC Converter  506  to step the 1.5 volt power supplied by the power supply.  
         [0041]     DC-DC Converter  506  has eight connections  508 ,  510 ,  512 ,  514 ,  516 ,  518 ,  520 , and  522 . Low-Battery Comparator Input  510  and Low-Battery Comparator Output  512  are not electrically connected to any other component. Ground  518  is tied to second connection  504  at the negative terminus of power supply  111 , while reference voltage  514  is electrically connected to 1.3 volts. Shutdown Input  516  is connected to power output  522 . This connection facilitates normal operation of DC-DC converter  506  without employing its shutdown capabilities. N-Channel and P-Channel Power MOSFET Drain  520  is connected through zener diode  528  to power output  522 .  
         [0042]     Dual-Mode™ Feedback Input  508  is connected to a resistor network to set the output voltage. Using such a resistor network allows the voltage to be set to preferably between 2.0 volts and 5.5 volts. However, it is contemplated that other resistor networks can be implemented that utilize different voltage ranges. For instance, other well known resistor values can be connected in parallel or in series as is well known in the art to increase or decrease the voltage range. Resistor  524  which ties Dual-Mode™ Feedback Input  508  to ground  518  is preferably 200 kΩ. Resistor  526 , which connects Dual-Mode™ Feedback Input  508  to power output  522 , is preferably 422 kΩ. Of course, other values can be used without departing from the spirit of the invention. The preferred embodiment produces an output voltage at power output  522  based on resistors  524  and  526  in the resistor network and reference voltage  514  per the following formula:  
         V   522     =       V   514     ⁡     [         R   526       R   524       +   1     ]           
 
         [0043]     The voltage at output  530  of DC-DC converter  506  is preferably 4.1 volts. However, the voltage output can be raised or lowered to accommodate other charge current requirements.  
         [0044]     The Charge current that is delivered to  556  is “sensed” by TLV27021DGK Operational Amplifier and Push-Pull Comparator  532  by the voltage difference across resistor  560 . Comparator/amplifier  532  has connections  534 ,  536 ,  538 ,  540 ,  542 ,  544 ,  546 , and  548  and is configured as both a differential operational amplifier and a comparator. Preferably, supply voltage  548  is connected to power output  530  of comparator/amplifier  532  and fixed at 4.1 volts.  
         [0045]     The differential operational amplifier has inputs  536  and  538  on comparator/amplifier  532 . The positive input  538  of comparator/amplifier  532  is connected to power output  530  of DC-DC converter  506  via a 14.3 kΩ resistor  550  and to ground via a 200 kΩ resistor  552 . Of course, other resistors can be used interchangeably. Preferably, negative input  536  is connected to amplifier output  534  via a 200 kΩ resistor  554  and also connected to connector jack switch  556  via a 14.3 kΩ resistor  558 . In addition to being connected to connector jack  556 , resistor  558  is also connected to power output  530  of DC-DC converter  506  via resistor  560 . Preferably, resistor  560  has a value of 1.0Ω although other low sense resistor values may be used.  
         [0046]     Output voltage  534  of comparator  532  has an output voltage based on the resistor network according to the following formula:  
         V   534     =         R     562   ,   554         R     550   ,   558         ⁢     (       V   538     -     V   536       )           
 
         [0047]     Connector jack  556  is a connector through which charge current to device  300  will flow by way of connection to  201  if charging. Accordingly, when no current is flowing through  201  to  300 , positive input  538  and negative input  536  of comparator/amplifier  532  will be fixed at the same voltage. Therefore, output voltage  534  will be near 0 volts. However, when connector jack  556  is connected to device  300  through  201  and charge current is flowing, this will result in a different voltage at positive input  538  from that at negative input  536 , resulting in a positive, amplified output voltage  534  from comparator/amplifier  532 .  
         [0048]     Amplifier output  534  is connected to positive input  542  of comparator  532 . When connector jack  556  is not connected to device  300  through connection  200 , and comparator/amplifier  532  has no voltage difference across input terminals  536  and  538  due to no or insufficient charging current flow through  560 , the output voltage  534  and in turn positive input  542  of comparator/amplifier  532  will be below 1.30V. However, when connector jack  556  is connected to device  300  through  200  and charge current is flowing through  560 , and there is a voltage difference across input terminals  536  and  538  of comparator/amplifier  532  due to current flow through  560 , the output voltage  534  and in turn positive input  542  of comparator/amplifier  532  will be above 1.30V.  
         [0049]     The negative input  544  of comparator/amplifier  532  is preferably fixed at 1.3 volts, effectively causing a near zero volts output (“Logic Low”) at  546  due to insufficient difference between  536  and  538  when little to no charge current is flowing to Device  300  through  200 . Conversely if sufficient difference between  536  and  538  exists due to charge current flowing at  556  to device  300  through  201 , nearly 4.1 volts output (“Logic High”) will be at  546 . Comparator output  546  will emit “logic high”, preferably approximately 4.1 volts, when connector jack  556  is connected to device  300  through  200  and charge current is flowing and a logic low, approximately 0 volts, when connector jack  556  is open and no charge current is flowing. Advantageously, integrated circuit  107  will not deliver current charge to a primary battery source of a wireless device when comparator/amplifier  532  determines that there is a difference in voltages between “logic high” and “logic low” positions.  
         [0050]     Comparator output  546  is connected to a transistor  562 , which is connected to output voltage  530  of DC-DC converter  506  through resistor  564  and a light emitting diode  566 . When comparator output  546  is “logic low”, no current runs through resistor  564  and light emitting diode  566 . In a preferred embodiment, resistor  566  is lkQ. However, when comparator output  546  is “logic low,” transistor  562  is saturated and current flows through resistor  564  and light emitting diode  566 , causing the diode to illuminate.  
         [0051]     Referring now to  FIG. 6 , disclosed is a method of charging a wireless device. Initially, a battery charger in accordance with the present invention is provided  601 . The battery charger has power source  111  already disposed within housing  101 . The battery charger is then attached to an adapter as depicted in step  603 . Preferably, the adaptor is adaptor  200  with a terminus as depicted in  FIG. 4  (i.e.,  202 A-D). Of course, power source  111  can be inserted into housing  101  after attaching an acceptable adaptor by removing housing base  105  and inserting in into housing  101 . After attaching the adaptor to the battery charger, the adaptor is attached to a wireless device. Attaching adaptor  200  to wireless device  300  results in delivering current charge to the wireless device, thereby charging wireless device  300  as depicted in step  603 .