Abstract:
An electrical unit outlet device is disclosed for controlling power isolation, based on a pre-determined time, for a device charger, while remaining plugged into a power outlet. A power isolating circuit cuts any power to the charging device off when charge is complete.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority from provisional U.S. Pat. App. No. 61/173,001 filed on Apr. 27, 2009, which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF INVENTION 
     The invention is generally directed to an electrical outlet unit providing surge protection and limiting the electrical power consumption of electrically connectable devices having rechargeable batteries by automatically removing the electrical power to the electrical outlet unit once charging is complete. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     No federal funds were used to develop or create the invention disclosed and described in the patent application. 
     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX 
     Not Applicable 
     BACKGROUND 
     The desired use of rechargeable battery operated devices has created an increasing demand of cordless electronic devices including but not limited to cell phones, PDAs, laptop computers, MP3 players, digital cameras, portable GPS units, cordless personal hygiene products, and cordless hand or yard tools. Often the corresponding chargers remain plugged into a power outlet and consume power when the devices are not being used. This consumed energy has required power plants to accommodate the futile power continuously consumed by the plugged in charger, thus increasing nonrenewable carbon based resources such as coal, oil and natural gas. 
     The present invention is designed to isolate the charger from the electrical power source when the device battery has reached a maximum charge. When electrical isolation from battery occurs, no power is consumed by the charging device. With power consumption cutoff, no unnecessary power and nonrenewable resources are wasted. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an apparatus for isolating power in a cordless device&#39;s charger while plugged into a power outlet. 
     It is another object of the present invention to provide an apparatus that will eliminate the waste of power and nonrenewable resources, through power isolation within the device and device charger&#39;s circuit. 
    
    
     
       DETAILED DESCRIPTION 
       Brief Description of the Figures 
       In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limited of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings. 
         FIG. 1  is a perspective view of one embodiment of an electrical outlet unit subject of the present patent application. 
         FIG. 2  is a front view of the electrical outlet unit of  FIG. 1 . 
         FIG. 3  is a side view of the electrical outlet unit of  FIG. 1 . 
         FIG. 4  is a view of the rear side of the electrical outlet unit of  FIG. 1   
         FIG. 5  is a top view of the electrical outlet unit of  FIG. 1 . 
         FIG. 6  is a front view of another embodiment of an electrical outlet unit subject of the present patent application. 
         FIG. 7  is a side view of the electrical outlet unit of  FIG. 6 . 
         FIG. 8A  is a simplified diagram of an exemplary electrical system for an electrical outlet receptacle connected to and or controlled by the timer unit. 
         FIG. 8B  is a simplified diagram of an exemplary electrical system for an electrical outlet receptacle not connected to and or controlled by the timer unit. 
         FIG. 9  provides a diagram of a first exemplary embodiment of the power isolation circuitry of a timer unit of an exemplary embodiment of an electrical outlet unit. 
         FIG. 10  provides a diagram of a second exemplary embodiment of the power isolation circuitry of a timer unit of an exemplary embodiment of an electrical outlet unit. 
         FIG. 11A  provides a simplified flow diagram of an exemplary electrical outlet unit having the circuitry of  FIG. 9  connected to a device having a rechargeable battery during charging. 
         FIG. 11B  provides a simplified flow diagram of an exemplary electrical outlet unit having the circuitry of  FIG. 10  connected to a device having a rechargeable battery during charging. 
     
    
    
     DETAILED DESCRIPTION 
     Listing of Elements 
     
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 Element Description 
                 Element Number 
               
               
                   
                   
               
             
             
               
                   
                 Electrical Outlet Unit 
                  1 
               
               
                   
                 Housing 
                  2 
               
               
                   
                 First side - housing 
                  3 
               
               
                   
                 Second side - housing 
                  4 
               
               
                   
                 First end - housing 
                  5 
               
               
                   
                 Second end - housing 
                  6 
               
               
                   
                 Front 
                  7 
               
               
                   
                 Rear 
                  8 
               
               
                   
                 Power cord 
                  9 
               
               
                   
                 AC power source 
                 10 
               
               
                   
                 Connection 
                 11 
               
               
                   
                 Surge protection circuit 
                 12 
               
               
                   
                 Distal end 
                 13 
               
               
                   
                 Surge protector resistor 
                 14 
               
               
                   
                 RC timer resistor 
                  14a 
               
               
                   
                 Charging status resistor 
                  14b 
               
               
                   
                 First power supply resistor 
                  14c 
               
               
                   
                 Second power supply resistor 
                  14d 
               
               
                   
                 Blank 
                 15 
               
               
                   
                 Surge protector LED (Light Emitting Diode) 
                 16 
               
               
                   
                 Charging Status LED (Light Emitting Diode) 
                 17 
               
               
                   
                 Varistor 
                 18 
               
               
                   
                 Surge protector fuse 
                 20 
               
               
                   
                 Fuse 
                  20a 
               
               
                   
                 Power supply 
                 22 
               
               
                   
                 First power supply zener diode 
                 24 
               
               
                   
                 Second power supply zener diode 
                  24a 
               
               
                   
                 Timer Unit 
                 25 
               
               
                   
                 Power supply rectifying diode 
                 26 
               
               
                   
                 Parallel relay snubbing diode 
                  26a 
               
               
                   
                 Power supply capacitor 
                 28 
               
               
                   
                 RC timer capacitor 
                  28a 
               
               
                   
                 Initiation switch (push button) 
                 30 
               
               
                   
                 RC timer 
                 32 
               
               
                   
                 Relay driver 
                 34 
               
               
                   
                 Relay 
                 36 
               
               
                   
                 Relay coil 
                 38 
               
               
                   
                 Relay contacts 
                 40 
               
               
                   
                 Electrical receptacle (AC Outlets) 
                 42 
               
               
                   
                 Power isolation circuit 
                 44 
               
               
                   
                 AC source hot line 
                 46 
               
               
                   
                 AC outlet hot line 
                  46a 
               
               
                   
                 AC source neutral line 
                 48 
               
               
                   
                 AC outlet neutral line 
                  48a 
               
               
                   
                 AC source ground line 
                 50 
               
               
                   
                 AC outlet ground line 
                  50a 
               
               
                   
                 Optocoupler 
                 52 
               
               
                   
                 Device charger 
                 54 
               
               
                   
                 Device battery 
                 56 
               
               
                   
                 Transformer 
                 58 
               
               
                   
                 Blank 
                 59 
               
               
                   
                 Transverse Axis - Housing 
                 60 
               
               
                   
                 Longitudinal Axis - Housing 
                 61 
               
               
                   
                 Ground prong (male) 
                 62 
               
               
                   
                 Blade 
                 63 
               
               
                   
                 Column 1 
                 64 
               
               
                   
                 Column 2 
                 65 
               
               
                   
                 Row 1 
                 66 
               
               
                   
                 Row 2 
                 67 
               
               
                   
                 Ground connection (female) 
                 68 
               
               
                   
                   
               
             
          
         
       
     
     Detailed Description 
     Before the various embodiments of the present invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that phraseology and terminology used herein with reference to device or element orientation (such as, for example, terms like “front”, “back”, “up”, “down”, “top”, “bottom”, and the like) are only used to simplify description of the present invention, and do not alone indicate or imply that the device or element referred to must have a particular orientation. In addition, terms such as “first”, “second”, and “third” are used herein and in the appended claims for purposes of description and are not intended to indicate or imply relative importance or significance. 
     Referring to  FIGS. 1-5 , wherein like reference numerals designate identical or corresponding parts throughout the several views, and to the following description, it can be understood that the present invention may be embodied in an electrical outlet unit  1  which comprises a housing  2  which includes a first side  3  and a second side  4 . A transverse axis  60  extends between the first side  3  and the second side  4 . The housing  2  further includes a first end  5  and a second end  6 . A longitudinal axis  61  extends between the first end  5  and the second end  6 . Housing  2  further includes a front  7  and a rear  8 . Housing  2  can be formed in various colors and of various materials. As required by codes and the market, the housing may also be constructed of non-conductive plastic and or insulated.  FIGS. 1-5  are of an embodiment of an electrical outlet unit  1  which is to be mounted to a standard AC power outlet  10  (commonly referred to as a “wall socket”) having 2 or 4 electrical receptacles during operation. A wall mounted AC power electrical receptacle is not shown as they are well known in the art and similar in design to the electrical receptacles  42  shown herein. The electrical charge outlet unit as shown in  FIGS. 1-5  includes a second grounding prong  62   a  mounted to the housing which serves to fully engage the outlets to which the unit may be mounted stabilizing the electrical outlet unit  1 . Additionally, the second grounding prong may be electrically connected to the grounding circuit. 
     Referring to  FIGS. 6-7 , wherein like reference numerals designate identical or corresponding parts throughout the several views, and to the following description, it should be understood that the present invention, without limitation, may also be embodied in an electrical outlet unit  1  having a cord  9  attached therein which also comprises a housing  2  which includes a first side  3  and a second side  4 . A transverse axis  60  extends between the first side  3  and the second side  4 . The housing  2  further includes a first end  5  and a second end  6 . A longitudinal axis  61  extends between the first end  5  and the second end  6 . Housing  2  further includes a front  7  and a rear  8 . The housing  2  of this embodiment may also be formed in various colors and of various materials. As required by codes and the market, this housing  2  may also be constructed of non-conductive plastic and or insulated. The power cord  9  is connected to housing  2  and has a connection  11  on a distal end  13  thereof that is shaped and sized to electrically connect to an AC power source  10  such as an electrical outlet receptacle of a home, office or the like. One of ordinary skill will appreciate that the embodiments shown in either  FIG. 1  or  6  may have more or less grounded electrical receptacles. 
     A plurality of grounded electrical outlet receptacles  42  (alternatively referred to as AC power outlets) are located on the front of housing  2 . In the example shown in  FIGS. 1-5 , the grounded electrical receptacles are arranged in two columns  64  and  65  and two rows  66  and  67 . As can be understood from  FIG. 1 , the columns  64 ,  65  are spaced apart from each other along the transverse axis  60  of the housing and the rows  66 ,  67  are spaced apart from each other along the longitudinal axis  61  of the housing  2 . Each outlet receptacle  42  has a ground connection, such as ground connection  68 . As best shown in  FIGS. 1 and 5 , profile of the front side (face)  7  of the electrical outlet unit  1  is non-linear and allows positioning the electrical outlet receptacles at an angle below the transverse axis  60  of the front side  7 . The advantage of this profile is that it allows for insertion and use of cords having a bulky connection end at the distal end of the cord therein (not shown).  FIG. 5  illustrates the angled relation of front side  7  having faces  7   a ,  7   b , and  7   c.    
     Electrical Outlet Unit  1  includes a timer unit  25  within the housing  2 . Timer unit  25  includes an electrical circuit which may be connected to each outlet receptacle of the plurality of grounded electrical outlet receptacles  42  to control operation of those receptacles as will be understood from the teaching of this disclosure. As disclosed and claimed herein, the exemplary embodiments, without limitation, have the timer unit  25  connected to all but one of the grounded electrical receptacles. Having one grounded receptacle always “hot” allows the electrical outlet unit to function as surge protector when the timing function is not beneficial or needed. 
     An electrical surge protector circuit  12  is located in housing  2  and is electrically connected to each outlet receptacle of the plurality of grounded electrical outlet receptacles  42 . The surge protector circuit  12  is common to power strips and thus will not be further discussed as those skilled in the art will understand what elements and connections are required for the surge protector circuit  12 . A grounding circuit electrically connects the grounding circuit of each of the grounded outlet receptacles to the grounded conductor of the power cord  9  or the ground prongs  62  and blades  63  of the wall mounted embodiment of the electrical outlet unit  1 . An initiation switch  30  is located on the housing  2 . As indicated in  FIGS. 1 ,  6 ,  8 A and  8 B, initiation switch  30  is electrically interposed between power  22  and the electrical surge protector circuit  12  and between power  22  and the timer unit circuit  25 . Initiation switch  30  includes an “off” position which electrically disconnects the electrical surge protector circuit  12  from power  22  when the initiation switch  30  is in an “off” condition, a “charging” position which electrically connects the electrical surge protector circuit  12  to the power supply  22  when the initiation switch  30  is in “charging” condition which electrically connects the timer unit  25  to power  22  when the initiation switch  30  is in a “charging” condition. The “charging” position and the “off” position are mutually exclusive of each other so that when the initiation switch is in one of the positions, it cannot be in any other of the positions. That is, if the initiation switch  30  is in a “charging” (on) configuration, the timer unit  25  will be activated and the electrical outlet receptacles will be powered during the charging cycle. If the initiation switch  30  is “off”, the timer unit  25  will be de-activated and the electrical outlet receptacles connected to the timer unit  25  will not be powered. 
     Operation and Circuitry of a First Exemplary Embodiment 
       FIGS. 8A ,  9  and  11 A, and the descriptions that follow, describe a first exemplary embodiment of the power isolating circuit  44  of the electrical outlet  1 . As is well known to those skilled in the art, several circuitry components may be used in conjunction with one another depending on the proper values to which circuitry can isolate power at a desired time. As shown in the various figures herein, when the alternating current (AC) source  10  is connected to a standard household 125 volt electrical outlet, electricity is sent to the surge protector circuit  12 . As long as the fuse  20  has not opened by a short, the status indicator LED  16  will illuminate indicating the surge protector is functioning. A resistor  14  is used to limit the electrical current through the status indicator LED  16 , to keep the status indicator LED  16  from failing due to excessive electrical current. A varistor  18  reduces resistance if or when voltage reaches an excessive trip point. When the voltage trip point is reached, the varistor  18  conducts or discharges electricity. Through conduction or discharge through varistor  18  the resulting power surge between AC source  10  hot line  46  and the AC source  10  neutral line  48  is shorted (absorbed). The shortage provides protection to devices plugged into Power Outlets  42  from a power surge. Trip voltage is reduced each time the trip point of the varistor  18  is reached. This voltage reduction eventually reduces the trip voltage to the applied line voltage. The varistor  18  will cause a direct short between the AC source  10  hot line  46  and AC source  10  neutral line  48  causing the fuse  20  to burn open once trip voltage is reduced to line voltage. When said fuse  20  has opened, the status indicator LED  16  will turn off indicating surge protection of the power isolating circuit  12  is no longer functioning. 
     Concurrently, when AC source  10  is connected to a standard household 125 volt electrical outlet, electricity is also sent to the power supply  22 . The power supply transformer  58  reduces the 125 volts AC down to 12 volts AC. The AC voltage is rectified to pulsating DC by rectifying diode  26  and then filtered to DC by a fixed polarized capacitor  28 . This low voltage DC is then used by the RC timer  32  which is primarily composed of a RC timer fixed polarized capacitor  28   a , and RC timer resistor  14   a.    
     The charge cycle transmission begins through engagement of initiation switch  30  allowing current to flow through the initiation switch  30 . As of ordinary skill will appreciate, the initiation switch may be a push button, a throw switch or any type of switch that may be engaged by a user. As current flows through initiation switch  30 , the RC timer fixed polarized capacitor  28   a  is charged to the power supply  22  Voltage. When the initiation switch  30  is released an RC timer resistor  14   a  will slowly discharge said RC timer fixed polarized capacitor  28   a . The discharge time of the preferred embodiment has been set but not limited to four hours by the RC timer resistor  14   a  and the RC timer fixed polarized capacitor  28   a . One of ordinary skill will appreciate that other times may be selected and the selection of 4 hours is no way limiting. 
     A relay driver  34  is an N channel FET used as an output driver by the RC Timer  32 . While the charge in the RC timer fixed polarized capacitor  28   a  is above the relay driver  34  gate to source voltage threshold, the relay driver  34  will conduct turning on the relay  36 . When the relay  36  is on, the relay contacts are closed sending AC power from the AC source  10  to the charging status LED  17  indicator. As a result, the charging status LED  17  indicates the charge cycle is in progress. A series relay resistor  14   b  is used to limit the electrical current through the charging status LED  17 , to keep the charging status LED  17  from failing from excessive electrical current. Additionally, while the relay  36  contacts  40  are closed, AC power is sent to the AC outlets  42 . This location is where battery chargers are plugged into the electrical unit outlet  1 . 
     After the set, but not limited to, four hours of charging in the RC timer fixed polarized capacitor  28   a  will drop below the gate to source voltage threshold of the relay driver  34 . As a result, this will cause the relay driver  34  to cease conducting, turning off relay  36  causing the contacts  40  to open. When the contacts  40  open AC power is disconnected from charging status indicator LED  17  causing the light to go out indicating the charge cycle is complete. When the contacts  40  open, AC power is removed from the AC outlets turning off any device plugged into the electrical unit outlet  1 . 
     When relay  36  turns off, the collapsing magnetic field of the relay coil  38  will cause voltage spike which has the potential to kill the relay driver  34 . To protect the relay driver  34  a parallel relay snubbing diode  26   a  has been connected across the relay coil  38  which negates the voltage spike generated by the coil.  FIG. 11A  illustrates an exemplary block diagram of the combination of circuits illustrated by  FIG. 9  working together to form a timing unit  25  using an RC timer circuit  32  and as relay circuit  36  in an exemplary embodiment of an electrical unit outlet  1 . 
     Operation and Circuitry of a Second Exemplary Embodiment 
       FIGS. 8B ,  10  and  11 B, and the descriptions that follow, describe a second exemplary embodiment of the power isolating circuit  44 . In this embodiment, a fuse  20   a  was added to the circuit&#39;s power supply to isolate electricity flow to the power supply  22  when the fuse  20   a  is not opened by a short in the circuit. The power supply  22  in the second embodiment is now comprised of a rectifying diode  26 , a zener diode  24 , a second zener diode  24   a , a capacitor  28 , a resistor  14   c , and a second resistor  14   d . The AC voltage is then rectified to pulsating DC by power supply rectifying diode  26  and then regulated to approximately 15 Volts by a first and second zener diode ( 24 ,  24   a ). The second zener diode  24   a  output is then filtered to DC by a capacitor  28 . The filtered DC is the power source used by an optocoupler  52  which acts as an opto-isolator. As one of ordinary skill will appreciate, the optocoupler uses an optical transmission path to transfer a signal between the various elements of the circuitry while maintaining electrical isolation because the signal goes from an electrical signal to an optical signal back to an electrical signal, electrical contact along the circuit path is broken. 
     A resistor  14   d  is used to limit the current through optocoupler  52  on the input side. The low voltage pulsating DC output of a first zener diode  24  is used by the RC timer  32 , comprising of a capacitor  28   a  and a resistor  14   a . The RC timer  32  controls the length of the charge cycle for the devices connected to the power isolating circuit&#39;s AC power outlets  42 . When the push switch  30  is engaged, current flows through, charging a capacitor  28   a  to the added second zener diode  24   a  voltage of 15 Volts. The power supply resistor  14   c  is used to limit the current rushing in from the RC timer capacitor  28   a . When the initiation push switch  30  is released, the resistor  14   a  will slowly discharge RC timer capacitor  28   a . While the charge in the RC timer capacitor  28   a  is above the relay driver  34  gate to source voltage threshold, the relay driver  34  will conduct turning the optocoupler  52  on, which in turn powers up the relay  36 . The optocoupler  52  will turn off, in turn, turning off the relay  36  causing the contacts to open when the relay driver  34  stops conducting at the end of a charge cycle.  FIG. 11B  illustrates an exemplary block diagram of the combination of circuits illustrated by  FIG. 8B  and  FIG. 10  working together to form another version of electrical unit outlet  1 . 
     Furthermore, although not shown, one of ordinary skill will appreciate that the electrical unit outlet may be embodied in any one of several implementations including as a stand-alone unit mounted in a plastic housing with at least one cord connectable to an ac outlet and having at least one, and preferably several, ac receptacles into which the device charger  54  for a device having rechargeable batteries  56  may be connected. In another embodiment, not shown, the initiation switch may also be remotely mounted as a stand-alone unit allowing the power isolation circuit  44  of the electrical unit outlet  1 , to be mounted in an outlet that is not easily accessible. This remote mounted initiation switch could be linked to the electrical unit outlet  1 , power isolation circuit  44 , by wire(s) or a wireless system. 
     Having described several exemplary embodiments, other features of the present invention will undoubtedly occur to those versed in the art, as will numerous modifications and alterations in the embodiments of the invention illustrated, including other combinations of circuits and components to limit the amount of time a device having a rechargeable battery may draw electric current, all of which may be achieved without departing from the spirit and scope of the invention.