Abstract:
An electrical unit outlet device is disclosed for controlling power isolation, based on a predetermined time, for a device charger, while remaining plugged into a power outlet. An electrical outlet unit circuit cuts any power to the charging device off when charge is complete. An electrical device to limit the electrical power consumed by battery chargers, that are used to recharge the batteries of devices is described which includes: (1) a means to initiate a charging cycle; (2) surge protection circuit to protect both the battery charger and the device being recharged; and (3) an automatic control circuit to terminate a charging cycle. Secondly for the device to maintain the battery at full charge for extended periods of time while limiting power consumption, which includes: (1) a means to repeatedly initiate an abbreviated charging cycle and (2) a means to control the amount of time between the abbreviated charging cycles.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part and claims priority from U.S. patent application Ser. No. 12/768,724 filed on Apr. 27, 2010 now U.S. Pat. No. 8,471,718 which claimed priority from provisional U.S. Pat. App. No. 61/173,001 filed on Apr. 27, 2009. Applicant also claims priority from provisional U.S. Pat. App. Nos. 61/311,721 filed on Mar. 8, 2010 and 61/317,722 filed on Mar. 26, 2010, all of which are incorporated by reference herein in their entireties. 
    
    
     FIELD OF INVENTION 
     The invention is generally directed to an apparatus for making electrical devices more efficient. More specifically, certain embodiments increase the efficiency of battery chargers by automatically removing the electrical power to the charger 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 electrical outlet unit may be designed to isolate the charger from the electrical power source when the device battery has reached a maximum charge. When electrical isolation from a battery occurs, the charging device consumes no power. With power consumption cut off, no unnecessary power and nonrenewable resources are wasted. Further, certain embodiments of the electrical outlet unit allow the user to select the amount of time the battery is to be charged. Further yet, certain embodiments of the electrical outlet unit maintain a full charge on the connected devices by intermittently reconnecting the power. 
     In previous versions of electrical outlet units, in order to reduce the electrical load from the battery chargers, a set time was used for charging a battery. Once this time had elapsed, the device would automatically isolate the charger from the electrical power source. Once the power source was electrically isolated from the battery charger, no power was consumed by the charging device. 
     Once the device had completed a charging cycle, the device would remain disconnected until the initiation switch was pressed again to start a new cycle. After charging, a battery slowly loses its charge even when not in use. Left unattended for long enough, the charge loss would be sufficient to render the battery unusable until such time it was recharged The prior art energy saving devices do not allow a user to adjust the charging time, or provide battery maintenance, to match the battery thereby maximizing the energy savings. 
     SUMMARY OF THE INVENTION 
     Unlike prior art devices, the present electrical outlet unit allows the user to specify the period of time that the electrical outlet unit provides power to the battery charger. Additionally, the present electrical outlet unit allows the user to select a charge maintaining state, in which the device provides power to the charger for 20 minutes out of every 72 hours. 
     In the present electrical outlet unit, an electromechanical device called a relay is used to turn the charger on and off. The relay has a set of electrical contacts that when closed allow electrical power to be supplied to the battery charger. When the electrical contacts are open they isolate the electrical power source from the battery charger. An additional circuit, called the command circuit, may control whether the relay&#39;s electrical contacts are open or closed. The command circuit may be comprised of an initiation switch, a processor, surge suppressors, status indicators, and a relay output driver. 
     All of these components may be mounted inside a plastic enclosure, which is referred to herein as the housing. The housing may be designed such that it will plug into any standard grounded 110-125 Volt A.C. outlet. The housing also may have from 1 to 6 receptacles that allow devices to be plugged in. The housing also may have additional openings for the initiation switch and for the status indicators to protrude through the case. 
     Once the housing has been plugged into a functioning outlet, electricity is sent to the command circuit. The command circuit may then illuminate a status-indicator LED to indicate the surge protection circuit is functioning properly. The surge suppression circuit will protect against voltage surges, regardless if a charge cycle is underway or not, while the device is plugged in and receiving power. If this LED does not illuminate, it indicates a fault condition and the device should be discarded. With the device plugged in and functioning properly, from 1 to 6 battery chargers then may be plugged into the receptacles on the device. Then, if at least one of the battery chargers has been connected to its associated device, the initiation switch would be used to start a charging cycle. 
     In one embodiment the charging cycle is initiated by pressing the start push-button repeatedly until the desired charging time is shown on the display. The charging times are shown on the display in decimal format, i.e., 3.5 equals three and one-half hours. Once the desired charging time has been selected an electrical signal is sent to turn on the relay output circuit. This closes the electrical contacts on the relay, sending electrical power to the battery charger(s) connected to the device. Additionally, the selected charge time is loaded into a digital timer inside the processor. Once loaded this digital timer starts counting down. As the time is counted down the display may be configured to continually update how much time is left on the current charge cycle. When the digital timer reaches zero the display may show “- -” indicating the charge cycle is complete and the relay output driver is turned off. When the relay driver turns off, the relay contacts open, turning off all battery chargers connected to the device, thereby completing the charging cycle. 
     Another goal of the present electrical outlet unit is aimed to provide battery maintenance to eliminate battery power discharge. In the present electrical outlet unit, when the relay driver turns off, the relay contacts open, turning off all battery chargers connected to the device, thereby completing the charging cycle. At completion of the charging cycle the battery maintenance component of the device may be configured to enter maintenance mode. While in maintenance mode the device will continually repeat maintenance cycles. 
     A maintenance cycle may be made up of a pause time and an abbreviated charge time. Each time a maintenance cycle is started, the digital timer starts counting down the pause time. In the current device the pause time is set to 72 hours, but this is by no means limiting. The status indicator flashes while the pause time is counted down. When the pause time reaches zero, the relay output driver is turned on causing the relay contacts to close. While the relay contacts are closed power is once again sent to the battery charger(s). The digital timer now starts counting down the abbreviated charging time. The status indicator may be turned on while the abbreviated charging time is being counted. In the current device the abbreviated charging time is 20 minutes, but this period is not limiting and may be set to any value optimal for the specific application of the present electrical outlet unit. When the abbreviated charge time reaches zero the output relay driver is turned off causing the relay contacts to open. When the relay contacts open the battery charger(s) are disconnected thus completing a maintenance cycle. 
     Pressing the initiation switch during either the initial charge cycle or while in maintenance mode will cause the unit to turn off. When the device is turned off, the relay and the status indicator may be turned off, thereby turning off any devices plugged into the switched outlets. 
     Since the device fills a standard outlet, it may be necessary at times to temporarily plug in a device that requires constant power. To accommodate this need a special HOLD mode or ALWAYS ON receptacle may be added to the device. 
     It is an object of the present electrical outlet unit 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 electrical outlet unit 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. 
     It is another object of the present electrical outlet unit to allow the user to select the amount of time the battery is to be charged. 
     It is another object of the present electrical outlet unit to provide a battery maintenance component to keep a battery at full charge while intermittently connecting and disconnecting the charging device. 
     These and other objects of the present electrical outlet unit will become apparent to those skilled in the art in light of the following drawings, descriptions, and claims. 
    
    
     
       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 illustrative electrical system for an electrical outlet receptacle connected to and or controlled by the timer unit. 
         FIG. 8B  is a simplified diagram of an illustrative 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 illustrative embodiment of the power isolation circuitry of a timer unit of an illustrative embodiment of an electrical outlet unit. 
         FIG. 10  provides a diagram of a second illustrative embodiment of the power isolation circuitry of a timer unit of an illustrative embodiment of an electrical outlet unit. 
         FIG. 11A  provides a simplified flow diagram of an illustrative 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 illustrative electrical outlet unit having the circuitry of  FIG. 10  connected to a device having a rechargeable battery during charging. 
         FIG. 12A  provides a diagram of a first illustrative embodiment of the power isolation circuitry. 
         FIG. 12B  provides a diagram of a first illustrative embodiment of the power isolation circuitry. 
         FIG. 13A  provides a diagram of a second illustrative embodiment of the power isolation circuitry. 
         FIG. 13B  provides a diagram of a second illustrative embodiment of the power isolation circuitry. 
         FIG. 14A  provides a diagram of a third illustrative embodiment of the power isolation circuitry utilizing the battery maintenance feature. 
         FIG. 14B  provides a diagram of a third illustrative embodiment of the power isolation circuitry utilizing the battery maintenance feature. 
         FIG. 15  is a perspective view of another embodiment of an electrical outlet unit subject of the present patent application incorporating the adjustable time component. 
     
    
    
     
       
         
               
             
               
               
             
               
               
             
           
               
                   
               
               
                 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 
                 17 
               
               
                 Diode) 
                   
               
               
                 Varistor 
                 18 
               
               
                 Parallel Varistor 
                 18a 
               
               
                 Surge protector fuse 
                 20 
               
               
                 Fuse 
                 20a 
               
               
                 Power supply circuit 
                 22 
               
               
                 First power supply zener diode 
                 24 
               
               
                 Second power supply zener diode 
                 24a 
               
               
                 Third power supply zener diode 
                 24b 
               
               
                 Timer Unit 
                 25 
               
               
                 Power supply rectifying diode 
                 26 
               
               
                 Parallel relay snubbing diode 
                 26a 
               
               
                 Low power supply circuit 
                 27 
               
               
                 Power supply capacitor 
                 28 
               
               
                 RC timer capacitor 
                 28a 
               
               
                 Output Circuit 
                 29 
               
               
                 Initiation switch (push button) 
                 30 
               
               
                 RC timer circuit 
                 32 
               
               
                 Relay driver 
                 34 
               
               
                 Relay circuit 
                 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 
               
               
                 Digital Timer Display 
                 69 
               
               
                 Diode Bridge 
                 70 
               
               
                 Standard Capacitor 
                 72 
               
               
                 Low Voltage Resistor 
                 74 
               
               
                 First Low Voltage Converting Capacitor 
                 76 
               
               
                 Second Low Voltage Converting  
                 76a 
               
               
                 Capacitor 
                   
               
               
                 Low Voltage Diode 
                 78 
               
               
                 Voltage Limiting Display Diode 
                 80 
               
               
                 Voltage Limiting Display Resistor 
                 82 
               
               
                 First LED Display 
                 84 
               
               
                 Second LED Display 
                 86 
               
               
                 Microprocessor 
                 88 
               
               
                 First Initiation Resistor 
                 90 
               
               
                 First Initiation Resistor 
                 90a 
               
               
                 First Initiation Resistor 
                 90b 
               
               
                 Programming Port 
                 92 
               
               
                   
               
             
          
         
       
     
     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 a “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 a “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 Illustrative Embodiment 
       FIGS. 8A ,  9  and  11 A, and the descriptions that follow, describe a first illustrative embodiment of the electrical outlet unit 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 electrical outlet unit 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 one 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 four (4) hours is in 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 illustrative 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 illustrative embodiment of an electrical unit outlet  1 . 
     Operation and Circuitry of a Second Illustrative Embodiment 
       FIGS. 8B ,  10  and  11 B, and the descriptions that follow, describe a second illustrative embodiment of the electrical outlet unit 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 circuit  22  when the fuse  20   a  is not opened by a short in the circuit. The power supply circuit  22  in the second embodiment is now comprised of a power supply rectifying diode  26 , a zener diode  24 , a second zener diode  24   a , a power supply capacitor  28 , a first power supply resistor  14   c , and a second power supply 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 power supply zener diodes ( 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 an opto-isolator. As one of ordinary skill will appreciate, the optocoupler  52  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 electrical outlet unit 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 illustrative 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 . 
     Operation and Circuitry of a Third Illustrative Embodiment 
       FIGS. 12 and 13 , and the written description that follows, describe a third illustrative embodiment of the electrical outlet unit circuit  44  in which the duration of charging may be adjusted (referred to by its trade name, “Adjustable Take Charge” by applicant, without limitation). In  FIG. 12 , when the A.C. source is connected to a household electrical outlet, electricity is sent to the Surge Protector circuit. As long as the fuse  20  has not opened by a short, the Status Indicator  16  will illuminate indicating the surge protector is functioning. A resistor  14  may be used to limit the electrical current through the diode  16 , to keep the diode  16  from failing from excessive electrical current. The varistors  18  are all in parallel and function as one to protect against a voltage surge between A.C. hot and ground. Additionally varistors  18   a  are all in parallel and function as one to protect against a voltage surge between A.C. hot and neutral. The resistance of either group of varistors reduces quickly when the surge voltage reaches a certain level called the trip point. Once this voltage trip point is reached the varistors starts to conduct, shorting the power surge from the A.C. hot to the A.C. neutral line or from the A.C. hot to ground. Thereby protecting devices plugged into the electrical outlet unit circuit  44  from the power surge. Each time the trip point of the varistors is reached, the trip voltage is reduced. Eventually the trip voltage will be reduced to the applied line voltage. When this happens the varistors will cause a direct short between the A.C. hot and neutral or the A.C. hot and ground causing the fuse  20  to burn open. Once the fuse  20  has opened, the Status Indicator  16  will go out indicating the surge protection circuit of the device is no longer functioning. 
     Additionally, as long as the fuse  20   a  has not opened by a short, when the A.C. Source is connected to a household 125 Volt electrical outlet, electricity is also sent to the Power Supply Circuit  22 . The Power Supply Circuit  22  is composed of the following, components including a fuse  20   a , a power supply diode  24 , a power supply capacitor  28 , a first power supply resistor  14   c , a diode bridge  70 , power supply rectifying diodes  26 , and power supply capacitors  28 . The Power Supply circuit  22  has two outputs, one is 24 Volts D.C. and the other is high voltage which is close to the applied A.C. voltage. The high voltage output is used by the displays after first being rectified to pulsating D.C. by power supply diode  24 . The applied AC voltage is also sent to power supply capacitors  28  and first power supply resistor  14   c . The power supply capacitors  28  acts as a charge pump, passing pulses of power from the AC source on to the rest of the Power Supply circuit  22 . First power supply resistor  14   c  is used as a biasing resistor for power supply capacitor  28 . The pulses of A.C. voltage from power supply capacitor  28   a  are then rectified to pulsating D.C. by a diode bridge  70 . The pulsating D.C. voltage is then filtered to D.C. by two capacitors  72  connected in series. The filtered D.C. Voltage is then regulated to 24 Volts by the first and second power supply zener diodes  24  and  24   a . This filtered and regulated 24 Volts D.C. is the power source used by Low Voltage Supply and to power the output relay  38 . 
     The Low Voltage Supply takes the 24 Volts D.C. from the Power Supply and regulates it down to 5 Volts DC to be used by the processor and it peripherals. The Low Voltage Supply is comprised of a low voltage resistor  74 , and two low voltage capacitors  76  and  76   a  connected in parallel with the low voltage diode  78 . The low voltage resistor  74  is used to provide the 19 Volt drop from the 24 Volts D.C. to the 5 Volts D.C. of the Low Voltage Supply. The low voltage diode  78  is used to regulate the Low Voltage Supply to 5 Volts D.C. by constantly adjusting the amount of current flowing through resistor  74  to produce a 19 Volt drop. Capacitors  76  and  76   a  are used as filter capacitors for the Low Voltage Supply. 
     The output of the electrical outlet unit circuit is comprised of relay coil  38 , parallel relay snubbing diode  26   a , and relay driver  34 . To turn on the output, voltage is sent from the processor to the input of the transistor  34 , thus turning on transistor  34 . When  34  turns on it supplies the ground for the coil of relay  38  thereby energizing the coil of  38 . When the coil of  38  is energized the relay contacts close. With the contacts of relay  38  closed the applied A.C. Voltage is sent to any device plugged into the switched outlets on the electrical outlet unit circuit. To then turn the output off the processor removes the voltage on the input to transistor  34 . This removes the ground to the coil of relay  38 . With ground removed from the coil of  38  the relay contacts of  38  open. When the contacts of relay  38  open the applied A.C. Voltage is removed from any device plugged into the switched outlets on the electrical outlet unit circuit. Also when ground is removed from the coil the resulting collapsing magnetic field of the coil produces a voltage spike which could destroy  34 . To protect  34  a diode  26   a  has been connected across the relay coil which snubs the voltage spike the coil generates. 
     The display is shown in  FIG. 13  and is comprised of transistors  80 , resistors  82 , and two LED display panels  84 . The display is used to show current status of the electrical outlet unit circuit  44 . There are two 7 segment displays  84  and  84   a  which are used to show either the time remaining on a cycle or to display two dashes to indicate the unit is off. The displays are common anode receiving their power from  24  of the Power Supply. To turn on a segment its corresponding transistor  80  is turned on by the processor  88 . When a transistor is turned on it supplies ground to the segment to be turned on. Between the display segment and the transistor  80  is a resistor  82 . The resistor  82  is used to limit the current in the display segments. 
     The controller is comprised of resistors  90 ,  90   a ,  90   b , initiation switch  30 , and microprocessor  88 . The controller handles all inputs, outputs and timing of the electrical outlet unit circuit  44 . The resistor  90   a  is used as a current limit to protect the data port on the processor. The resistor  90   b  is used to bias the input to  34  to ground as its normal state which keeps the output turned off. To start a charge cycle, the Initiation Switch  30  is pressed which supplies a logic level of zero to U1 the processor. To do this the biasing resistor  90  that normally supplies logic level of one is pulled to ground by the closure of Initiation Switch  30 . When the processor  88  receives the start signal it loads 1 hour of time into the internal timer of the processor  88 , updates the displays  84  and  86  to read “1.0”, and turns on the output via  34 . The processor  88  then waits for the release of the initiation switch  34 . Upon release of the initiation switch  34  the internal timers of  88  start counting down the time. As the internal timer of  88  counts down the displays  84  and  86  are updated to show the remaining time. When the internal timer of  88  reaches zero the output is turned off. The processor  88  also sets the displays  84  and  86  to display dashes to indicate the timing is done and the switched outputs are turned off. 
     The Programming Port  92  of the processor  88  is used when the unit is first assembled to load the program software into the internal memory of the processor. The Programming Port  92  can also be used to update the software with later versions. 
     While there has been shown and described what is the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the broader aspects of this invention. For instance, although a relay has been used to electrically isolate the power source from the charger, a Triac, or another solid state device could be used. Furthermore, the Processor could be replaced with a solid state timer or a mechanical timer. Additionally the Initiation Switch could be remote mounted on a stand alone unit. This would allow the electrical outlet unit circuit  44  to be mounted in an outlet that is not easily assessable. This remote mounted Initiation Switch could be linked to the Take Charge by wire(s) or a wireless system. 
     Furthermore, although not shown, one of ordinary skill will appreciate that the electrical outlet unit 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. 
     Operation and Circuitry of a Fourth Illustrative Embodiment 
       FIG. 14  and the written description that follows, describe a fourth illustrative embodiment of the electrical outlet unit circuit  44  in which the duration of charging may be adjusted and/or managed. In this embodiment, referred to generally and interchangeably as either a “Charge Stop” or a “Take Charge” by applicant, the problem addressed is restoring power to the battery charger after a longer period of time for a shorter “charging” period to maintain a battery at a full charge. By not leaving the battery charger on all the time power savings are made and by means of abbreviated charging cycles the battery is maintained at full charge. In the present invention, an electromechanical device called a relay is used to turn on and off the charger. The relay has a set of electrical contacts that when dosed allow electrical power to be supplied to the battery charger. When the electrical contacts are open they isolate the electrical tower source from the batter charter. An additional circuit called the command circuit, controls whether the relay&#39;s electrical contacts are open or dosed. The command circuit is comprised of an initiation switch, a processor, surge suppressors, status indicators, and a relay output driver. 
     All of these components are mounted inside a plastic enclosure called the housing. The housing is designed such that it will plug into any standard grounded 110-125 Volt A.C. outlet. The housing also has from 1 to 6 receptacles that allow the battery chargers to be plugged in. The housing also has additional openings for the initiation switch and for the status indicating LED to protrude through the case. 
     Once the electrical cord from the housing has been plugged into a functioning outlet. electricity is sent to the command circuit. The command circuit will then illuminate a status indicator LED to indicate the surge protection circuit is functioning properly. The surge suppression circuit will protect against voltage surges, independent of the initiation or operation of the charge cycle, while the Take Charge with Batten/Maintenance is plugged in and receiving power. If this LED does not illuminate it indicates a fault condition and the Take Charge with Battery Maintenance should be discarded. With the Take Charge with Battery Maintenance plugged in and functioning properly, from 1 to 6 battery chargers are then plugged in into the receptacles on the Take Charge with Battery Maintenance. Then if at least one of the battery chargers has been connected to its associated device, the initiation switch would be used to start a charging cycle. 
     In the present invention this is done by pressing the start push-button, but in no way is this limiting as one of ordinary skill in the art will appreciate. Once a charging cycle is started, an electrical signal is sent to turn on the status indicator and a signal is sent to turn on the relay output circuit. This closes the electrical contacts on the relay, sending electrical power to the battery charger(s) connected to the Take Charge with Battery Maintenance. Additionally the battery charging time is loaded into a digital timer inside the processor. Once loaded, this digital timer starts counting down. When the digital timer reaches zero, the relay output driver is turned off. When the relay driver turns off, the relay contacts open, turning off all battery chargers connected to the Take Charge with Battery Maintenance completing the charging cycle. 
     At completion of the charging cycle the Take Charge with Battery Maintenance now enters into maintenance mode. While in maintenance mode the device will continually repeat maintenance cycles. A maintenance cycle is made up of a pause time and an abbreviated charge time. Each time a maintenance cycle is started the digital counter starts timing down the pause time. In the current device the pause time is set to 72 hours, however, in no way is this limiting to the present invention as other periods of time, longer or shorter in duration, could also be selected. While the pause time is being counted down the status indicator flashes. When the use time has been counted down the relay output driver is turned on causing the relay contacts to close. While the relay contacts are closed, power is once again sent to the battery chargers. The digital timer now starts timing down the abbreviated charging time. While the abbreviated charging time is being counted down the status indicator is turned on. In the current device the abbreviated charging time is 20 minutes. When the abbreviated charge time has been counted down the output relay driver is turned off causing the relay contacts to open. When the relay contacts open the battery charger(s) are turned off thus completing a maintenance cycle. Pressing the initiation switch during either the initial charge cycle or while in maintenance mode will cause the unit to turn off. When the Take Charge with Battery Maintenance is turned off the relay and the status indicator are turned off, which also turns off any devices plugged into the switched outlets. 
     As one of ordinary skill will appreciate, the operation and circuitry of the present embodiment is similar to the third illustrative embodiment shown at  FIGS. 12-13  as compared to  FIG. 14 . The output of the electrical outlet unit circuit is comprised of relay coil  38 , parallel relay snubbing diode  26   a , and relay driver  34 . To turn on the output, voltage is sent from the processor to the input of the transistor  34 , thus turning on transistor  34 . When  34  turns on it supplies the ground for the coil of relay  38  thereby energizing the coil of  38 . When the coil of  38  is energized the relay contacts close. With the contacts of relay  38  closed the applied A.C. Voltage is sent to any device plugged into the switched outlets on Take Charge with Battery Maintenance. To then turn the output off the processor removes the voltage on the input to transistor  34 . This removes the ground to the coil of relay  38 . With ground removed from the coil of  38  the relay contacts of  38  open. When the contacts of relay  38  open the applied A.C. Voltage is removed from any device plugged into the switched outlets on the Take Charge with Battery Maintenance. Also when ground is removed from the coil the resulting collapsing magnetic field of the coil produces a voltage spike which could destroy  34 . To protect  34  a diode  26   a  has been connected across the relay coil which snubs the voltage spike the coil generates. 
     Although the display for this embodiment is not shown, it operates similar to the display shown in  FIG. 13  and is comprised of transistors  80 , resistors  82 , and two LED display panels  84 . The display may be used to show current status of the electrical outlet unit circuit  44 . In this embodiment, the displays  84  and  84   a  are used to show either the time remaining on a cycle or to display whether the unit is providing a short charge for maintenance or whether the unit is off. The displays are common anode receiving their power from  24  of the Power Supply. To turn on a segment its corresponding transistor is turned on by the processor  88 . When a transistor is turned on it supplies ground to the segment to be turned on. Between the display segment and the transistor is a resistor  82 . The resistor is used to limit the current in the display segments. 
     The controller is comprised of resistors  90 ,  90   a ,  90   b , initiation switch  30 , and microprocessor  88 . The controller handles all inputs, outputs and timing of the electrical outlet unit circuit  44 . The resistor  90   a  is used as a current limit to protect the data port on the microprocessor  88 . The resistor  90   b  is used to bias the input to  34  to ground as its normal state which keeps the output turned off. To start a charge cycle, the initiation switch  30  is pressed which supplies a logic level of zero to microprocessor  88 . To do this the biasing resistor  90  that normally supplies logic level of one is pulled to ground by the closure of initiation switch  30 . When the microprocessor  88  receives the start signal it loads 3.25 h hour of time into the internal timer of the microprocessor  88 , updates the displays  84  and  86  to read “1.0”, and turns on the output via  34 . The processor  88  then waits for the release of the initiation switch  34 . Upon release of the initiation switch  34  the internal timers of microprocessor  88  start counting down the time. When the internal timer of microprocessor  88  reaches zero the output is turned off. The internal timer is then loaded with 72 hours and starts counting down. It will be apparent to one of ordinary skill, that other durations of time may selected and or preferred and the duration selected herein is in no way limiting. 
     While the 72 hours is being counted down the displays  84  and  86  are repeatedly turned on and off as to make the LED flash. After the 72 hours have been counted down, the microprocessor  88  turns on the output via transistor  80  and status indicator  82 . The internal timer is then loaded with 20 minutes and starts counting down. When the internal timer of microprocessor  88  reaches zero the output is turned off and the internal timer is set to 72 hours again. This 72 hour pause time followed by 20 minutes of charging continues to repeat until the initiation switch  30  is pressed and released again. When the initiation switch  30  is pressed while a timing cycle is going on, the internal timer is cleared, the output is turned off, and the status indicator  82  is turned off completing the timing cycle. 
     Having described several illustrative 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.