Abstract:
An apparatus and method for supplying alternating current power to electrical devices wherein a subpanel having a plurality of switches allows a user to preset selected electrical devices for either automatic or manual load pick up by a battery during a utility power loss. Battery power is supplied only to predetermined electrical devices so as to avoid overload of the battery.

Description:
FIELD OF THE INVENTION 
     This invention relates to an apparatus and method for supplying alternating current power to electrical devices, and more particularly, to an apparatus and method which allows for setting predetermined electrical devices for either an automatic or manual change from electric utility power to battery power during a power outage. 
     BACKGROUND OF THE INVENTION 
     Various types of backup power supply systems are known which provide backup battery power to sump pumps, refrigerators, computers, heating equipment and other types of electric devices. 
     These devices do not provide the capability to select specific electrical devices for either an immediate or manual switch to battery power in the event of a power outage. In other words, the known devices cannot be set to supply power only to selected electrical devices so as to avoid overload of the battery. 
     An additional disadvantage of some of the known devices is that they are not connectable to power generating devices which can prevent battery burn out by charging the battery during a loss of main power. 
     Further, a disadvantage of known 12 volt auxiliary power systems is that a high current is needed to supply a substantial amount of power to the electrical devices. A high current flow through battery cables causes energy loss and, as a result, these 12 volt systems do not make the most efficient use of the stored battery power. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide an apparatus and method for supplying alternating current power to electrical devices such as sump pumps, refrigerators, computers, heating equipment and the like, which will, in the event of a power outage, automatically switch only predetermined electrical devices to battery power, with the remaining electrical devices switching to battery power only upon manual operation by a user. 
     It is an additional object of the present invention to provide a method and apparatus for supplying alternating current power to electrical devices wherein the battery is charged by a backup power generating device during a loss of main power. 
     The foregoing objects are achieved and the disadvantages of the known power supply devices are overcome by providing an apparatus which supplies alternating current power to electrical devices from an electric utility power supply or, when the utility power supply is not available, from a battery. The apparatus includes an inverter connected to the battery at a direct current input portion of the inverter. The inverter changes direct current power to alternating current power and outputs the alternating current power at its output portion. 
     The apparatus also includes a conversion relay connected to the utility power supply and the output portion of the inverter. The conversion relay supplies power from either the utility power supply or the battery via the inverter to the electrical devices connected to a final output portion. The final output portion includes a plurality of AC receptacles to receive plugs from electrical devices. 
     A charging system, such as a pulsed charging system, is connected to the utility power supply via the conversion relay and to the battery so as to enable charging of the battery with power from the utility power supply. At least one charge controller can be connected to the charging system and to a power generating device, such as a wind turbine, a solar array or the like, to charge the battery with power supplied from the power generating device. 
     The device includes a power converter, such as a twin inversion power unit, a triple (for 3-phase systems) inversion power unit, or a step-up transformer, that connects to a subpanel. The step-up transformer increases an input voltage from 110 volts to 220 volts to accommodate the electric devices with higher voltage requirements, such as well-pumps or the like. An inversion power unit may be used in place of a step-up transformer when, for example, the input voltage is already 220 volts. 
     The subpanel consists of a plurality of switches which correspond to predetermined electrical devices connected to the apparatus. Some of the subpanel switches are set in the “on” position to effectuate automatic load pick up by the battery in the event of power outage. Therefore, when the utility power supply is unavailable, the electrical devices which correspond to the switches set in the “on” position are supplied with power from the battery. 
     The electrical devices corresponding to the subpanel switches set to the “off” position will not receive power during a power outage unless the switches are turned to the “on” position. Limiting the power supply to the devices corresponding to the activated switches prevents overload of the battery, as well as providing a means by which reserve capacity of the system may be maintained. 
     A device which filters incoming power and protects electronic equipment from damage due to distorted utility voltage caused by an energy crisis situation, such as a line conditioner, can be connected to the power converter and between the inverter and final output portion. A line conditioner may be necessary when one of the electrical devices is, for example, a computer. Additionally, the device can include a fan positioned therein to maintain a cool temperature. 
     In order to ensure an adequate supply of battery power during a power outage, a battery may be linked to a second cell bank. In addition, to further charge the battery, any number of charge controllers included the apparatus can be connected to the power generating devices described above. 
     A method for supplying alternating current power to the electrical devices from the electric utility power supply or from a battery when the utility power supply is unavailable, includes the steps of connecting the inverter to the battery at the direct current input portion of the inverter; changing direct current power to alternating current power; outputting the alternating current power at the output portion of the inverter; connecting a conversion relay to the utility power supply and to the output portion of the inverter; supplying power from either the utility power supply or the battery via the inverter to electrical devices connected at the final output portion of the apparatus; connecting the charging system to the utility power supply via the conversion relay and to the battery source; charging the battery source with power from the utility power supply; connecting the power converter to the subpanel having the plurality of switches; assigning each one of the switches to an electrical device; setting a first group of the switches to the “on” position to cause automatic load pick up by the battery when the utility power supply is unavailable; and setting a second group of the switches to the “off” position to cause manual load pick up by the battery when the utility power supply is unavailable. 
     The method may also include the steps of connecting at least one charge controller to the charging system and a power generating device; and charging the battery with power supplied from the power generating device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features and advantages of the invention will become apparent upon review of the following detailed description of the preferred embodiment, taken in conjunction with the following drawings, in which: 
     FIG. 1 is schematic diagram of an embodiment of the present invention; 
     FIG. 2 is a front view of an embodiment according to the present invention; 
     FIG. 3 is a side view of an embodiment according to the present invention; and 
     FIG. 4 is a cross-sectional side view of an embodiment according to the present invention. 
    
    
     DETAILED DESCRIPTION 
     The present invention relates to an apparatus and method for supplying alternating current power to electrical devices from a utility power supply or, in the event of a utility power loss, from a battery, wherein the switch to battery power occurs automatically and without any downtime for predetermined electrical devices. 
     Referring to FIGS. 1-4, the apparatus  100  plugs into a standard electrical outlet  101  which provides a source of electricity for the apparatus  100 . The electricity may originate from a utility company or an on-site generator  180 . The design of apparatus  100  may be that shown in U.S. Design Pat. No. 417,650. 
     The leads in the outlet  101  extend from first input terminals  108  included in the conversion relay  107 . The conversion relay  107  also includes second input terminals  109 , a pick coil  110 , moveable terminals  111  and output terminals  112 . 
     When power is supplied from the outlet  101 , the pick coil  110  causes the moveable terminals  111  to contact the first input terminals  108  so that power travels from the first input terminals  108  through the moveable terminals  111  to the primary output terminals  106  of the inverter  103 . From the primary output terminals  106 , the power travels to the final output portion  117  and is distributed to any number of electrical devices through the AC receptacles  118 . In an alternative embodiment, the apparatus  100  includes a line conditioner  116  so that the power flows through the line conditioner  116  before reaching the final output portion  117 . The line conditioner  116  protects solid-state electronic equipment, such as computers, from damage by producing a clean filtered output of power. Additionally, the apparatus  100  may include a fan  170  positioned therein to control temperature of the apparatus  100 . 
     The power supplied from the outlet  101  is also supplied to the transformer  114  via the conversion relay  107 . The transformer  114  then provides the power to the charging system  113 . The charging system  113  charges the battery  102  with DC power supplied through the input terminals  104  of the inverter  103 . In an alternative embodiment, the battery  102  is charged when DC power from a wind turbine  130  and/or a solar array  131  is supplied to the battery  102  via respective charge controllers  120 ,  121  and the input terminals  104 . The power received from the wind turbine  130  and/or the solar array  131  keeps the battery  102  charged in the event of a loss of power from the outlet  101 . 
     In the event of a utility power failure, the apparatus uses power from the battery  102 . The battery  102  is a 12 volt/200 AH cell and can be connected to a 12 volt/200 AHx2 linkable cell bank  160  to provide additional battery power. The linkable cell bank  160  is a collection of electrical energy storage and delivery units, such as batteries, which are used in conjunction with each other as a single device. Additionally, the battery  102  can function as charger for an electric device when it is directly connected via a power cord to the electric device. 
     When no power is supplied from the outlet  101 , the pick coil  110  does not cause the moveable terminals  111  to contact the first input terminals  108 . Instead, the moveable terminals  111  contact the second input terminals  109 . As a result, the inverter  103  inverts DC power supplied from the battery  102  to AC power. The inverted AC power is then supplied to the AC receptacles  118  via secondary output terminals  105 , secondary input terminals  109 , moveable terminals  111 , primary output terminals  106  and the final output portion  117 . As described above, the line conditioner  116  may receive the power flow before the final output portion  117 . 
     The apparatus  100  includes a subpanel  150  connected to a power converter  115 , such as a twin power inversion unit, a triple power inversion unit, or a step-up transformer. The subpanel  150  can connect to the power converter  115  with a twist-lock mechanism  153 . The twist-lock mechanism  153  allows for easy removal of the subpanel  150  from the apparatus  100  in the event of an emergency. 
     The subpanel  150  includes a plurality of switches  151 . Each one of the switches corresponds to respective electrical devices plugged in at each of the AC receptacles  118 . Some of the switches are set to an “on” position and some of the switches are set to an “off” position. Those electrical devices corresponding to the switches in the “on” position will automatically receive power from the battery  102  in the event of a utility power failure. In contrast, the electrical devices corresponding to the switches in the “off” position will not receive power from the battery  102  unless a user manually closes the switches. For example, the “on” position switches might control heat, a refrigerator and a sump pump, while the “off” position switches might control lighting and televisions. 
     The embodiments described above are illustrative of the invention, which is not limited to the embodiments described. Various changes and modifications may be made in the device by one skilled in the art without departing from the spirit or scope of the invention.