Emergency light and charger system

Abstract

A battery powered device that interfaces with the power source of a target device, such as a lamp, and detects when the primary power source has been removed. When the primary power source is available, the battery is charged and when the primary power source is not available, the battery drives an illumination device to provide emergency safety light to an area.

What is claimed is: 
     
         1 . An electrical apparatus that includes a battery powered safety feature, the apparatus comprising:
 a primary device coupled to an AC voltage source;   a battery coupled to a first side of a switch;   one or more ancillary devices coupled to a second side of the switch;   an AC to DC power supply coupled to the AC voltage source and configured to provide a DC voltage output;   the switch configured to detect the presence of the AC voltage from the AC voltage source and, when the AC voltage is not present, coupling the battery to the one or more ancillary devices; and   the switch configured to detect the presence of the AC voltage and, when the AC voltage is present, decoupling the battery from the one or more ancillary devices and coupling the battery to a charging output of the power supply.   
     
     
         2 . The electrical apparatus of  claim 1 , wherein the power supply comprises a battery charger that provides an output voltage to the charging output and is configured to prevent over charging of the battery and to prevent over discharging of the battery. 
     
     
         3 . The electrical apparatus of  claim 1 , wherein at least one of the one or more ancillary devices is a USB charging port. 
     
     
         4 . The electrical apparatus of  claim 1 , wherein at least one of the one or more ancillary devices is a low power illumination device. 
     
     
         5 . The electrical apparatus of  claim 1 , wherein the AC to DC power supply and the switch is an assembly that is attached in series to the AC supply of the electrical apparatus. 
     
     
         6 . The electrical apparatus of  claim 5 , wherein the assembly attaches to the power cord of the target device by receiving a severed end of a first portion of a power cord distal from a plug into a first connector and receiving a severed end of a second portion of a power cord distal from the electrical apparatus into a second connector whereby the severed cord is rejoined through the assembly. 
     
     
         7 . The electrical apparatus of  claim 1 , wherein the assembly includes a light detector configured to detect low lighting levels and the switch interfaces to the light detector and in response to the detection of a low lighting condition, the switch is configured to couple the battery to at least one of the one or more ancillary devices. 
     
     
         8 . The electrical apparatus of  claim 1 , wherein the switch is further configured to decouple the DC voltage output from the one or more ancillary devices when a voltage level of the battery drops below a threshold value. 
     
     
         9 . The electrical apparatus of  claim 1 , wherein the assembly includes a current sensor coupled to the primary device and configured to detect a decrease in current levels and the switch interfaces to the current detector and in response to the detection of a decreased current condition, the switch is configured to couple the battery to at least one of the one or more ancillary devices. 
     
     
         10 . An assembly that is coupled to an electrical apparatus, the assembly comprising:
 a power supply that is communicatively coupled to a primary power source, wherein the primary power source is connected to a primary device, and the power supply is configured to convert a signal from the primary power source to a DC voltage level;   a battery;   a battery charger electrically coupled to the battery and configured to charge the battery when the primary power source is available;   one or more ancillary devices; and   a switch electrically coupled to the battery, the one or more ancillary devices and the power supply, the switch being configured to detect a loss of the primary power source at the power supply and in response to such detection, couple the battery to the one or more ancillary devices.   
     
     
         11 . The assembly of  claim 10 , wherein the power supply taps into the power cord of the primary device. 
     
     
         12 . The assembly of  claim 11 , wherein the primary device is a light fixture. 
     
     
         13 . The assembly of  claim 10 , wherein the battery charger monitors the charge on the battery and terminates charging when the battery has reached a threshold charge level. 
     
     
         14 . The assembly of  claim 10 , further comprising a voltage level detector and the switch is further configured to decouple the battery from at least one of the one or more ancillary devices if the voltage level of the battery drops below a threshold value. 
     
     
         15 . The assembly of  claim 10 , wherein at least one of the one or more ancillary devices is a device charger for charging an external device. 
     
     
         16 . The assembly of  claim 10 , wherein the device charger is driven by the power supply when the primary power source is available and by the battery when the primary power source is not available. 
     
     
         17 . The assembly of  claim 16 , wherein the device charger conforms to the USB interface. 
     
     
         18 . The assembly of  claim 10 , wherein the assembly is integrated into the base of a table lamp. 
     
     
         19 . The assembly of  claim 10 , wherein the assembly is integrated into a lamp shade. 
     
     
         20 . The assembly of  claim 10 , wherein the assembly is integrated into a screw in socket that can be inserted into a light bulb socket and that also can receive a light bulb into its socket.