Method and apparatus for operating LED array and charging battery for emergency LED operation including DC boost circuit allowing series connection of LED array and battery
Patent 5739639 Issued on April 14, 1998. Estimated Expiration Date: 
July 3, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 3, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesEmergency sign Lighting device used in an exit sign Patent #: 5459955 InventorAssigneeApplicationNo. 675109 filed on 07/03/1996US Classes:315/86, AUTOMATIC SUBSTITUTION OF THE POWER SUPPLY307/64Substitute or emergency sourceExaminersPrimary: Pascal, RobertAssistant: Vu, David Attorney, Agent or FirmInternational ClassH02J 009/06AbstractCircuitry for operating an array of light emitting diodes such as in an emergency exit sign in a non-emergency AC mode while concurrently charging and maintaining the charge of a low-voltage battery used to drive the array in an emergency mode, the circuitry also allows operation of the same LED array in the emergency mode from the low-voltage battery. The advantages of the invention are realized in part through provision within the circuitry of a boost converter wherein the LED array and the battery are connected across the output of the usual boost circuit output capacitor, thereby allowing connection of the array and the battery in series to simplify operation from line power and to allow the same current limited source to operate the array and simultaneously charge the battery through the same current path. The functions so provided can be embodied in a form which allows all circuitry components including the battery to be mounted on a single, compact substrate such as a printed circuit board.Field of SearchAUTOMATIC SUBSTITUTION OF POWER SUPPLY OR LIGHT SOURCELIGHT EMITTING DIODE SIGNS AUTOMATIC SUBSTITUTION OF THE POWER SUPPLY With load device or electrode substitution PLURAL POWER SUPPLIES Plural load devices Series connected current supplies Discharge device and/or rectifier in one of the supply circuits Periodic switch in one of the supply circuits Condenser in one of the supply circuits Plural diverse pulsating or A.C. supplies Diverse-type current supplies Simultaneous application to the load device DISCHARGE DEVICE AND/OR RECTIFIER IN THE SUPPLY CIRCUIT PERIODIC SWITCH IN THE SUPPLY CIRCUIT CURRENT AND/OR VOLTAGE REGULATION Substitute or emergency source Storage battery or accumulator Using light emitting diodes | |
