Emergency lighting circuits
Patent 4686424 Issued on August 11, 1987. Estimated Expiration Date: 
January 21, 2006. 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.
January 21, 2006. 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 References 3486068 3659179 3833817 Emergency lighting system AC line voltage sensing Apparatus and method for sustaining the operation of HID lamps Emergency lighting system Emergency lighting system Emergency lighting system Patent #: 4454452 InventorsAssigneeApplicationNo. 06/820723 filed on 01/21/1986US Classes:315/86, AUTOMATIC SUBSTITUTION OF THE POWER SUPPLY315/87, With load device or electrode substitution315/90Plural load devices with selective substitution of load device or electrodeExaminersPrimary: Dixon, Harold A.Attorney, Agent or FirmInternational ClassesH02J 9/06 (20060101)H05B 41/28 (20060101) H05B 41/285 (20060101) AbstractAn emergency lighting circuit includes a lamp which can be energized by a battery-inverter circuit upon power failure. The battery is connected to the inverter circuit and the lamp by operation of a relay which is connected to the rectifier supplying charging current to the battery. The rectifier is connected across the line in series with a ballast reactor. The circuit can be used as emergency lighting only or the lamp can be employed for normal lighting purposes and switched to the inverter power when line voltage is interrupted. | |
