Constant illumination, remotely dimmable electronic ballast
Patent 4716343 Issued on December 29, 1987. Estimated Expiration Date: 
November 15, 2005. 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.
November 15, 2005. 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 3449629 3611021 Photo curing light source Power supply for a high intensity discharge or fluorescent lamp Varible frequency current control device for discharge lamps Patent #: 4585974 InventorAssigneeApplicationNo. 06/798265 filed on 11/15/1985US Classes:315/307, Automatic regulation315/206, Discharge device and/or rectifier in the primary circuit of the supply transformer315/224Impedance or current regulator in the supply circuitExaminersPrimary: Dixon, Harold A.Attorney, Agent or FirmInternational ClassesH05B 41/392 (20060101)H05B 41/39 (20060101) H05B 41/28 (20060101) H05B 41/285 (20060101) AbstractA solid-state ballast for discharge lamps includes a device for sensing the instantaneous current flowing within the load to produce illumination. A signal representing this load current is differentially processed with an external control signal representing the desired illumination, to produce an removed signal which controls an oscillator that provides the operating signal for the load. In addition, the voltage across the load is sensed and the signal representing this voltage is fed back to a circuit which controls the oscillator so as to limit the maximum load voltage during initial start-up and when a lamp is removed. | |
