Abstract: Disclosed is an LED bulb having a current-compensated driving circuit. A compensation current 352 is coupled to a main driving capacitor used to power LEDs and functions to keep the load current more constant. This has dual advantages of saving power and making the light output more uniform. Saving power also means that the circuit runs cooler than without compensation. Additionally this circuit includes an inductor placed in line with a driving capacitor. The inductor functions to reduce rapid current influx to the capacitor during operation of the driving circuit, which reduces EMF and reduces component stress. One benefit of using an inductor is that most of the current absorbed by the inductor is provided back to the circuit during a later portion of the AC cycle, which also limits energy losses by the driving circuit.

Abstract: A method, apparatus, and system for compensating for lamp lumen depreciation. The method includes operating the lamp under rated wattage for a period towards the first part of operating life of the lamp. Operating wattage is increased at one or more later times. Energy savings are realized. The increases also restore at least some light lost by lamp lumen depreciation. The apparatus uses a timer to track operating time of the lamp. A few wattage changes made at spaced apart times can be made in a number of ways, including changing capacitance to the lamp, or using different taps on the lamp ballast. In one aspect the invention pertains to solid state sources. The invention can pertain to a variety of applications including wide area lighting, indoor lighting, pathway lighting, parking lot lighting, street lighting, under-counter or -cabinet lighting, and others.