Described is an improved LED-based flashlight with discrete mechanical, electrical or electro-mechanical actuation to adjust operation of the flashlight. The control of power to the device is accomplished by switching brightness modes electronically through use of multiple drivers and/or dynamic microcontrollers. The system may apply to current regulators as well as voltage regulators. Efficiency may be optimized to minimize power losses by operating each driver chip within fixed bands, handing off regulation to other chips that function well at different input currents or voltages.