Early design intent (not my own) for a hybrid spotlight powered by extension cord, 18V battery, or 12V car outlet.
The maze of electronics that I managed to pack into the housing included an AC-DC adapter, 3 buck converters, an Arduino Tiny, an AC plug, an 18V battery connector, a 12V coaxial port, an LED driver, and probably something I'm missing. This spotlight prototype had a white LED with 3 brightness settings controlled by PWM and a red LED.
