lion mclionhead
Ever since the lion kingdom burned $5 on a crummy 3 AAA head lamp many years ago, lions longed for something lighter & brighter. Today, the same 3 AAA head lamp is $20 & still dim.
Whacked together something out of PETG to withstand high LED temperatures, a COB LED from a $1 flashlight, & the elastic from the original head lamp.
Glued on a sheet of EVA for friction.
This would rely on a pocketable battery & regulator. Just plug it in to turn it on. The regulator outputs 3.7V which drops to 3.5V at the LED. This is expected to burn 200mA from the battery when it's warmed up.
Some scotch routed the cable around the lion mane.
Would consider it just bright enough to work on close objects but not enough to run.
In a comparison with the phone light in the same position, there is no contest. The only evidence the phone light was on was the monitor reflection. The camera didn't see anything.
It seems about as bright as the cheapest modern lights but more omnidirectional. The mane need is washing a car in the dark. It's definitely lighter than any commercial option, despite the inconvenient cable.
The light is angled 10 deg down. It might need 15 deg. There are brighter COB lights, for a price that approaches the cost of the worst head lamps.
David Thomas
You certainly know that Leds are current driven, not voltage, thus you need to control the current through the Led and don't care for the voltage. Poorly designed systems count on the internal impedance of the voltage source to limit the current. The Led manufacturer specifies the control current, from 350mA to several amps depending on the power of the Led, a 3W white Led needs 750mA to 1A.