100 Watt LED Headlamp

Lamp head:

Main body with a pocket for the LED...
Back with channels for the water cooling system and some room for 2 buttons and a temperature sensor...
Hinge to attach the lamp to my helmet...
I've glued some strong magnets into the hinges so the lamp head can be removed and turned.
They however proved to be a bit too strong for my taste...
Removed the mesh from a flat braided metal hose...
And put 2 small tubes for coolant, 2 thick cables for the LED and a flat cable for the buttons and temperature sensor in it...
Buttons and sensors installed, then filled with hot melt glue to avoid short circuits...
Other side with the LED...
The bracket at the helmet...
Milled circuit board for the boost converter...
The circuit is a simple boost converter controlled by an Arduino. It intentionally works in discontinuous mode to keep it easily controllable. Due to this you need to take care to use the same Amidon T200-2 core with 30 windings if you plan to build this circuit.
Assembler program for the Arduino
  • A: Water tank
  • B: Pump
  • C: Boost converter
  • D: Arduino UNO
  • E: Fuse and on / off switch
  • F: Charger jack
  • G: 4x LiFePO4 12Ah with balancer
The (almost) finished headlamp with batterypack - just the glass panel in front of the LED is still missing...
Bottom line:
  • As expected: extremely bright...
  • Pump and heat sink on the lamp side are more than sufficient. If you supply water from a big bucket the head will practically not heat up at all and the LED can even run at 130 Watt without any problems. But the tank / heatsink on the battery pack side proved to be a bad design - it will heat up considerably after just a few minutes.
  • Another issue: there is too much noise for the ADC - especially for the temperature measurements.
  • The Arduino takes up too much space, is a pain to mount and the messed up cabling surely did not help with the ADC noise...
  • The lamp head is still rather heavy
I'd change this:
  • Reduce lamp head light: plastics housing with just a little copper for the water cooling system and using glue for the LED instead of screws.
  • Improve heat transfer for the battery pack.
  • Get rid of the Arduino and replace it by an Attiny directly on the boost converter.

First test:

Christian Knüll / Heidelbergerstr. 6 / 74746 Höpfingen / Deutschland /