Looking around in my shop, I found I already had all the necessary materials to construct such a time-honored headpiece. The materials used were:
- an old hard hat
- an old power tube from a previous project (https://www.instructables.com/id/Rescue-a-vintage-TV-cabinet/)
- a toggle switch
- an "AAA" battery holder (and batteries)
- a "mystery" red LED (I call it a "mystery," because it came unmarked in a box of junk parts I bought once upon a time)
- an empty wire spool
- an old coiled cord
- a little round "thingy" from an lamp
- a couple of feet or so of brass rod
- heat shrink tubing
- and my old standby....hot glue
The tools used were pretty simple: a drill, drill bits, and soldering gun
Step 1: Preparing the Hard Hat
My plan was to mount a huge old vacuum tube on the top (sort of like an "idea" light bulb), stuff a red LED up through the base so it would shine through the glass, and wire it all together with batteries and a switch.
Looking around, I realized that the pins of the tube would fit nicely inside of an old plastic wire spool, so I bolted the wire spool to the top of the hat (photo 2).
Step 2: Preparing the Vacuum Tube
Since this was a "mystery" LED, I had no idea what it was rated for, so I began testing by applying 3 volts, and then testing a variety of resistors in the circuit. I wound up staying with 3 volts and using no resistor. I suspect this is probably a 5v LED, but 3 volts with no resistor seemed to work fine.
Step 3: Installing the Vacuum Tube
I then attached a coiled cord on the left and right sides (through holes I drilled), and hot glued the center to the unknown lamp part I had placed on the top of the tube.
Step 4: The Electrical Stuff....
Step 5: The End Result
If you've ever thought, "Gee, I wish I had a Thinking Hat," I hope this little Instructable will inspire you to make one. Have fun!