I was struggling with ideas for my next project, then it dawned on me. I needed a Thinking Hat!

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)
- wire
- an empty wire spool
- an old coiled cord
- a little round "thingy" from an lamp
- a couple of feet or so of brass rod
- solder
- 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

The hard hat stood before me like a pure white canvas (photo 1), ready to be magically transformed into a Hat Of Deep Thinking.

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

The vacuum tube I used was from the power supply of an ancient television (photo 1). I began by soldering wires to the leads of the LED, then carefully drilling a hole through the bakelite base and stuffing the red LED all the way up to the base of the glass part of the tube (photo 2). I had marked the wire for the positive side of the LED before stuffing it inside the tube's base so I wouldn't have to experiment when it came time to wire up the circuit.

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 hot glued the vacuum tube to the empty wire spool I had previously bolted to the hard hat, then made a couple of wire bales that attach to the top of the tube (using some unknown lamp part from my junk drawer), and attaching to the hard hat through holes I drilled. I reinforced all these attachments with hot glue.

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....

The electrical stuff was very simple. I bolted an "AAA" battery holder inside the hard hat, drilled a hole in the front for a small toggle switch, then hooked it up to the LED wires coming from the vacuum tube.

Step 5: The End Result

I have been noticing that simply wearing the Thinking Hat can make a big difference, but when I want to do some really deep thinking, all I have to do is flip the little toggle switch on the front of the helmet and, WHAM, the thinking really gets DEEP quickly!

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!