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Drinkin' Cap

I've got an epic St. Patty's Day planned for this Saturday and I thought: wouldn't an LED-ified hat be awesome? Then I thought: "I have to. It's a moral imperative."

A couple days shopping around for a bowler hat and green LEDs and here's the result:

The LEDs were mounted by using a new (sharp) x-acto knife blade to slice a single small slot in each LED position. I pinned a shamrock pattern to the hat first... The circuit was wire wrapped not soldered. Once all the LEDs were poked through the hat I used copious amounts of hot glue to make them permanent. A 10 kO pot is in line with a 9 volt battery to current limit (and provide a brightness control). A Velcro wire management strap was sacrificed and hot glued in the brow to hold the battery in place. The circuit:

Original Image Source:

The top of my head does touch the top of the hat but there's actually just enough room in the front tip for the battery. It fits quite nicely... "I was thinking of the immortal words of Socrates, who said, "... I drank what?""


  1. This made me laugh. You are so creative :)

  2. You need more resistors because your LEDs wont all have the same forward voltage drop...

  3. Yeah, normally I would totally agree. These happened to all be really closely matched when I bread boarded this circuit, so I didn't bother (17 resistors is a significant addition of time considering this s a component to component connection project...).

    Visually it looks fine, and it only has to work for a few more days :).

  4. Hey,

    Great site. Absolutely love this build. Classic stuff :) Do you have an email I can grab you on? I have a few questions i'd love to fire your way. My email is rgibson(a)farnell(dot)com