What is it?

The Blinky-Board is a fun wearable kit that will blink two LEDs back and forth when the lights dim. The Blinky-Board kit has been designed with the beginner in mind and is very robust and easy to assemble and solder. The kit contains 17 pieces, including the CR2032 battery, to give you over 100 hours of continuous blinking!

There are 5 different Blinky-Board kit designs to choose from: Peace Sign, Heart, Acorn, Turtle and a Robot, of course, because who doesn’t like Robots! Following the detailed instructions, the Blinky-Board kit takes about 45 minutes to an hour to complete.

Why did you make it?

I originally designed the Blinky-Board kits for a series soldering-skills workshops that I taught at the 2017 Live Oak Music Festival in California. The festival is an annual three-day event to help raise funds for KCBX public radio station based out of San Luis Obispo, CA and is a family friendly environment with a dedicated craft area for kids and adults alike. It was really awesome to see all the Blinky-Board makers walking around at night wearing their Blinky-Boards!

What makes it special?

The Blinky-Board is based on a simple two-transistor astable multivibrator circuit, also known as a relaxation oscillator, modeled after the first relaxation oscillator invented by French engineers Henri Abraham and Eugene Bloch in 1919. The Abraham-Bloch relaxation oscillator was originally built with triode vacuum tubes. That’s right, vacuum tubes! What makes the Blinky-Board circuit special from the original circuit is the addition of two LEDs and a CdS LDR (cadmium sulphide light depended resistor) sensor that turns the circuit on when the lights dim, plus the cool graphics design, and it’s wearable!

What’s in the kit?

• Professionally made PCB from OSH Park
• 5 - resistors
• 2 - LEDs
• 2 - NPN Transistors
• 2 - Capacitors
• 1 - Light Dependent Resistor (LDR)
• 1 - CR2032 Battery Holder
• 1 - CR2032 Battery
• 1 - Jumper Ring
• Length of Lanyard
• Detailed downloadable instructions (PDF)

What’s needed?

• Soldering iron with small tip
• Solder – 60/40 or 63/37 rosin core or no-clean solder is recommended. (Lead-free solder is very challenging for beginners to use due to the need for a higher soldering iron temperature and it doesn’t re-melt/flow easily.)
• Wire cutters
• Pliers
• Helping hand / Third hand PCB holder
• Eye protection
• Enthusiasm and a Big Smile!