I took apart a light up yoyo. When functioning, the yoyo would flash it's led when spun sufficiently quickly.
Taking the yoyo apart revealed a simple mechanism. There was a button cell battery, a spring and an LED. When the yoyo vibrates, energy is transferred to the spring. When the spring oscillates, it connects…Continue
The stove in my kitchen was being replaced in the morning, and inspired my idea. I wanted to make an oven knob that would also be a timer. The knob would have LEDs embedded in it that light up to indicate the time elapsed. A switch would reset the timer. For simplicity, the timer will light up an additional LED every 10 minutes.…Continue