30 Second Light Sabre Autopsy

What we have here. A battery holder, 2 tactile switches, 4 LEDs, and a chip with a blob on that makes a crappy noise. I don't even want to know how the plastic shaft got broken but no ambulances were called. Nothing to salvage or Halloweenify. Let's move on.

LED Dimmer PWM Hack

This cheap dimmer is designed to blink LEDs with a variable duty cycle. The default frequency can be altered by swapping out a single capacitor. 20 kHz makes a whine-free speed control for a DC motor, 1 Hz gives slow PWM for high power resistive heating loads.

3x Battery Teardown

So if you open up a 9 V battery, you find 6 thin 1.5 V cells inside. But what was inside that lantern battery, the rechargeable PP3, or the funny shaped lump on the back of my laptop? Confronted with dead metal in the recycling drawer, I tried to find uses for the contents.

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