Darkness-activated LED circuit

Our homeboy Windell, over at EMS Labs, has posted a simple circuit for creating a dark-detecting LED light. It’s a power-conserving LED Throwie.

A Simple and Cheap Dark-Detecting LED Circuit – Link

12 thoughts on “Darkness-activated LED circuit

  1. That’s cool how it’s an infrared-detecting switch… it’ll go off under sunlight, but it’ll remain on even if an LED (like the one it’s connected to) or a streetlight shines on it.

  2. Here’s what I want, a dark sensing, joule thief, flashing, throwie. The idea is a minimal circuit that will give a brief flash once every few seconds, only comes on at night and uses a battery sparingly until it’s completely dead.

  3. It would be interesting if they used the LED itself to sense the ambient light (LEDs can be used as photodiodes). Flash it really fast when it is dark – it will look like it is just on, and alternate with sensing and illuminating.

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Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. And he has a new best-of writing collection and “lazy man’s memoir,” called Borg Like Me.

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