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Darkness-activated LED circuit

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. morcheeba says:

    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. aragao says:

    It might be linked to the joule thief, so an old 1.5 V battery would power it.
    I´l try it.

  3. Julian Bond says:

    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.

  4. Sean says:

    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.

  5. bre says:

    Oh ya! This is awesome… promptly passing this along to my pals at GRL!

  6. cyenobite says:

    Thanks for posting this one! I’ve been wanting something similar to this for a while now.

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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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