Comments on: Fun family science project — electric lighting from trash

By: SamSam

SamSam — Thu, 06 Dec 2012 18:39:00 +0000

The switching mechanism is fun, but it’s unregulated.

Waiting for the Obama Administration to start regulating it…

By: cservant

cservant — Wed, 05 Dec 2012 08:38:00 +0000

Also electrical NOISE. Keep it away from or shield sensitive equipment.

By: KWillets

KWillets — Wed, 05 Dec 2012 00:23:00 +0000

It’s just a boost converter, like in every single-cell LED flashlight. It charges a coil, switches it through the load, rinse, repeat.

The switching mechanism is fun (induced voltage from a secondary winding into the transistor), but it’s unregulated.

By: SamSam

SamSam — Tue, 04 Dec 2012 23:32:00 +0000

Some of you are thinking “wait, maybe it enables you to use a single 1.5 volt battery to light a 3V LED instead of the usual two, but doesn’t it just make that battery last half as long? Great question, but the answer is that the Joule Thief [...] actually is more efficient than using a battery directly because it PULSES the energy to the LED

Uhhh, so it enables you to use a single 1.5 volt battery to light a 3V LED instead of the usual two, but it makes the light half as bright.

That is either very carefully make unclear, or the original author wasn’t clear about it.

By: Sam Archer

Sam Archer — Tue, 04 Dec 2012 22:20:00 +0000

So you can run a 3v LED, at (essentially) half-brightness, from a 1.5v battery. Useful in a limited extent, I suppose, but I don’t know that there’s a lot of application for this beyond flashlights…

By: Itsumishi

Itsumishi — Tue, 04 Dec 2012 22:16:00 +0000

Breaking Bad taught me this lesson well! (video 9)