LED flash light(0.3-1.5V)

• It’s a little wisp of a circuit that allows you to drive a blue or white LED from a low voltage.
• Normally, if you want to light up a blue or white LED you need to provide it with 3 – 3.5 V, like from a 3 V lithium coin cell.
• But a 1.5 V battery like a AA cell simply will not work. But using the Joule Thief, it works like a charm. Not only does it work with a brand new battery, but it works until the battery is nearly dead– down to 0.3 V.
• That’s well below the point where your other toys will tell you the battery is dead, so it can steal every last joule of energy from the battery (hence the name).

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S:electronicsuite.com