How-To: Make a touchless switch LED lamp

Furniture & Lighting

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. His free weekly-ish maker tips newsletter can be found at garstipsandtools.com.

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July 2nd, 2010 2

This Instructable shows you how to make a USB-powered LED lamp that turns on (and off) via the wave of your hand (and the QT113 IC):

The touch switch circuit is based on the QT-113 integrated circuit. It works by detecting changes in capacitance. When it is first turned on it measures capacitance at its sensor plate. When a human touches or comes near to the metal sensor plate the capacitance is changed and the circuit turns on.

The sensitivity is adjustable so that at a lower setting it will require you to directly touch the sensor plate. At its most sensitive setting, it will detect your finger through paper, plastic, glass, or even a brick.

The larger the sensor plate the more sensitive the switch. The sensor plate is the triangular circuit board at the front bottom of the lamp.

Curved Circuit Board Art: Make a Touchless Touch-Switch LED Lamp

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