Article

Luxeon Logic, brightness control for LED torches

The small super-bright Luxeon LEDs from Philips are suitable for many applications, including small but handy (that is, bright) pocket torches. However, you don't always need maximum brightness, so it would be nice to have a simple brightness control. The circuit described here is baed on an ATtiny microcontroller to enable convenient one-button operation. Three brightness levels can be selected by pressing the button one to three times in succession.

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Materials

081159-PCB.pdf

081159-11.zip

Gerber file

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PCB

Download Gerber file: 081159-1-V11

Extra info / Update

Features

* Three selectable brightness levels
* One-button operation
* Microcontroller control circuit
* Current consumption in sleep mode only 1.2 µA

Component list

Resistors
R1 = 3O3 (1206)
R2 = 390Ohm (1206)
Capacitors
C1 = 100nF (1206)
C2 = 22µF 10V (SMD)
Semiconductors
T1,T2 = 2N2222 (SOT-23)
IC1 = ATtiny25-20SU (SOT-8)
LED1 = Luxeon LED, 1W (SMD), white
Miscellaneous
Pushbutton
PCB # 081159-1