How to control power LEDs
Thanks to our Technology Editor, Steve Bush for flagging this one.
Dr Matthew Ford of Forward Computing and Control in Australia has put up an excellent tutorial on controlling power LEDs using an Atmel Tiny AVR microcontroller.
The webpage goes through both hardware and software step-by-step, with lots of good detail, including discussion of alternative techniques. There are circuit diagrams, parts list, phots, etc.
This tutorial describes the construction and programming of a basic pulse width modulator controlled linear current regulator for driving a LED at 500mA. No SMD devices are used. You can use this same basic design for supplying up to 5A or more by changing the current sense resistor.
Further tutorials add different sorts of wireless control, including by phone. The URL to follow is: www.forward.com.au/torches.html