I'm wanting to know what circuit people are using to drive the 3w led. I don't want to run direct or even use a resistor, but rather step up a 3v supply. I don't see anything at Dat2zip's site running at around 700ma. Any suggestions?
I forgot this in the previous thread. I notice that some of the MadMax converters are rated at 700ma. Would one of these work or not? Thanks for your help as I'm not very swift when it comes to the electronic stuff.
The BadBoy is a current regulator and the MadMax is a voltage regulator. What this means as a practical matter, is that a light built around a MM will dim as the battery drains. A light built around the BB will remain constant for as long as the battery can keep up. Although it sounds, on its face, like the BB is the way to go, both boards have their advantages.
The MM will drain a battery down to almost nothing, whereas the BB will fall out of regulation when the batt reaches in the neighborhood of 2.2-2.5v. Someone correct me if I'm wrong. This could leave you stranded with a very dim light. The MM lets you know when it's time to change the batt.
Heat is also an issue. BadBoys are notorious for generating heat and are recommended for short term use at the bias level that you have mentioned.
Each circuit has its advantages. I personally like the BadBoys, but you may be disappointed if you need something for long runs and runtimes with a single cell. The MM will generate less heat and give you more time in the "bright."