Candle Power Flashlight Forum

Hey guys,

First post! FWIW I'm in Australia at uni, studying things unrelated to electrickery.


My current bike liight currently revolves around a Luxeon III I bought at jaycar (Australia).

Currently there's a 6V lantern battery, 1.8 ohm 5W resistor and the Luxeon all in series.

Under load my (new) lantern batteries drop to 5.3V, there's less than an amp flowing, I think more like 800mA. It certainly doesn't get hot, but then it is well heatsinked.


I have the following questions:

This new 2x bright Nichia innovation is impressive. I've never heard this 2x brightness mentioned WRT to luxeons though, are there 2x brighter luxeons around? How would I know which mine is? (I noted down the serial number on the back before the thermal compound went on)

How hard is it reasonable to drive a this luxeon III when well heatsinked?

This is the big question:

I need some current regulation circuitry that I want to meet the following:
- Over 70% efficent
- Will operate in the voltage range 13.8V to 3V
- Adjustable level of current regulation (say, 100mA - 1000mA, or maybe 1300mA?)
- To power a white Luxeon III

I would also prefer the following things, if possible/reasonable:

- Some gauge, even if only 3 LEDs, of current draw (say red>1000mA, 1000mA>amber>700mA, green<700mA)
- Some gauge of battery voltage, once again 3 LEDS would do
- Adjustable level of current regulation (say, 100mA - 1300mA)
- To power either a white or red Luxeon III

I can solder, I should be able to manufactor a PCB at uni using the machine in the electrical engineering faculty (don't ask me what it is exactly...all I remember is a arm moving in 2 dimensions drawing the tracks).
I also have plenty of time.
The biggest obstruction is I want this done soon, so ordering parts from the US isn't really favourable.
My jaycar store is the preferable source of components, www.jaycar.com.au.

The following is on the path to a agreeable solution I suspect:
MC34063 DC to DC Converter IC
http://www.jaycar.com.au/productView.asp?ID=ZK8837&CATID=&keywords=34063&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=



I know this is probably a old question, I did search. You guys use alot of jargon that is unique to you folks (fatman, uflex..etc..) that takes a bit of effort to work out.
Links to information/previous threads would be greatly appreciated.
As would links to circuit schematics