Anything similar that would run cooler? The problem is that the V difference between the VIN and the LED VFWD will vary a lot depending on LED choices and battery solutions used. One such issue is using several for RGB control.. VFWD is different for the R G and B dies.... so for instance red overheats when B and G are fine.
Or, is the entire approach faulty and I should be doing something else?
The only way to supply a high current to a led without heat, is using a swithing constant current supply (with an inductance).
I think that something like that can not be combined with the STCS2.
I'm trying to design something that will work with several LEDs, although it will start with a single driver under PWM control. The eventual goal is a "shield" designed to fit on an Arduino Nano. (LED Driver, microSD, Accelerometer, Audio Amp)
The idea being is you want just a single color LED the driver will be on the board. (If you wish to drive RGB(A) then you would add on a 2x or 3X driver sub-board.) Most folks would just want to drive one LED.... somewhere between 350 ma to 1200 ma.
My personal favorite is the RGBA by Ledengin (Red, Green, Blue, Amber)
Although I was running mine using the STCS2 @1200 ma. (I'm OK with a lightsaber LED that only burns for thousands of hours instead of 10's of thousands. 4xAA Nimh Pack so 4.8v source. http://www.ledengin.com/files/products/LZ4/LZ4-00MA00.pdf
(Opps.. meant to include link to LED.)
It is however, not sufficiently beefy for your application.
Depending on your power requirements, you are likely looking for a to220-5 chip. The SimpleSwitcher from National would fit the bill - and it is multi-sourced, to boot. The ON equivalent of it is also a good choice.
Another way is to get those dc/dc converters from ebay and mod them - easily done.
If its only for a toy light sabre , stick a 1.2 ohm 1 watt resistor in each of the 4 wires to the LEDs, you will waste a bit of power, but its only going to last half an hour per recharge anyway.
To balance the current in each LED :- ( or you could use different resistors )
put one 1N5401 and a 1N5822 in series with the red LED, will bring the Vf to 3.6v ( at 1 amp )
for the Amber put two 1N5422s in series, will make it 3.5v ( at 1 amp )
Yes, that drives the LEDs, but part of the "illusion" is carried by ramping up the light so it appears to extend down the blade, adding a pulse or shimmer effect when the blade is extended, a flash coinciding with an impact and blade retraction effects (etc.) so the PWM control is part of the whole package.
My main goal is to make an open platform lightsaber controller available... there are commercial controllers out there up to $150 or so but not much for folks who would brew thier own. It will be larger than most "pro" ones but being programmable opens a lot of possibilities (hopefully some of which I haven't though of, LOL.)
Dhenry, looking at the Simpleswitcher... it may be a winner.