Xenodius said:Thanks Daedal, that makes WAY more sense!
I am sort of used to the N*zi Regime of RougeScience.org, they pretty much require you to have perfect grammar, and only ask one question per question you answer or finding that you contribute, but you get 3 "starter" questions... LOL!
And that driverboard sounds quite appealing.... I figured about 5 bucks for misc caps and resistors at radio shack, but that thing has a pot, right? Thats sweet! I can tune my laser down for amiable pointing, or up for burnination!
Thanks again!
Not a problem... I'm glad I could help.
The driver board does in fact have a pot, but these things are usually extremely sensitive and would pretty much jump from about 30mA to about 100mA just by slightly vibrating the screw! It's fairly annoying, so be EXTREMELY careful when working with one of these. I personally suggest working with an LM317. It's fairly excellent and very powerful. You can get a multi-turn potentiometer and ideally fine-tune the current going through from 12.5mA to about an Amp with just one 100-ohm potentiometer. When trying to get so high though, I would suggest using a carbon resistor in series with the pot to control any accidental drops in the resistance... with pots, these do happen at the ends sometimes. For example... to limit the MAX current to 200mA you use a 6.25 ohm resistor. For 150mA you use an 8.3 ohm resistor. For these red diodes, I'd say limiting to about 250mA is excellent for CW drive. So a 5 ohm carbon resistor in series with a 100 ohm pot would give excellent play room and controllability over the range that the diode would run safely under CW mode
The LM317's work this way... It uses the simple Ohm's law of V=I*R or I=V/R The V for the LM317 is the reference voltage built into the LM317, that is 1.25V on average, with very nominal variance. The R that I am talking about is the resistance that you would put in right after the Vout pin of the chip itself and then the Adjust pin would connect to it after the resistor (other side of where the Vout connects to). Your output positive terminal is the point where the Adjust plugs in. The ground is direct to battery ground.
Hope that helps;
DDL
Good luck;
DDL