Buckpuck Specs

[RevengeoftheSeth]

I know that there are different amp ratings for buckpucks, but what tells it how many volts to put to the LED. For example, how does it know the difference between a Lux V and Lux III?

[Rafalema]

I don't know how it knows the difference, but buckpucks give each LED as many volts as they want/need.

[Jedi-Loreen]

You can check out the Data Sheet and see if it says anything about that.

http://ledsupply.com/03023-d-n-1000.php

[Don Se Wion]

Actually all constant current regulators (like BuckPucks) cause a voltage drop.

Checking the datasheet for the BuckPuck suggested by Jedi-Loreen I found this reference:

"Due to the nature of the buck regulator, the input voltage must always be higher than the total forward voltage drop of the LED junction (s) connected in series (2.0V for DC models, ~4.0V for the AC models)"

So to drive an LED with a 3.8V junction voltage you need to supply 5.8V to the BuckPuck.

[Sunrider]

Buck drivers need 1.5v over led vf. Keep in mind battery voltage drops down as they drain.

[RevengeoftheSeth]

Oh, good to know, then. 2V seems pretty reasonable to work around. I just wanted to make sure if I decided to try out a Lux V, what kind of supply voltage I needed to put to it.

[RuleOfTwo]

I am running a rebel tri-star in a series configuration with a 700 mA buckpuck, and I find I need ~ 2 V over the LED series vf