Led Dynamics MicroPuck

[koala]

I am trying to find a suitable driver to run 3 LEDs but the output of a MicroPuck is kinda high at 375ma. I am wondering if anyone have experience, ripping apart MicroPuck casing and have access to the internal circuit board?

 

[McGizmo]

Nukiez,

I think you may find that the MicroPuk is fine with 3 LED's if you limit your power to a single cell. It depends on the Vf of the LED's as well as your target current but I made a light with three Nichias, the MicroPuk and a single AAAA cell and it worked out fine:

- Don

 

[e=mc²]

Hey Don,

I was thinking along the same lines a single celled multiple white LED design. What is the typical runtime that you get on that light that you show? I will probably go with a triple A design, as quad A's are still hard to come by unless you order them, but then again I'm just looking for convenience of replacement when "on the road" or away from home. Very interesting. How flat (or not) is the light output over the discharge of the battery. Does the brightness fall off with the discharge curve of the battery?
I know I ask a lot of questions, but before I invest in micropuck's I just want to be sure of a regulated output. I have their Everled, and when hooked up to 4.5V or greater, it seems relatively flat over the useful lifespan of the batts. On two cells (3V) the brightness seems to taper down with usage, an effect I am trying to avoid.

TIA for any advice you may offer.


Ed.

 

[koala]

Yeap Don, I saw your Titanium 3LED AAAA before I posted! I am wondering how did your 3 Nichias survive the 375ma. The MicroPuck datasheet says 375ma fixed output. Or am I wrong?

 

[LED_ASAP]

MicroPuck is "semi-regulated" and the output drops with lower than 3V input. At sub-1.5V, as in the case AAAA's under some load, the output is likely <100mA, which is fine for sharing between 3 Nichias.

I don't think it's possible to open up a MicroPuck---they are epoxy-sealed.

If you want a special LED driver, I can build you one that is significantly smaller than the MicroPuck. I can even add a trimpot so you can adjust the output. Send me PM if interested.

 

[OddOne]

Build a ZLT and tune it to the current your array of LEDs will draw. Simple but effective.

oO

 

[koala]

LED mods As Small As Possible - thanks for the info. I know you have the smallest LS light /ubbthreads/images/graemlins/smile.gif You are right, I was thinking of getting a MicroPuck and mod the circuit. Since it's expoxied, I think it won't happen anymore. I will PM you when I give up searching for good cicuit /ubbthreads/images/graemlins/wink.gif

OddOne - yes I know the ZLT, but shipping to my place is not economical :| Maybe I will try farnell.

 

[McGizmo]

As stated above, the MicroPuk is varible (a voltage regulator?) and I did a bench test with an input voltage from 1.5 down to .9 as I recall and I think the current through the three Nichias in parallel went from 90 mA down to 45 mA; or at least that's my recollection. I never did a run test on the light and have since given it away as a gift so I can't say how the illumination over run charts out. I think any single cell will do a good job on three LED's using the MicroPuk. This statement is based on a Vf of the LED's being around 3.7 volts. If lower Vf's are the case, the current levels will be higher. (red, amber and IR)

- Don