Uh...Battery Drainer

Okay, this probably doesn't deserve a place here. But I built this for fun. I had acutally plan to use it as a bicycle light or as a "flashlight" for macro photography (cast the light from overhead)



*In case you are wondering what's the blue patch at the back ground of the picture, it's 2 pieces of half used Energizer Photo Lithium 123s.

I had used a bread board, 56 5mm LEDs (sorted out for low Vf of below 3.5 volts @ 30ma), 56 pieces of 47 ohms resistors, all in parallel, using the resistor to limit the current.

I discovered that I can power this off a very much dead 123 battery, a full 123 battery, 2 123 batteries, 3 to 5 pieces of AA batteries in varaying levels of discharge.

The amazing thing is that the entire board of light works down to 50 ma of current draw and provides much much more light than a Arc AAA. (Given the number of 5mm leds used here, actually it's not too surprising) If I want 25 ma to each LED, it's 1.4 amps of current draw from the battery, which needs around 5 volts. Since as the battery voltage drops, the thing becomes more efficient

I'm willing to bet it would have run time ranging in hundreds of hours on 5 AAs. Don't ask about the run time on 4 D cells. /ubbthreads/images/graemlins/icon15.gif

Did I mention that I'm roughly better than a pre-schooler at soldering? /ubbthreads/images/graemlins/help.gif I find it pretty amazing that I manage to do it at all. I probably shouldn't show you the bottom side of the board. /ubbthreads/images/graemlins/tongue.gif

Some of you guys will most probably ask why don't I use a LS or a Lux 3? Simple, I don't want a point source light, I want a broad source of light that makes me very visible at night when I'm cycling. I gotta do somethign about the air resistance though. /ubbthreads/images/graemlins/icon15.gif

Beam shots? Comparism? Uh, it's not even dark here yet! It's only 3pm in the afternoon. /ubbthreads/images/graemlins/jpshakehead.gif
Plus I sold my ARC LSH-P some time ago. Lemme see if I can dig up some old beam shots. /ubbthreads/images/graemlins/grin.gif

Finally thanks for reading through my rambling and boring stuff, hope this post shows a whole new view 5mm LEDs as being useful for something. /ubbthreads/images/graemlins/wink.gif

hey, you are actually creative /ubbthreads/images/graemlins/twakfl.gif /ubbthreads/images/graemlins/grin.gif

btw, it seems like you are using low angle led, so it will still be a point source light, right? well, make it points source light /ubbthreads/images/graemlins/blush.gif
I love the array. It looks pretty neat and perfectly aligned. Thanks for sharingthis with us /ubbthreads/images/graemlins/grin.gif

Thanks shiftd! /ubbthreads/images/graemlins/whoopin.gif /ubbthreads/images/graemlins/grin.gif

I aligned it by pressing it onto the board as I soldered the LEDs. I'll have to say given the temp I'm soldering at (300 degrees celsius) and duration (3-5 seconds), I'm pretty surprise these LEDs are not toasted yet! /ubbthreads/images/graemlins/grin.gif

5 more hours to darkness..../ubbthreads/images/graemlins/rant.gif

It's hard being a flashaholic some times. These are 20 degree 8000 mcd LEDs from www.besthongkong.com. The spot (if you can even call it) is slightly blue, not at all white like the inova X5s that were discussed around here, I've another cheap 4 LED boost circuit 2AA light around here that has white LEDs, so these are rather blue in comparism.

Did I mention that there is quite some flood as well?

holy sh*t nerdo! /ubbthreads/images/graemlins/eek.gif

that thing's freaking insane! /ubbthreads/images/graemlins/drool.gif /ubbthreads/images/graemlins/yellowlaugh.gif

paypal sent! /ubbthreads/images/graemlins/grin.gif

You sure you want this? It's yours for $20 USD. /ubbthreads/images/graemlins/grin.gif $12 for the LEDs, probably around $5> for the bread board and the resistors. ~$3 for the time and effort and the crap poop soldering. /ubbthreads/images/graemlins/grin.gif

No way I'm selling this, this is a poor representation of my modding prowress (if any) LMAO!

Judging by the shot you posted, it appears as though you already have an overhead diffused light source for macrophotogaphy. How did you achive such a great color balance? My pics always look like they were taken in a Disco that couldn't pay the electric bill.

Having a Canon A40 helps (the white balance is doing okay)

Nope, no over head diffuse light source for macrophotography. Too poor to afford one. /ubbthreads/images/graemlins/grin.gif

Adobe photoshop does fantastic for touching up flaws. /ubbthreads/images/graemlins/grin.gif

seriously nerdo, that things awesome.

now i want to make one with 500leds /ubbthreads/images/graemlins/icon15.gif

/ubbthreads/images/graemlins/eek.gif
geez roth, you will soon be sending nerdo to oblivion /ubbthreads/images/graemlins/tongue.gif

sounds tempting! /ubbthreads/images/graemlins/grin.gif

Guess I'm there already... shiftd

Long live the Nichia! /ubbthreads/images/graemlins/naughty.gif

Here's the beamshots!

Driven at 1.4 Amps, probably 30% going to the resistors, we have.. the array of 56 LED nichias!



And here we have the E2E with fresh batts!



Not bad eh? But the LED array consumes more power, 6 volts @ 1.4 amps. All because I'm not using some constant current circuit and the resistors didn't really help. At 1.4 amps, each LED is suppose to be getting around 20-30 ma. Probably more like 20 because of the resistors.

wow, it actaully has a beam! That's pretty bright. You could make ceiling tiles full of white led's wired to a sealed lead acid car battery, or pack of D cells for emergency back up lighting! /ubbthreads/images/graemlins/smile.gif