hooking up 3 watt LEDS

[Mohrenberg]

ok, so i've got about 30 of these 115 lumen LEDS that come from the coleman host.

i'd like to wire them all onto a huge platform to make a huge bright light bar.....but i'm not sure how to wire them up to power them all correctly.

should i wire them in series or parallel? and what power should i use?

they are intended to run off 6v (2x CR2), and all of them still have their drivers attached.

 

[Tech_Junkie]

Talk to Jerry...AKA lasersbee

 

[Mohrenberg]

i'm curious as to how bright it is.....

bah off to bed for me, i have packages to ship and post office is only open for 1 hour on saturdays....so i gotta be awake and ready for em.

 

[...]

If all of them still have the drivers, just rum them all in parallel and and feed them with their normal 6v.  Keep in mind that its going to draw about 20-30AMPS, so size your batteries and wiring accordingly!  Just build a bank of 10 parallel by 2 series 138650 lithium batteries and add a high current rocker switch to power the beast.  You can charge the pack using any old lithium battery charger, just set it for its maximum current and let it charge (depending on the current I would expect it to take up to a day to fully charge the bank).  I have had great luck with an old version of this charger, which would charge 10 parallel 18650's in about 10 hours.  

That will be a pretty intense light bar when you are done, 3500 lumens of light is a ton of light, should be about the same as 4x 35w car headlights.

 

[Cyparagon]

or a 35W HID, or 250W incandescent equivalent!

If it were me, I would make 12 pairs of series in parallel (does that make sense? :-/... think 2x12) and power it with 12V (lead acid or ATX PS)

If they run on 5V okay, perhaps all of them in parallel with a 5V rail of an ATX PS... Or maybe all of them in series with a bridge rectifier to be powered by mains!

 

[diachi]

I saw you turn them into a huge strobe

 

[FireMyLaser]

Hooking all of them in parallel would be the easiest way. But like Cyparagon said, make 12 groups of 2 LEDs in series would bring down the current, which is more convenient. When using allot of LEDs you should connect as many of them as you can in series to bring down the current and use a higher voltage to power them. But I don't know how the drivers work, how they will act when two or more are connected in series...

 

[Mohrenberg]

the driver is just a small pcb with 2x 8.2ohm resistors on it....

 

[FireMyLaser]

In series or parallel?

 

[Mohrenberg]

In series or parallel?

parallel

 

[FireMyLaser]

Then this will work. 12 groups, two LEDs is series and will draw roughly 0.8A through each LED. Total current will be roughly 9.6A @ 12V.

Edit: keep in mind that this is not regulated so there's a great chance of thermalrunaway in the LEDs, so keep watch of the duty cycle.

 

[Mohrenberg]

Then this will work. 12 groups, two LEDs is series and will draw roughly 0.8A through each LED. Total current will be roughly 9.6A @ 12V.

Edit: keep in mind that this is not regulated so there's a great chance of thermalrunaway in the LEDs, so keep watch of the duty cycle.

ok.

should the "two leds" be in series, or the 12 groups be in series?

 

[FireMyLaser]

You make 12 groups of two LEDs in series in each group. Then you connect your 12 groups in parallel.

 

[Mohrenberg]

You make 12 groups of two LEDs in series in each group. Then you connect your 12 groups in parallel.

heh ok...

so i connect two leds in series.

then i take all those groups of two leds, and connect them in parallel


just making sure before i solder all this crap lol

 

[lasersbee]

[quote author=FireMyLaser link=1238810502/0#12 date=1238890272]You make 12 groups of two LEDs in series in each group. Then you connect your 12 groups in parallel.

heh ok...

so i connect two leds in series.

then i take all those groups of two leds, and connect them in parallel


just making sure before i solder all this crap lol[/quote]
Yeah... that's what he said...

Jerry

 

[Mohrenberg]

heh ok i'm bored with this....

i wired them all up......something goes wrong about half way through so the most i can get to light up is 10

but even with 10 i'm not supplying enough power so it's not THAT bright, on the other hand if i'm only powering up 6, it's VERY bright.......

these things would be amazing if they were all powered up all the way.