Luxeon circuits ?

[Gungrefjaert]

I'm one the total noobs of this forum and as I can read in different posts it would be nice have a thread with a summery of the usable boost/driver circuits around, which can keep those Luxeons happy.
Drawings, links and so on would be nice if possible.

Thanx.

 

[Lucien]

Actually that would be nice. Perhaps a sticky at the top of the forum containing links to all the posts about circuit designs. Have to ask a mod to make it happen tho...

In the meantime, you could do a search for "ZLT" (minus the quotes). The original post is waaaay long, but IMHO has a lot of useful info (and insight) into putting togehter a circuit, and brewing up your own.

 

[Gungrefjaert]

I'll give it a look.
Thanx

 

[flashlightlens]

Gungrefjaert - Check out OddOne's site.

Also, take a look at Jeff1500's collection.

Hope this helps!


*****ADDED****** - Here's an old post about circuit collections.

 

[Gungrefjaert]

Texas instruments makes alot of gadgets including current regulators, as far as I can see. Did anyone of you, who knows stuff, take a look there? It might not be of any use since I can't see what is good or bad :-)

 

[OddOne]

Also, check my article on Zetex drivers, inspired by thr ZLT driver pioneered by several of the CPFers. The ZLT variants, such as MrAl's improved ZLT-CCR-2 are probably the best 3-volt Luxeon driver circuits, as they're very simple and easy to build and just plain work.

oO

 

[Gungrefjaert]

I'm looking for a simple and safe way to run a 5w from 6 AA's if possible.

Thanx

 

[OddOne]

Maxim makes a series of 10-watt DC-DC switcher ICs, their MAX641/642/643, that might be useful. However, they're hardwired for an output of 5, 12, and 15 volts DC, respectively - you can get around this by biasing the IC's sense pin with a divider network to "fake" it into using a different output voltage. This will require fine adjustment of the output so as to deliver the right current, and the resulting circuit is a constant-voltage approach, not the more desireable constant current.

oO

 

[INRETECH]

Question was

I'm looking for a simple and safe way to run a 5w from 6 AA's if possible.

Since the 6xAA will make 9v, that would seem enough to direct drive the Luxeon thru a resistor, but the internal resistance of the batteries will limit the max amount of current that you can pull from them, and even so - the current draw of 750ma thru a AA battery is quite high and could cause problems

If the switcher is ripple-mode, you would need to
run the batteries thru a inductor to charge up some very low ESR caps so that the switcher has a "good clean" supply, without this buffer, the ripple mode switcher would "see" the voltage drop from the batteries and do a false osc period

Even with large batteries like the D-cells; Alkaline has a very high ESR, I would suggest using Lithium, NiCad or Nmh

 

[paulr]

Use 8 NiMH AA's if you can, along with a dc/dc converter like a Powerpuck.

 

[LEDmodMan]

[ QUOTE ]
Gungrefjaert said:
I'm looking for a simple and safe way to run a 5w from 6 AA's if possible.

Thanx



[/ QUOTE ]

Direct Drive!!! The simplest way. I run two parallel sets of 6AA's (12 total!) in series without resistance to a 5W SE and have no problems here. This is on Costco Alkalines though, I'm not sure if NiCd's would be a good idea in this set-up. I am on my second set of batteries without any trouble so far, and I've been using this at least every other day since I built it! You can direct drive off of 9v without too much risk on either 6xAA or 3x123 as long as you have a good heatsink set-up for the Luxeon. If it gets too hot, it'll fry. The only unknown is that when overdriving like this, it is possible that you are reducing the life of the emitter, but we haven't proven that yet. /ubbthreads/images/graemlins/icon3.gif Now if you want to use regulation, then all of what I just said is trash...

 

[Gungrefjaert]

I've thought of doing that after reading a bit in these forums, but since I might, if succesful, make some for a few friends (who will pay for the parts), I have to be sure it doesn't fry or I'll have a surtain bodypart kicked :-)
I'd also like to be able to run it of recharables without compromising runtime and brightnes to much.
I might have a bit to many demands to make this all that simple ??

 

[Gungrefjaert]

I found someone who can do all the soldering now.
Does anyone have some "ready to go" drawings of a 700/750 mA driver/boost circuit ?