Help me build my first flashlight, please.

Hi
I've been browsing around this forum a few weeks now, after buying my first light (Led lenser power-chip). It's got a nice look and decent performance but then .......
I WANT MORE, GRRRRRRR.
Ive just got two problems. I'm rather low on funds and I live in Denmark, the country with nothing but old Surefires and diving lights.
Now I have decided that the only way (for now)to get a real "performer" is to build it myself.
I found a place which sells 5W Luxeons and somthing that looks like Fraen optics. I'm sure I'll find a way to make the body, but I need to find a small standard powerdriver too which I don't have to order from the US.

5W LS run 9V 700-750mA, right ??

It would be nice if I could use rechargeables without the whole thing ending up being too big.

Any suggestions for parts and other usefull tips ?

I know I can find a lot by browsing the forums but this makes it a bit easier for a total noob to survey.

I hope You'll spare a bit of goodies in this thread.

J

Check out dat2zip's converterboards /ubbthreads/images/graemlins/wink.gif
Don't forget to read the Converter Boards Technical Support Page . /ubbthreads/images/graemlins/thumbsup.gif

Hope this helps,

Well it does for a start but once again, I would perfer to find some standard driver which I can buy in Europe. If I order above 10$ from the US, customs will tjeck the package and I'll have to pay 25% of tax on top of the price of the product and of course the shippingcost

[ QUOTE ]
Gungrefjaert said:

5W LS run 9V 700-750mA, right ??



[/ QUOTE ]

Actually the 700 mA Voltage is closer to 6.84 typically (5.43 to 8.31) according the the maker's specs. Understand a half Volt 'error' there is a 500 mA change in current (probably fatal to the part or 'mighty dark' depending). Voltage control seems at best questionable. The specs would indicate that two or three times this much error is easily 'still within spec'.

A true current regulator is easy enough to build with parts you should have available to you. Look for National's 'current regulator' IC, LM 334. Under one dollar here, should you need to order a few. This combined with a high gain, low saturation voltage PNP transistor, a couple of resistors and a capacitor will do a very good job for you (at least in my experience). Mr Al proposed it some time back, it's the 'higher current' example on the National spec sheet page 8, available on the Jameco site at <http://www.jameco.com/Jameco/Products/ProdDS/23739.pdf>. Jameco is a recommended source, BTW.

I've used two feet or so of 'wire wrap' wire (30 AWG) to get the .2 Ohm resistor needed (for 350 mA) which I trim to exact value with a bit of 'cut and try' in the final circuit. I typically get full current output to down under .1 Volt 'across the regulator'. Typically this means the battery is on it's last 10% of charge well before the light output starts to change. 3 NiMH cells (or 4 alkaline) seems the call for 1 Watt units, twice that for the 5 (which is really four one Watters in series parallel).

Speak up if you have trouble with the circuit or getting parts.

Cheers.

Doug Owen

Well I haven't got anything but trouble
I don't know much about electronics an how they work. Actually the only soldering I've done is jackplugs and a bit of modding to a few harddisk controllercards. But it should be possible for me to learn what I need before starting. Usually I just start out with my projects and learn as things go but this one I'd better take it easy on, I don't have the money to by too many Luxeons.

Thanx for an very useful reply.

By the way.
any small rechargeable batteries that can be used to run the 5w ?

[ QUOTE ]
Gungrefjaert said:
By the way.
any small rechargeable batteries that can be used to run the 5w ?

[/ QUOTE ]

Sure, several, some better than others. You're up against it WRT run time, of course.

Consider AAs. You can probably get two hours or a bit more at 700 mA. AAAs will give something like 45 minutes I would guess. There are a whole host of similar cells out there (1/2 A, 5/8 AA and so on).

Someday I plan to cobble up a 6 AA version of this in a 'mag like' flashlight I have. FWIW I intend to run mine a little lower (probably something like 500 mA). Remember to keep a close eye on temperature, it's quite easy to mess up that lovely (and expensive) Luxeon. Serious attention to heat sinking seems in order.

Doug Owen

I know 5w's get really hot. I've spend quite a lot of time on different cooling solutions (passive too) for Computers and I think I'll be able to work out a good heatsink of some kind.
Isn't there any smaller rechargeables ? If not what about small and cheap batteries who will do the job?
My aim is a light not to much bigger than a 2aa mag.

Again, sure there are lots of options. Check out <http://www.batteriesamerica.com/newpage3.htm>, even though a US company, they're Japanese products, should be available there. 1/3 AA or N cells should meet your goal (at very short run time). So would 123 cells (although expensive), three would be needed.

You could consider two (or even more) different resistors and a switch to give you the option of lower level and longer run time or 'full blast'. Remember, the 5 Watt units are very bright, probably too bright for many uses.

Another option in the 'quick and dirty' end of things might be a 9 Volt 'transistor radio battery'. Short run time, but available as fairly cheap primary batteries and as rechargables. They'd go quick as well of course, perhaps 10 minutes at full blast.

Thems the rules. You want lots of light, it's gonna cost you lots of battery.

Doug Owen

What about buttoncells ? Any of these that could work ?

Sure, for even less time. Check the specs.

"The light that burns twice as bright burns half as long".

Not really true here, it is in fact *less* than half. Push it to extremes, like you're doing and it is a lot less.

Personally, I kinda draw the line at the AAAA cells in the 9 volt battery.

Doug Owen