Noob questions

[nihilist37]

Well I'm trying to build my first light.

My basis was that I dont have the money to buy a serv-light (http://www.serv-light.com/) or a scurion (http://www.scurion.ch/ms/index.php?lamp) and I will get more joy out of building my own light to my own specs.

I think its easier to show my specs first and then we can figure out how it can be done.

Housing:

I can machine Aluminium or a PVC pipe to make a nice housing that can fit on a Helmet. I would like it to be waterproof to i guess 1m or so. I need to work out a switch but we can wait to my settings to work that out.

Power supply:

For ease of recharging, cost and portability on a helmet i think the Ultrafire 18650 3.7v 2400mAh are the easiest option. 4 would be the maximum to carry on a helmet. Whether they are in parallel or series is yet to be decided.

LED's

Essentially I would like 2 separate systems that can be used at the same time. the first being for short distance flood the other being for long distance throw and wide angle throw.

For short distance flood I would like to run 2 CREE MC-E (warm and cool white). These are also to be my low power lights using the least battery. I would like to have two settings on these 100mA each and 200mA each (total of 200mA and 400mA respectively)

For long distance throw and long distance flood I would like to use 2 SSC P7. with the following settings 350mA each, 500mA each and 700mA each (total 700mA, 1000mA and 1400mA respectively)

My reasoning for 2 systems is that for larger cave areas i can use the Longer distance and brighter flood while in closer conditions and in squeezey areas i will have bright light for illuminating grips etc.

Switching:

So far I've not found any switches that are exactly what I want. Caves like to reach out and bump bits of helmets and lights and stuff so toggle switches are not too practical so I'm trying to find rotary switches with the positions necessary.




Being used in a cave environment I obviously want to get the greatest battery time rather than burning it all off in resistors. I was told that buck pucks might be the way to go but i cant figure out what the hell is going on .


So thats it. What are my options? or am I dreaming that it can be done?

 

[nihilist37]

Bump.

Is it best to have the LEDs in series or parallel?

I figure I can get that current to them through two buck pucks in parallel but again i dont know how to deal with the voltage. If i have the batteries in series i should end up with (4 X 3.7v) 14.8v the pucks will be fine with this but what about the LED's? Do they draw only the voltage they need? Do I need to use resitors after the pucks to draw only the right voltage?

I dont want to have to swap between 3 sets of paralleled buckpucks as a switch is there some easier way?

 

[yellow]

I ll type the same I type every time, maybe You see the improvement, maybe not ...

Sure one might be able to build a housing from bare metal, but
* what about the other parts (front glass, O-rings, ...)
* even when working good, it will still be bare metal on the outside (optics)
* work involved

solution: You buy a cheap light like a Mag, or one from dealextreme that features a head sized like You want.
The use just this head, skip the body.
You have a nice, anodized housing, all parts, with the DX-solution an additional thermal/heatsinking plate perfectly fitting the housing to mount the led onto ...
All You have to do additionally is to make a cover at the end - but even with the homemade housing this had to be done.
Ordering and placing of led, reflectors, ..., all the same as with the full homemade housing.


the P7 with its wider emitting surface is said to do flood, the XR-E makes a tight beam in the right model focusing device


the drivers You want to use depent mainly on Your battery pack voltage.
4 Li-Ions in series would ask fo step-down (buck) driver for the XR-Es and the P7s.