Need help (lots!): Homemade BRIGHT hat light

[FlaMtnBkr]

I am looking to make a bright light that I can strap to a hat or hardhat internals. I have tons of 9 volt batteries and I am thinking of having an external power supply that you wear on your belt.

I was thinking that maybe 3 of these newer LEDs in a housing could possibly do the trick. I have lots of tools, mills, and a lathe. I was thinking of maybe mounting this in a piece of square aluminum tubing.

I think reflectors, emitters, and drivers can all be pretty much bought off the shelf and with the right knowledge hooked together. Does this sound like something that is possible? Can these parts be purchased from DX or some place else (better)?

Would anyone be willing to give a newbie some guidance? Hopefully with part numbers and a general description of what would need to be done to wire things up correctly?

It would be nice to have maybe 2 floods and 1 spot and be able to turn on maybe just one light for a low and all three when I need the bright light.

I can make a battery pack with the 9 volts if there is an emitter that will run off this and just hook the batteries in parallel. Maybe have 3 sets of batteries for each circuit?

Does this sound do-able? Am I out of my mind thinking I can make it work?

I have seen really bright headlights that use a bulb for an auto application but it requires a cord hooked to a car battery. I guess I was hoping to use the effieciency of LEDs and a battery pack to make something more portable.

Any thoughts on this? Anyone feel like helping a newbie out? Any and all help will be greatly appreciated and I hope I can figure out something that will work. I am not set on my format, it's just my thought path for now.

Thanks and please feel free to comment no matter how trivial you may feel it is!!!

Ryan

 

[AnAppleSnail]

I think reflectors, emitters, and drivers can all be pretty much bought off the shelf and with the right knowledge hooked together. Does this sound like something that is possible? Can these parts be purchased from DX or some place else (better)?
Ryan

Well, I guess I'm a newbie myself (Note when I registered and all!). You can get the electronics quite easily, but to make the light useful is a bit trickier. You may enjoy DIYBikeLED.org for ideas on easy-to-make cases for lights. I don't know part numbers in particular, but you know your needs and can probably match an emitter to a driver. You may consider not running your LEDs at the maximum rated current, because it's a shame to kill them off early.. Concerns for you will be:

-Heat dissipation. These nifty new LEDs take 3-8 watts, and they are dimmer and die sooner if they get hot. Lots of metal, good thermal connections, and efficient electronics.
-Durable case. Once things start falling on your hard hat, it's nice to still be able to see. That's where your tools will come in handy.
-Water resistance. Because a bit of hatsweat shouldn't ruin your day, use caulk where it's needed.

Even a bare Cree emitter is a floody light, having about 160 degrees of fairly even light. All of the LEDs at DIYBikeLED.org are designed for very narrow optics - which on LEDs look like a big cone you put on top of the silicon 'bulb.' These are described in size and degrees of spread, and you'll want a mix of flood and spot. I do not know what to do if you want to switch one of the lights off, but maybe someone can fill us both in on how a current-limiting driver would react to a short-circuit around one emitter of a few in series (Reduces voltage of the LED stack, keeps current the same, these supposedly pick the right voltage...somehow). CPF help?

 

[mahoney]

If we are talking the standard 9 volt batteries like go in transistor radios and garage door openers, these are not going to be a very good choice as a power source for a really bright light. They are not good at supplying much amperage, so you will have to run at least a few in parallel, and that opens the door to problems like leakage or reverse charging if the cells are not well matched in capacity.