Sold/Expired Interest: Custom High Powered Lantern!

[havand]

Hi,

I'm going to be producing a high powered LED lantern. This is the interest thread for it!

Basically, it is going to be a ~6.5" long x 3.5" tube with 6 CREE (Q5) or SSC (P4) stars. Variable brightness from a few mA up to the maximum the SHARK drive will supply. The final product varies a bit from the one pictured below. I don't have a model of it currently because my cad program has thrown a fit when I switched to vista. I will have a final product model up the first few days of this coming week.

I have 2 charging options at this point. I have plans to include a built in charger, but it is of the buck type. So, the source for charging must be 12.6-14V. This is ideal for a running car or a solar panel. My personal car is 12.6V after sitting, but I know some dip lower, so I am looking for feedback about the charging feature. Would you guys rather have this built in charger (possibly a regulator if I can find one) or an external charger supplied by me or you (depending on preference). The value of having the built in charging system is being able to charge the lantern from any 12-14V source. Car, solar panel or DC transformer. However, even without an integrated charger the lantern will run from your car battery for extended run sessions, totally bypassing the battery.

The real advantage of using the shark driver is the variable input, high output and high efficiency. At nearly a month runtime on low, the output is still plenty bright enough to move around in a tent or read next to. On high, the output is enough to light up a small room nearly as well as the room's native lighting.


There will be a handle of some sort. Whether it's 2 strap holes in the aluminum protruding upwards or a custom fitted nylon holster that fits to a lip, i'm not 100% sure yet. I'd like to hear your opinions on that as well.


Features:
- 6 CREE (Q5) or SSC (P4) stars
- Shark Driver
- 20k logarithmic pot
- Ability to run from an external input ~12V (such as a car battery) for extended run sessions
- ~11.1V 6600 mAh battery pack with PCB protection. Important!
- Battery level indicator! Shows battery level in 20% steps. Flashes below 20% power. Easily checked with a quick press of a button.
- ~ 1 month runtime on low
- ~ 3-4 hr runtime on high (depends on the VF of the final LEDS), however I'd really recommend using the lantern between 300-500 mA draw. Not too much difference between it and high and significant battery savings.
- SOLID construction. 6061 Aluminum endplates. 1/4" acrylic walls.
- Watersealed switches.

Price: I'm currently looking at ~ $300. If most people do not want the integrated charging option or need a transformer, the price drops a little, obviously. Just remember, the batteries are INCLUDED!

[FONT=&quot]So, to recap….. I need to know your opinion on charging options. This is not yet a signup thread! It will become one once I have the final details ironed out. I will be aiming to build a minimum of 25 of these lanterns. I can do more the first run if the interest is there, but I need to hit near 25 to consider it.


[FONT=&quot]Here is the prototype running on my table outside on high. The light to the left is a Dereelight SSC on high with tight focus. The four support post obstructions will NOT be present in the final product and will NOT obscure the light output. Around the campfire a few days ago, the lantern, on low, was enough to light up faces and the trees above where we were sitting. The final production unit will not have the square end plates, but sized circular ones that notch into the tubing. [/FONT]

Added 8/27/07

Preliminary Model: How's this look? 1" Strap holes and cord notches. Switches and knobs will be located outside the strap 'path' across the top of the unit, but not pictured.

[/FONT]

 

[jch79]

Awesome idea - this would fill a void in the custom market that I've been waiting for!

I would be In like Flynn on this, provided it was made in the USA. :thumbsup:

john

EDIT: My preference for charging would be plugging it into a wall outlet with a cord/supply that is ideally supplied. :shrug:

 

[acourvil]

Tentatively interested, but the price point might take me out.

 

[shakeylegs]

 

[havand]

Updated first post with preliminary model. Let me know what you guys think. Maybe this will coax a few more to post

 

[photorob]

I think you mite be better off just running 4 leds instead of 6. Six seems like a little overboard. Your really only covering 4 sides so what would 5 and 6 be for. It would definitely help runtime also.

 

[havand]

I think you mite be better off just running 4 leds instead of 6. Six seems like a little overboard. Your really only covering 4 sides so what would 5 and 6 be for. It would definitely help runtime also.

My main thought was more brightness when you want it. Also, by having more LEDs, it keeps them in their most 'efficient' running currents for typical use. The other problem I see is that by lowering the number of LEDs, the forward voltage will no longer be more than the batteries while dimming. A quick glance at their datasheet says something like 150-200mA would be the most they could be dimmed. Unless, I changed the battery configuration to 7.4V, which, during high output situations would lower efficiency a bit. Right?

EDIT: Ok, what about a smaller, cheaper version? Something with say, 3 led and say 3 batteries?

 

[photorob]

My main thought was more brightness when you want it. Also, by having more LEDs, it keeps them in their most 'efficient' running currents for typical use. The other problem I see is that by lowering the number of LEDs, the forward voltage will no longer be more than the batteries while dimming. A quick glance at their datasheet says something like 150-200mA would be the most they could be dimmed. Unless, I changed the battery configuration to 7.4V, which, during high output situations would lower efficiency a bit. Right?

Opps didn't know all that. Three and three sounds better though. People around hear love small and efficient.

 

[dksd39]

very interesting--i'll be watching this one

 

[Hodsta]

I'm interested and subject to seeing a proto and some tests you can count me in on being in the 25.

 

[London Lad]

 

[bombelman]

I like the idea, I like it very much.
However, I wonder how you are mounting the leds.
If you are mounting them all 4 (or more) on a flat horizontal surface,
do you have a reflector of some sort for reflecting the light that
would otherwise hit the "ceiling" of the lantern ?

Or have you considered mounting the Leds to the sides of a big
square "block" (heatsink)...

 

[havand]

I like the idea, I like it very much.
However, I wonder how you are mounting the leds.
If you are mounting them all 4 (or more) on a flat horizontal surface,
do you have a reflector of some sort for reflecting the light that
would otherwise hit the "ceiling" of the lantern ?

Or have you considered mounting the Leds to the sides of a big
square "block" (heatsink)...

My prototype had 3 pieces of cut 1/16" thick aluminum. I took each piece and bent a leg on each side down. I then stacked them staggered so they made a hexagon, put thermalpaste between the flat part of the 3 pieces as well as the end plate. The leds sit rather close to the tube edge, they are not lined up near the center. I didn't see the need for reflectors because I saw the light being projected up and down (toward the ground) as a benefit.

Yes, I have considered mounting the LEDs on a large hexagonal shaped piece of aluminum stock. However, I was concerned about the weight this would add to the design. The battery count and the aluminum endplates have already risen the weight up to a hefty level and I was a bit concerned about that little bit extra. I wouldn't be opposed to using the aluminum stock though. It would certainly make my life easier as far as fabrication goes

EDIT: Just realized I didn't directly answer your question. Yes, light is hitting the top and being projected down within the tube, but it's at such an angle to the LEDs, I don't think it is too much wasted light. Just a quick estimation says they're sitting maybe 1.5" down and 0.75" from the wall. that would put them in the 30 degree range from the edge, which, on the CREE data sheet is (even if my estimation was off by a bit) in the 60 to 70 degree range. The relative intensity is down near 5-15% there. So, yes. Some light is being wasted. However, i'm afraid of making it project the light like a flashlight does Am I making sense there? If you have other thoughts about it, please fell free to suggest them.

 

[photorob]

I don't know if this would be butting in but I just finish a mod a while ago and It seems to fit this project very well. I'll start a new thread shortly to show the results. The basic rundown is maxflex, pot, four leftover Lux 3's. An 8 AAA holder, a computer heatsink and a riverrock lantern as host. Link to fallow

 

[stockae92]

 

[wvaltakis2]

 

[bombelman]

However, i'm afraid of making it project the light like a flashlight does Am I making sense there?

I agree, it should not project like a flashlight.
By reflector I meant some kind of reflecting dome of some sort maybe.

The Hexagonal or square shaped heatsink to which the leds would be mounted would not have to be that wide, or could even be hollow or have holes in it for cooling and would reduce weight.

An idea, *could* even be to house the batteries within such a cilindrical
or hexgonal heatsink ? :naughty: Just my idea . . .

To me, it made more sense for a lantern to have leds pointing to the sides, rather than upward... :thinking:

Cheers ! :thumbsup:

 

[havand]

An idea, *could* even be to house the batteries within such a cilindrical
or hexgonal heatsink ? :naughty: Just my idea . . .

To me, it made more sense for a lantern to have leds pointing to the sides, rather than upward... :thinking:

Cheers ! :thumbsup:

I had thought about making a lantern similar to what you're referring to. But it makes the endplate width very large and the aluminum stock seems to go up pretty quickly in price.

Why did you say that? My LEDs DO point toward the sides. The flat part of the heatsink is mounted to the endplate with an led on each of the downturned 'legs' of the formed heatsink. All 6 LEDs point outward. I see what you're saying about a clear dome on the top to let the little bit of sidewards projected light out the top. However, this poses a whole new host of problems for the narrow area just above the lantern. The heatsinking would have to be pulled up through batteries from the bottom endplate to dissipate the heat.

 

[photorob]

An example. http://www.candlepowerforums.com/vb/showthread.php?t=173505

 

[havand]

An example. http://www.candlepowerforums.com/vb/showthread.php?t=173505

Nice project! It's amazing what one can pull off with leftover, common, household parts. Do you have any estimation of runtime off those NIMH?