Im new to this so i didn’t really know what i was doing with the wiring. Just went straight off the battery to the LED so its not running at the upper limit of its output. Im ordering parts now to add an LED driver to get a few more lumens out of the next version.
Welcome! Great work! It's nice to see yet another unique light here. Did you make that optic yourself?
Also, I assume the battery you used has a lot of voltage sag under load, which in your case is a good thing being that it's direct-driven, otherwise it could really get that XM-L cooking and possibly burn it up.
No, its a carclo optic i had from a previous project - and then ground down to fit the space i had….
ive actually pulled it out since then as the set up was directing a lot of the light into the wood holder. You can kinda see the problem here: http://i.imgur.com/ONtnv5eh.jpg the continuity of the light path from the surface of the optic to the holder is bad news bears.
Im now just using a reflector out of a mini-maglite, ground down to fit.
Welcome to the Forums. What a great way to start out! Very inventive and lots of hard work! The hands sure take a beating doing all that kind of work, but it's a lot of fun to make something by hand. Great build! Thank you for posting it here.
Well you certainly know what you're doing. That's a great driver to use, and if you haven't seen the threads around here yet it can be customized to provide whatever modes you want. You can even hook up a secondary switch to it to do the mode changing if you'd like.
Hi! Welcome on the board nihlton. I like it and have some tips for next version of your light
You have done a nice job on your flashlight but you are wrong about the electronics. If you direct drive an XM-L from Li-Pol like this and without solid heatsink, it can’t survive on the long run… Driver is there to limit current from the battery (unless it is a boost driver). In your circuit the only added resistance is the switch - so you are running the led at unregulated full power without proper cooling. I would suggest you to improve the led cooling (if not cooled the efficiency drops fast) in next version and using the driver to prevent led damage and for gaining a longer runtime. I also wonder if the hot glue doesn’t ruin optical properties of the TIR optics that you used. IMHO that reflective surface of reflector shouldn’t be touching anything so maybe using a TIR in plastic holder may improve the performance too.
Well, the LED is conductive-epoxied to the copper enclosure so most of the heat is dissipating that way. You can’t see, but i also soldered two extra layers to the inside so there is more mass to pull heat off it. I ran it for 50 minutes without noticeable dimming. I have use the same LED on another project (motorcycle headlights) and have seen what happens if its not heatsinked well (ooops) turns yellow and gets dimmer… [edit: project gallery link: Imgur: The magic of the Internet]
you’re right about the optics. Ive actually pulled out the optic pictured and replaced it with the reflector from a minimag. the output is significantly improved.
About drivers - so the driver i have in mind (http://www.shiningbeam.com/servlet/the-132/3-dsh-Mode-Regulated-Circuit-Board/Detail) will basically only limit the juice going into the LED - to protect it - it wont step it up? So say i wanted to drive that LED at 2.8 amps (around the max safe) - would I need to use two batteries in series? or what would i need to do?
Those drivers can only be used with a single Li-Ion cell. With a good cell it should pull 2.8 amps and gradually step down as the battery loses voltage. But you're correct, it's only a "buck" driver (it only drops voltage), it doesn't boost the voltage.
What a great way to start out! Very inventive and lots of hard work! The hands sure take a beating doing all that kind of work, but it's a lot of fun to make something by hand. Great build! Thank you for posting it here.
