Budget headlamp setup...beginner needs some second opinions.

Flashlight Modding and DIY Parts
1

Hello friends. My first post here, hoping to get as many opinions as possible on my build. I am a beginner, so bear with me please.

I am looking to make a headlamp using 2 XM-L LEDs. I want the option to drive them at full blast (3Amps), and to realistically use them at half of that power to not just burn through batteries. This will be used for mountain biking at night.

I want to keep it as inexpensive as possible. I have a large number of high quality Sanyo AA 1.2v nimh batteries, so I want to use them for this build. I don’t mind the weight, and I have them already. The number and configuration is up for debate, the use of nimh AA’s isn’t.

I have tons of battery holders to wire things in series, parallel, you name it. I am basing my current plan around two 6xAA battery holders wired in parallel.

Drivers for these high amp requiring beasts are more of a pain. I don’t want to drop the money on the more expensive taskled drivers, and they are out of stock and I am impatient.

I have purchased two of these drivers: http://www.lightmalls.com/super-output-ssc-p7-led-driver-board-low-high-middle-5-5v-15v-2

I was planning on running them in parallel, each supply a full 3A at high if wanted.

Here is my crude drawing:

Please correct the things I have messed up. I am worried I have this wired incorrectly. My goal is the wire the two batteries in parallel, and wire the two drivers in parallel.

My main question is switch placement. Is this in the correct spot? How will this control the various modes the drivers have to offer. I know I need a high amp capable switch, but does anyone have any exact recommendations? I feel like putting it between the battery and the drivers might not be correct?

Thanks folks. I wish this stuff came more naturally to me, but it has been like 10 years since I have taken a physics class!

2

Looks like you got it right. Most of those drivers change modes via power interrupts, so a quick on-off-on will get you to the second mode, or a quick off-on will move to the next mode.

3

Welcome to BLF y0bailey.

Looks like a fun project you're about to build there. Looking forward to hearing about your progress.

Other then that? What gunner12 said :-)

4

Yep, looks right as far as I can tell. What drivers are you using? Or are you slaving them?

5

Thanks for the responses guys! Out of all of the forums I have posted to, you guys get the big award for speed!

scaru, the drivers can be found here: http://www.lightmalls.com/super-output-ssc-p7-led-driver-board-low-high-middle-5-5v-15v-2

I don’t know what slaving them means (I am a noob), but please inform me if it will make a more effective setup!

Last thing for you folks to check. Would this switch work?: http://www.digikey.com/product-detail/en/GPB554B05BB/SW644-ND/2235516

It is rated at 6amps, on-off so I can just double click to cycle, etc.

6

Slaving is a way of making a 4.2 volt driver work with higher voltages. That switch would work but it would be best to use a reverse clicky since it will be a multimode light. And a quick word about that driver, it generally only supply around 2 amps. However that is probably better since this will be 2 XM-Ls in a headlamp.

7

Cool…reverse clicky it is.

The driver states 3A on the website, but in reality it will be closer to 2A? Is that due to efficiency? You used it before or read about someone who did? In reality you are right…2A might be more desirable in this setup!

It doesn’t seem like I would need to slave this setup, due to this driver doing the voltage regulating? Correct?

8

Yeah, I have used that driver before and measured around 2 amps unless you get above 12 volts. I think it just needs higher voltage to supply more current. I would suggest wiring it something more like this so you could turn on only 1 LED if you wanted to.

9

Hah….I just ordered an extra switch for that reason! Funny how that works.

Anyways, thanks for the info. I am looking forward to getting this up and running.

I have already ordered everything, but just to make myself angry, how would you achieve a similar setup (using AA nimh batteries and 2 XMLs)?

10

I would probably power it from 4 eneloops (around 6 volts at full charge) using a E1320 7135 driver. It is a driver that a member here(E1320) buys and reprograms so they have 5 modes going from moonlight to 3.1 amps. Then just repeat for the second XM-L.

Or if I got adventurous I might try to make one of the QTC variable output ones. QTC is a material that when pressure is applied conducts electricity, and more pressure is more conductive. With that it can be infinitely variable. What your are doing definitely has potential and sounds like a fun mod.

11

Very cool. Well hopefully this doesn’t turn out to be a complete fail! Hehe. If I can get 1000-1500 lumens out of it and 2 hours of runtime, I am sold. You think that is possible?

12

Interesting project! but this is SO far above my comfort level pay grade....I have nothing to add....but will watch the thread.

13

Yeah that sounds like a fairly realistic goal. What are your plans on heatsinking them? And what about optics? I'm guessing one flood one throw?

@Gnarly, why don't you try modding something. It isn't that hard to make a P60 drop in. :)

14

yObailey had the switchs on the +, scaru has them on the -.

Does it make a difference ?

15

I bought several optics with various beam widths to see what I like best. Basically mix and match until pleased. They were $1 a piece, so I splurged a bit here.

I have tons of computer heatsinks around, so the LEDs will be very well cooled. I run a more “wide open” design so they get plenty of airflow.

The drivers themselves I worry about slightly, but I will probably find bits of aluminum and epoxy em on to be safe. I am hoping I have the newer revision of the drivers, which seem to overheat less frequently.

16

Shouldn’t matter. The switch basically just closes the circuit to allow electricity to move through (think of it like cutting the wire). If you cut the wire on either + or -, things still shut off. If you reconnect it, things turn back on.

17

That would be my uneducated guess.

18

It's a pleasure to know you, y0bailey!

19

I built a double XML headlamp thingy for my helmet a while back but, eventually took it apart because the heatsink, reflectors etc, were a bit heavy and cumbersome. If ambient temperature is low and you’ll be going fast enough on high mode, then, you may not need something that stresses your neck. I wish you luck with the build!

20

You guys were right it shouldn't matter which side the switches are on.