How's my dual MC-E setup look?

[4thpage]

Hey, all you extremely-knowledgeable folks! Here's what I have so far in mind for my first light. I would appreciate all thoughts, suggestions, recommendations, etc.

LED
2 x parallel wired MC-E M bin emitters, premounted on 20mm circle mounts, wired in series
http://www.cutter.com.au/products.php?cat=Cree+MCE+Multichip

Battery
Li-Ion 11.1V, 4400 or 5200mAh, protected cells
http://www.all-battery.com/li-ion18650111v4400mahrechargeablebatterypackwithpcbprotection.aspx
http://www.all-battery.com/li-ion18...rypackpcbprotectionwith20awgbareleads2x3.aspx

Driver
I need suggestions/recommendations/advice here. I was thinking something along these lines, but maybe that's more than I need:
http://www.cutter.com.au/proddetail.php?prod=cut863

Here're what I'm looking for in a driver: CC up to 2800mA, buck (obviously), multi-mode. What am I missing? What are better options?

Switch
I would like suggestions here too, please.

If I calculate correctly, I could run this light on high (=~7V + 1V at 2800mA) for =~1.85 to 2.19 hours, assuming around 85% efficiency from the driver. This may actually be more runtime than I need.

Please, all, give me your thoughts.

Thanks!

 

[MtLuke]

You don't need 2800ma for a driver, a Maxflex would be fine if you buy the SERIES wired MCE's.
By doing this you lower the ma requirements but raise the voltage requirements.If you buy the parallel ones they only need about 3.5 volts but higher amps-like a P7.
Wire them 2s2p, you'll need about 15fv to drive them so an 11.1 v Li-ion would work well(13v peak). Maxflex is a boost driver good for 1200 ma.
I'm using the same setup with a 6600ma battery and I should get about 3.5 hours at 1200ma. I don't run it full tilt all the time because it puts out enough light at about 700ma.It also creates less heat at lower amp settings
As for a switch,a judco momentary would work with a waterproof boot or a rated (ip67?) for extreme conditions.
What kind of housing/heat sinking? Higher amps means more heat to get rid of.
Optics? The Fraen MR11's work well for throw-maybe too narrow. For helmet use 1 narrow-1medium. Big housing though.
Ledil's are great for handle bar setups. CMS and LXP.Smaller housing too.
Some of my builds;
http://forums.mtbr.com/showthread.php?t=573906
http://forums.mtbr.com/showthread.php?t=488603

 

[4thpage]

You don't need 2800ma for a driver, a Maxflex would be fine if you buy the SERIES wired MCE's.
By doing this you lower the ma requirements but raise the voltage requirements.If you buy the parallel ones they only need about 3.5 volts but higher amps-like a P7.
Wire them 2s2p, you'll need about 15fv to drive them so an 11.1 v Li-ion would work well(13v peak). Maxflex is a boost driver good for 1200 ma.
I'm using the same setup with a 6600ma battery and I should get about 3.5 hours at 1200ma. I don't run it full tilt all the time because it puts out enough light at about 700ma.It also creates less heat at lower amp settings
As for a switch,a judco momentary would work with a waterproof boot or a rated (ip67?) for extreme conditions.
What kind of housing/heat sinking? Higher amps means more heat to get rid of.
Optics? The Fraen MR11's work well for throw-maybe too narrow. For helmet use 1 narrow-1medium. Big housing though.
Ledil's are great for handle bar setups. CMS and LXP.Smaller housing too.
Some of my builds;
http://forums.mtbr.com/showthread.php?t=573906
http://forums.mtbr.com/showthread.php?t=488603

Thanks, MtLuke! I like the looks of your builds, by-the-way. Can you tell me a bit more about what you used for the heat sinks/cases. I read what you called it, but I don't know what that is.

Also, what do you consider to be the advantage of running a boost over a buck driver? I know the current can be lower with the higher voltage, but what's the advantage?

Thanks!

 

[MtLuke]

In the first link the case is made from 1"x2" tubing with heat sinks AA'd to the sides. They're filed slightly rounded to taste.
The tricky part is closing up the back, I made some small brackets, tapped some holes and screwed them on.
The second link is a Hammond case, check the stock number in the post.
This was a much easier build but It lacks a bit of finesse.Look up Hammond cases on Newark.com or Mouser.com- they have a good assortment.
Hammond also makes finned cases, expensive but made to control heat buildup.
Both builds use an internal piece of angle to mount the LED's to. It's rather thick, about 1/4". I wanted to give the lights some mass to help control temps. You still need some heat sinks on the outside to dissipate the heat though.
As for boost versus buck they both have a place.
The first post uses a boost setup(1200ma max) running an 11.1-6600mah battery.Theoretically boost drivers should have less battery(less cells mean less weight) but it depends on how many watts you're using.
I could have downsized and got the 5200mah to save some weight.
The second is a buck setup(1000ma max) using a 21.2 volt AA battery which I made. It's a lttle bigger than the 11.1v Li-ion.
Both setup give comparable run times-about 3.5 hours on high.
I do like the bar setup with the square Ledil's, but for a helmet setup it's pushing it for throw.
I'm currently building another MCE setup using the Fraen MR11 reflectors, which as it turns out are too narrow of a beam for my tastes.
I need to mix a medium and a narrow and all will be good.
If you plan on running these setups maxed out plan on dissipating a ton of heat. Running at 500ma each generates a lot of light but not as much heat as running them at 700 each. It's diminishing returns, less lumens per watt at the high end and a ton more heat as well.
You also could run your setup as planned with 2800ma into each LED.I just have not done a setup this way.Just remember heat.
My helmet light is a P7 Hoffman unit (great setup, 3.6v run at 2800ma max) and the battery is the same size as my others, just wired in parallel.
It's just a different approach, same result different way.

 

[4thpage]

You don't need 2800ma for a driver, a Maxflex would be fine if you buy the SERIES wired MCE's...

...As for a switch,a judco momentary would work with a waterproof boot or a rated (ip67?) for extreme conditions.

Yes, it looks like a Maxflex would be fine for me. An extra 100 mA per die is not going to make that much difference to me, and I'd feel a little better not running them that close to max current anyway.

Another question: I was reading over the manual for the Maxflex, and I don't understand how a momentary switch (as you and the manual both recommend) can correctly operate the driver. I'm sure I just don't understand how a momentary switch works :thinking:, but I thought the switch either opens or closes the circuit. So it seems like clicking the switch to turn the light on, then clicking it again to change to a different dimming mode would simply open the circuit and turn the light off. What am I missing here? :shrug:

Thanks, again!

 

[ifor powell]

Yes, it looks like a Maxflex would be fine for me. An extra 100 mA per die is not going to make that much difference to me, and I'd feel a little better not running them that close to max current anyway.

Another question: I was reading over the manual for the Maxflex, and I don't understand how a momentary switch (as you and the manual both recommend) can correctly operate the driver. I'm sure I just don't understand how a momentary switch works :thinking:, but I thought the switch either opens or closes the circuit. So it seems like clicking the switch to turn the light on, then clicking it again to change to a different dimming mode would simply open the circuit and turn the light off. What am I missing here? :shrug:

Thanks, again!

The switch is not on the power feed its conected to a microcontroller running software. Works the same way as a key on your keyboard or a button on your mouse.

 

[4thpage]

The switch is not on the power feed its conected to a microcontroller running software. Works the same way as a key on your keyboard or a button on your mouse.

Ah, so the microcontroller interprets the input from the switch based on its firmware? Is the "microcontroller" the Maxflex, or an additional component?

Also, if I'm not interested in flashing modes, would a simple single-mode driver with a pot work for dimming?

Thanks for all your advice, by-the-way! I really appreciate it. :thanks:

 

[MtLuke]

The maxflex has the controller built in.
The Maxflex driver is configurable in 3 modes, I use mine in bicycle mode which means it's got a high and low setting-no flasher.
The hardest part is the soldering of all the wires to the unit. If you take your time and have a small soldering iron you should be able to do it.Just don't get it too hot, pre tin wires and unit, use a 25 watt iron.
You can configure it to do various things like turn power down if it's getting too hot, low voltage from battery(useful for long rides), read the online manual for more details.
I have both the bflex and maxflex and also have used the 3021 buck drives from LED supply. I prefer the Task LED units because they are configurable and have high low settings.You can also set them up for multi mode setting-5 in all.
The 3021 is easier to solder but it's just on-off. No frills, no adjustment, no warnings.

 

[HEY HEY ITS HENDO]

you can buy taskled drivers direct ...http://www.taskled.com

here`s a recent video,
you can scroll up and down the brightness levels
ideal for saving power when only low illumination is required
.... http://www.youtube.com/watch?v=2UYNCB7XMX8

3 x MCE Light ,http://www.dstar-led.com/Products/products_lights.html