# P7 Info and Questions



## tamen00 (Mar 10, 2004)

OK, so the Seoul P7 is out... and 700+ lumens from a single led (well, with 4 die) looks very very appealing to me... a 700+ lumen Dinotte style light... sweeeeeet!! Not having to mess with multiple leds... sweeet!! So, lets get a thread going and see if we can get a good useable light based on this led:

So on Kaidomain there is a driver available... http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=4338

You can get the P7 at kaidomain also:
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=4312

So what about Optics/Reflectors?? Someone on this board has to have some info or modified some kind of reflectors or optics to work with this thing, or at least suggestions on what to use.

To make this easier... when replying with info include a link to the optic, driver, sources, whatever you used to make this thing work... Have Fun!!!


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## tamen00 (Mar 10, 2004)

What about these optics... found them in a google search. I know nothing about this company, and their website was in chinese or something, however they did have a US contact... I sent an email and will call to see how we can get a hold of these things....

http://www.sekonix.com/modules/catalogue/(P7)_P7-CL_spec.pdf

Looks a little big... like 37mm wide, however it is one option!!


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## zemike (Sep 3, 2007)

excellent finds!

I think that currently the easiest way is to use a C2 flashlight as host with a 18650 cell in direct drive or with this driver from KD

this Romisen is the cheapest I have found:
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=4075
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=4077


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## I like to bike (May 25, 2007)

tamen00 said:


> So on Kaidomain there is a driver available... http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=4338


I find it hard to believe that you can run a P7 at 2.8A for over an hour on 4AA Enelope's.

That just doesn't seem right.

But I can't wait to see what people come up with using these LED's.


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## Ochils11 (Mar 22, 2008)

*Seoul P7 - driver and optics*

Hi all,

first post

Just ordered a P7 C bin LED and 2.8 amp driver from Kai to build into a decent light for offroading.

I've also emailed Sekonix to see if they'll sell me some optics, probably the 15 degree ones.

You'll be able to run the P7 for over an hour on 4 AA's, however the lumens will drop quickly after about 45 minutes as the volts drop.

I'm currently building some lights using the Cree XR-E Q5's, alu tubing, boost circuit and a few AA's, hopefully they'll turn out right.

any tips/thoughts/suggestions welcome

Regards,


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## znomit (Dec 27, 2007)

Ochils11 said:


> I've also emailed Sekonix to see if they'll sell me some optics, probably the 15 degree ones.


Me too...and I got a reply ...

_Dear Tim.

Thank you for your e-mail and interesting.
I am charles in sale department of Sekonix.
As you know, we've produce P7-optics and it is possible to send our sample to you.
Before sending our samples, could you tell me your plan to cunsume the P-7 lens per year?
and could you let me know your home-page address?

The attached files are about our products, please refer to them.

If you have any question, don't hesitate to contact me.

Best regards,
Charles_

And I replied along the lines "just a couple of narrow and a couple of wide for me and my mates to build some kick ass bike lights"
Funny enough, thats the last I heard from Charles. Hope you have better luck


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## zemike (Sep 3, 2007)

znomit said:


> And I replied along the lines "just a couple of narrow and a couple of wide for me and my mates to build some kick ass bike lights"
> Funny enough, thats the last I heard from Charles. Hope you have better luck


oh well, that was a wrong approach, I guess.

So the right answer would have been:
we intend to consume up to 500 lenses and our homepage address is http://forums.mtbr.com


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## znomit (Dec 27, 2007)

Yeah, put me down for one (dx just shipped my driver, yay)


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## tamen00 (Mar 10, 2004)

I sent an email also, and even received a pricing sheet on the optics... The minimum order that I was quoted was 5000 lenses and 5000 of the filters, or whatever else you need with them. Funny thing, the first email was exactly the same as yours, word by word... the next emails all came to me in taiwanese and I had to translate them. Lets see... if 5000 people on MTBR want the lenses, I will order them!!!


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## captn_kirchoff (Mar 2, 2007)

My dog's farts smell like dog poo.


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## Ochils11 (Mar 22, 2008)

Well, no surprise there then and I've not had a reply yet. I've also asked if they have a distributer/retailer that will seel to the public.

Someone somewhere must be selling these optics or will be soon, just need to keep looking.

I'll try and machine and polish a reflector when I get round to machining the housing.

These LEDS must be awesome when built up into a double or triple unit (I've tried the 1400 lumens Lupine Betty and its unbelievable but way to expensive for me to buy

I'll post pictures once I've finished and once my braodband connection is back up and running.


Regards,


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## SkUG (Feb 19, 2008)

is this the right lens / reflector?
http://www.dealextreme.com/details.dx/sku.12229


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## Guest (Apr 26, 2008)

SkUG said:


> is this the right lens / reflector?
> http://www.dealextreme.com/details.dx/sku.12229


Good find, SkUG.:thumbsup:


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## Ochils11 (Mar 22, 2008)

Looks good, I'll order one up to try. hopefully it will give a nice spot beam

Cj


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## [email protected] (Mar 28, 2007)

If you are handy with a belt sander, or maybe if you have a tiny modeler's lathe, you should look at some Fraen reflectors.

I found some at Arrow (despite their really lame web site), go search for: FRC-N1-XR79-0R at www.arrownac.com you'll find out if they have them in stock. This by the way is a classic example of how not to design a part's distributor's web site. You can only find these if you have the part number (which I might have gotten from Fraen's web site ... but I don't remember).

Anyway these are cree reflectors, made of plastic, small and all shiny on the inside. You sand the small end down till there is just enuff room for the reflector to fit over the dome on the P7. I guess you could go further, but you'd have a pretty short reflector.

The final result is kind of a wide flood, that's amazingly bright. Does have a bit of a donut hole in the middle, but I've been experimenting with a diffuser over the front. That seems to help. This is car headlight bright.

The hard part is finding a suitable driver. I've been playing with the LM3401 evaluation board. I had to change a few parts to get it up to around 2 amps, but haven't blown up anything yet. I'll try pumping up to a full 2.8 amps sometime early this week.

Mark


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## Ochils11 (Mar 22, 2008)

just received my P7 and driver from Kaidomain, tried it out with a 4.8 volt battery pack and managed to blind myself, doh!

The emitter came with a "free" small plastic reflector that fits over the emitter. It looks like it has a nice beam, no protective cover though, bit of a bummer as I've just ordered a couple of reflectors from DX

Roll on the weekend so I can build it into a light and go and play in the dark

Cj


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## [email protected] (Mar 28, 2007)

Could you post a picture of the reflector? And maybe a beamshot?

I'm getting tired of trying to make my own. Only one of my attempts so far has had a halfway decent beam.

Damn! If I'd know kai was throwing in optics, I woulda ordered my P7s there.

Mark


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## Cat-man-do (May 16, 2004)

*another option*

So far DX is the only place I've seen reflectors for the P-7. Because the DX one is not too deep I have a feeling it is mostly a flood. The only other option I can think of at this time is by using the reflector from this flashlight > http://www.qualitychinagoods.com/2mode-lumens-4xssc-flashlightfsp7-p-982.html
Yes, I realize that you would have to be desperate to spend $65 just to get the reflector but at least it is made for the P-7. It might be possible to write the people there and maybe just buy the reflectors. (?) Since the reflector is for a flashlight I would think the beam would have more of a hot spot than the DX version..."if" that is what you are looking for. What the hey...if you can't make it work at least you would still get a really bright torch.  I should also note that the Chinese web site sells the P-7 too. Maybe not as cheap as DX but they have it.


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## Nouia (Nov 30, 2007)

Cat-man-do said:


> The only other option I can think of at this time is by using the reflector from this flashlight > http://www.qualitychinagoods.com/2mode-lumens-4xssc-flashlightfsp7-p-982.html
> Yes, I realize that you would have to be desperate to spend $65 just to get the reflector but at least it is made for the P-7. It might be possible to write the people there and maybe just buy the reflectors.


Keep in mind that the $65 flashlight includes a perfectly good $25 P7, so you're only dropping $40 for just the reflector.

If you can wait, I think more and more cheap P7 lights with deep tight-beam reflectors will trickle onto DX over the next couple of months.


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## [email protected] (Mar 28, 2007)

I finally got around to trying the DX P7 reflector (http://www.dealextreme.com/details.dx/sku.12229) last night. Woah! nice beam. Very hot spot in the center, with no donut-hole issues, and a very wide flood around that. The throw of this thing is awesome. I was lighting up trees several hundred aways with lots of light. The reflector is probably too large and bulky to be practical for a bicycle light, but it gives you a good idea of what the P7s will be capable of with decent small optics.

Finally got the LM3401 eval board up to about 2.75 amps. You need to replace the transistor with something that can handle more current, change the inductor to something with higher saturation current, and change the current limit resistor to something around 470K. Seems to work fine, nothing gets hot, except the P7. The heat sink it's mounted on gets too hot to hold after less than 30 seconds.

I'm pretty sure once I find some decent optics (that don't have minimum order size > 1000) I'm going to make all my bike lights with these.

Mark


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## Turveyd (Sep 30, 2007)

Add me to this as going P7 shortly ish to ( likely September time )

Waiting on DX to have dual 18650 versions for longer run time mainly, want 2 off to mount on my helmet and need batterys + charger to so all adds up 

Tempted by this one http://www.dealextreme.com/details.dx/sku.12060 should run for 2hours as it's approx 400lumens which would do, huge flood though lack of range and skint  Add a spot version to it aswell later and kick ass system.


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## kwarwick (Jun 12, 2004)

Turveyd said:


> Add me to this as going P7 shortly ish to ( likely September time )
> 
> Waiting on DX to have dual 18650 versions for longer run time mainly, want 2 off to mount on my helmet and need batterys + charger to so all adds up
> 
> Tempted by this one http://www.dealextreme.com/details.dx/sku.12060 should run for 2hours as it's approx 400lumens which would do, huge flood though lack of range and skint  Add a spot version to it aswell later and kick ass system.


I have one of those lights and it is very bright. The beam seems like it would be perfect as a helmet light... run time on full could be a problem as it draws 2200ma from the single 18650 battery. I haven't had a chance to run it for a long period of time, but I think you'd be lucky to get 45 minutes of reasonable bright run time as the light isn't regulated so as the battery voltage drops so does the current. What we need are some regulated drivers that can handle the current requirements of the P7 (2.8 amps). But still for $45, you can't complain about a light that seems to be as bright as a Dinotte 600L.

Karl


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## Tom Brown (Jan 18, 2008)

Turveyd said:


> Tempted by this one http://www.dealextreme.com/details.dx/sku.12060 should run for 2hours as it's approx 400lumens which would do, huge flood though lack of range and skint  Add a spot version to it aswell later and kick ass system.


Bridge the limiting resistors and you can ramp the drive current up.

See post #87 in this thread: http://www.candlepowerforums.com/vb/showthread.php?t=195228&page=3


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## Turveyd (Sep 30, 2007)

kwarwick said:


> I have one of those lights and it is very bright. The beam seems like it would be perfect as a helmet light... run time on full could be a problem as it draws 2200ma from the single 18650 battery. I haven't had a chance to run it for a long period of time, but I think you'd be lucky to get 45 minutes of reasonable bright run time as the light isn't regulated so as the battery voltage drops so does the current. What we need are some regulated drivers that can handle the current requirements of the P7 (2.8 amps). But still for $45, you can't complain about a light that seems to be as bright as a Dinotte 600L.
> 
> Karl


45mins would be annoying, like my C2 off 2xCR123a's. Medium power 90mins might be more useful saving full for when really required, but 300L might not be enough allowing for the focusing.

Needs better drivers and to be able to take 2x18650's to get a sensible run time of really, then PERFECT!!!

Still make a good BURST mode light, interesting section, ON then OFF straight after, likely get a full ride with 1 battery like that.


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## mtbAndy (Jun 7, 2004)

Ochils11 said:


> just received my P7 and driver from Kaidomain, tried it out with a 4.8 volt battery pack and managed to blind myself, doh!
> 
> The emitter came with a "free" small plastic reflector that fits over the emitter. It looks like it has a nice beam, no protective cover though, bit of a bummer as I've just ordered a couple of reflectors from DX
> 
> ...


Any specs on the "free" reflector? Mainly I'd be interested in the outer diameter.


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## dazzat3 (May 4, 2008)

Just received my MTE P7 SKU 12060 from DX today. I'm impressed, $44.50 bargain!

Should make a good bar or helmet mounted light. Plenty of grunt.

:idea: I'm thinking of drilling a hole into handle to run wires into unit so that I am able to power it using 2/3 x 18650's in parallel, for longer run times.


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## Turveyd (Sep 30, 2007)

Personally I'd run 2 packs of 2700ma AA's x 4 together, so 4.8volt for abit more kick, 5400ma so @2hour run time.

Mainly cause you get get AA holders for 4 AA's really cheap, and AA's last longer life wise than 18650's and easier to get!!

( wouldn't use just 1 pack, doubt the batterys can handle the drain )


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## zemike (Sep 3, 2007)

dazzat3 said:


> :idea: I'm thinking of drilling a hole into handle to run wires into unit so that I am able to power it using 2/3 x 18650's in parallel, for longer run times.


No need to drill holes - just unscrew the tailcap and pass the wires through the rear of the light. You can use silicon button caps to seal the wire.


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## dazzat3 (May 4, 2008)

*Food for thought*

Food for thought.

Zemike - Have you done this? Have you got any images of this Modification?

Turveyd - AA's definitely cheaper but would they handle the current draw?

Great feed back!

Keep it coming.:thumbsup:


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## znomit (Dec 27, 2007)

dazzat3 said:


> Turveyd - AA's definitely cheaper but would they handle the current draw?


Check out the CPF battery shootout tests for some good info on AAs. Should give you some idea of voltage and runtime.


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## dazzat3 (May 4, 2008)

Thanks znomit for the CPF tip.

I figure the best run times I could hope for using AA's would be approx. 1.5 hrs before a noticeable drop off in lighting performance? Does that sound about right?


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## zemike (Sep 3, 2007)

here is the setup which inspired me:


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## Cat-man-do (May 16, 2004)

zemike said:


> here is the setup which inspired me:


Cool...I like the idea...but...aren't you still drilling?  ...I gather if you drill through the rear clicky switch that the clicky isn't going to switch anymore? :skep: The one you show would work great if you wanted to bar mount the torch and put the pressure switch on the handlebars. The problem as I see it is that not all end caps look the same. Some of the ones I have look like you can take them apart but others don't. Personally, I'd like to still be able to use the rear clicky for when I use mine helmet mounted. Add to that, if I upgrade to a different light/torch later I could easily use the torch as just a torch without having to replace the end cap. If you drill a hole in the side you can always plug it up later if you change your mind. If you drill a hole in the rear end cap/switch I have no idea if you can reverse the procedure later if you change your mind. (* note, with some torches replacement parts are cheap and easy to get. However if I couldn't find a replacement end cap I'm not sure I would drill through the end cap. )

Now about the battery choice for running a P-7 torch: I like the idea of running an external battery. With the current draw of the P-7 being as high as it is I would probably use a BatterySpace 7.4 volt set-up...maybe 4800 to 6000mah depending on the how much run time was needed. A plus side to using a BS set-up is that the Li-ion batteries are protected against over-discharge with the built-on PCB. The only problem with running an external battery as I see it is that you have to run wires. The plus side is that you get longer / more brighter run times without having to change batteries every hour or so. :thumbsup:


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## zemike (Sep 3, 2007)

there is no need to drill the tailcap to make this modification - just disassemble the tailcap!

currently I am aware of only one driver which can hadle P7 from 7.4 volts
http://www.candlepowerforums.com/vb/showthread.php?t=192833


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## dazzat3 (May 4, 2008)

I tend to agree with you Cat-Man-Do,

I like the idea of being able to use the clicky switch to go through all the available modes. The new cap does look interesting though.

For those of you out there that are after Lenses to suit the P7 try Warren at Litemania he has the Sekonix range of lenses. About $5 US each.

http://www.sekonix.com/modules/catalogue/(P7)_P7-CL_spec.pdf


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## Turveyd (Sep 30, 2007)

Likely not, thats why I'd run 2 packs in parralel, but to be honest it might need 3+ packs, although if the batterys are going to be in your rucksack anyway you might aswell connect them.

The issue then is charging 12AA batterys for the next ride, after every ride my house turns into a charge startion, 2 x CR123a charges and 2x AA chargers going if it was a long ride.


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## znomit (Dec 27, 2007)

Turveyd said:


> Likely not, thats why I'd run 2 packs in parralel, but to be honest it might need 3+ packs, although if the batterys are going to be in your rucksack anyway you might aswell connect them.
> 
> The issue then is charging 12AA batterys for the next ride, after every ride my house turns into a charge startion, 2 x CR123a charges and 2x AA chargers going if it was a long ride.


I was running 12AAs before I went dynamo. Just get on and ride now. :thumbsup:

There are problems with running packs in parallel. Generally not a good idea. If one pack goes bad the others discharge through it or something.
How about some D cell NiMH?


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## Cat-man-do (May 16, 2004)

*Zemike said*:


> currently I am aware of only one driver which can hadle P7 from 7.4 volts


Oh, shoot!..:eekster: ...somehow I got the idea that the P-7 torches were using 2x 18650's... ...sorry, my bad, all the ones on D/X are using one. In that case that I'd do what *Turveyed said *;



> Personally I'd run 2 packs of 2700ma AA's x 4 together, so 4.8volt for abit more kick, 5400ma so @2hour run time.


...or I would buy something like this > http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2178
...hopefully it would maintain the needed voltage long enough to get decent run time.
*However..*.I did see this P-7 torch on the China Goods site > http://www.qualitychinagoods.com/trustfire-high-power-900lm-flashlightfstfp7-p-1005.html
somehow they must of figured a way to drive it off of two 18650's in series. Nice torch, I like how it comes apart...very interesting..:thumbsup:


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## Turveyd (Sep 30, 2007)

If 1 pack gets a fault, then it'll draw all the current through the working packs, so 3 is likely sensible as 2 is the min, so if 1 drops out then your still fine, it'll only drop the output anyone and the power.

D's are a option, but there HUGE and heavy and don't seem to offer enough MA's to make up for it, there 4000 ?? compared to 2700ma max, or is that C's ??


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## Turveyd (Sep 30, 2007)

Just use the head off that torch i guess, without the extension tubes on it to keep the weight down.

Batterys wise, your better off just buying 4x18650's, IF you can find something to mount them, you can use a standard 18650 cheap charger from DX then and it's easier to lug around more 18650's.

It's just Nimh AA's are much more reliable than Li-ion, but there cheap and throw away.

But then you end up with leads from your helmet to your rucksack and HASSLE.

My Twin R2's enough, but if i had the cash I'd run 2 x P7's on my head, get the 5mode 1 use 1 at a time on Medium mode so 90mins each ( 3hours total without stopping ) and use both on full for fast sections 

Likely move over to above September time, when the P7 torches drop in price abit and the nights draw in.


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## Team Cyborg (Feb 26, 2008)

I have 2 MTE SSC P7 flashlights, 2 mode. I run 1 on the helmet and 1 on the bars. I carry extra 18650's in my pocket. Most times I only use the helmet light, the light output is amazing, I can easily ride at race pace with only 1 light on and I'm able to ride for close to 2 hours on a single charge. Truly amazing and the best part - 2 lights, 4 batteries and charger and 2 bar mounts for $160 from China!


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## Turveyd (Sep 30, 2007)

2 gives you more, or atleast similar performance in theory to a Lupine Wilma all in, at a fraction of the price  thats the best part.

2hours nice, will go P7 for sure soon, R2's are GREAT, but always the quest for more!!


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## dazzat3 (May 4, 2008)

*Litemania P7 accessories*

Turveyd,

No need to hold back, now that Warren @ Litemania has a good range P7 optics (Sekonix) & reflectors not to mention htat he stocks the highest bin P7's. Good value too!


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## Turveyd (Sep 30, 2007)

Just upgraded 2 100lumen ish torches to 250lumen ish R2's and can't afford P7's + 18650 + new charger is the real reason.

2 R2's on @500lumens is plenty for even the fastest sections anyway.


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## zemike (Sep 3, 2007)

Cat-man-do said:


> *However..*.I did see this P-7 torch on the China Goods site > http://www.qualitychinagoods.com/trustfire-high-power-900lm-flashlightfstfp7-p-1005.html
> somehow they must of figured a way to drive it off of two 18650's in series. Nice torch, I like how it comes apart...very interesting..:thumbsup:


that's a very poor design, because all the power from the 2nd battery is wasted as heat!

check this for how to make an external battery pack: http://mmm.ic.cz/liion/


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## dazzat3 (May 4, 2008)

*Just a few specs*

The DX MTE P7 SKU 12060 weighs in at 160 grams with battery (1 x 18650/2500mAh @ 47grams). Resonably lite, for helmet mounting if compared to something like the Trinewt etc. 
Very happy! I may even buy another for mounting on the bars, when the wife gets over the shock of buying the first unit.


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## msxtr (Dec 10, 2006)

Hi, here a few beamshots of a german forum










MTE P7










Fenix P3D Premium Q5 with Smo Reflector










IRC 50 W +P7+ Fenix










Greetings - Saludos

msxtr


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## Turveyd (Sep 30, 2007)

WOWSA's thats alot of output !!!


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## dazzat3 (May 4, 2008)

*Great Beam shots*

Hi msxtr,

Great Beam shots. Any idea where to get a bar mount like the one used in the first image?

The DX MTE P7 SKU 12060 should make a great commuter light with Hi, Med, Low, Strobe & SOS.

After using this light for a couple of nights now I can say that it pumps out so much light that it works well as either a bar or helmet mounted light.

Team Cyborg - "Truly amazing and the best part - 2 lights, 4 batteries and charger and 2 bar mounts for $160 from China!" I agree with you 2 x SKU 12060 + 4 x 18650/2500mAh batteries SKU 5790 + 4 x mount SKU 12000 under & 2 x chargers SKU 4151 for under$160 US delivered. bargain! There are cheaper batteries and chargers available too but they were out of stock when I placed my order.

I have also found helmet mounting this light is a little better than bar mounting but that's really splitting hairs.

Running two of these flash lights should be more than enough for any situation, cross country, commuting and even downhill, I imagine.


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## dazzat3 (May 4, 2008)

Hi zemIke, http://mmm.ic.cz/liion/

Magic external battery set up. Do you know what sort of container was used and where to get one?


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## zemike (Sep 3, 2007)

these are piece of 50mm PVC tubes


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## msxtr (Dec 10, 2006)

dazzat3 said:


> Hi msxtr,
> 
> Great Beam shots. Any idea where to get a bar mount like the one used in the first image?


Hi, you can buy here

Greetings - Saludos

msxtr


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## theoneonhi (Jul 14, 2008)

I have 1000 Sekonix narrow lenses, 1000 Sekonix wide clipon filters, and 250 Seoul P7 D-bin (900lm/brightest) LEDs for sale. I had to purchase these high quantities just to get a dozen for prototype. It is impossible to get D-bin emitters in anything less than a reel of 250. I was lucky enough to get the lenses from Sekonix as there are no US distributors currently. According to the sales guy in Korea, I am the only guy in the US to have them. Let me know if anybody out there wants to buy some from me. Thx


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## Baulz (Sep 16, 2005)

theoneonhi said:


> I have 1000 Sekonix narrow lenses, 1000 Sekonix wide clipon filters, and 250 Seoul P7 D-bin (900lm/brightest) LEDs for sale. I had to purchase these high quantities just to get a dozen for prototype. It is impossible to get D-bin emitters in anything less than a reel of 250. I was lucky enough to get the lenses from Sekonix as there are no US distributors currently. According to the sales guy in Korea, I am the only guy in the US to have them. Let me know if anybody out there wants to buy some from me. Thx


Post an ad in the classified section unless you want the mods to remove your post. :thumbsup:

I look forward to seeing more info about the lenses along with pricing. D-bins are tempting...

ibex


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## searchtime (Jul 6, 2008)

Now I know this might sound like a foolish question but would it be possible to run one of these http://www.dealextreme.com/details.dx/sku.12623 using two 18650 batteries wired in parallel?? or would there be a need to regulate the amps??


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## zemike (Sep 3, 2007)

searchtime said:


> Now I know this might sound like a foolish question but would it be possible to run one of these http://www.dealextreme.com/details.dx/sku.12623 using two 18650 batteries wired in parallel?? or would there be a need to regulate the amps??


I think there is no need to regulate the amps. Or to be safe use a cheap regulator from Kaidomain


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## dazzat3 (May 4, 2008)

theoneonhi said:


> I have 1000 Sekonix narrow lenses, 1000 Sekonix wide clipon filters, and 250 Seoul P7 D-bin (900lm/brightest) LEDs for sale. I had to purchase these high quantities just to get a dozen for prototype. It is impossible to get D-bin emitters in anything less than a reel of 250. I was lucky enough to get the lenses from Sekonix as there are no US distributors currently. According to the sales guy in Korea, I am the only guy in the US to have them. Let me know if anybody out there wants to buy some from me. Thx


Hi theoneonhi,

List your Sekonix lenses and P7 D-bin LED's in the classifieds under lighting also list with CPF.... I'm sure you'll have have success selling through these mediums.


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## znomit (Dec 27, 2007)

theoneonhi said:


> I have 1000 Sekonix narrow lenses,...


Beamshots?


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## dazzat3 (May 4, 2008)

Yep....Beam shots, will speak a thousand words....nothing will sell your gear quicker!


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## ajm8127 (Apr 1, 2008)

Just bought a P7 and reflector from DealExtreme. I'm pretty pumped. I've been working on a driver based on the LM3489. I think it should be pretty freakin' bright.


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## Turveyd (Sep 30, 2007)

Wait for the CREE MR-E's might not be as efficent lumen wise, but it puts the light where it's needed so likely makes for a brighter light with better throw.


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## ajm8127 (Apr 1, 2008)

I mean they both seem to have a multiple dies and outputs around 10 watts. Only difference I can see is the P7s are available now, and things have been really slow at work as of late...


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## Turveyd (Sep 30, 2007)

Bored, is a justifiable excuse for anything 

P7's spread the light over 180degrees, Cree's over 120degrees so the Seoul's aren't suited in torches really, the Seouls put very little forward sadly remove the reflector and nothing going forward, with a CREE you still have the Spill pretty much without a spot, P7 nothing at all.


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## ajm8127 (Apr 1, 2008)

The way I look at it though, there is so much light there, I was thinking about setting the P7 up in a more flood than spot configuration. I figure that would be well suited to the bars. Then, if I require more light, I'll put a spot on my helmet.

I also purchased a reflector specifically for a P7, so that will help I do believe.


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## znomit (Dec 27, 2007)

ajm8127 said:


> I mean they both seem to have a multiple dies and outputs around 10 watts. Only difference I can see is the P7s are available now...


MC-E seems to have a bunch of optics lined up. Ledil, carlco etc. We see a few reflectors for P7... 
You can run it in series too so lower current. Lots more options for drivers as drive voltage 3.6 -> 14.4V. Will be interesting to see comparisons. Haven't seen any good drivers for P7 yet.


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## znomit (Dec 27, 2007)

Turveyd said:


> ...the Seouls put very little forward sadly remove the reflector and nothing going forward, with a CREE you still have the Spill pretty much without a spot, P7 nothing at all.


Thats what makes the SSC best for torches. More light goes to the reflector so you get very good throw.
Though we ride in the spill mainly so Cree better for a bike if you're using reflectors...best option regardless is optics though so you get a nice shaped beam.


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## ajm8127 (Apr 1, 2008)

znomit said:


> Haven't seen any good drivers for P7 yet.


That one of the things that appeals to me about the P7s. I get to make the driver too. National Semiconductor's LM3489 is a nice chip that has both current and voltage regulating capabilities. It also can be Pulse Width Modulation controlled, for a variable dimming effect, from 0 to 100%, and includes a under voltage feature that won't drain you batteries too low. Whats neat is instead of using PWM to dim the LED, you can adjust the current adjustment resistor to vary the current to the LED to get the same effect, although I'm not sure how linear it will be. Time will tell.


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## Turveyd (Sep 30, 2007)

znomit said:


> Thats what makes the SSC best for torches. More light goes to the reflector so you get very good throw.
> Though we ride in the spill mainly so Cree better for a bike if you're using reflectors...best option regardless is optics though so you get a nice shaped beam.


Disagree my R2's with 26.5mm Reflectors out throw the P7 even with a smooth reflector on the P7 and 50mm area reflector.

Hence 2 x R2's using 18650's for good run time, will wait and go MCE when readily available and good torch versions out so December I guess  But run time will drop so maybe just run 4 x R2's  ( Nahhhh 2 is all my neck can take )


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## searchtime (Jul 6, 2008)

Now here comes the age old question from someone that knows very little,

1 - Which LED (at this point in LED evolution) is the brightest?
2 - Are optics better than reflectors or is it the other way?
3 - What are the advantages of optics over reflectors (or reflectors over optics)?
4 - I like riding with a powerful spot will two SSC P4s with a 8deg optics achieve this?

Now back to the heart of this thread,

1 - Is there another company producing an LED similar to the P7?
2 - What are the best amps and volts to run a P7?
3 - Without a driver will an LED pull to many amps or do they self regulate?


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## znomit (Dec 27, 2007)

searchtime said:


> Now here comes the age old question from someone that knows very little,
> 
> 1 - Which LED (at this point in LED evolution) is the brightest?
> 2 - Are optics better than reflectors or is it the other way?
> ...


No simple answers really but here you go anyway
1 Osram Ostar = most light. Cree XR-E R2 best efficiency. SSC P7 in between. 
2 They are different.
3 Optics have a smoother beam.
4 Yes

1 In a month or two MC-E from cree will be out. Supposedly better than P7
2 Rated 2.8A, normal single led V around 3.6 volts
3 Generally a bad idea to direct drive LEDs off batteries.


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## znomit (Dec 27, 2007)

Turveyd said:


> Disagree my R2's with 26.5mm Reflectors out throw the P7 even with a smooth reflector on the P7 and 50mm area reflector.


Your P7 led die is 4x the size of R2 and half the surface brightness (going by the 400lm estimates from the cheap P7 torch reports). Yes, will be much poorer thrower in this situation, the larger the LED the harder it is to focus into a spot. A SSC P4 however should throw a little better than a cree XR-E.
If you wan't really good throw get an aspheric lens.


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## ajm8127 (Apr 1, 2008)

Simple way to limit current to an LED is with a Resistor. Use Ohms law:

Voltage (volts) = Resistance (ohms) x Current (amps)

So if you have 6 volts, and you want to drive a P7 at 2.8 Amps, you would need a 2.14 Ohms resistor in series with the LED. Since you wont really find a 2.14 Ohm resistor you may have to make some adjustment to your circuit. but the formula below assumes a resistor of perfect value for your application of 6 volts with is totally arbitrary to begin with. Also, also go with a bigger resistor (more ohms) than a smaller one. A three ohm resistor will not burn up your LED but will dim it a little, while a two ohm resistor will brighten your LED but will decrease its lifespan. LEDs usually last very long, and it is practice to over drive them sometimes to achieve more lumens. Since 2.14 is very close to 2.0, it may work here.

Resistance = Volts / Amps
2.14 = 6 / 2.8

Now 2.14 is a very low resistance, and there is going to be a lot of current flowing through it so you want to make sure you have to power handling calculated right or you will let all of the magic smoke out of your resistor and possible your expensive LED. Besides ohms, resisters are also rated in power. 

Power (watts) = Current (amps) x Voltage (volts). 

Therefore, your Resister would have to be around 17 watts. (17 ~ 6 x 2.8) Twenty Watts is the next typical size in power resistors. If in doubt, also go with a high power handling. The whole problem with the resistor theory is that all of that power wasted in the resistor is turned to heat, and lost from the system. This is not efficient whatsoever. That is why people use constant current drivers for high output LEDs

I could not find a suitable driver for the P7 LED when I was looking (earlier this week). So I decided to build one. It will deliver a constant 2.8 amps to power one ten watt P7. It is based on the LM3489 chip from national semiconductor. I can let you know how it turns out, I plan on ordering the parts this friday.


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## dojomaster (Aug 24, 2008)

Hi everyone.
what a great post. i learned a lot. thank you.

i have a Question:
her: http://zhangxingming.diytrade.com/sdp/489907/4/pd-2645629/4513460-1298069.html
they have a SSC P7 where the operating voltage is between 5.5v and 15v.

will it mean that if i buy it, i would be able to connect it to an external battery running 11V? (i have a used laptop battery running at 10.8v/5.5Ah - very light)


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## Turveyd (Sep 30, 2007)

I had the single 18650 version of that torch, it's to BIG too HEAVY even without batterys, the lense was trying to be a spot and it really didn't suite a P7 so really don't bother.


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## ajm8127 (Apr 1, 2008)

With an LED you need to drive it at a constant current, 2.8 amps in the case of a P7. The voltage is not as important. I suspect that the 5.5 to 15 volts is an input voltage. So I would think that is you connect a 11 volt battery, everything would be good. The LED driver will take care of delivering a constant 2.8 amps, even as the voltage fluctuates.


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## bikerjay (Sep 16, 2007)

AJM 8127, let us know how building that driver goes. Linear IC's are awsome! They even have a way to fill out and send a sample request online, and deliver quicker than mouser/digikey which charge a lot for shipping.
A while back I was able to assemble a LTC3490 350ma constant current supply with battery protection for 2cell NiMh. I put it into a 2AA maglight with a Cree xre p4 and a fraen 30deg lens. I just rubber band it to my handle bars and its the best commuter light I have ever used. It starts pwm dimming when the voltage reaches .9v/cell and shuts down at .85v/cell to protect my rechargeable battery's. I used a board less point to point layout that is really dense, It makes a driver that is less than 1cm^3.

credit to >> http://cpf.peterbarrette.com/LTC3490/index.html

Mine was a little bigger because I used a high quality coil craft inductor I salvaged from another failed project. Man it was hard soldering together the little surface mount components.

It would be awesome if some one came up with a cheap elegant solution like this for the 3489 even if it was just a simple perf board layout!
I am predicting that when the mc-e becomes available the P7 will be super cheap like the p4 bin cree's. I would be really interested in a higher bin P7 if it were less 15 bucks.


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## ajm8127 (Apr 1, 2008)

Actually, from what I've been seeing, the 3489 is not the best solution. Even though National touts it as a constant current LED driver, it only works alright to drive the P7. The way it limits current is with a 9uS turn off of the FET. I checked it with an oscilloscope and the duty cycle was about 50% at a frequency of about 55 kHz, which caused the FET to get WAY to hot. I put a rather large and ridiculous active heat sink on it, but its just not practical. 

Someone named Mark on this board was telling me about the LM3401 which uses hysteresis to control the current instead of jut turning the FET off for 9uS, which should increase the switching frequency and make it more efficient, forgoing the large heat sink on the FET. I'm going to try and make my own boards for this project because the high switching frequency almost demands a ground plane. We'll see what happens.


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## Baulz (Sep 16, 2005)

I finaly broke down and ordered a P7 and reflector, and am waiting for the sea turtles to deliver them from dealextreme......

So I need to figure out a driver, can I just wire 3 of these in parrallel? It's been a long time since high school electronics. Was thinking I could get a switch in there for a low power setting as well by just using one driver.


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## ajm8127 (Apr 1, 2008)

Yeah that would work. You could have a SPDT switch wired up with a center off that would allow one of the boards to be powered in one position, and all three in another. 

That's four of them for like 7 bucks too. I think thats a pretty good deal. If I wasn't as OCD, I would just go that route, but I'm set on building my own driver. Then use a 555 for PWM dimming...


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## Baulz (Sep 16, 2005)

ajm8127 said:


> Yeah that would work. You could have a SPDT switch wired up with a center off that would allow one of the boards to be powered in one position, and all three in another.
> 
> That's four of them for like 7 bucks too. I think thats a pretty good deal. If I wasn't as OCD, I would just go that route, but I'm set on building my own driver. Then use a 555 for PWM dimming...


Cool, thanks for the help!


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## Turveyd (Sep 30, 2007)

The driver should also keep the voltage at 3.7volts, or vary the Amps to allow for a higher input voltage.


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## Baulz (Sep 16, 2005)

Turveyd said:


> The driver should also keep the voltage at 3.7volts, or vary the Amps to allow for a higher input voltage.


I will be using a 4.8v NiMH battery (4 AA's) or a 7.2v NiMH or a 7.4v Li-Ion.

It's nice to have options, but I worry about the board heating up with the higher voltage battery packs.

What about optics or reflectors? I ordered a huge reflector from dealextreme, but have no idea what kind of beam to expect.


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## bikerjay (Sep 16, 2007)

*constant voltage??*

So, I know you are supposed to used a constant current supply on an LED. However in many instances direct drive, and voltage regulation seem to work. People have used constant voltage supplies with cree led(s) and achieved a reasonably accurate current level because most led(s) will only draw a given amount of current at a given voltage as long as the voltage stays below the thermal run away point. Most led manufactures even publish a curve showing typical vf vs current. I am sure you can see what I am getting at here. Why dosnt some one try using a good off the shelf constant voltage dc/dc converter. Is there really a huge problem with this approach? This thing http://www.recom-international.com/pdf/Innoline-2008/R-7xxxP_D.pdf looks to be up to the task. Particularly the R-733.3x The data sheet shows a +/- 2percent output voltage accuracy.There not 20mm x 20mm small and need some external components but there not huge either. If I read the data sheet correctly it could be programed to a desirable out put voltage around the devices 3.3v nominal output. I guess the big question is if the output voltage remains constant across the 6-8.2v range of a 2 cell Li-Ion battery or even the 12-16.8v range of a 4cell lion. It seems like really the worst case would be a badly flickering output, maybe correctable with a filter capacitor? Would I even be able to see a 1 to 2 percent flicker in output?


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## yetibetty (Dec 24, 2007)

bikerjay, 
I have 2 SSC P4's stuck to a heatsink wired in series and I run them straight off a 7.4v 5200mah battery and have had no probs for a year. 
It has never left the house as it is a test bed for optics and gives me a place to plonk different optics and saves me taking my light apart(the posh one I made with a driver)and fitting new optics only to find that I don't like them. 

The point is that even when the battery is fully charged to 8.4v no harm has ever come to the LED's

So I thought about direct driving a P7 but with a 4 x 18650 cell pack but wired in parallel to give 3.7v 5000ish mah. Should run for quite a while but the problem with direct drive is lack of control (dimming etc.).

I may use it for testing but I always play safe when on a night ride and a light is no use if it goes pop. 

But I may just give it a try one day.

EDIT; I had a look at your link to the driver thingy and the numbers look good with 3.3v and 3amp but I wouldn't know what to do with all of those pins and other "bits" you have to add


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## Cat-man-do (May 16, 2004)

yetibetty said:


> bikerjay, ...I have 2 SSC P4's stuck to a heatsink wired in series and I run them straight off a 7.4v 5200mah battery and have had no probs for a year. ..:


...just wondering..what is the longest time that you ever ran that setup??...did you ever think to measure the current that was being drawn? ( just curious :skep: )


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## yetibetty (Dec 24, 2007)

Cat, 
I've had it running 'till the battery shuts down loads of times, something like 4.5 hours.
I'm always forgetting to turn it off. I use it to see in the shed at night, then come in and remember that it is on after an hour or so, also use it to see when the kitchen bulb blows so that I can cook. But have never measured the current draw.

They are on a very large heatsink, a lot bigger than you would whant hanging off your bike so that helps.

I'll measure the current draw this weekend. 
I may wire 4 SSC P4's in parallel to smulate a P7 and see how that goes, that's if I can get a 3.7v 4400mah somehow.


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## bee (Apr 7, 2008)

yetibetty said:


> So I thought about direct driving a P7 but with a 4 x 18650 cell pack but wired in parallel to give 3.7v 5000ish mah. Should run for quite a while but the problem with direct drive is lack of control (dimming etc.).


Instead of going direct drive with a P7, wouldn't it be easier to just buy a regulated P7 light and then do the modifications you propose? You wouldn't have the problem with dimming. And I was also curious, how do you plan on attaching a 4 x 18650 cell pack to the light? Drill a hole through the back of the flashlight? What about the 4 x 18650 cell pack? How would you house that near the handlebars? Just wondering. It does sound like a good idea.


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## [email protected] (Mar 28, 2007)

Direct drive usually works, even if the voltage from the batteries is a bit higher, because batteries have an internal resistance, they are not pure voltage sources. As you increase the current drawn from them, their output voltage drops. Typically the smaller the battery, the more the drop.

So a voltage regulator may not be a good idea. Especially if the voltage drop across the LED decreases as temperature goes up. As the Vf of the diode drops, when driven from a constant voltage, the current goes up, and eventually your LED goes poof.

A current limited driver, should be a safer way to drive a LED, but it's pretty tricky to design one. If you want to use a voltage regulator as a driver, consider using a small resistor (that can handle several watts) in series with the LED.

Mark


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## yetibetty (Dec 24, 2007)

]Instead of going direct drive with a P7, wouldn't it be easier to just buy a regulated P7 light and then do the modifications you propose? You wouldn't have the problem with dimming. And I was also curious, how do you plan on attaching a 4 x 18650 cell pack to the light? Drill a hole through the back of the flashlight? What about the 4 x 18650 cell pack? How would you house that near the handlebars? Just wondering. It does sound like a good idea.

bee 
The only reason that I'm going to give this a try is simply because I'm curious and the results may be interesting or useful to others.
I don't think I would ride with a direct drive P7 but from what I have read there are very few, if any regulated P7's on the market that actually deliver the full 2.8 amps that the LED can handle.
As for the battery pack it would be exactly the same size as my 7.4v 5200mah just wired differently ( four 18650 2600mah cells) and this size pack fits nicely under the stem.

I'm going to do my test in an hour or so (food comes first) and will post the results soon.


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## yetibetty (Dec 24, 2007)

OK done the test with the 2 x SSC P4s in series running off a 7.4v 4800 mah battery as mentioned earlier and the LED's draw 1.28 amps from the battery.

4 LED's wired parallel to simulate a P7 off a 3.7v 4 cell pack (silly big mah) to follow in a moment.


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## yetibetty (Dec 24, 2007)

Not good, the most I can get into the four is 1.53 amps.
Oh well at least I know now.


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## pbarrette (Sep 1, 2008)

Hi Bikerjay,

If you build the LTC3490 circuit again, you may want to check Digikey for the Toko A920CY 3.3uH inductors, which is what you see in my photos. They have a very low ESR, a low profile, and are shielded to keep magnetic inductive effects down since the "board" doesn't have a proper ground plane.

Also, I hope you saw my build instructions page, which details the dead-bug assembly process step by step:
http://cpf.peterbarrette.com/LTC3490/Build-Instructions/index.html

pb


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## Cat-man-do (May 16, 2004)

> *bikerjay wrote:*..So, I know you are supposed to used a constant current supply on an LED. However in many instances direct drive, and voltage regulation seem to work. People have used constant voltage supplies with cree led(s) and achieved a reasonably accurate current level because most led(s) will only draw a given amount of current at a given voltage as long as the voltage stays below the thermal run away point...


..in keeping with what bikerjay wrote, I have a similar question. *What would happen if a P-7 had 6volts across the emitter but had the current ( regulated ) and limited to 2A?* I ask this because BatterySpace sells a Li-ion battery that has a 6v regulated output. The current output on this battery is limited to 1A by the regulator. Two of these batteries in parallel would have an output of 2A. That should be good enough to drive a P-7 in the 500-600lm range (?) I suppose you could put a 1.1ohm (4.6 watt) resistor ( or pot ) in series with the P-7 to take some of the voltage drop but what would happen if you didn't ?? I hate the thought of wasting 4.6watts of power. That would definitely cut the run time down. Thoughts.. (??)


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## yetibetty (Dec 24, 2007)

Cat-man-do,
Your dea may work but that is a lot of battery to carry around not to mention the regulators in the battery packs, just for 500-600lm.
May as well use 3x Cree R2, one driver and a 14.8v battery and the same if not more lm.

I just think that these P7's are just to hard to drive to the full unless you know how to make a driver.


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## bee (Apr 7, 2008)

yetibetty said:


> bee
> The only reason that I'm going to give this a try is simply because I'm curious and the results may be interesting or useful to others.
> I don't think I would ride with a direct drive P7 but from what I have read there are very few, if any regulated P7's on the market that actually deliver the full 2.8 amps that the LED can handle.
> As for the battery pack it would be exactly the same size as my 7.4v 5200mah just wired differently ( four 18650 2600mah cells) and this size pack fits nicely under the stem.
> ...


MTE now has an 8 mode P7 flashlight. And it is regulated. So, no more problems with dimming. It's only like $1.50 more than the 5 mode p7 flashlight that DealExtreme is selling.

http://www.dealextreme.com/details.dx/sku.13060


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