# P7 reflectors?



## sortafast (Oct 6, 2008)

What options are out there for optics/reflectors for the P7? I have seen the one on DX, but I am looking for something a bit smaller in dia.


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## PsycoBob[Q2] (Oct 8, 2008)

I've got several P7's otw, and I'm looking for small optics too. P7's have a die even bigger than a Lux-V, and a HUGE housing. That housing killed the idea of reusing some of my spare optics, and the die will severely limit the throw with smaller reflectors. 

If anyone finds an optic (reflector, lens, combo) that will give throw similar to Fenix lights that doesn't need a Maglite-size head- please, share!


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## jirik_cz (Oct 8, 2008)

ledil is preparing one http://ledil.fi/datasheets/DataSheet_Boom_p7.pdf


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## Jamesdh266 (Oct 9, 2008)

When will that be out and where can we buy it?


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## PhotonFanatic (Oct 9, 2008)

Khatod is also coming out with a reflector for the P7; I am waiting for a sample. I've also got the Ledil reflector on order, but they haven't made them yet.


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## Nitroz (Oct 9, 2008)

PhotonFanatic said:


> Khatod is also coming out with a reflector for the P7; I am waiting for a sample. I've also got the Ledil reflector on order, but they haven't made them yet.



Will you have these for sale?


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## Jamesdh266 (Oct 9, 2008)

when are you expecting to have stock of either in?


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## sector_cleared (Nov 10, 2008)

Any news here? I got the host already and the LEDs are on the way...only thing missing is a proper reflector :mecry:

I need those LEDILs


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## PhotonFanatic (Nov 10, 2008)

I received the Khatod reflector samples--one is 23mm in diameter, the other is 28mm in diameter. I will try to test them out tomorrow and get some beam shots posted. Delivery is still 2-3 weeks out though.


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## PhotonFanatic (Nov 12, 2008)

Just a quick update on the new Khatod P7 reflectors.

I wired up a P7 on a massive brass heatsink and installed the 28mm diameter reflectorn (smooth surface), which, btw, is just a slip on fit over the black plastic ring, and fired it up. At low amperage, one can just barely see the faint outline of the dies, but by 750mA, they are merged beyond recognition, of course. My wall was about 2' from the LED. Cranking it up to 2.8A and one gets a nice distinct hotspot, fairly large, with still a good amount of sidespill. 

The 23mm reflector was, as one would expect, a lot more floody, so much so that I really don't see why one couldn't just use the LED alone rather than using the 23mm reflector. There was a hotspot, fairly diffuse and there was a lot more sidespill than from the 28mm reflector.

I will be off to buy some white poster board in the next couple of days and will attempt to post beam shots thereafter. 

In the meantime, I like this reflector, i.e., the 28mm, enough that I will be placing an order for them tomorrow. I will also try to order the stippled version at the same time.


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## sector_cleared (Nov 13, 2008)

Thanks for the info PF.

It's a pity that the 23mm reflector is doing such a bad job. My intention is to squeeze 3 P7's in a Mag D head. But 23mm would be to big anyways i guess.

Do you have news regarding the LEDIL Boom-S for the P7?


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## PhotonFanatic (Nov 13, 2008)

It's not that the 23mm reflector is poorly made, it is just the parameters of the light output and the size of the reflector that yields the floody pattern.

Re the Ledil's--I will check once again with the supplier, although they promised to let me know when they could get them from Ledil.


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## CM (Nov 13, 2008)

sector_cleared said:


> ...My intention is to squeeze 3 P7's in a Mag D head.



I think you're getting carried away. One P7 in a Mag D head gets hot pretty fast. A single P7 is about 10W of heat. Three at 30W plus power supply heat in a Mag D just won't cut it unless you plan on using the light for short bursts. It's just not a practical platform.

It's also a challenge to find an *efficient* driver to drive one of them, let alone three. You can get the cheap DX or KD crap but most of them will shut down on you due to inefficiency and heat generated. One P7 is plenty. I built one using a D bin from Photonfanatic and it was measurably brighter than a 10W Welch Allyn Solarc HID.


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## PhotonFanatic (Nov 13, 2008)

Cris,

Great point--I tend to overlook the obvious. :laughing:

Perhaps because I never make any mulit-LED lights. 

What did you use to drive the P7?

I'm thinking of using the D2DIM with a resistor to limit the current--when I eventually do get around to making a P7 light. :naughty:


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## CM (Nov 13, 2008)

PhotonFanatic said:


> Cris,
> 
> Great point--I tend to overlook the obvious. :laughing:
> 
> ...



A TI PTH08T230. It's constant voltage so you need to tweak the sense resistor for the particular LED. With an input of 7.2V, measured efficiency was about 95%


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## sector_cleared (Nov 13, 2008)

CM said:


> I think you're getting carried away. One P7 in a Mag D head gets hot pretty fast. A single P7 is about 10W of heat. Three at 30W plus power supply heat in a Mag D just won't cut it unless you plan on using the light for short bursts. It's just not a practical platform.
> 
> It's also a challenge to find an *efficient* driver to drive one of them, let alone three. You can get the cheap DX or KD crap but most of them will shut down on you due to inefficiency and heat generated. One P7 is plenty. I built one using a D bin from Photonfanatic and it was measurably brighter than a 10W Welch Allyn Solarc HID.



Carried away? Dunno what u r talkin about :santa:
Of course this won't be a light to use for extended periods on the highest setting. I will turn a heatsink with a big mass so I have a big thermal capacity. This should be good for at least 5 mins runtime on maximum.

As driver I will use my selfmade synchronous step down converter with continously variable output current. BTW there is no difference in heat dissipation for the driver if you drive 1 or 3 P7s (assuming that u connect them in serial).

But without the reflectors this won't be possible :mecry:


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## CM (Nov 13, 2008)

sector_cleared said:


> ...BTW there is no difference in heat dissipation for the driver if you drive 1 or 3 P7s (assuming that u connect them in serial)...



Actually there is. If the efficiency is fixed but your load triples in power, the amount of power the driver dissipates will also triple.. Of course you might see some improvement in efficiency but it's not enough to offset the 300% load increase.


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## sector_cleared (Nov 14, 2008)

But the efficiency is not fixed. What is fixed is the voltage drop of your driver at a certain amperage. You have the MOSFET-, Inductor-, path-resistance, sense resistor and other losses (ESR, inductor losses). If you add up all the resistance in the path of the current and multiply it with the current, than you'll get the voltage drop.

For example:

Total resistance: ~100mOhm

Current: 3Amps

Voltage drop: V=R*I=0,1Ohm*3A=0,3V

Power dissipated: P=V*I=0,3V*3A=0,9W

Lets say you drive a Load with 10W you get a efficiency of:

Eff= PLOAD / PIN = 10W / (10W+0,9W) = 91,7%

What is important in this calculation is the fact that the driver's voltage drop is dependend on the ampereage, not on the voltage. Therefore its power dissipation won't change even if you connect 100 P7's (which is not possible due to voltage strength of the capacitor and the MOSFETs).

Ok, enough offtopic... I need those LEDILs


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## Al Combs (Nov 23, 2008)

sector_cleared said:


> My intention is to squeeze 3 P7's in a Mag D head. But 23mm would be to big anyways i guess.



I ran across this thread while looking for something else. The larger circle that contains three smaller ones is 2.1547 times the diameter of the smaller. If the Khatod's are really 23 mm, that's a 49.56 mm housing to contain them. My Mag's reflector housing has a 50 mm I.D. for the first 2¼ mm depth at the very front. Further back, the bulk of housing is ≈ 48.1 mm in diameter.

Depending on the shape of the reflector, it might fit without modification if the housing is turned to bring the reflectors up against the cover glass. At worst, it would only take a little bit of filing to make them fit.:thumbsup:


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## steve6690 (Nov 23, 2008)

Al Combs said:


> I ran across this thread while looking for something else. The larger circle that contains three smaller ones is 2.1547 times the diameter of the smaller. If the Khatod's are really 23 mm, that's a 49.56 mm housing to contain them. My Mag's reflector housing has a 50 mm I.D. for the first 2¼ mm depth at the very front. Further back, the bulk of housing is ≈ 48.1 mm in diameter.
> 
> Depending on the shape of the reflector, it might fit without modification if the housing is turned to bring the reflectors up against the cover glass. At worst, it would only take a little bit of filing to make them fit.:thumbsup:



cheers for that. I couldn't find a formula for this so I ended up working out my own way of figuring out how many reflectors (for example) would fit inside a housing. It's probably wrong of course but this was it...

if A is the ID of your housing
and B is the diameter of your reflector

(A - B) x 3.1416 
take the answer and divide it by B

In my case I had a housing with an ID of 52mm and I had 6 x 18.5 mm diameter reflectors to try and squeeze in.

52 - 18.5 = 33.5
x 3.1416 = 105.2436

divide by 18.5 = 5.688 reflectors that would fit, so it was a no go. I ordered the reflectors anyway and they truly did not fit. Using this "formula" I calculated that I'd need to have reflectors of no more than about 17.8mm diameter to get 6 in the housing. Out came the file....they're all at around 17.6mm dia now and it nice and snugly. The formula makes sense to me but I was never very good at mathematics...


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## Al Combs (Nov 24, 2008)

Figuring out six is the same as seven reflectors (52mm/3=*17.33mm*). If you don't use the seventh reflector, the geometry of the remaining six is still the same. Here is a picture that should help.


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## steve6690 (Nov 24, 2008)

yep, I noticed that if you can fit 6 in, you can fit 7 (1 in the middle)


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## Fog-John (Nov 25, 2008)

Hi all Flashaholics here,my first Post 

Kathod have a new Reflector  with 23 mm Diameter for the P7 Led.
Who can buy this Part?:help:
Fred?
Greetings Fog-Jonny


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## PhotonFanatic (Nov 25, 2008)

The Khatod 28mm P7 reflectors are already on their way to me. Received the tracking info today. 

I will post them for sale in the Dealer's Corner once they arrive. Price will be $5 each, less in multiples of five.

I did not order the 23mm as it did not work any better than the 20mm IMS or Khatod reflectors that are bored out to fit the P7.


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## Fluor (Nov 25, 2008)

Me want some!

Can't i buy them from khatod myself? Incase not, how many did you order Fanatic??

And how can i calculate how many to fit in my 52mm heatsink?


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## PhotonFanatic (Nov 25, 2008)

I have 100 of the smooth ones coming in within the next couple of days. I've also ordered some stippled ones, too.

I don't believe that Khatod sells to individuals, but I really don't know that for sure.

BTW, isn't there a post in this thread about calculating how many reflectors fit in a circle??


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## Fluor (Nov 25, 2008)

PhotonFanatic said:


> BTW, isn't there a post in this thread about calculating how many reflectors fit in a circle??


 
Did't notice that.......Hmm, the 28mm reflectors are too big for my use. Maybe just bore out some then.....


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## PhotonFanatic (Nov 27, 2008)

The smooth Khatod 28mm P7 reflectors are in. Stippled version is on order.


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## K_Labs (Jan 6, 2010)

So is it impossible 2 get a beam from a p7 with a 23mm reflector? The only thing I get is a flood light


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## PhotonFanatic (Jan 6, 2010)

Since the emitting area of the P7 is so large, it's going to be hard to focus the beam well unless you use a very large reflector--like 45mm or so.

The Boom-S works as well as any reflector for the P7, given its small diameter.


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## easilyled (Jan 6, 2010)

I've heard that the P7 works surprisingly well with McR20S reflectors considering their small size.
Obviously the hole in the McR20S need to be enlarged in order for the P7 to fit.

It also works very well in the McR27XR reflector. This reflector as a bonus has a hole which is spot on for the P7. Its almost like it was designed for it even though it was originally designed for the Cree-XRE by McGizmo.
You will get a nice balanced beam which although floody does have a hot-spot too.

The P7 also works well in McR38 reflectors although the hole in these need to be enlarged a little. Again a well balanced beam with a bit more of a hotspot than the McR27XR due to the larger diameter.


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## K_Labs (Jan 7, 2010)

I just bought 4 so will this give me more of a beam?


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