Zebra H30: surgery was successful, but the patient died [UPDATE: Patient #2 LIVES!]

[LLCoolBeans]

Alright! Good work! Nice pictorial as well.

 

[Barrie]

well done:thumbsup:

 

[jdriller]

Wow!

 

[John_Galt]

BEAMSHOTS!!! Good job, man.

This lends me to ask a total newb question... Are red high power LED's more efficient than white high power LED's? As in lumens/watt? Or is that only right for 5 mm LED's?

 

[ambientmind]

woo hoo! good job! not being able to do emitter swaps was seriously holding me back from these...thanks for showing us how!

 

[gunga]

Yes, now, has anyone done an H50?!

 

[kevinm]

While you guys are taking stuff apart...you can direct drive an MC-E with a single lithium ion. That's how I have my Sgt Burkett set up. BRIGHT! So, who's feeling like setting his head on fire?:tinfoil:

Kevin

 

[DonShock]

BEAMSHOTS!!! ........

Here ya go:

Low Med High

Light was placed 4 feet from wall.
Camera at about 8 feet and off to left side slightly. That's why the hot spot doesn't appear centered.
Camera adjusted to approximate color and brightness seen by eye.

 

[Shorty66]

Thats no hotspot, its a reflection.

 

[Yoda4561]

BEAMSHOTS!!! Good job, man.

This lends me to ask a total newb question... Are red high power LED's more efficient than white high power LED's? As in lumens/watt? Or is that only right for 5 mm LED's?

Lumens/watt is deceptive for monochrome LEDs. The short answer is yes, red leds are far less efficient in lumens/watt than a similar white LED. Lumens are calibrated according to our eye's sensitivity, so an equivalent amount of red light will have fewer lumens than a lower amount of yellow/green/white light. Not quite sure how or why since I find *ed: red * LEDs to be extremely bright looking, maybe they constrict the pupil less than blue light? It's also why the brightest blue LED die (the foundation of a white LED) have higher lumen/watt with the white phosphor applied, even though it's certainly blocking some of the light coming off the blue die.

 

[Shorty66]

Well, there is an easy answer to the question of effiency:
The luminosity function.

Lumens are the same as steradiant by candela.
Candelas depend on the wavelenght of light with the luminosity function.
That means, that a LED with a wavelanght of 555nm is the most energie efficient as seen in the black curve of this wikipedia image:

To get the efficiency of a red led, just get the value of the black curve at about 620nm wavelenght which should be around 0.5-0.6. That means, that a red LED is about half as efficient as a green one.

Now what to calcutlate for a white one?
You would have to know the spektrum of the white LED to accomplish this. White LEDs to not emmit light of only one wavelenght but several wavelenghts bacause there is no such thing as a white color. White is a mixture of all colors. To get a white LED we will have to emmit many different wavelenghts in succession. The reason why white LEDs are still more energy efficient than other light sources is, that only visible wavelenghts are emitted and certain wavelenghts are left out as they are not so badly needed to give the impression of white light.

As we do not know the spectrum of white LEDs (at least i dont), we have to believe the manufacturers rating in terms of efficiency.

 

[gunga]

Hey Bean...

Did you have to re-add some potting compound on re-assembly? Is the light still water proof (ish) after the mod?

 

[Daekar]

Yes, now, has anyone done an H50?!

I attempted to, but the construction is such that, after you manage to break the threadlocker on the head, the only thing you're left with is a tube with one closed end and one with nothing but a flat PCB to work with. I used a very fine blade to scrape out the material between the housing and the PCB, but the only thing I succeeded in doing is breaking electrical contact between the PCB and the housing... I couldn't move the PCB because there was nothing to gain purchase with. I toyed with the idea of a solder-blob and wire to pull with, but something told me that was a bad idea. It turns out that a tiny bit of solder melted to seam between the PCB and housing fixed the contact problem I created, but I can't see further disassembly going well. Here's hoping somebody will prove me wrong! :duh2:

 

[LLCoolBeans]

I attempted to, but the construction is such that, after you manage to break the threadlocker on the head, the only thing you're left with is a tube with one closed end and one with nothing but a flat PCB to work with. I used a very fine blade to scrape out the material between the housing and the PCB, but the only thing I succeeded in doing is breaking electrical contact between the PCB and the housing... I couldn't move the PCB because there was nothing to gain purchase with. I toyed with the idea of a solder-blob and wire to pull with, but something told me that was a bad idea. It turns out that a tiny bit of solder melted to seam between the PCB and housing fixed the contact problem I created, but I can't see further disassembly going well. Here's hoping somebody will prove me wrong! :duh2:

You can't push the PCB out the battery tube?

 

[Daekar]

You can't push the PCB out the battery tube?

At that point of disassembly, the head is separate from the battery tube. I would have to pull the board out, rather than push it.

 

[gunga]

So bean... DId you have to repot the led in the H30 mod? Is it still waterproof?

 

[LLCoolBeans]

So bean... DId you have to repot the led in the H30 mod? Is it still waterproof?

It would be, but I have not yet found a silicone based thermal encapsulant to replace the stock gray goo, mostly because I've been busy and haven't been looking. If one were to replace the factory goo with such a product, it would be just as waterproof as before.

 

[gunga]

So in your current mod, it is not re-potted.

Is there any kind of seal between the lense and the body? If not, I guess any mod would render the light a lot less waterproof if unpotted. Is this correct?


BTW, I still think that's a fantastic job on the mods.

 

[LLCoolBeans]

So in your current mod, it is not re-potted.

Is there any kind of seal between the lense and the body? If not, I guess any mod would render the light a lot less waterproof if unpotted. Is this correct

Sort of.

It wouldn't really need to be repotted, I'm sure you could get away with a little dab of silicone sealant around the lens before reassembly.

I just want to use the encapsulant to make it as close to stock as possible.

 

[gprefix]

For what it is worth I asked Zebralights about the gray thermal compound and the possibility of modding H501 for red Cree. Here is the response:

-- begin --

The grey stuff is a Dow Corning two part thermal conductive material. It's not easy to handle other
than a production environment. You might try those thermanl stuff for computer CPUs. A Cree red
LED will work in an H30 circuit, but won't work in the H501 circuit. I don't know much about the
circuit but I was told by our engineers that they had to add something else to make a red LED work
in an H501.

Best regards,

Lillian Xu
ZebraLight

-- end --