Grey kit mod questions

[Tree]

I asked in the Grey kit thread (thanks for the responses), but I figured I'd bring the discussion over here since it is about modding.

Also this can serve as a question and answer thread if others have questions about modding their grey kits. Feel free to use this thread if anyone else has questions about modding their grey kit.

Now I'm somewhat new to modding electronics. I have soldered and pieced together many electronic items, but I've never had to pick the components therefore never had to learn what they do. Now is a good time to learn right!!

Anyhoo, I asked in the Arc thread how to make it brighter regardless of runtime. One answer was to drop the value of the r15 resistor by putting another resistor in parallel with it. What value will get the highest and safest current running to the LED? Please be specific since I am kind of new to all this.

I didn't want to spend more than I paid for the kit to buy a 5w (maybe later

), so sticking with the LS that came with it are there any other ways of safely (and cheaply) turbocharging this Grey Kit?

Also, would the McFlood fit? Any better optics for better throw? Just curious.

Thanks

 

[CM]

Tree,

The safest current running to the LED is with the stock resistor

If you want to overdrive it, the problem will be getting a low value resistor that will fit on top of the original 0.15 Ohm. If you can get low value resistors like 1.2 ohms, three of them stacked on top of the 0.15 ohm will drive the LED at 458mA which is probably safe since the Arc head has good thermal management. Or, if you can cannibalize the other circuit board (you did get two in the kit didn't you?) you can steal the resistor off that and stack it on top of the other one for a whopping 667mA! Still not outrageous compared to others who have overclocked their LED's to an amp or more. Of course, you will severely shorten it's life.

Why don't you tell us what value resistors you can get and we'll (I'll) tell you what kind of LED drive options you have.

The McFlood I believe is for flood, not throw. Sounds like you're after the WOW factor so it may not be for you. If a bright flood is what you're after, the McFlood would fit in place I believe.

 

[CM]

...deleted, duplicate post

 

[monanza]

Before you turbo-charge your kit put it together and check the color. The LED on my kit had a blue spot so decreasing the sense resistor (increasing the current) would only make it bluer/more violet. If you have a 'greenie' LS or you are OK with the colors whatever they may be then you can try:

1. 500 mA requires a 0.30 ohm resistor in parallel with the 0.15 ohm resistor (R15).
2. 400 mA requires a 0.7 ohm in parallel with the R15. The closest from the digikey catalog is 0.68 ohm type RL1220 on page 710.

The above numbers are based on a rated current of 330mA (Arc boards using R15 at 0.15 ohm).

Cheers.

PS Someone jump in and correct me if I made a mistake.

 

[Tree]

Good point, I should just make sure everything works properly (when I get the diode) before I go putzing around.

Ok, some more questions.

A resistor is a resistor right? If I find any resistor as long as it fits and it's the correct value I'm OK? What about just replacing the r15 with some other resistor all together.

Would stacking the two r15's with everything else the same power a 5w? Does the NX05 collimator fit the 5w Ls?

What kind of life would the 1w have at 600+ma? Waynes Badboy 500 is 500ma right? Is 667ma too much?

The McFlood was going to be for the stock grey kit since everyone seems to say it's better for utility use.

 

[Tree]

Oh and another question. Would giving a 5w and a 1w the same current (like 667ma for example)be the same brightness? Would the 5w just live longer?

 

[yclo]

Wayne's magic automatically adjusts for the required voltage level of the particular emitter it is connected to, regardless of the led's Vf.

Lets have a look at the specs of the 5W and 1W:
5W @ 7.2v and 700ma
1W @ 3.6v and 350ma

This means that to drive the LS at the rated current level, the voltage will need to be at the rated level too.

Even if overdriving a 1W to 700ma, might only push it up to 4.0v, still using less power than the 5W.

Hope this makes sense, I think...

YMMV with the Vf of the led though.

-YC

 

[monanza]

It is not a good idea to stack another R15 for driving a 5W unless you have a 2x123 tail pack. Actually it will likely not work with a 1x123 pack (there is a limit on input current which translates to a limit on output current or input voltage). I would recommend a maximum of 500mA for a 1x123 and preferably 400mA for around 2.75W of output from a 5W LS.

By the way you do not have to stack the resistors. Another CPF member confirmed that the two solder points adjacent to the R15 are electrically parallel to it so if you get an SMT resistor you can just lay it there and apply some heat and voila.

Any resistor should work as long as it has the right power rating. If you are pushing the limits though it is a good idea to use a precision resistor (1%). Other more experienced members can advise you better than me.

Cheers.

 

[Entropy]

I would keep it at 330 mA (The stock setting) if trying to drive a 5W LS from a 1x123 tail pack.

A 5W LS will be twice as bright as a 1W at the same current. The 5W is constructed using 4 1W dies in a 2 series 2 parallel config. This doubles the Vf of the diode (the 2 series part) and doubles the current handling capacity (The 2 parallel part)

 

[BeamChucker]

Can someone recommend a particular Schottky for me so that I can run my Grey kit with a 3.6 LiIon rechargeable? I've gotten some feedback so far but it would be helpful if someone could be more specific. Or will it be ok with a 3.6V LiIon and I don't even need to worry about it? I think 3.6V LiIons are charged normally to about 4.2V and discharge to about 2.5V. Thanks for any help you can provide.

StreamChucker

 

[Doug S]

Originally posted by StreamChucker:
Can someone recommend a particular Schottky for me so that I can run my Grey kit with a 3.6 LiIon rechargeable? I've gotten some feedback so far but it would be helpful if someone could be more specific. Or will it be ok with a 3.6V LiIon and I don't even need to worry about it? I think 3.6V LiIons are charged normally to about 4.2V and discharge to about 2.5V. Thanks for any help you can provide.

StreamChucker

<font size="2" face="Verdana, Arial">This circuit is not really suitable for driving a 1W luxeon with a Li-ion. You *might* get away with it if you can find a luxeon with an abnormally high Vf. If using a li-ion cell you would do better with simple resistive current limiting. Note that this circuit is capable of destructively overdischarging a li-ion cell so you would need to add circuitry for low voltage cutoff.

 

[CM]

Originally posted by Entropy:
...A 5W LS will be twice as bright as a 1W at the same current. The 5W is constructed using 4 1W dies in a 2 series 2 parallel config. This doubles the Vf of the diode (the 2 series part) and doubles the current handling capacity (The 2 parallel part)

<font size="2" face="Verdana, Arial">Correct, if and only if the diodes are from the same die. In practice though, you probably will get about twice the total light output but the light distribution will be different, giving a different perceived brightness level. The 5W LS does not project the beam as well as a 1W high dome, you tend to get beam artifacts due to the layout of the 4 dies on the substrate. I prefer the 1W high dome for throw, and a 5W for flood.

If driving a 5W from a 1x123, I agree that the stock resistor is preferred since decreasing it will tend to increase the load on one cell to make the whole setup an inefficient mess.

CM

 

[dat2zip]

OK, I have an idea for the grey kit. A small mod that would turn make the circuit work differently.

I'm now wondering if I should post it.

I'm having a difficult time twisting my arm to release this publicly. It is rather proprietary in nature and... well, you know what I mean.

Wayne

 

[CiTY]

Wayne,
If it also benefits you, why not?
After all, you are the "father" of the these circuits...

Would you rather have us torture your boards?

 

[shiftd]

Also, you have the (unwritten) copyright of your boards, are you not, Wayne?

 

[CM]

Originally posted by dat2zip:
OK, I have an idea for the grey kit. A small mod that would turn make the circuit work differently.

I'm now wondering if I should post it.

I'm having a difficult time twisting my arm to release this publicly. It is rather proprietary in nature and... well, you know what I mean.

Wayne

<font size="2" face="Verdana, Arial">Waaaayne, you're teasing here!

Come on, spill the beans.

 

[BeamChucker]

Wayne, you're cruel. Well, just for that, I know how to create world peace and I'm not gonna tell either.

StreamChucker

 

[ab]

Wayne, I can see how you'd be reluctant to release this in public. How about in private - may I send you an email to inquire?

Thanks,

A.

 

[dat2zip]

Those who wish to know and want to send me a PM or an email.

Not on this or any other public forum.

Right now I'm in negotiations on a major contract for another one of my designs and this would compromise my position. I'm sure most of you will understand.

That said, send me a pm.

Wayne

 

[dat2zip]

OK, Let me just say this. Don't do the mod just for the heck of it. It will decrease efficiency dramatically.

Unless, you have the specific needs as listed below, contact me. Otherwise, use the grey kit as is.

Q: Do you have a requirement to install a low Vf Luxeon like the Amber or Red Luxeon emitter?

Q: Will you be running the head off a different power pack? Like a 2X123 or 4AA or a LiION?

If you didn't nod you head violently up and down to either one of the two questions, you need not bother with the mod.