Kudos to Fenix on the L0D Q4 holiday special edition light

[Wolf]

+1 about the holiday fenix logo not really being a deal breaker, I got mine last week and the copper color has grown on me and bells/bow dont really stick out much. Heck I knew it was a 1xAAA light when I ordered it and was still surprised at how small the thing is when I got it in...

 

[GBone]

+1 about the holiday fenix logo not really being a deal breaker, I got mine last week and the copper color has grown on me and bells/bow dont really stick out much. Heck I knew it was a 1xAAA light when I ordered it and was still surprised at how small the thing is when I got it in...

here! here! I agree 100% :twothumbs

 

[moses]

I actually like the Christmas logo....

 

[Marduke]

Christmas logo? What Christmas logo???

 

[PAB]

I figured out a use for those stupid little bar code tags that some stores hand out. They work great as spacers to keep the light on your keychain from being scratched up. I've had my light on my keychain since the 23rd of November and I still don't have a scratch on it. Wish I had thought of it earlier. I had a good sized SKA on my keychain and it really beat up my last light.

 

[swxb12]

Christmas logo? What Christmas logo???

If you look at it, you can only think xmas. Close enough.

 

[Luminescent]

If you look at it, you can only think xmas. Close enough.

Actually I would rearrange that statement a bit to say;

If you look at it close enough, you can only think xmas (because we are talking about tiny symbols the size of newsprint, and you do have to look pretty closely to even see them).

The 'Christmas Logo' consists of very tiny font sized symbols at either end of the normal "Fenix L0D" logo, a tiny snowflake and ribbon on the left and a tiny snowflake and bell on the right.

In forty years when you show this little jewel to your great grand children, the red color and those tiny marks will help you remember that you and your trusted little friend first got aquainted way back in Dec '07 ("Or was it '06? Grandpaw has such a bad memory these, days ... Here pull my finger") :hahaha:

 

[Ice]

Well, isn't Christmas the time when the "Living Light came into our world" anyway?! :twothumbs

 

[Luminescent]

I created this image to illustrate a point about how much better a cutting edge LED light is than an incandescent in another thread, but I thought that folks who have picked up an L0D-Q4 special edition light (or or thinking about it) might be interested –

Runtime for the big D-Cell Mags is just over an hour to 50% with output dropping from the first minute.

The L0D can do more output right from the start and then keep doing it for an hour and twenty minutes on a single L92 Lithium AAA cell with almost no light falloff, and will also run on a single AAA NiMH cell if you want to run rechargables, with a good hour of runtime.

Mag 4 D-Cell weight with batteries is about 2.2 pounds (1Kg)

L0D-Q4 weight with one L92 Lithium cell is less than 1 ounce (22.1 grams)

 

[thwang99]

Luminescent, thanks you for your very informative post. I have been running L0Ds on 10440 on and off, and had decent success. 3 out of 4 were fine, but 2 tended to flicker on low mode for some odd reason. One flickered on low, then died eventually.

After reading your post, I see your logic on low mode not protecting the light. I think I will switch back to nimh full time. I don't get the blinding brightness, but I get a long running low mode back and I don't have to worry about killing my battery all the time.

I'll save the 10440s for a light designed to handle them (LF2, maybe new Lumapower) or just skip it.

Great info, makes sense.

:thumbsup:

Would it be possible guys to take out the spring, and put some sort of resistive element there? Even just 0.1 ohms of resistance should help protect the LED, and you wouldn't lose much brightness, or must efficiency, since the voltage is so low, right?

- Tony

 

[Luminescent]

Would it be possible guys to take out the spring, and put some sort of resistive element there? Even just 0.1 ohms of resistance should help protect the LED, and you wouldn't lose much brightness, or must efficiency, since the voltage is so low, right?

- Tony

I have thought of the same thing.

You could tinker with the resistor values to get 400 or 500 mA of drive max.

A major change in 10440 Lithium cell chemistry or brand might require you to recheck the current and tweak the resistor values, but it would definitely be more stable during day to day operation and would give some way to compensate for the variable Vf of the Q4.

A pair of 1/8 watt SMT resistors could be embedded into a small circular piece of standard thickness 0.062 inch FR4 double sided PCB material, which would be cut with small rectangular openings to allow the two 1/8 SMT resistors to be embedded inside the board with one side of each resistor soldered to the top side copper foil and the other side soldered to the bottom side copper foil.

The resistors would be selected to have slightly less thickness than the PCB material (which should be true for most 1/8 Watt SMT resistors), and would be mounted at a slight angle in the cutout opening so one end of the resistor is flush with the upper surface and the other end is flush with the lower surface. This angled mounting arrangement would help keep the side of each resistor that is not connected to it's respective layer from shorting to the unwanted side.

I think such a tiny disk would easily fit under the tail spring, though you might need to trim a turn or so off the spring so it's not as tight.

The disk could also simply be dropped into the top side head between the top of the battery and the bottom of the driver board. A small solder bump could be added to the side of the disk which contacts the underside of the driver to insure good contact.

The top position would be better for day to day swapping between battery types, but the bottom position would be simpler for full time use of 10440's and would give the resistor disk good heatsinking into the body of the light at the bottom of tube where there is not much going on to create heat which would even out the temperature distribution much better.

To cut the current to the Q4 down to a more reasonable level the resistors would only have to dissipate less than 1/4 watt, but even this small amount of heat coupled right on the top post of the battery might make the 10440's thermal protect trip early, so the position under the tail spring is by far the safest bet.

Personally, I would love to work all this out in more detail and post some pics, but I am quite pleased with the light level my little L0D-Q4 puts out on plain old NiMH cells and really impressed with the way it works on L92 Lithium cells, so I don't really plan to run 10440's any time soon. Sorry.

With Slightly dimmed down 10440's you would still probably be looking at less than 1/4 to 1/6 the runtime of L92 lithium cells and one of the things that attracted me to the L0D was it's 'best in class' efficiency and runtime.

Take a look at this image again.

Now keep in mind that this comparison was based on actual measurements reported at FlashlightReviews.com with normal NiMH and L92 type batteries.

Do you really need more light than a 4 D-Cell Maglight?

 

[tsask]

Anyone know if the LOD Q4 will be available in other colors, or any rumors of a Q5 version?

That's what I would need to hear.

My Q5 P1D CREE blows away my SSC lights. a Q5 in the L0D could be impressive.I would want black, not the red, or if custom colors are an option what about navy blue?

 

[Ice]

Well, I recently got my L0D Q4 and like it, but I compared it to a regular L0D-CE and have to say there is a very small difference if any!
The light colour is much whiter or "bluer" if you want, so it may look a little brighter but I tested the two lights outside and there really was no big difference.
Also the colour of my L0D Q4 is more orange than red. Well, better then pink...
At least I like the christmas logo a lot since I'm a huge Christmas-fan!

P.S.:
I would really prefere a higher PWM frequency over a few percent more light!

 

[Luminescent]

Well, I recently got my L0D Q4 and like it, but I compared it to a regular L0D-CE and have to say there is a very small difference if any!
The light colour is much whiter or "bluer" if you want, so it may look a little brighter but I tested the two lights outside and there really was no big difference.
Also the colour of my L0D Q4 is more orange than red. Well, better then pink...
At least I like the christmas logo a lot since I'm a huge Christmas-fan!

P.S.:
I would really prefere a higher PWM frequency over a few percent more light!

The original L0D-CE was spec'ed at only 50 Lumens where the new L0D-Q4 is spec'ed at 75 Lumens.

This is enough of a difference to definitely be noticeable but it takes something like a 2 to 1 difference before it will really start to look dramatic.

Also the Lumens spec may have been a little on the conservative side on your original L0D-CE as later P4's improved in output, and tended to fall near the top of their bin.

In any case this is one bright little light!

I agree 100% on the PWM frequency. My C-LE uses about 3 times higher frequency, and that does make a difference.

With the L0D I rarely notice the PWM, but with the C-LE I NEVER notice it.

In Europe standard fluorescent lights flicker at about 100Hz just like the L0D (they turn on and off twice in each full 50Hz AC cycle, once on the positive swing and once on the negative swing), but in the U.S.A. this would be 120Hz, which is a just bit higher than the frequency the Fenix L0D-Q4 uses for PWM so I think we are a little less able to tune it out.

I think Fenix felt that they were on solid ground because the 100 Hz they used is higher than even ergonomic computer monitors (that only have to refresh at 75 Hz or higher), but the light output created by the PWM is choppier than a monitor, so you need a higher frequency like 300 to 1000 Hz to make the PWM really unnoticeable.

At first I thought that this would only involve a software change in the lights processor, so was a little miffed that Fenix hasn't made the change to a higher PWM frequency yet.

Now, as an engineer I think that I can see at least one reason that Fenix may be holding off.

I think you can probably blame the 10440 crowd for this situation. You see the L0D was never designed for these cells, but does work after a fashion. Fenix is well aware that this is going on, and may be concerned that the change to a higher PWM frequency would result in much more stress on the PWM chopper MosFet when 10440's are used.

They may have done some testing on this and decided to leave things as they are to avoid problems, with higher failures in the PWM circuit.

The old V1.0 C-LE used a lower PWM frequency which was even more annoying than the L0D, but with the V1.2 and V2.0 versions, now the frequency is much higher, and I find that it is almost completly unnoticeable, but the V1.0 C-LE would work with 10440 cells and the V1.2 and V2.0 will NOT.

Even the slight increase to 300 Hz like the C-LE uses would be a big improvement, and there are small SMT MosFET's available now which should be able to handle this higher frequency even with the higher current of a 10440.

In any case, even if they have to do a little re-engineering on the driver, I hope that Fenix will figure out some way to bump up the PWM frequency by at least a factor of two or three, because this low frequency PWM issue keeps some folks from even considering the L0D, and they are loosing sales as a result of this.

 

[StandardBattery]

Wouldn't it be more likely that they are sticking with 100Hz so that they keep their place on top of the hill as runtime king?

 

[Luminescent]

Wouldn't it be more likely that they are sticking with 100Hz so that they keep their place on top of the hill as runtime king?

You could be right. MosFET's can switch in nanoseconds, so even several thousand Hz PWM should not technically be a problem, but it all depends on how you drive them. Another issue is that when you chop the light drive on and off very quickly the lights boost regulator either has to respond to these changes in load or get gated on and off with the same PWM signal, and some regulator circuits don't stay stable when the load is switched too quickly.

All this technical mumbo-jumbo aside, I agree with you 100 percent about the L0D being the most flexible light out there when it comes to offering both jaw dropping brightness in high and super long runtimes in low.

I don't know a single other AAA light which can do 75 lumens on high and still offer as long a runtime on low, as the L0D.

The Lumapower 'Avenger' could be a contender, but it looks like it already has a few issues, like the light doesn't really come anywhere close to 100 lumens, and some have already reported having trouble with the two position twisty level switch.

Have to wait and see how that all turns out, but with Fenix finally starting to get a little competition in the single AAA category, we may finally be able to see some changes.

Overall, aside from tweaking the PWM frequency and maybe driving the emitter a tad harder in high I wouldn't really change much, because the L0D is a super little light

I would be willing to see the runtime in high go down to 45 minutes to get 100 plus lumens. This wouldn't be too bad a tradeoff, because unlike the Lumapower Avenger the L0D has a very nice MEDIUM mode which comes up by default anyway, and using a higher PWM frequency would make this medium mode and the low mode even nicer.


Also we should mention that this PWM thing shouldn't be much of an issue with the folks who are considering a single mode light because those lights run in the equivelent of the L0D's high mode all the time, and when you put the L0D in it's highest mode there is also NO PWM.

 

[garence]

I second the Kudos to Fenix.

The L0D Q4 is a very good buy, despite the silly bell and bow imprinting. My L0D appears much more like copper than red, which I think looks sharp (although I do like the red too on the L0P--it has that spacecraft anodized aluminum look going for it).

Despite the PWM at the low setting, this light looks clean and bright. The center spot is bright and the spill is usable. I found the UI a little odd at first, but now that I've gotten used to it I like it. This makes a great general purpose EDC. I wouldn't lash it to a keychain though, as the anodizing feels like it will probably scrape off over time. I think I might try some heat shrink tubing on it. Can anyone suggest a good place to get some reasonably priced?

 

[jbviau]

I know a lot of people have hesitated on this light due to its color, so maybe you all will find this interesting:

http://www.amazon.com/dp/B000ZM8CNA/?tag=cpf0b6-20

Yes, a black Q4 L0D-CE! I don't think it's a typo (i.e. that the red color was mistakenly not listed) because you can find this listing for a red one alongside it on Amazon:

http://www.amazon.com/dp/B000UTQ4WO/?tag=cpf0b6-20

Can anyone confirm? I'm finding it hard to resist buying one of these. If it were in olive, I'd pull the trigger for sure.

 

[bourget117]

I know a lot of people have hesitated on this light due to its color, so maybe you all will find this interesting:

http://www.amazon.com/dp/B000ZM8CNA/?tag=cpf0b6-20

Yes, a black Q4 L0D-CE! I don't think it's a typo (i.e. that the red color was mistakenly not listed) because you can find this listing for a red one alongside it on Amazon:

http://www.amazon.com/dp/B000UTQ4WO/?tag=cpf0b6-20

Can anyone confirm? I'm finding it hard to resist buying one of these. If it were in olive, I'd pull the trigger for sure.

I think its either a typo or the seller thinks that anyone looking wouldnt know better. I noticed this myself a few days ago and thought that it was exactly what im looking for. I want the 75 lumens but in black, not red. I emailed the seller and have yet to hear back from him. Also when you go to his storefront(its not directly coming from Amazon) and click on that light, it brings you to a LOD CE.

 

[Ducati]

DOA!!!!

:thumbsdow

I just received two L0D Q4s via USPS First-Class mail today. I'm very upset and disappointed that one of them does not work. I've tried different batteries and it doesn't turn on. I tried calling them but they're closed for the day. Now I have to go to the post office and ship this thing back to them and then hope that they'll send one back to me. Can they ship one immediately? I bought these lights as gifts and now I'm screwed...

I read somewhere on this forum that Fenix-Store has an active member on this forum. Who is this person?

BTW: these lights are not red (it's not even close) contrary to what the Fenix-Store website states and illustrates. Plus, the color isn't the same between the two that I received. What kind of company is this???