Novatac questions

[manoloco]

After reading in whc´s posts that the performance of novatacs 120p changes (for better output) when changing SSC P4 U bin emitters, i have some doubts:

is it possible that this could fix flickering problems on low light level settings?

and why do they flicker even much more noticeably when the energy cell has less charge?, bad power management in the power supply, on the programming?

of course as read in a lot of other posts the problem is in the software itself, but that answer is very vague, does anyone know exactly what is wrong in the software or on the settings or calibration that makes this happen?

its really bad that such a premium priced light has a bug or a problem that cant be guaranteed to be solved as seen in many responses.

 

[qadsan]

All the Novatacs made for the last few months should already be SSC P4 U bins from what I understand. You can verify this by calling Novatac.

We have 14 Novatac 120P's in our group. We would have had a lot more in use, but most of them ended up being sold off instead of being used due various circumstances. None of these 14 lights have this flicker issue. I know it's a real issue, but not all the flickering being experienced may be happening for the same reasons. For instance, on a couple of the lights that I've seen with flicker at low levels, their flickering problem was caused by the tail cap not being properly seated due to the way the clip was installed.

I've watched people install the factory clip and they almost always do so without first removing the o-ring on the threaded tube. When the clip is installed with the o-ring left in place on the threads, the clip mostly fits over the o-ring and appears to seat. But, there's often a tiny bit of o-ring stuck between the inside of the clip and the threads. When the cap is screwed down, this part of the o-ring that's stuck ends up twisting and coming through the other side of the clip and it doesn't allow the cap screw down as far as it could. The giveaway here is that the clip is fairly tight and doesn't spin about the body as easily as it normally would.

The best way to install the factory clip is to pinch / squeeze the o-ring on the threads, which allows you to remove the o-ring without the use of a pick, etc. I start out with my fingers squeezing the threads at opposite sides of the tube. As I work my fingers closer together over the o-ring while squeezing the tube, the o-ring starts to slack and stick out far enough to where I can easily grasp and remove it. With the o-ring removed, the clip easily falls to its seat and then you can install the o-ring. Once the cap is installed, the clip spins about the body much easier than if it were bound up with the o-ring.

From what I've read, I know there is a flicker issue that won't be solved by making sure the cap is screwed down all the way, but this might account for some of the flicker issues out there. I also wanted to note that we've only used our Novatacs with primary cells and maybe this has something to do with why we haven't had any flicker.

If you search CPF for the word flicker, you'll find plenty of threads on different brands & models of lights with this issue and different reasons why this happens.

 

[manoloco]

Hi Qasdan!, thanks for the response.

I havent used the clip at all, used different types of energy cells: primaries, li primaries,aw li ion rechargables, the flicker is with all of them

I think the issue is more common than what it seems, since novatac has already responded and recognized this is a software issue and that they dont guarantee a non flickering light in return, as such statement, its obvious they have a high percentage of lights with this problem or the software isnt reliable at all on this matter.

I love how the light is built, the interface, the ergonomics and size, the versatility, the output (from very low to very high)

the issue seems to be a bug, and there shouldnt be bugs on premium lights, in the very least, responsable parties should be able guarantee a free of problems light free of charge.

i think i will have to send mine for an exchange, but believe me i really like the light, its very useful, but flawed, and there are times like when reading or looking at a map or plans in low light levels, where the flickering totally obliterates the light usefulness.

also if you havent tried, use the light for a couple of minutes on high at 120 lumen then go directly to its minimum output level: 0.08 lumen, if you are using the factory defaults (0.33 lumen low) you wont see flickering, but then again, its more than 4 times the output i want on low.

 

[qadsan]

Is it the same flicker as reported about the HDS lights in threads such as these?

http://www.candlepowerforums.com/vb/showthread.php?t=90536

http://www.candlepowerforums.com/vb/showthread.php?t=89110



I also noticed this quote from the HDS user manual...

"Note: you may notice a slight flicker on the very low brightness levels. This is normal."

http://www.hdssystems.com/Legacy/XEdcUltimateUsersGuide.pdf

Are these the same issues between the HDS and Novatac lights that you're experiencing?

 

[manoloco]

Is it the same flicker as reported about the HDS lights in threads such as these?

http://www.candlepowerforums.com/vb/showthread.php?t=90536

http://www.candlepowerforums.com/vb/showthread.php?t=89110



I also noticed this quote from the HDS user manual...

"Note: you may notice a slight flicker on the very low brightness levels. This is normal."

http://www.hdssystems.com/Legacy/XEdcUltimateUsersGuide.pdf

Are these the same issues between the HDS and Novatac lights that you're experiencing?

i can only guess, since i cant see the problems they have first hand, but based on the description, some of the posters have similar symptoms than my novatac, cant tell you for sure its the same thing.

which brings me to this:

HDS did mention the flicker in the manual, Novatac doesnt.

HDS used a Luxeon III emitter, which is far hotter to run and less efficient compared to a U-bin SSC P4, by logic thermal or driving issues should be less concern (as discussed in those threads)

altough from what it seems, the flaws are inherited since HDS EDC times.

i had already thought about some of this info which i read before, and thats why i came to the questions i posted first:

regarding the possible reasons for the flicker, one of them is the efficiency of the emitter, maybe some lights are not correctly calibrated, or not correctly configured, maybe a more efficient emitter could fix this?

of course im only assuming this from the data i could read, its in no account an stated fact, i just want to have a light that works well with no flaws, thats all, and if the company cant guarantee me that, i thought maybe i can look for info of others who have tried to fix this, if there wasnt any or if i couldnt find a fix, i will try novatac service, to see if i am lucky to get a light working like the one i have now (which i really like, and like to use, more than my other lights) but without the flicker, something they dont guarantee will happen as stated on their responses.

this may sound picky but it really isnt specially since one of the reasons i bought this light, is the 0.08 lumen level

 

[matrixshaman]

Does this only happen at the 0.08 lumen level? I'm aware this has been an issue with some of the lights. But if it's only at the .08 level I'm going to take a guess at the problem. That's an extremely low level - in fact I'm not sure what it's useful for but I guess everyone may have different needs. The first thing I did with my Novatac was to set it up to about the 4th level up from lowest as my 'Lowest' triple click level. I did this while in an underground completely light tight setting where I couldn't even see my hand in front of my face without a flashlight. To me this 4th level up seemed just right as a minimum level for my eyes. I've never experienced the flicker problem with mine but if it's only happening from high to the .08 level then it may be that I've never used it that way.
I'm going to guess that the LED trigger voltage or current on these varies from one LED to the next and that it may be so close to not being enough at that low level that either the LED fires and then goes off because the startup drops the input V just enough that it lowers and then this whole pattern loops thus making the flicker OR it is something similar in the circuit responding to the LED initializing. I know this may be a bit vague but what I would conclude from this assumption is that changing out the LED might fix the problem if you are lucky and if you get a SSC P4 with a low Vf. This is all a guess so I'm not saying to run out and get another LED and go through a lot of trouble to put it in there just based on what I'm saying. The other half of my guess is that it could the the circuit side that is the problem so a different LED may do nothing. I'm putting about 60/40 odds on the LED as a possible fix if you find a good low Vf one though - again this is all based on info from the psychic network :tinfoil:

 

[tebore]

I agree with the above. Most of the HDS' flickering at low level can be fixed by getting a low Vf LED.

This was proven when people started replacing the Lux 3 with SSCs. High Vf LEDs would flicker and switching to a low Vf LED would stop the flickering.

I can understand why the HDS flickered the Lux 3 was driven hard and the light's engine was able to take a larger input Voltage range. Top bin Lux 3s were expensive and rare. It was bleeding edge. The SSC is cheaper than that Lux 3 low vfs aren't as rare. The light engine also can't take as wide input voltage. Not to mention years more refinement was allowed.

Why does the Novatac still flicker?

 

[manoloco]

Looks like we are sharing a logic here, and Tebore has already upgraded many HDS EDCs, so theres only one way left to see if this works, and that is for someone to try this with a flickering Novatac 120p, i would but i cant afford to waste my light experimenting, specially since i used the limit of my budget for such purchases when i bought the Nova.

Maybe someone has already tried this before? Milky might have seen results of this since he has modded many Novatacs.

Matrixshaman: i have seen it happen, coincidentially in the lower 3 levels, if you want to try and see if yours has it try using a 120 lumen setting for a couple of minutes, and then go directly to 0.08 lumens if it doesnt happen instantly it might happen in a minute, for a more noticeable flicker use cells that are not full but have a reasonable charge, but it does happen sometimes with a full cell.

Tebore: my guess for the flickering Novatacs is that they cant afford the quality control needed to calibrate individual emitters, so they must have generic ranges to use with them, hence the fact that they cant guarantee that you will have a perfect one. the perfect HDS EDC or Novatac would be one that adjusts to the led throughout its life. Now theres something to support what i say but doesnt make it a fact, i rememer from your mod thread that Milky said there was room for improvement on output and efficiency on SSC P4 emitters since they werent at its best when new, they needed to be primed with use. That would explain why some Novatacs fix themselves whithout apparent reason, like i have read from other posts, however mine as many others havent "fixed" theirselves.

Lets hope someone can give us more info, this is getting interesting...

Henry must have surely taken care of this in his next designs, will be great to see his products evolve.

 

[nMotion96]

Is it the same flicker as reported about the HDS lights in threads such as these?

http://www.candlepowerforums.com/vb/showthread.php?t=90536

http://www.candlepowerforums.com/vb/showthread.php?t=89110



I also noticed this quote from the HDS user manual...

"Note: you may notice a slight flicker on the very low brightness levels. This is normal."

http://www.hdssystems.com/Legacy/XEdcUltimateUsersGuide.pdf

Are these the same issues between the HDS and Novatac lights that you're experiencing?

mine 120p flicker like that when turn on in low, but if you switch to a higher brightness then back the flicker goes away.

 

[manoloco]

nMotion96:

Yes, this does fix mine sometimes as far as testing goes, but in real use its no good as it ruins my night vision, and also if you are on a place that needs privacy you will get complaints for flashing a light (covering it before flashing helps but i guess im not happy beign the "human fix" when the light should do this without my help)

however thats another common symptom to the flickering issue, why does it bothers more when going from a high output to lowest, and why sometimes going from low to high, back to low fixes it?.

 

[HDS_Systems]

Qadsan,

The low serial numbered HDS EDC Ultimate and HDS EDC Basic flashlights did have a slight flicker problem on the very lowest setting - below the default minimum setting. The flicker was actually a slight pulsing at a regular interval due to a bug in the software. That problem was found and fixed early on in the production cycle. The warning was left in the User's Manual because the User's Manual applied to all production variations of the flashlight. The higher serial numbers showed a steady light at the lowest setting.

The behavior this thread was started to discuss is an unstable irregular flickering that has been reported by many owners. The 85P I have (SN > 10,000) exhibits this erratic flickering behavior with both primary and rechargeable batteries. And even the normal turn-on setting will flicker momentarily - which I find very annoying. You would think that a problem like this would have been fixed by now. The fact that lights are sent to customers exhibiting the same problem after a warranty return demonstrates that the problem has not been resolved. I have not seen anything from them to indicate they are working to solve the problem. Have you? Needless to say, I don't use this flashlight.

Having designed uP-base power supplies for some time, and having fixed the EDC Ultimate and Basic flicker problem, I can only comment that the cause of the flickering is probably quite different from what has been suggested by most of the guesses. For instance, the LED can have an influence on how bad the flickering is but is probably not the cause. And the type of battery or the state of charge on a battery can have an influence on how bad the flickering is but is probably not the cause. Although the cause may be very simple, how the cause interacts with other factors can result in a wide range of observed symptoms.

Henry.

 

[manoloco]

Thanks for sharing your thoughts Henry, very informative.

does an ultimate 60 sn #0055 have this flickering problem?, if so, is there a possible fix for it? (i am about to receive this light)

 

[kromeke]

Henry, would you characterize the flicker as what they call "ripple" in DC power supply rectifier circuits? That is my off the cuff guess, not having hooked it up to a o'scope. But I'm no EE, so it's just a guess.

-Keith

 

[HDS_Systems]

Manoloco,

HDS EDC Ultimate 60 serial number 55 will have the pulsing on the lower levels. As I remember, a few hundred lights got shipped before we found and fixed the problem. One of the reasons for picking the default minimum setting was that it did not exhibit the pulsing. The problem was a software bug - not a hardware problem. It was easily fixed once I had identified the true cause of the problem. I have the code but I no longer have the hardware and fixtures needed to download the code and calibrate the flashlight. It is a fairly long and messy process to disassemble the flashlight, clean everything up, reprogram it, calibrate it and then reassemble it.

Kromeke,

The pulsing of the early HDS EDC Ultimate and EDC Basic flashlights (early 2005) was a pulse that happened about every half second or so. It was not like ripple, but more like a quick spike. It was caused by the interaction of two timed events - when the two events collided, it created the pulse. The conditions needed to create the two events only happened at very low power levels. The fix was very simple - just prevent the two events for interacting.

Henry.

 

[manoloco]

Manoloco,

HDS EDC Ultimate 60 serial number 55 will have the pulsing on the lower levels.

Man, i cant catch a break , i guess im not having a perfectly working order premium light for a while, spent quite a bit more than i planned for this, was about to buy another Novatac from the marketplace as a favor for a friend that liked it (he doesnt speak english and asked me to do the buy and he would pay it), but it has the flicker also, so i will recommend him not to do it, maybe he will have more luck than me in the future, its really frustrating specially since i live very far and dont have much money.

Novatac should really put a warning about this issue in its lights, its upsetting and i dont have money to waste, specially when you make efforts to buy stuff.

well at least i hope the thread makes more people aware of this BEFORE they make a mistake.

Henry: thanks for the sincerity about your products, specially for such an old one in your line.

 

[luminata]

Hey Henry,

How about an update in the HDS 120(Twisty) thread ? Seems like your new line of lights will be the best solution to any Novatac woes and many are anxiously waiting for some sign of life out there in that thread:wave::welcome:

 

[gottawearshades]

<irony> I'd like to see Henry respond to this thread http://www.candlepowerforums.com/vb/showthread.php?t=186353
and say whether the Twisty will survive a nuclear war. </irony>

 

[gottawearshades]

What I don't understand about this bug in the NovaTacs is that it is not consistent.

I have two of these lights. One has the bug, one doesn't. I was told that some lights do this, some don't, and there was no way to tell whether a replacement would have the bug.

I thought one good thing abut computers is that they always do the same thing every time, whether it's the right thing or the wrong thing. It must be a quality control problem, it seems to me, which they are unable or unwilling to fix.

Cheers.

 

[redryder]

If a Novatac doesn't have the flickering issue, does anyone know if it will develop it later on? I have an 85P with no flickering. Hopefully it will stay that way.

 

[Bort]

My 120p worked very nicely for a week. It now has sporadic flickering at the lower levels, and sometimes the higher levels when ramping up or down. It is very frustrating for a light at this price. I would not recommend Novatac to anyone.