Novatac 120P Pulsing Problem

I have had my 120P for almost a week now. I have 2 HDS lights and can say that like the rest of you I believe this is an improvement on a great design. However, I started to notice that my light will flicker sometimes when changing from one level to the next. It is not consistent which is what is so frustrating. It is most noticeable on the minimum setting. Particularly when I go from maximum to minimum. It is almost like seeing a PWM but much more pronounced. Sometimes it will continue to do this for about ten to 20 seconds and then settles down to a steady output. I tried raising the minimum setting one level and that seems to somewhat minimize the effect. I have also noticed that when going from primary to secondary it seems to hesitate and search for a fraction of a second. Not a true flicker, but still perceptible. I have been searching for a commonality that would create this scenario consistently. Everything from rechargeables to primaries. Custom settings on/off etc. When I called Novatac they told me they were aware that some lights were doing this and could not yet pinpoint the cause. I like the tint on my light and have thus been trying like crazy to get to the root of the problem. Just when I think it won't do it anymore, it proves me wrong. Here is a list of the things I have tried so far. 1)Installed new primary cell. 2)Installed fully charged RCR123 cell. and yes I did reset the light for the different cell types. 3)Turned options on and off. 4)Put De-Oxit Pro Gold on contact points and battery. Frankly I am puzzed. Has anyone else noticed these symptoms in their light????????????

I have 3. basic, T and P. so far I only opened the T version and when i put it on the lowest setting, i also notice the pulsating for few seconds its like a heartbeat. I never thought of anything until i read this. Any input will be appreciated.

I notice a pulse on the lowest programmable setting (not the factory low, but the lowest possible setting). Sometimes it pulses, sometimes it doesn't. To me it isn't something that bothers me. But it is there.

Yes I notice it when going from higher to lower settings. Like it's settling into place. Only lasts for a second at most, and I don't notice it every time, and only when white wall hunting.

That is correct Kromeke. Perhaps I didn't make it clear but I was also referring to the minimum light setting not the factory default setting for this level.

Yeah, my 120P does the same thing. At first I thought I was seeing things. Going from maximum or secondary to minimum there is a pronounced pulsing that lasts for a few seconds. It doesn't do it every time and is not noticeable when switching to levels that are closer together.

I think (please, someone correct me if I'm wrong) it has to do with excess energy being spent so the electronics can function correctly at the lower level. My HDS B42GT light does it. I don't think it's anything to worry about.

I'm not going to let it bother me. I still like the my 120P and will buy another soon.

Griz said:

Yeah, my 120P does the same thing. At first I thought I was seeing things. Going from maximum or secondary to minimum there is a pronounced pulsing that lasts for a few seconds. It doesn't do it every time and is not noticeable when switching to levels that are closer together.

I think (please, someone correct me if I'm wrong) it has to do with excess energy being spent so the electronics can function correctly at the lower level. My HDS B42GT light does it. I don't think it's anything to worry about.

I'm not going to let it bother me. I still like the my 120P and will buy another soon.

Click to expand...

sounds like my experience:shrug:

I get a pretty consistent pulsing on the 7.5 lumen setting. Almost constant, doesn't stop. I have an 120P with an RCR123. If I bump it up or down in brightness it goes away.

I was kind of hoping this was a problem that is unique to my light. From the looks of it this seems to be common. Hopefully Novatac will sort it out and find a simple fix.

Re: Novatac Pulsing Problem

The problem happened on my 120T yesterday after I had removed the battery (to check the voltage with my DMM) and reassembled the unit. At first I thought it might have been due to a loose end cap, so I checked that.:thinking:
Hmm, that wasn't it. I made sure the battery was placed in the correct position with the + end pointing towards the head of the lamp, then re-tightened the end cap.

The light was acting very strange from then on. When I turned the unit on, it would only go to the lowest output. If I tried to change the brightness, it would try to ramp up, then flicker and go back down again.

What was even more disheartening to me, after a few tries, the light simply failed to respond to the switch. There would be nothing at all - the light seemed for all practical purposes "dead".:sick2:

I removed the battery once more (this was the Duracel that shipped with the light) and replaced it with a fully charged RCR123 from AW. For whatever reason, and this might have been chance - the light began to function normally.:twothumbs

For the time being, I am hesitant to do anything with the light and have chose to leave the AW in place.

Here's hoping someone at NOVATAC gets to the bottom of this issue.

Mine flickers as well when dropping from a higher to a lower level.

Should not affect overall operation though.

I noticed this a couple of times with my 120P as well, when switching from a higher level to a lower one. I never noticed it happening when I was actually using the light, just when I was testing it out and observing it.

I haven't noticed this behavior on my unit.


How noticeable is it? Does it happen on NEW batteries? Or a cell which has a little time on it?
My guess is that it has something to do with the calibration of the driver circuit to the emitter. Maybe after the emitter has been run for some time it has "broken in" a bit. The calibration may be slightly off after the emitter has a little burn time on it.
I know that in the past I have noticed that LUXeon emitters would actually increase their output once they were installed and used for a time.
Just a shot in the dark but maybe this effect causes an irregularity in the "calibration" thus the voltage:current ratio may be causing the pulsing.

Maybe emitters should be run for a couple of hours before the calibration work is done on the light.

Just guessing.
Yaesumofo

Mine does this flickering as well...

This issue is kinda turn me off. I have A19 head running Cree P4 with a FluPIC and doesn't show any flickering at all. I hope someone can give a definitive answers on this problem before I pull the trigger to buy this Novatac. Cheers!

Frids

this is stange.i have used my 85p and 120p alot the last five days.and i can honestly say no flicker problems.yet!!! anyway i hope novatac sort it out for you guys.and soon.

My 85P does not seem to have a pulsing problem. I've went from higher to lower settings and left the light on the minimum setting with no pulse or flicker.

yaesumofo said:

I haven't noticed this behavior on my unit.


How noticeable is it? Does it happen on NEW batteries? Or a cell which has a little time on it?
My guess is that it has something to do with the calibration of the driver circuit to the emitter. Maybe after the emitter has been run for some time it has "broken in" a bit. The calibration may be slightly off after the emitter has a little burn time on it.
I know that in the past I have noticed that LUXeon emitters would actually increase their output once they were installed and used for a time.
Just a shot in the dark but maybe this effect causes an irregularity in the "calibration" thus the voltage:current ratio may be causing the pulsing.

Maybe emitters should be run for a couple of hours before the calibration work is done on the light.

Just guessing.
Yaesumofo

Click to expand...

Yaesumofo, I also thought this might be the problem so I ran no less than three cells all the way down in my 120P. I used rechargeable AW RCR123 cells and turned the light on maximum. The light burned for about 50 minutes before it started to step down the output. I then replaced the cell and did it over again. I was hoping this was also a "burn in problem" however that does not seem to be the case. Any other suggestions????? I agree with most of the posts that it really isn't a huge issue but it is annoying.

Mine has the same "problem". Also noticed when cycling throw the levels (click-click-press-hold) when passing the 10 lomens I don't just get a "blink" but it kind of "flickers" gets two quick blinks (that I can see).

Does not bother me, though would be nice if it could be fixed, hope it is only a "firmware update" or some thing like that is required.

I was going to start a thread on this very topic.

Mine pulsates as well on the first few lower settings. It doesn't always do it and sometimes it goes in and out of pulsating mode. The overall effect is very distracting, particularly if you're using the light to read in bed.

I wrote to NovaTac about it and their response was that it's a bit unusual but not necessarily defective. If it persists, I'm supposed to let them know. No explanation was provided as to why it would suddenly cease exhibiting this behavior.

I'll give it a couple more weeks just to see if it magically does stop pulsating, but for the life of me I cannot fathom why it would.