Novatac 120P frustration

I'm now on my 3rd 120P that has a slight pulse when going back down from 120 lumens to secondary 30 lumens, or below. It's a small thing that settles down quickly into a stable beam, but its worrisome nonetheless. I emailed Novatac about it, they said it's normal. The one I have now has a great tint, and otherwise is great. My 85P doesn't do this, nor does my 120E, but the other 120's I've had do. I realize this is a really popular EDC light, have other folks just accepted the pulse? It doesn't make you worry about the circuit?

As you point out, it happens when you drop down to a low low from a high high.
From a practical standpoint, I can't imagine a REAL situation where you would do that because once you've gone to a high high, you've already blown out your night vision so a low low doesn't do you much good.

My 120P only does it when I played with it and went from 120 down to under 5 lumen. But that was playing with it, not actually using it in a practical way.

When I turn mine on at it's 30 lumen main setting and then go to .3 lumen, it doesn't blink at all so it's not a problem for me although it obviously may be for you.

I also notice that when I tromp the pedal to the floor of my '75 Corvette, it breaks traction and loses control to where it will spin enough to almost go off the road.
Since that's not how I normally drive the car, I don't worry about it enough to get bigger tires.

That traction situation does sounds like a problem I'd like to have.
Flashlight wise though, I find it pulses when going from 120 to 30, not just to the low low... I think your logic is probably the right way to look at it though...

I've played with a lot of the NovaTacs and this is normal. Some do, some don't. The issue isn't with the circuit. They typicaly settle down after a bit. Using the light in a practical sense, it has never made a difference to me.

I have one of the first olive sold and a black one. When I put either light in a lightbox to watch the lux numbers when I switch levels, neither one of them fluctuates when going from highest to lowest. When I switch between the higher levels, the numbers jump around a bit then settle down. I cannot see this with my eyes. It seems to me like it's trying to find the correct current and when it finds it, it holds.
I hope that makes sense.

My 120e does this as well and i notice that there is a correlation between this symptom and a weakening primary cell. It's just letting me know that it's almost time to change out the battery.

candlelight001 said:

I'm now on my 3rd 120P that has a slight pulse when going back down from 120 lumens to secondary 30 lumens, or below.

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Is this the 120P that I just sent you last week? If it is, did you do a battery reset/re-detect sequence? I did a battery reset with a AW 3.7v RCR123 and it looked fine except when switching from 120 to 0.3lm. I then did another reset when I put the Surefire 123 in it and checked it before shipping it to you and same thing, it only did a very brief pulse/flicker when going from 120 to 0.3lm. It looked fine when jumping from 120 to 30 and 10lm. Either that or your eyes are more sensitive than mine.

I've only ever seen this when my battery is weakening. About the time that high starts to step down, it gets worse. Like others here, I've never noticed any flicker in actual use.

mine does it on low low sometimes. I reckon its a control loop issue personally. I have had similar problems in a different application where my current transducer response time was slower than the speed at whichthe control could react. slowing the max rate of change got rid of the oscillation. Delays in system feedback causes instabilty.....same reason that when you are drunk......your reactions are slowed by the alcahol in your system.

Stu

RustyKnee said:

.....same reason that when you are drunk......your reactions are slowed by the alcahol in your system.

Stu

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Like yourself, I also find that when I'm drunk with alcahol, my spelling goes to hell.

(Yea, I know, we all hate the spelling Nazis. But you have to admit that you walked right into that one. )

Zenster said:

Like yourself, I also find that when I'm drunk with alcahol, my spelling goes to hell.

(Yea, I know, we all hate the spelling Nazis. But you have to admit that you walked right into that one. )

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:drunk:

I'm a little lost in the feedback loops ;-), but here's what I've got to say:

a) Thanks for the responses!
b) put a new battery in and did a reset, seemed to help
c) clearly I'm obsessing way too much about this. Fact is you gotta really look for it, when not looking, you don't see it...

I would also try cleaning the contacts with DeOxit/ProGold. The flicker on mine has completely disappeared when i did this.

-Aaron

+1
DeOxit/ProGold is fantastic

~Deicide~ said:

I would also try cleaning the contacts with DeOxit/ProGold. The flicker on mine has completely disappeared when i did this.

-Aaron

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clearly I'm obsessing way too much about this

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I'd agree

Some people continue to gripe about flickering at .08, some complain about the clip or the anodizing. The other 99% just use and carry the light every day, knowing that there's nothing else that does so much in that size package.

precisionworks said:

I'd agree

Some people continue to gripe about flickering at .08, some complain about the clip or the anodizing. The other 99% just use and carry the light every day, knowing that there's nothing else that does so much in that size package.

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Not yet but hopefully soon:devil: