I don't see the moonlight as that big of a deal. TA offers multiple hex's with different moonlight settings. IF you're selling a single light you only need to find one that works on that light reliably, and from the sounds of it 5khz would fix it almost entirely and still isn't slow pwm. I think 20khz is still fine though. I guess it just means you need the +1 channel, don't try to do moon with 12 7135's. But that doesn't actually add any cost. It's just about doing it right.
Exactly. Ultrafire 100 Hz PWM is annoying, but I doubt we need a poll to figure that out.
It’s interesting that people interpret “no PWM” to include “no visible PWM” though. What does “PWM” mean to people? More on that below.
I don’t see any “NoPWM” lights there. What I see there are four PWM-based lights. This confirms to me that the disagreement is about the definition of PWM, not people’s preferences about the physical properties of light.
Left to right, the PWM speeds on those lights are (approximately):
- Zebra: 5000 Hz
- Quark: 2200 Hz
- Eagle: 4500 Hz
- Malkoff: 1350 Hz
All four of those are too slow. I have the same Zebralight and EagleTac lights reppans used in that pic, and I can see the PWM on both during normal use. All four are examples of what I call “bad PWM”.
The v2 Pineapple driver is spec’d at 9000 Hz, which is ~2 to ~6 times faster than the premium-brand lights shown above. Not bad, but not what I’d call good either. Most BLF drivers run at around 14,000 to 18,000 Hz. The new Convoy C8 runs at 32,000 Hz. I find ~20,000 Hz to be ideal, preferably with a FET+1 or FET+N+1 driver for better efficiency.
I like true CC circuits for their efficiency (when done well), but a 2-channel or 3-channel PWM driver is close enough for my purposes. Here’s a qualitative comparison of 1-channel, 2-channel, and 3-channel PWM drivers and their efficiency as compared to an ideal CC driver:
Wow! Great and informative post!
x2… I tried to elude to this in my earlier post, but didn’t really have the detailed information to clarify what I was talking about.
FWIW I am totally OK with PWM, so long as I can not readily see it. My understanding is PWM is the most efficient way to lower LED output too, although I am not sure why. My Thrunite TH20 I just realized uses PWM for its lowest-low / candle setting. I didn’t even realize it until I had it on and was washing my hands in the middle of the night, under the water it became more noticeable. I am OK with that, since its high enough frequency to not be readily visible all the time.
x3 (thanks!)
I would now have to vote for the following after learning the above and when considering the UT01 in transit to me now):
“PWM” speed (as now better understood, thanks to toykeeper)…
…quality LVP protection (as evidenced by the NiMH ‘only’ shutoff apparently exhibited by the UT01)
…and ‘tint’ would be my (off-topic) answers to the OP’s poll involving a 14500 capable light (you can buy a Nichia 219 tinted BLF ‘backup’ light for $7 and a Jaxman for less than $20 so ‘tint’ has become less important to me…yet it’s always nice to have).
I’d really like to standardize more on AA cells and the protected versions for at least 500 lumens in a single cell EDC light.
fwiw, I wrote to Malkoff to ask the speed of the PWM, and got this reply direct from Gene Malkoff:
“The PWM frequency is 310 Hertz. Most people can’t see it.”
regarding Zebralight pulse speed, see
http://www.candlepowerforums.com/vb/showthread.php?415838-Zebralight-SC5Fc-measurements-(AA-warm-tint)
“PWM is used to control output on all modes except H1. The PWM is not visible to the eye, because of its low amplitude, but possibly shows up on camera. The cycling frequency is higher on higher output modes and ranges from 775 Hz to 5000 Hz. The amplitude however is higher on the higher modes.”
Note that when I say Zebralight is not “technically” using PWM, it is because the pulses do not drop to zero. That is why there is a blurr between the dots in the reppans PWM progression photo, the LED is not turning all the way off. The brightness is fluctuating, like in the quark, where you also see a blurr between the dots.
Even the Eagletac pulses do not drop to Zero, in fact Selbuilt says he cannot detect PWM, just “noise”
http://www.candlepowerforums.com/vb/showthread.php?401362
“There is no sign of PWM that I can see, at any output level…
I did detect some high frequency noise as shown below:”
obviously everyone has different definitions and tolerance of PWM. Some people dont care, some people object to calling pulses PWM unless they drop to full zero, and Zebralight as well as Eagletac, claim they do not use PWM (technically this is correct, but in the real world, some people can see the flashes, or get headaches from them)
thanks for the discussion… I really dont expect to convince anyone whether PWM is good or bad, it is clear to me that the majority of people, given a choice, will prefer NoPWM, but, they will still buy a light that has pure PWM (eg Malkoff and Pineapple), or hybrid PWM (eg HDS, Zebralight, Eagletac) that does not drop to full zero between full power flashes.
ps, here is a definition of PWM with examples https://www.arduino.cc/en/Tutorial/PWM
“when I say Zebralight is not “technically” using PWM, it is because the pulses do not drop to zero. That is why there is a blurr between the dots in the reppans PWM progression photo, the LED is not turning all the way off. The brightness is fluctuating, like in the quark, where you also see a blurr between the dots. “
I think my Thrunite TH20 uses this same kind of “PWM” on its candle mode. When I vigorously shake the light in my hand… Theres a faint trace of the LED between the “dots”.
Interesting. I used the EagleTac stripe as a reference at 4.5 kHz (since that’s the speed mine was), and calculated the others based on the pulses shown in the picture. But I haven’t actually measured a Malkoff, and can’t say for sure that reppans’ EagleTac unit goes at the same speed as mine. If I use Malkoff=310 as the reference, that would mean the speeds are:
- Zebra: 1150 Hz
- Quark: 500 Hz
- Eagle: 1040 Hz
- Malkoff: 310 Hz
That doesn’t sound right though, since I’ve never seen my ZL or ET lights (2014 model) pulse that slowly. So I tried measuring my other EagleTac D25A (2012 model), which oscillates between two levels but doesn’t actually shut off like the one in the pic. It got 984 Hz on its low and medium modes. Moon was slower (much slower), but not bright enough to measure.
- ET D25A (2012): 984 Hz (2-level oscillation)
- ET D25A (2014): ~4.5 kHz (hard on/off PWM) (can’t measure right now since it’s in pieces)
I also tried measuring my ZL SC52 again, and got these results (with an Eneloop):
- L1: 3.3-3.5 kHz (ish)
- M2: 15.3 kHz
- M1: None
- H2: 29.1 kHz
- H1: None
The one I’ve noticed during use is L1. That reading was unstable though, which means it probably wasn’t accurate because it wasn’t bright enough for my sensor to measure correctly.
Out of curiosity, I measured my JB RRT01, the continuously-variable magnetic ring light. It measured at only 1.01 kHz, but it looks like the oscillation is a fairly smooth sine-like wave so it’s hard to see.
- JB RRT01: 1.01 kHz
… and the BLF Q8 driver Tom sent me. At low levels (up to ~140 lm), it shuts off between pulses, but medium and high levels (140+ lm) do a 2-level oscillation. Neither range is visible, and the transition is seamless.
- BLF Q8: 15.7 kHz
Cheap 3-mode SK-68:
- SK-68 (medium level): 130 Hz
I find it hard to stand PWM 
I would buy a light that is inexpensive and I can easily take apart. I don’t care what cell chemistry it was made to support as I can determine that with driver choice.
ToyKeeper, thanks for all your input
if you only had 2 choices, what AA driver would you choose: #1. With PWM and LiIon, or #2. With NoPWM and NoLiIon
everyones opinion on the Merits of PWM varies, and Im not trying to start a pro and con of PWM debate
I was trying to figure out how much market share each of these options represents:
- dual chemistry AA and LiIon with YesPWM, or
- AA only with NoPWM
I myself intentionally do not buy PWM lights. I also dont happen to use LiIon in AA sizes. So I am a Type #2 buyer. I think Im in the minority, cant tell from the poll, I did not structure it correctly to find out. I got confused by too many possible options, when the last one really is not realistic and should not be in the poll… too late for that
to anyone still reading, which of the two buyer types do you represent, AA/LiIon option w PWM, or AA only w NoPWM?
Pwm and liion.
Thank You, may I suggest a Pineapple?
I would have voted 3 times, for the bottom three options, if possible. Just sayin. But I piled on the last option to help make that a reality.
jon_slider,
I want to remind you that there are at least a few NoPWM lights you’ll want nothing to do with… so specifying CC instead would be more specific.
NoPWM != CC
(ahem, Zebralight, cough cough)
What we want is CC, and not NoPWM, nor PWM.
Single-chemistry lights usually have slightly more efficient drivers. For example, my Zebralight SC5w (AA only) is about 10% more efficient than my Zebralight SC52w (AA and 14500).
Besides, with 1xAA lights now getting 500 lumens out of an Eneloop, there’s really not much need to go with 14500 cells anymore.
PWM sucks, even if it has unnoticeable high frequency. It kills efficiency!
Constant current is better for runtime - and my eyes! 
Sorry to add even more confusion, but for the visible PWM light we are assuming there’s at least one mode (usually its turbo) with no PWM… correct?
For the AA only light we are assuming it also takes ~1.7V Lithium primaries correct?
Assuming its YES to both scenarios above I would vote for the AA-only light. ~250-300 relatively cool running lumens is more than enough for my needs.
Dual-chemistry boost drivers can have Li-ion low-voltage protection. The driver needs to disallow a range of about 1.8 to 2.6 volts. Several lights do this, including the Zebralight SC52, Armytek 1xAA lights, the Klarus Mi7 and that prototype Illumn was showing off last year.
As for PWM, I’m fine if it’s fast, not fine if it’s slow. I’d probably give up Li-ion compatibility rather than accept slow PWM in a small, budget EDC type light if I had to make the choice. I bring an 18650 light if I actually think I’ll be using a light though.
correct PWM is only used on dimmed modes
correct an AA light will also accept Eneloop and Lithium Iron (primaries)
however it is imho not realistic to expect more than 140 lumens from a single AA with a 90+CRI LED
if your goal is to have more than 200 lumens, you are getting into CR123 territory, or LiIon
thank you
apparently that was considered too large and too expensive for the Pineapple
Zebras dont offer 90+CRI, and they are also not constant current.
Klarus also does not offer 90+CRI, and it does not have real overdischarge protection, it just “automatically lowers output levels”. And Klarus calls their low of 5 lumens a “moonlight”, I think they have an English language challenge.
Finding an AA light with constant current and 90+CRI is quite rare
I cant think of any ATM that have all 3 features: constant current, 90+CRI, AND dual chemistry.
I think it should be very possible to get a 90+ CRI light on a single AA (NiMH cell). Zebralight SC5Fc and SC5Fd offer 85 CRI and 375 lumen output on a single AA. Switching to a 90 CRI LED would certainly be able to output more than 140 lumens. I think the reason it isn’t offered is because there isn’t enough demand for it. Zebralight seems to think the sweet spot between high output and high CRI is the 85 CRI EasyWhite LED.
Even the lowly Astrolux A01 Nichia 219 does close to 90 lumens, on a single AAA cell, at ~92 CRI. It’s not asking much more from a AA cell. I have an old L3 L10 that does about 100 lumens using the old Nichia 219A at 92 CRI. Just swapping in a 219B should get it up to 140 lumens, and it’s not driven hard at all.
Again, Zebralight SC5 does 535 lumens on a single AA. Manker T01 does over 400. Two years ago, sure, you needed to go with 14500 for that kind of output, but now you can do it with a NiMH cell.
I don’t see a need for 14500 any more. An Eneloop has the same energy, can deliver almost as much power, and does it way more safely, cheaper, and lasts for a couple of thousand charges.