Zebralight SC5c mk II 4000k ugly green tint

I just hope ZL uses the LH351D or something comparable in more of their lights next generation, it’s still superior in many ways with only a slight efficiency sacrifice.

I think I chose my words poorly - filters allow me to completely disregard whether the particular emitters on a light I’m interested in have good tint, whether I can reflow something else, etc. The biggest pro of that is being able to always pick CRI over tint, since the latter can be improved very easily.

The 10-15% hit in output is almost imperceptible as far as I can tell. I carry a 64 LE or a H600c most of the time.

Looking around for AA lights today. Only Lumintop AA Tool and Fenix E21 seem to have constant current, and besides McGizmo Haiku AA (also constant current) and Zebralight SC5c/w II & SC53c/w, I don’t see any that are current regulated.

Anyone know of any other current regulated single AA lights?

I've got this one, Skilhunt M150 V2

Just awesome!

Hey id30209, we chatted years ago on CPF about Eneloop. chillinn there. I was foolishly pushing some cell with a claim of higher capacity, and you held to your guns. I was wrong, you were right, of course. Recently came across that thread and cringed.
Love my Eneloops. :slight_smile:

So which is it, current regulated, constant current, or both?

“Constant current” is by definition “current regulated” unless you’re trying to describe something different.

Hey chilinn! :)

BurningPlyd0h is right.

This one like ZL has constant output the whole runtime so regulated veeery nice

I heard a rumor that some were being ambiguous with “constant current.”

Current regulated means the mode will keep its brightness constant.

Constant current means no PWM.

Zebralight, Thrunite, Skilhunt and some more names have almost flat runtime line so as PWM on osciloscope. Better google for reviews by Zeroair, Liquidretro and 1lumenreviews cause they have graphs with meassurements and stuff. Not only few pictures

I knew Zebralight wasn’t strictly constant current, but also not strictly PWM because it doesn’t dip to zero output, still, it pulses brighter and dimmer. I wasn’t aware any other lights also had a similar scheme. Whether it is a problem for me depends on the light and frequency, and it isn’t necessarily that faster frequencies are better, and I don’t care if I see it or not as long as it doesn’t cause problems for me.

I know what are you talking about but please look at the tests and graphs.

What you’re thinking of is output stabilization. The terms are used interchangeably here and probably on CPF too but are completely different. Every flashlight that has some sort of driver vs the LED/bulb/etc. being wired straight to the battery is “regulated”, and a CC driver operates on the principle of regulating the current that flows to the LED (with various ways of achieving that) and does NOT guarantee a stable output regardless of input voltage changing. Buck, boost and buck-boost drivers are the best (only?) at doing that, and there may be some CC designs that accomplish it as well… but I don’t understand how (maybe because buck drivers are still “CC” and accomplish it vs linear regulated CC drivers that don’t? i.e. Convoy’s new driver)

This is the last version from the 1lumen review. I call that regulated.


Looks huge in the product images, but this shows how little it is.

Skilhunt uses a buck driver in many of their lights, don’t know why that wouldn’t be the case with the M150 when using li-ion cells. That graph shows a “stabilized” output.

“Regulation” simply means controlling the voltage, current or power in literally any way. The term has simply been used to describe all sorts of things rather than words that really describe them.

Mine looks yellow-orange’ish. Doesn’t matter, its warm and powerful.

Only thing is, the switch started acting strange. After some time unused, it kind of double clicks. Not really two registered clicks, but you can feel and hear a pre-click.

Not the only light doing this, a fitorch k3 lite develops this misbehavior too.

But if specifically referring to “current regulation,” the effect is going to be, as you say, a stabilized output, which is precisely the same as… constant brightness. There is meaning here, BurningPlayd0h. A constant current circuit does not necessarily regulate current, case in point, many Fenix drivers are lovely in that they’ll produce a constant current, a current that is constant without any PWM whatsoever. But these drivers do not hold their brightness constant, and the light will dim steadily as the voltage of the cell diminishes as the capacity is depleted, and this because these drivers are not current regulated. We can use these terms to mean these exact things because, in fact, that is what they mean. You seem to be trying to say these terms are vague and can mean many things, but I believe you are mistaken. They refer to very specific characteristics of certain drivers as they are related to the characteristics of the light that is produced. Constant current, CC, is a feature that, while there may be current ripple, there is not any implementation of PWM, while current regulation will always result in brightness that remains at a certain output without dimming, at least as long as the cell can maintain that current before stepping down and the brightness remaining constant at a lower light level.

This is going to be way above my head.

Current regulation does NOT always result in constant output, like in any light with a CC driver consisting of a FET partially opened via a sense resistor. As cell voltage drops, so to does output. All the Convoy lights with the new CC driver show this behavior.

A linear driver cannot step-up voltage at all, so any mode where the emitter’s Vf is above what the cell supplies will drop in output as well.

PWM is regulation as well. The driver is regulating the flow of power to the LED. I have no idea how a term that was well understood at the advent of electronic drivers for flashlights has come to be used for something entirely different.

I believe it does, and it is precisely how constant output, or more commonly referred to in the industry as constant brightness, is achieved. How else can be it be achieved? Do you at least acknowledge that constant brightness exists as a feature in some drivers and lights?

As far as I am aware, up until very recently, this year, every implementation of FET drivers utilized PWM, therefore, are not necessarily constant current. If the FET is implemented as constant current without PWM, this is not something the manufacturer should hide, but instead market thoroughly as a superior implementation.

As does current.

I would assume this is indeed because constant current, referring to a constant stream of current without interruption, is strictly not current regulation, which is keeping a current regulated, i.e. increased or decreased (below the threshold of what the cell can provide) to achieve constant brightness while the cell can still hold that current before stepping down and then holding a lower brightness while the cell current can hold that lower brightness, before stepping down again, etc., as is indicated quite clearly in the output chart I stole from a 1lumen review and posted above.

So you’re saying there is no such thing as a driver that provides constant brightness. I think this is a straw man, as I’m not arguing anything about linear drivers, only the clear distinction between a driver’s constant current feature and a driver’s feature of current regulation, the latter which provides constant brightness. These terms are very commonly used to describe these specific and distinct features whether you’re aware of it or not.

That may be, but colloquially, while current regulation may be applied in many ways, when it is discussed as a feature of a driver that a consumer might be interested in, it is always referring to constant brightness, because one causes the other, so they may often be used interchangeably even if one is not the other, but again, one causes or provides the other.

Perhaps because language evolves and the lords of electronics and design are not in charge of language. Within the scope of driver features that may appear in a list a consumer might consider, there is no ambiguity between the two terms. I admit perhaps in the circles and rhetoric of electronic engineering they may become synonymous or ambiguous, but not the meanings of how they are commonly used to describe two very different driver features to a consumer and end user, and further, the mere word “regulation” is used interchangeably with “current regulation,” as in the sentences, “at the end of the cell’s capacity, you can see on the runtime chart where the driver drops out of regulation into a low output direct drive,” or “when the cell can no longer provide enough current, the driver drops out of regulation and implements PWM until the cell is depleted.” These are full of specific meaning, and I have trouble believing you don’t understand. I think you just want everyone off your lawn.

Frankly, I think you’ve been led to believe that something exists which doesn’t - because of the poor choice of language by many. Absolutely any electronics that change the flow of electricity to the LED (or “X” diode, bulb, heating coil a la e-cigs, etc.) is regulation - whether that’s through PWM or control of constant current/voltage. Using “regulation” to describe a very specific feature of flashlights when basically everything but hotwire incandescent builds has it really, really muddies the waters.

Can you be any less specific? What are you referring to? Just name it, please. Are you saying current regulation and constant brightness does not exist? Because the runtime chart I posted proves that it does. Are you saying there is no such thing as constant current drivers? Because a number of drivers do not use PWM or anything like it and provide output that is completely smooth as one would expect of a constant current driver.

So what? If they are not referring to constant brightness, they’re referring to something else. Problem solved. I’d like to introduce to the concept of the homonym.

I am not forbidding the use of the phrase to mean something else, merely protecting one narrow meaning of it, and one that is commonly used, and has been used for at least a decade if not more. This is, in fact, what you are attempting, to forbid others from using certain language to describe a specific driver function, and you will fail, because it exists in marketing literature, and it exists in threaded conversation spanning flashlight forums. I don’t see how it matters what it is called, but convention has chosen current regulation to describe how constant brightness is implemented. You’re going to have to deal with that, and I wish you all the best with it.

Here’s a counter example to prove that you are mistaken, that “regulation” very commonly does mean that the output is regulated to be constant:
This old CPF post shows an old use of the word regulation to mean constant brightness.

Are you sure that it muddies the water? Does anyone not know what Don is trying to say here… in early 2013?

Here’s another counter example:

This page is only a few years old, but if you wish I can find the same phrase meaning the same thing, constant brightness, on an old product page of a discontinued product much deeper in the past using Archive.org.