# Constant Current incan modes. Why not?!!?



## chillinn (Jan 16, 2017)

Went off the topic in another thread. Starting here fresh. I think this deserves examination.

Naive and young for my age, I was seduced by Computer Science. FYI, CS has _nothing whatsoever_ to do with computers. The "computer" in "Computer Science" is in fact a person, i.e. one who computes, or one who reckons. They should have called it "Reckoning Science." Only when it was too late did I discover that Electronic Engineering was a thing. That was what I should have studied. 



vicv said:


> Unfortunately there's no such thing as current controlled Incan. They're controlled by voltage and pwm.



I see this repeated, that incan can't do CC.

What I want to know is not if "there are no CC incans," but if it is absolutely logically and physically impossible in this Universe for incan to do CC, or if it is rather the case simply that no one has yet attempted, or no one clever enough has come along to create it. Aren't there three mode lightbulbs? Aren't they CC? Isn't the round fader on my mother's dining room chandelier CC? Why not an incan flashlight? If it is impossible, there are likely good reasons. But if it is merely difficult, then a little elbow grease, ingenuity, and perseverance could bring this into the world. So which is it? Impossible? Or merely difficult, and so far has not been attempted?

Let's try to avoid discussing or promoting the idea that PWM incan modes don't suck. PWM sucks, period, and it doesn't matter if you personally don't mind it. That it doesn't bother you personally is in no way a positive argument for PWM, but instead that is merely a positive argument for apathy. Also, even if something cannot be seen or detected does not eliminate the possibility that it can harm you or others. PWM is harmful to me, even when I can't visually detect it. So I want to head off at the pass those that are prodigiously loyal to their favorite flashlights despite the fact that they utilize PWM. 

I really appreciate the sharing of knowledge by those that understand the stuff I don't. Thanks.


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## bykfixer (Jan 16, 2017)

I think mini moog did a thread about regulating one of his ancient lights...


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## chillinn (Jan 16, 2017)

bykfixer said:


> I think mini moog did a thread about regulating one of his ancient lights...



I think I found it. Thanks. But isn't regulation, which is awesome, technically Constant Brightness, and not necessarily Constant Current?


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## bykfixer (Jan 16, 2017)

That's the one.

You posted while I searched. :thumbsup:

Hmmm, I kinda figured thats what you were seeking


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## chillinn (Jan 16, 2017)

Well, it would be even _more awesome_ to have an incandescent flashlight with modes that is regulated for constant brightness and is also a constant current circuit. And while we're at it, let's add a low voltage cut off to protect the cell and the user. I can't imagine that anyone that appreciates incan would be opposed to the idea.


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## bykfixer (Jan 16, 2017)

If it could be done PK or Pentagon probably did at some point.

Matter of fact I do remember PK talking to Scout24 about why one of the SureFire switches wouldn't work on his PR-1 due to the switch being hi/lo. That was somewhere in the PKDL thread. Then the other day I saw where Pentagon had a hi/lo tape switch on the MD2 or something... It was one of their weapon lights.

So yeah I think it can be repeated, but is there enough demand?


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## chillinn (Jan 16, 2017)

Demand is irrelevant, imo, just like the height of a mountain is irrelevant to the reasons for climbing it. My intention is not to evoke a resurgence in market demand for incandescent flashlights (though this would not bother me in the least). But if the design and creation of such a modern driver for incan is not unfeasable economically for a dozen or a hundred to be produced and funded by the rarer incan consumer, that it should be attempted and completed simply because it can be done. Such a rare batch would have inherent value, and it's market value would increase with age, assuming MagLite or any other brand still manufacturing incan flashlights didn't pick up the idea and mass produce it (which, again, would not bother me in the least).

Also, not for nothing, I have already been shot down and educated in another thread regarding a McE2S-style hi/lo switch for incan in another thread. I confess I exaggerated a bit there. The truth is I had won an auction for an E2E with incan head that advertised it came with a hi/lo switch, and made the poor assumption that it would work. When the light arrived, I discovered it was not a hi/lo switch, but probably a McClicky, and the seller made an honest mistake. The seller never got back to me, but being that the deal was still a great bargain, I'm not going to complain or pursue it. 

Still it makes me wonder if it could possibly be as simple replacing the resistor in a hi/lo switch with some other kind of electrical doodad to make an incan hi/lo switch viable and operable for a couple incan modes. But I don't know what I am talking about. ><


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## vicv (Jan 16, 2017)

Another great part about constant current is it would also provide soft start. Now constant current is actually voltage controlled. An led's VF changes as it's temperature increases which is why it can't be controlled by voltage regulation. Also an led will increase its current exponentially from a small increase in voltage. An Incan bulbs current draw rises evenly with voltage. The reason why we don't have current controlled Incans is the same reason we don't have voltage controlled ones. Lowering the voltage for a lower output cause a big tint and efficiency shift in the wrong direction. Most people don't want that. So modes are out. You could have a voltage regulated circuit for one mode but most seem.to be pwm. A simple DC DC switching regulator. No idea why pwm is always used. The circuit would use pwm on the source side and filter it to get a constant DC output to the bulb. It's easier to rapidly turn a fet on and off I guess.
Your dimmer in your house uses a potentiometer to lower the voltage to the bulb to dim it. For a 120v bulb tint shift will not be too sever. For a bulb under 10V it will which is why it's not used for modes on a flashlight. Also as the cells drain it would get worse and worse and you'd just be wasting the extra voltage as heat
Those 3 mode light bulbs contain 3 different elements inside


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## chillinn (Jan 16, 2017)

It would be pointless, I suppose, to have a multi-mode incan where the lower modes did not stretch the battery capacity. I hope this is not the only possibility if designing CC for incan.


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## vicv (Jan 16, 2017)

It would stretch the runtime a bit but not as much as pwm does. Did you try the 9v bulb on a single cr123 or 2xaa like I suggested in the other thread? That's how a dimmed Incan on anything other than pwm will look.


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## chillinn (Jan 16, 2017)

vicv said:


> It would stretch the runtime a bit but not as much as pwm does. Did you try the 9v bulb on a single cr123 or 2xaa like I suggested in the other thread? That's how a dimmed Incan on anything other than pwm will look.



I did not try, though I take your word for it. Have you ever tried lighting your room with candles? I would not mind burning candles, but for the soot it puts into the closed atmosphere of a room and the inherent danger of an open flame. I don't mind tint shift at low modes. I love the colors of dawn, and I love an orange-red sunset (either golden hour is exquisite). I like the ambiance of that color. With dark adapted eyes, poor yellowy tint from an incan filament is not intolerable and in fact it can be rather romantic. In fact, I have full intention of having Vinh fix me up an LED flashlight with an amber X-PE. Amber is a good color for outdoors, espescially here in Florida, where there are a gazillion light-attracted flying insects per resident. vivc, I realize that it might be obvious to you, but you never detailed any reasons why you couldn't tolerate or enjoy yellowy incan... feel free to bash it, but what are your personal reasons for despising it?


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## vicv (Jan 16, 2017)

Oh I love incans and I love the tint. I do prefer overdriven ones but one of my most used light is my maglites solitaire and it's quite yellow and weak. Reasons why I like it. So when I tell you that light will look like a cool led compared to what you're asking for is what I'm talking about. Not just an under driven incan but a badly underdriven one. Ten times worse than a maglites on dead cells. That's why no one makes current controlled modes with incan lights


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## chillinn (Jan 16, 2017)

Back to the fader on my mom's chandelier... I know others have done this. When you turn the fader to the point where the light is almost off, and the filiment is barely producing any light. idky, I love looking at those badly underdriven lamps.

That said, little compares to a properly overdriven incan lamp.



vicv said:


> That's why no one makes current controlled modes with incan lights



So is this the answer to my OP query? That a multi-mode CC incan driver is neither logically nor physically impossible, but instead it is impractical? If so, the follow-up question is "can the impractibility of a multi-mode CC incan driver be mitigated, either through trial and error or the brilliance of epiphany?"


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## ma tumba (Jan 17, 2017)

Great thread! 

And regardless of the answer to the original question I think that it would be great to have a regulated switch for incands, kind of aw type, but with regulated output. And compatible with smaller size tail caps, like that of a e2e.


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## chillinn (Jan 17, 2017)

ma tumba said:


> Great thread!
> 
> And regardless of the answer to the original question I think that it would be great to have a regulated switch for incands, kind of aw type, but with regulated output. And compatible with smaller size tail caps, like that of a e2e.



AW's switch uses PWM. Get an incan A2 Aviator; has 2 modes, it is regulated and has constant brightness, though it is not thread-compatible with E-series. Tad Customs has a bipin socket available for A2 as well.


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## vicv (Jan 17, 2017)

The a2 also used pwm


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## chillinn (Jan 17, 2017)

vicv said:


> The a2 also used pwm



Yup, but it does have regulated output, and it is easier to come by than AW's switch replacement. But I suppose an even easier item to find, if unphased by PWM, is the LightSaver Miser tailcap for E-series, though it is not regulated for constant brightness.


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## ma tumba (Jan 18, 2017)

I had no idea that someting like Light Saver existed for e-series lights. Will definitely try that offer from the bay.

Now, your issues with pwm, especially with that in the Lightsaver is an interesting case. I am very sensitive to any sort of flickering, like that in luminiscent lamps, CRT monitors etc. Having said that I have never had any issues with incand, including a2, aw 3-stage switch. So may I ask a few questions about your experience?

1. With the lightsaver, do you have the issues at all 3 levels, including the 100%, and are these issues equally bad for all levels?
2. Do you have any issues with traditional incand bulbs, fed by 60Hz mains? 
3. Can the issues be associated with the sound, generated by PWM in the Lightsaver, rather than the light pulsations? Some people (including myself) just cant stand it even below the hearing threshold.

Now, regarding your (and my own) quest for ultra warm dim incand light. The best thing that I have found is a 2xaa maglite with a SF F04 diffuser. MiniMag is also a 1 inch light so F04 fits like a glove. The great thing about this setup is that it is effectively a multi-mode light. When you switch the light on you have a wall of light at about 15lm. When you unscrew the head further you have kind of more concentrated but still very diffuse hot spot. But when you unscrew the head even further you get, again, that wall of light which is much dimmer because a lot of lumens are lost now inside the light. I would say, that in this mode I have about 3lm at most. I am very happy about this setup for night time indoors. And it works for a long time.


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## chillinn (Jan 18, 2017)

ma tumba said:


> So may I ask a few questions about your experience?
> 
> 1. With the lightsaver, do you have the issues at all 3 levels, including the 100%, and are these issues equally bad for all levels?
> 2. Do you have any issues with traditional incand bulbs, fed by 60Hz mains?
> 3. Can the issues be associated with the sound, generated by PWM in the Lightsaver, rather than the light pulsations? Some people (including myself) just cant stand it even below the hearing threshold.



Certainly,

1. I can't distinguish between the levels regarding the onset of headache. First it starts with something like tenitus, and that "noise" gets louder like a wave approaching, then normal levels of headache pain, but this leads to greater levels of pain in migraine eventually, and within minutes. But I do believe even the 100% first mode has the same or closely similar effect on me, leading me to believe the LightSaver is using PWM even on it's brightest and first mode.

2. No I don't, and I am aware they are actually flickering, if fed by 60Hz mains, at 120Hz. I speculate reasons why this may be here. But it is only speculation. I am not a neurologist nor do I play one on TV. ;-)

3. Good question! I don't hear any sound from it, but rather the "sound" I hear is of a tenitus-like ~14kHz audio effect that is surely internal to me. My ears are pretty sharp, and if it was producing sound, I should be able to identify that as the source of the problem. In fact, I have subsonic hearing, and quickly can identify that diesel bus going past is what is painful, when others near me can't hear the extremely low frequencies. This is one reason why thumping subs in compact cars is silly, because most people can't hear subsonic frequencies. Also, low frequency waves are far longer than the inside of those cars, so even the thumping sub lover can't hear those frequencies inside the car, because the sound waves can't fit in there.


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## ma tumba (Feb 22, 2017)

Chillinn, I finally got a multiple level tail switch for maglite mini (made by nite ize, based on the same IQ circuit as the lightsaver mizer) so I can now make informed comments to what you shared.

1. There is a clear and significant flicker at 25% and 50% levels, it is not PWM because it is very low frequency (few Hertz), but it is there. To see this flicker you need to illuminate an area so you can see low surface brightness. You would't see it when you stare at the hot wire since your retina is oversaturated. In this case you don't see it but are still affected by it. 

2. There is a whining sound. It is not the low freq one you mentioned, rather it is a very high pitch tone, typical for pwm. It is higher that 5kHz, so, again, the PWM at 5+ kHz has nothing to do with the flicker which is 1000 times lower in frequency. 
I can hear it when the switch is very close to my ear, not more than 10cm away, so I don't think that it may have caused your problem. When I put a silicone butt over the switch the sound was completely eliminated.


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## ssanasisredna (Feb 26, 2017)

chillinn said:


> Went off the topic in another thread. Starting here fresh. I think this deserves examination.
> 
> Naive and young for my age, I was seduced by Computer Science. FYI, CS has _nothing whatsoever_ to do with computers. The "computer" in "Computer Science" is in fact a person, i.e. one who computes, or one who reckons. They should have called it "Reckoning Science." Only when it was too late did I discover that Electronic Engineering was a thing. That was what I should have studied. So the result is that I know very little about electicity, having dropped out of Physics early in the second semester, just as I was introduced to Maxwell.
> 
> ...



PWMing INCAN does not product visible effects and practically, does not produce any invisible effects either. It's a hot wire. It does not cool much between PWM cycles unless you were PWMing at a really low frequency which there is really not much practical reason to do..

Even for an LED, if the PWM is high enough frequency, again, there are no invisible effects.


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## ssanasisredna (Feb 26, 2017)

vicv said:


> Another great part about constant current is it would also provide soft start. Now constant current is actually voltage controlled. An led's VF changes as it's temperature increases which is why it can't be controlled by voltage regulation. Also an led will increase its current exponentially from a small increase in voltage. An Incan bulbs current draw rises evenly with voltage. The reason why we don't have current controlled Incans is the same reason we don't have voltage controlled ones. Lowering the voltage for a lower output cause a big tint and efficiency shift in the wrong direction. Most people don't want that. So modes are out. You could have a voltage regulated circuit for one mode but most seem.to be pwm. A simple DC DC switching regulator. No idea why pwm is always used. The circuit would use pwm on the source side and filter it to get a constant DC output to the bulb. It's easier to rapidly turn a fet on and off I guess.
> Your dimmer in your house uses a potentiometer to lower the voltage to the bulb to dim it. For a 120v bulb tint shift will not be too sever. For a bulb under 10V it will which is why it's not used for modes on a flashlight. Also as the cells drain it would get worse and worse and you'd just be wasting the extra voltage as heat
> Those 3 mode light bulbs contain 3 different elements inside



Dimmers in houses are not potentiometers, they cut the waveform which does the same thing as lower the voltage and the shift in CCT is the same for any other incandescent bulb.


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## chillinn (Feb 27, 2017)

ssanasisredna said:


> PWMing INCAN does not product visible effects and practically, does not produce any invisible effects either. It's a hot wire. It does not cool much between PWM cycles unless you were PWMing at a really low frequency which there is really not much practical reason to do..
> 
> Even for an LED, if the PWM is high enough frequency, again, there are no invisible effects.



Apologies for my dissenting opinion, but concerning incan filaments and PWM, this often repeated theory looks good and sounds good, but a single counter-example proves it is nonsense. Whether or not it is true (about a hot wire fluctuating) has no bearing on whether it is detectable, and whether it is detectable has no bearing on whether effects are undesireable or harmful. Unfortunately, it is also a strawman fallacy to argue that PWM is harmless if it has no visible/invisible effects.

The PWM used by the LightSaver tail switch (for incan E) can under certain conditions cause me to get headaches and migraines, and I have finally discovered how to visually detect it. Also, LED lights with PWM rates in 17kHz range have caused me to get headaches. These facts you've posted about PWM are no longer facts as they are false, respectfully, sir.


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## Timothybil (Feb 28, 2017)

Yes, there is a potentiometer in a household dimmer switch. But it does not have a direct effect on the light. It is used to control the amount of time that elapses after the beginning of the voltage cycle before the semiconductor switch turns on and applies voltage to the light. At one end of the potentiometer's range the semiconductor turns on almost instantly in the cycle, and essentially all of the input voltage is applied to the output. As the potentiometer is turn to dim the light, it causes the semiconductor to turn on later in the cycle, which effectively dims the light because current is flowing for a shorter period of time in each cycle, therefore not allowing the filament to heat up for as long and reducing the total output. Due to the way that A/C works, the output voltage does not start to fall until very late in the cycle. That is why the tint doesn't change very much until the light is down to less than about 30-40%. Just like in an undimmed light, the voltage to the bulb is going to zero 120 times a second, but the latency of the filament makes this much less noticeable then it would be if the light were an LED, with its instant on/instant off. 

Now, if this has your brain going zzzt! zzzt!, :shakehead just ignore this and go to the next post.


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## ssanasisredna (Feb 28, 2017)

Timothybil said:


> Yes, there is a potentiometer in a household dimmer switch. But it does not have a direct effect on the light. It is used to control the amount of time that elapses after the beginning of the voltage cycle before the semiconductor switch turns on and applies voltage to the light. At one end of the potentiometer's range the semiconductor turns on almost instantly in the cycle, and essentially all of the input voltage is applied to the output. As the potentiometer is turn to dim the light, it causes the semiconductor to turn on later in the cycle, which effectively dims the light because current is flowing for a shorter period of time in each cycle, therefore not allowing the filament to heat up for as long and reducing the total output. Due to the way that A/C works, the output voltage does not start to fall until very late in the cycle. That is why the tint doesn't change very much until the light is down to less than about 30-40%. Just like in an undimmed light, the voltage to the bulb is going to zero 120 times a second, but the latency of the filament makes this much less noticeable then it would be if the light were an LED, with its instant on/instant off.
> 
> Now, if this has your brain going zzzt! zzzt!, :shakehead just ignore this and go to the next post.




... And there may not be a potentiometer. There may be a digital rotary dial, a capacitive strip, push buttons or a micro hooked up an RF link ... And the turn on or turn off may be delayed.

The point is the pot does not directly control voltage which I think was clear in my post.

The instant the voltage drops the CCT starts to change, not at 30-40%. It's always on the black body so one could argue there is no tint. Now you were not clear 30-40% what? Voltage? Total conducted phase angle? Losing the lowest voltage part of the AC waveform has the least effect this is true, but need to be clear about what you are communicating. The effective measure for and incandescent is RMS voltage. At 75% of the rated RMS the CCT of a 2700k incandescent has dropped about 320K ... Quite noticeable. 

The flicker is similar to an undimmed bulb but with some higher harmonics that are mostly filtered out.


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## ssanasisredna (Feb 28, 2017)

chillinn said:


> Apologies for my dissenting opinion, but concerning incan filaments and PWM, this often repeated theory looks good and sounds good, but a single counter-example proves it is nonsense. Whether or not it is true (about a hot wire fluctuating) has no bearing on whether it is detectable, and whether it is detectable has no bearing on whether effects are undesireable or harmful. Unfortunately, it is also a strawman fallacy to argue that PWM is harmless if it has no visible/invisible effects.
> 
> The PWM used by the LightSaver tail switch (for incan E) can under certain conditions cause me to get headaches and migraines, and I have finally discovered how to visually detect it. Also, LED lights with PWM rates in 17kHz range have caused me to get headaches. These facts you've posted about PWM are no longer facts as they are false, respectfully, sir.



If you think a 17khz pwm is giving you headaches than you are mistaken. The chemical processes/ neural receptors just don't respond at all at those rates. Nothing is getting through but the equivalent DC signal.

Far more likely with the flashlight is simple eye strain from either inability to focus and/or chromatic effects.

The only way 17khz PWM could impact you is if there is something in your environment that is modulating that 17Khz down to a much lower frequency.

I know you have convinced yourself this is the cause of your migraines but the reality is it is far far more likely to be something else and I suggest seeing an opthalmologist and/or doctor to determine if there is an underlying issue.

You do realize that Incandescent bulbs in the home are for all intents and purposes PWMed at 100 or 120hz right? Flashlights PWM even faster. With an incandescent that means almost no change in output level as the response time of the filament is slow. 

With LEDS as noted they respond instantly.


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## chillinn (Feb 28, 2017)

Apparently you have convinced yourself that PWM has no bad health effects. Unfortunate for you that you believe false things. PWM is unnecessary. It is an engineering shortcut indicative of half-assing. I don't understand why individuals insist on defending it. The virtues of PWM are _small_. It is not worth defending. It is crap. Constant current and voltage circuits are superior in nearly every application. If PWM disappeared from the earth, no one would cry about it. Tint shift at low levels solved by PWM does not outweigh the problems PWM causes for countless individuals, namely, fatigue, and intolerable, crippling pain. The heartless people that PWM doesn't bother seem to want to campaign about how great PWM is and deny that it is harmful to anyone, and they do this, irrationally, in the face of incontrovertible evidence to the contrary. This is absurd.

If you love PWM, that's great. But as for me, nowadays, I only invest in _quality_ hosts and drivers, and I leave the inferior designs for the ignorant masses.


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## vicv (Feb 28, 2017)

As stated already all AC light are are basically pwm because of the 60hz AC frequency. That being said it's also been said over and over it doesn't matter whether you like it or not I'm afraid to say. It's the only way to dim an incandescent/halogen/xenon bulb. Cc circuits limit the voltage to the led. That will not work for a filiment bulb. Period. End of story. What you want isn't beyond the scope of current technology. It's beyond the scope of physics


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## chillinn (Feb 28, 2017)

vicv said:


> As stated already all AC light are are basically pwm because of the 60hz AC frequency. That being said it's also been said over and over it doesn't matter whether you like it or not I'm afraid to say. It's the only way to dim an incandescent/halogen/xenon bulb. Cc circuits limit the voltage to the led. That will not work for a filiment bulb. Period. End of story. What you want isn't beyond the scope of current technology. It's beyond the scope of physics



AC lighting in fact oscillates at 120Hz, twice 60Hz. It is similar in theory to PWM, but not in practice. The dimming of the filiment in fixed lighting due to AC power is miniscule, as shown by slowed video (I've seen on youtube). If AC fixed lighting was the same as PWM, then it would have the same effects. It is not the same in effect, thus it is really not at all the same.

What you have explained before that you now left out is concerning the tint shift yellowing of the lamp at lower voltages. This is unacceptable to you and some others, but it still is a valid way to power a lamp, and this is proven by your own practice of on occassion using your primary cells until empty (why would you ever do that if you could not use the yellow dimmer light of the lamp?). 

Everything you posted is true, but if and only if you preface it by "in order to run a lamp at the specified designed voltage in order to get the proper efficient output and color temperature, then..."

You must see your statements as false, otherwise. My dimmer switch proves it, unless it is magic.


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## vicv (Feb 28, 2017)

Ok the install a pot in series with the bulb. I wouldn't consider it state of the art driver but will do everything you want
And no it's 60hz. It flips from +~170v to -~170v 120 times a second for an rms voltage of 120v but that's still 60hz


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## chillinn (Feb 28, 2017)

fyi



> Lamps operating on AC electric systems (alternating current) produce light flickering at a frequency of 120 Hertz (Hz, cycles per second), twice the power line frequency of 60 Hz (50 Hz in many countries outside North America). Essentially, the power is turning on and off 120 times a second (actually the voltage varies from +120 volts to -120 volts, 60 times or cycles a second and is at zero volts twice in one cycle).




Thanks, vicv. I think something similar has been done for LED, but smooth dimming isn't really what I'm after, just modes... and the reason is the pathetic capacity of secondaries. A 50% power mode to double capacity, and a 25% power mode to quadruple it, and implemented in a way that the light is reasonably constant output as it dims from the depleated cell voltage, and with the understanding that the lamp is not going to be ideally lit at those lower voltage levels, and I'd be very satisfied. Add softstart and regulation... and fit this all in a common E tailcap, and I'd need to find homes for all the kittens suddenly appearing on my seat.


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## vicv (Feb 28, 2017)

That does all sound great. Only possible with pwm. Also realise that even cc LEDs are done with pwm. Any voltage regulator is called a switching DC-DC convertor. The switching part means turning off and on. That's pwm. It's just filtered before it gets to the emitter


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## chillinn (Feb 28, 2017)

vicv said:


> That does all sound great. Only possible with pwm. Also realise that even cc LEDs are done with pwm. Any voltage regulator is called a switching DC-DC convertor. The switching part means turning off and on. That's pwm. It's just filtered before it gets to the emitter



Interesting, but the only PWM of concern is the kind that messes with the light output level. 

Also seems like this insurmountable request should not be so. Consider that a single mode incandescent flashlight will output x brightness when the cell voltage is 3.3V, and a lower y brightness when the cell voltage is 3.0V, and still yet a lower z brightness when the cell is 2.7V. If only there were some existing and well-understood engineering or science where we could introduce some kind of voltage resistence to effectively limit or buck the voltage of a fully charged cell without using PWM and without incurring too much disadvantage of losing the capacity of that extra voltage, and implement it in such a way that it was switchable between these modest couple extra lower modes. But of course this is the stuff of science fiction.


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## ssanasisredna (Feb 28, 2017)

chillinn said:


> Apparently you have convinced yourself that PWM has no bad health effects. Unfortunate for you that you believe false things. PWM is unnecessary. It is an engineering shortcut indicative of half-assing. I don't understand why individuals insist on defending it. The virtues of PWM are _small_. It is not worth defending. It is crap. Constant current and voltage circuits are superior in nearly every application. If PWM disappeared from the earth, no one would cry about it. Tint shift at low levels solved by PWM does not outweigh the problems PWM causes for countless individuals, namely, fatigue, and intolerable, crippling pain. The heartless people that PWM doesn't bother seem to want to campaign about how great PWM is and deny that it is harmful to anyone, and they do this, irrationally, in the face of incontrovertible evidence to the contrary. This is absurd.
> 
> If you love PWM, that's great. But as for me, nowadays, I only invest in _quality_ hosts and drivers, and I leave the inferior designs for the ignorant masses.



If you have read what I wrote, I know for a fact that PWM causes headaches in many people at low frequencies, generally sub 200Hz. There are visual effects with 100% modulated PWM up to 500Khz, and you can detect with perfect conditions up to 1KHz (i.e. cause sub-frequency modulation). At 17KHz, there is not. That is not me convincing myself, that is the body of evidence of people who have studied this, PLUS a fairly good knowledge of how the eye detects light and processes optical signals. 

There is nothing "inferior" about PWM, in fact a truly superior driver will mix both constant current and PWM as it maximizes the efficiency of the LED.

Quite a few LED drivers for commercial lighting use PWM as well when dimmed. It is relatively common and is going to become more common as more fixtures incorporate white point tuning, color changing, etc. Planes with color changing LED lighting are also typically PWM. For many requirements it is a superior technique.

Incandescent off the AC mains IS effectively PWM, but without full modulation depth due to thermal mass of the filament. You can try to call it something else, but the effect is PWM, hence why there is 120Hz ripple in an incandescent lights output. When you hook up a dimmer, it really does become PWM, but again the filament has "heat storage". PWM of an incandescent bulb will behave EXACTLY the same. There is no difference. None, nada, nothing.

High frequency PWM of LED behaves the same too, but in this case, you have chemical storage (eye, etc.) that smooths out fast changes. 

Vicv, the line frequency is 60Hz, but from a lighting standpoint, it's 120Hz.


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## Kestrel (Feb 28, 2017)

I don't really have anything to add here, but if anybody here hasn't read up on the ph-d M6 regulated battery pack project for the M6, it really is fascinating reading. There are ~3 threads for about ~100 pages total; probably the finest work ever done with flashlight incan technology. Highly recommended reading.


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## chillinn (Feb 28, 2017)

Thanks, Kestrel

ssanasisredna, the problem is that you believe these things, concerning PWM rates above 17kHz, even though I am telling you in fact these PWM rates (17.5kHz specifically) caused me to get headaches and migraines. The effect is not instantaneous, but cummulative. There is nothing else in the environment modulating anything, and nothing else to mitigate the plain fact that this is so, and yet, you resist the notion based upon idk what you're talking about, these unreferenced "studies." "Not possible," you irrationally and quite frankly, incorrectly and wrongly believe these falsehoods, even though I am telling you honestly, first person experience here, not something I heard or read about, supposedly, but in fact _me the man himself and a source of grievance concerning this menace of a technology_ telling you *in fact PWM rates are indeed actually a real health issue for me and likely many others.* "No," you're going to eventually reply. What's the smiley for this?

To avoid the PWM battle and get back on track...

what I have gleaned so far is that the issue is unlike the way the problem is solved with LED, using a constant current, because lamps are voltage controlled. Further, lamps are designed to be efficient and have the ideal color temperature at a certain voltage, and lower voltages will cause efficiency to drop (please confirm), and color temp to dip warmer and yellower. PWM with incan attempts to solve this, but in my experience, and documented elsewhere on CPF by others, there is still tint shift with incan PWM implementation.

Ignoring the efficiency and color temperature issues, if anyone has the patience or inclination, I would not mind a better understanding of how the current is controlled (or not) in a simple incan as the cell voltage drops. What exactly decides what the current is in an incan without a driver? I realize current and voltage are going to be related, but I don't have my head around it. 

Lastly, if the efficiency and color temp issues could be ignored or tolerated, by what method could voltage be limited in a couple different stages without pulsing the filiment with PWM or something like PWM?


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## fyrstormer (Feb 28, 2017)

The basic answer is: Electronics that can regulate current flow at the amperage incandescent bulbs use would be too large for flashlights. It is much easier to pulse the power supply as a form of regulation, and an incandescent bulb won't show the pulsing because the filament takes time to cool down and stop glowing.

EDIT: There IS, however, a small amount of noise generated by the filament vibrating from the PWM effect, and it's possible you're hearing that noise and it's causing you to get headaches. But there is no way you are *seeing* the pulses, not with an incandescent bulb. It is physically impossible for you to see it because your eyes couldn't respond fast enough, even if the bulb itself were flickering at 17.5kHz.


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## chillinn (Feb 28, 2017)

fyrstormer said:


> The basic answer is: Electronics that can regulate current flow at the amperage incandescent bulbs use would be too large for flashlights. It is much easier to pulse the power supply as a form of regulation, and an incandescent bulb won't show the pulsing because the filament takes time to cool down and stop glowing.
> 
> EDIT: There IS, however, a small amount of noise generated by the filament vibrating from the PWM effect, and it's possible you're hearing that noise and it's causing you to get headaches. But there is no way you are *seeing* the pulses, not with an incandescent bulb. It is physically impossible for you to see it because your eyes couldn't respond fast enough, even if the bulb itself were flickering at 17.5kHz.



Thanks fyrstormer, first part feels like another death blow, but an example would still help. 

Second part there... concerning this business about seeing PWM. Whether it is seen is irrelevant. I cannot see 17.5kHz PWM. Using the Lightsaver tailcap (for incan), I generally cannot see the PWM in the lower modes. This is kind of a red herring bit of evidence trying to support the idea that PWM isn't bad. You can't see CO2, so it's not killing you. You can't see that cavity, so it must not be causing you any pain. 

But I've read enough of your posts that I welcome anything you have to share. The bit about the amperage levels in incan and modern analog electronics... new to me... i mean, had some idea the amps were going to be greater in incan, but no idea that the hardware wasn't there for minature high amp apps.


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## archimedes (Feb 28, 2017)

Have you tried QTC ?


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## chillinn (Feb 28, 2017)

archimedes said:


> Have you tried QTC ?



I wonder if that could work in a momentary switch/twisty like the z52, to the effect of the momentary action and twisty action allowing the user to adjust the light level by pressure. I wonder if it could be that simple, to just stick some composite in a switch, around the inside lip where it contacts... I wonder if I could just contact Peak and have it made... :thinking:


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## TinderBox (UK) (Feb 28, 2017)

I have one of those old battery manager adaptors, it use 8xAAA in the same dimensions of 2D cells, it gives a regulated constant brightness, it also has soft start to slowly increase the brightness when you turn the light on to reduce shock on the filiment and it flashes the bulb when the battery's are getting low.

it does not have any modes and I don't know if it,'s constant current 

John.


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## Timothybil (Mar 1, 2017)

vicv said:


> Ok the install a pot in series with the bulb. I wouldn't consider it state of the art driver but will do everything you want
> And no it's 60hz. It flips from +~170v to -~170v 120 times a second for an rms voltage of 120v but that's still 60hz


Yes, the A/C power is 60hz. But each one of those 60 cycles per second involves the voltage going from zero - positive max - zero - negative max - zero. Since modern semiconductor dimming circuits start their dimming cycle every time the voltage passes through zero, that results in two dimming cycles per voltage cycle, or 120hz.


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## fivemega (Mar 1, 2017)

TinderBox (UK) said:


> I have one of those old battery manager adaptors, it use 8xAAA in the same dimensions of 2D cells, it gives a regulated constant brightness, it also has soft start to slowly increase the brightness when you turn the light on to reduce shock on the filiment and it flashes the bulb when the battery's are getting low.
> it does not have any modes and I don't know if it,'s constant current
> John.


*Did you mean regulated 8AA to 2D?*
http://www.candlepowerforums.com/vb/showthread.php?65593-Regulated-8AA-2D-adapter-W-Hunt-S-Langan
*It's not constant current or constant voltage.

I offere this item at GB of market place long time ago.*
http://www.cpfmarketplace.com/mp/showthread.php?62263-Regulated-8AA-to-2D-battery-adapter


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## TinderBox (UK) (Mar 1, 2017)

fivemega said:


> *Did you mean regulated 8AA to 2D?*
> http://www.candlepowerforums.com/vb/showthread.php?65593-Regulated-8AA-2D-adapter-W-Hunt-S-Langan
> *It's not constant current or constant voltage.
> 
> ...



Yeah, bcs powerstik is what i have.

I have been running it on an 3Cell maglite bulb instead of the originals, is there any negatives to doing this?

John.


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## chillinn (Mar 1, 2017)

TinderBox (UK) said:


> Yeah, bcs powerstik is what i have.
> 
> I have been running it on an 3Cell maglite bulb instead of the originals, is there any negatives to doing this?
> 
> John.



I never heard of the BCS Powerstick, so I did some googling...



> The advantage of the BCS Powerstik lies in -
> PWM regulator 3.6V-rms output, so no matter how the battery voltage changes, the lamp brightness throughout the stable.
> There is a soft start (Soft Start) function, turn on the lights, the light bulb is gradually brightened from the low light, effectively increase the lamp life.
> There is a low voltage warning.
> Usually with 8 batteries to drive, if necessary, 4 can also be. (So ​​it's 4 strings and 2)


source

Not sure I believe all that. Seems to be a strangely overengineered accessory. Why didn't they just make their own flashlight?


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## bykfixer (Mar 1, 2017)

So can a "smart" battery fulfill the request?


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## chillinn (Mar 1, 2017)

bykfixer said:


> So can a "smart" battery fulfill the request?



A battery with modes? Yeah, I think it could. 

I was reading earlier about Zener diodes and avalanche diodes. They can be used to limit and regulate voltage. So my first crazy thought was, what if instead of a resistor in a two-stage tailcap, somehow an appropriately matched diode was used to limit voltage when half-pressed, or partially twisted in the on position? I really don't know what I'm talking about, but if it works, it would be ironic for a diode to solve the absense of a moded PWM-less solution for incans. I got the idea from an old HKJ post (discussing how to create a secondary RCR123A with the voltage of a primary CR123A):



HKJ said:


> Use a normal LiIon battery in 16340 size, but add a diode in series with the battery. This will reduce the output voltage with about 0.6 to 0.7 volt. The voltage will be close to CR123, but still too high and the diode will heat the battery at high loads.


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## Tachead (Mar 2, 2017)

chillinn said:


> Thanks, Kestrel
> 
> ssanasisredna, the problem is that you believe these things, concerning PWM rates above 17kHz, even though I am telling you in fact these PWM rates (17.5kHz specifically) caused me to get headaches and migraines. The effect is not instantaneous, but cummulative. There is nothing else in the environment modulating anything, and nothing else to mitigate the plain fact that this is so, and yet, you resist the notion based upon idk what you're talking about, these unreferenced "studies." "Not possible," you irrationally and quite frankly, incorrectly and wrongly believe these falsehoods, even though I am telling you honestly, first person experience here, not something I heard or read about, supposedly, but in fact _me the man himself and a source of grievance concerning this menace of a technology_ telling you *in fact PWM rates are indeed actually a real health issue for me and likely many others.* "No," you're going to eventually reply. What's the smiley for this?
> 
> ...



Your headaches could be psychosomatic or caused by a number of other things. Believe what you want but, your single opinion/belief doesn't overthrow the findings of actual scientific research. If all frequencies of PMW were harmful they would likely be regulated by like you said. Did you ever consider you may actually be causing these headaches by worrying about PWM so much? Do you often eat dark chocolate while staring into your PWM flashlights LED's? I bet if a double blind test was conducted on you with a few different light sources the headaches wouldn't be replicated consistently. 

Anyway, until you have some scientific proof, quit trying to force your opinion down peoples throats man. Your single belief is proof of nothing and you're not going to convince everyone to hate PWM. PWM is used in devices all around you everyday and it's not going anywhere anytime soon. You really should stop stressing so much about it(oh the irony considering your name is chillinn) because stress is scientifically proven to be harmful to you:thumbsup:


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## chillinn (Mar 2, 2017)

Oh, fantastic, the PWM fan boi himself, Tachead, stopped by for an offtopic troll. Wonderful, Tachead, but if you can't stay on topic, and if you cannot do anything but post trolls, please, I beg you, do not litter this thread with your intolerable garbage. Thank you.

From the link I provided in post #31 above



> Although humans cannot see fluorescent lights flicker, the sensory system in some individuals can somehow detect the flicker. Ever since fluorescent lighting was introduced in workplaces, there have been complaints about headaches, eye strain and general eye discomfort. These complaints have been associated with the light flicker from fluorescent lights. When compared to regular fluorescent lights with magnetic ballasts, the use of high frequency electronic ballasts (20,000 Hz or higher) in fluorescent lights resulted in more than a 50% drop in complaints of eye strain and headaches. There tended to be fewer complaints of headaches among workers on higher floors compared to those closer to ground level; that is, workers exposed to more natural light experienced fewer health effects. [ Fluorescent lighting, headaches and eye-strain. A. J. Wilkins, I. Nimmo-Smith, I., A. Slater & L. Bedocs. Lighting Research and Technology, 1989. Vol. 21, 11-18]



Many people experience pain due to the effects of flickering lighting, including PWM. There is a mountain of scientific evidence, as well as the evidence of the testimony of those it effects. Strobe lighting is used as a weapon, yet there is still a lie-spewing holdout, an absurd clown-troll-thing, that insists on believing incorrect and false things, such as that PWM has no detrimental health effects, and insists arguing about what is plain as day to rational individuals.

*The topic is not PWM nor its poor health effects, but looking for a path to a constant light output for moded incan, to reveal an effecient way to reduce the voltage to the lamp without utilizing PWM.*


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## ssanasisredna (Mar 3, 2017)

Whether you use a capacitor as a storage element or a hot wire really does not matter now does it? The result is exactly the same, constant light at least with Incan.

Of course there is the chemical storage element in the eye too ..


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## bykfixer (Mar 3, 2017)

I get a headache everytime I whack my head with a hammer.

Is there scientific proof replete with graphs n charts? 
I dunno, but I do know from trial and error it happens everytime. I also know it's completely irrelevant to this thread.
So....

As entertaining as a good geek spat can be can we please get this train back on the tracks toward constant current in an incan flashlight? 
PWM with a filament sounds like a recipe for short lifespan'd light bulbs. 
I kinda figured this thread was about keeping a bulb as bright as possible in a more consistant amount, without the typical dimming that takes place as the fuel cell depletes...
Hence my comment about smart batteries.

Good topic Chillin. Perhaps if those uber efficient bulbs MIT and some Koreans in lab coats are working on become reality, by then someone will have a way to regulate the output.


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## Kestrel (Mar 3, 2017)

In my grumpy old age I am less inclined to sift through threads to delete the personally-argumentative posts and to clean the thread up via edits - it is more time efficient just to close a thread if it has outlived its purpose. 
I think the points about PWM have been made and we can move forward on the thread topic as a whole. Thank you,


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## bykfixer (Mar 3, 2017)

^^ Love the friendly green font in that post. lol. Does that make it a "frumpy" post?

If they could send a man to the moon using direct current in the 1960's (if you believe them lol) then certainly somebody could provide a constant flow to a light bulb using direct current.


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## chillinn (Mar 3, 2017)

bykfixer said:


> PWM with a filament sounds like a recipe for short lifespan'd light bulbs.



Can't say either way, but I do know softstart is an implementation of something like PWM, but ramping the lamp up slowly, and the effect is lamps lasting longer (at least this is how it is advertised). But after the filiment reaches it's ideal temperature, I wonder if PWM pulsing is worse for its lifespan than a constant applied voltage. 

I have experienced strange things with PWM and cells. When I use a primary in my E1e with the stock or any mechanical tailcap, I can use that cell until it is close to 1.5v or less before the filiment won't light at all. When I use Lightsaver tailcap with PWM, I may get the same runtimes, but the cell will get to a point that it won't fire the lamp with any tailcap, yet still read 2.85V resting. This concerns me for my use of more expensive secondary cells with the Lightsaver, though I haven't seen any odd behavior from my secondary cells yet. Obviously I am not depleting my secondary cells entirely, but recharging whenever the voltage is below 3.6V. 




bykfixer said:


> I kinda figured this thread was about keeping a bulb as bright as possible in a more consistant amount, without the typical dimming that takes place as the fuel cell depletes...
> Hence my comment about smart batteries.



...which lead to my personal discovery of Zener and avalanche diodes, which I am hoping someone that knows electrics can discuss regarding my suggestion of tailcapping one instead of a resistor...



bykfixer said:


> Good topic Chillin. Perhaps if those uber efficient bulbs MIT and some Koreans in lab coats are working on become reality, by then someone will have a way to regulate the output.



That will be sweet with... was it 40% efficiency? It will be "so long LED!!" And then some of the better flashlight manufacturers will be reading this thread trying to figure out how to run moded lamps without PWM so they can advertise their lights are superior.


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## ssanasisredna (Mar 3, 2017)

chillinn said:


> That will be sweet with... was it 40% efficiency? It will be "so long LED!!" And then some of the better flashlight manufacturers will be reading this thread trying to figure out how to run moded lamps without PWM so they can advertise their lights are superior.



I guess it would be pointless to point out that:

- That was highly specific lab made thought exercises that achieve 40%
- That they no longer have a blackbody spectrum, so while the underlying tech is "hot wire" they output spectrum is not
- Similar to advanced halogen, they don't like to be dimmed ... you can, but then lose efficiency/life advantages
- They still have poor life
- That LEDs are already >60% .... production, not in the lab
- That they last 100K+ hours maintaining high output

I don't think anybody making LED anything is losing any sleep over "incandescent" technology. This LED thing is just a fad after all.

... and no, no MFR of INCAN will be "reading this thread trying to figure out how to run without PWM" as either A) They will just use PWM or B) they know that there are millions of engineers who can do that in their sleep.


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## Tachead (Mar 3, 2017)

ssanasisredna said:


> I guess it would be pointless to point out that:
> 
> - That was highly specific lab made thought exercises that achieve 40%
> - That they no longer have a blackbody spectrum, so while the underlying tech is "hot wire" they output spectrum is not
> ...




He is talking about this...

http://news.mit.edu/2016/nanophotonic-incandescent-light-bulbs-0111

It says that most commercial LED's only have a 5-20% energy to light efficiency where as these new Nanophotonic incandescents could achieve up to 40% through light recycling.


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## chillinn (Mar 3, 2017)

ssanasisredna said:


> I guess it would be pointless to point out



Not pointless. Pointful, actually.




ssanasisredna said:


> - That LEDs are already >60% .... production, not in the lab



The most efficient LEDs don't create the highest quality light. Where the efficiency advancement matters most is in phosphors for best color rendering, and the trend appears to be that the efficiency of the best LEDs for color rendering lag a decent ways behind the most efficient LEDs.




ssanasisredna said:


> I don't think anybody making LED anything is losing any sleep over "incandescent" technology. This LED thing is just a fad after all.



Fair enough, but LED tech is rapidly approaching theoretical max efficiency. There's just a few more more years of innovation left, and then you can stick a fork in LED advancement. Incan tech, unless it be for heating (which it seems to be more efficient at than lighting), appears to be all unconquered territory ripe for decades or another century's worth of advancement. Smart engineers will want job security, and will see LED advancement as finished once it approaches its theoretical max efficiency, and will abandon further LED research as pointless, instead opting for the endless opportunity in incan advancement. Hang on to your LED flashlights as they will be collectors museum pieces soon enough, relics from a less elegant age when people just endured poor lighting simply because it was more efficient than quality lighting.




ssanasisredna said:


> ... and no, no MFR of INCAN will be "reading this thread trying to figure out how to run without PWM" as either A) They will just use PWM or B) they know that there are millions of engineers who can do that in their sleep.



Pardon my misunderstanding, but do what in their sleep? And you never know, maybe some who've already posted on the thread will go on to be the next great American incan flashlight manufacturer. :rock:






Tachead said:


> He is talking about this...
> 
> http://news.mit.edu/2016/nanophotonic-incandescent-light-bulbs-0111
> 
> It says that most commercial LED's only have a 5-20% energy to light efficiency where as these new Nanophotonic incandescents could achieve up to 40% through light recycling.



Thanks for posting that and totally redeeming yourself in the end. I almost went looking for it again, but you saved me the trouble.


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## Tachead (Mar 3, 2017)

chillinn said:


> Not pointless. Pointful, actually.
> 
> 
> 
> ...



*Theoretical - *Existing only in theory; hypothetical.

I wouldn't put too much faith in theory, it is after all just an educated guess and theories have been consistently proven wrong over and over again throughout history. No one really knows what the future of lighting technology will bring.


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## ssanasisredna (Mar 3, 2017)

Chillin,

I do not think you have adequate knowledge for us to have this discussion. I think you will have a more realistic position once you gain that knowledge. There is lots on CPF and if you ask questions you will get honest answers.

You are trying to promote a position to people who are essentially experts who are trying to tell you reality. We don't have a "position" other than facts.


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## Tachead (Mar 3, 2017)

chillinn said:


> Not pointless. Pointful, actually.
> 
> 
> 
> ...



No problem. Just so you know, I am not a PWM fanboy by the way. I actually hate visible PWM and generally avoid lights with PWM. I just don't believe that all frequencies of PWM are harmful.


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## bykfixer (Mar 3, 2017)

Once upon a time this was a fun thread. 
Maybe Kestrel will come back the fork in it so the poor dead horse can rest in peace.


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## chillinn (Mar 3, 2017)

bykfixer said:


> Once upon a time this was a fun thread.
> Maybe Kestrel will come back the fork in it so the poor dead horse can rest in peace.



Personally, I'm not accepting the empty explanations for dening the possiblity of PWM-less moded incan. I feel like I have provided the proof of concept of a way it could work already, through HKJ's suggestion concerning lowering the voltage of Li-ion secondary cells to the voltage level of Lithium primary cells. I have a feeling there's probably a half-dozen ways to limit voltage no one has mentioned. Accepting that a lamp driven at a lower voltage than it is specified for is not going to be lit idealy is a given. I don't see it as much of a problem if what you get for the sacrifice of ideal color temperature is quadrupal runtime on lower modes. I kind of wish the negative nellies would move on, as there's only so many ways to express the personal opinion "I don't think you can do that," before it starts sounding like "I don't want you doing that."


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## ssanasisredna (Mar 4, 2017)

Deleted


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## bykfixer (Mar 4, 2017)

When they come out with an incan with pwm I can imagine using one while walking in a thunderstorm. 
The song "singing in the rain"- the disco version will be playing in my head. 

As my progress continues I'll chuckle as everyone in my beam will be flailing about in epileptic siezures. 

I see what you are getting at ssandre, but it seems pwm is not something that would be on a list of wants by the author of this thread. 
It'd be like the time Richard Petty built a race car then refused to drive it. Why? He replied "man that thing'll kill ya".


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## ssanasisredna (Mar 4, 2017)

bykfixer said:


> When they come out with an incan with pwm I can imagine using one while walking in a thunderstorm.
> The song "singing in the rain"- the disco version will be playing in my head.
> 
> As my progress continues I'll chuckle as everyone in my beam will be flailing about in epileptic siezures.
> ...



That's quite a wild imagination.


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## Kestrel (Mar 5, 2017)

bykfixer said:


> Once upon a time this was a fun thread.
> Maybe Kestrel will come back the fork in it so the poor dead horse can rest in peace.


Lol, not against PWM discussion per se; in fact it may be a primary aspect of this thread topic - the two regulated incan iterations that I know of both utilize pwm.

But I posted earlier because the discussion was starting to get personal - the old standby still works: "attack the post, not the poster".



ssanasisredna said:


> That's quite a wild imagination.


Posts like this, come to mind. :ironic:


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## bykfixer (Mar 5, 2017)

Kestrel said:


> the two regulated incan interations that I know of both utilize pwm.
> 
> :



So pwm does not mean automatic premature death sentence to the light bulb?
Cool!!! 

My morning commute involves tree lined interstate travel at sunrise so the constant flicker of sunrise at 60+mph is no big deal. Nor is working around massive multi colored disco light flashers on vehicles. But I do understand PWM bothers a whole lot of people. It is an awesome invention. But it seems many manufacturers have figured out how to throttle back LED's without dramatic tint changes and being an arm chair quarterback kinda figure somebody could do it to the old edison bulb. 
Perhaps my krypton bulb'd table lamp is flickering away without me noticing? Hmmm, maybe that's why my wife and one of the kids keep getting headaches? 

Thanks for keeping this open sir.


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## fyrstormer (Mar 12, 2017)

chillinn said:


> Thanks fyrstormer, first part feels like another death blow, but an example would still help.


I have a Lumens Factory 9V 320lm incandescent drop-in. Lumens Factory says it will run for ~40 minutes on a pair of RCR123 batteries. RCR123s are rated at .75 amp-hours when new, so if they can be drained in 40 minutes by an incan bulb then the bulb is consuming an _average_ of 1.125 amps. That doesn't seem like much, but remember that it's running without regulation, so it's actually pulling several amps when the batteries are fully-charged, dropping steadily downward as the batteries drain. The peak amperage is probably closer to 3 amps. That still isn't a significant amount of amperage for short bursts, but to run for more than a couple minutes the current-regulating electronics would need heat-dissipation to avoid overheating. The drop-in occupies the entire head of the light, so there would need to be a second compartment for the current-regulating electronics to sit in, and adequate heat dissipation would be difficult to provide with the electronics sitting right next to a chamber occupied by a white-hot piece of tungsten that's heating the entire body of the light. They would probably be better-positioned in the tailcap. The incan light that I'm using for my example is fitted with a 4-mode PWM tailcap that I pulled from an old Jetbeam LED light, and it's about a half-inch longer than a normal P60-size tailcap to make room for the PWM circuit board and the mode-selector button. I honestly don't know how much larger it would need to be to contain current-regulating electronics that could handle 3 amps for a sustained period of time; the only light I have that burns that much power is a P60-compatible light with an Oveready 1000lm drop-in, and that uses PWM in the megahertz range to regulate power to its 3-LED array. Even using PWM the drop-in is still as big as a normal P60 drop-in; at a guess, current-regulating electronics that could do the same job would probably take up the same amount of space as the entire drop-in does, including the 3-LED array and the TIR optics that focus the LEDs. So for a current-regulated P60-compatible incan light, you'd probably be looking at a light big enough to hold two P60-size drop-ins instead of one, with separate chambers at each end of the battery compartment. I guess that's not a problem if you prefer large flashlights, but I prefer ones that easily clip into my pocket with room to spare.



chillinn said:


> Second part there... concerning this business about seeing PWM. Whether it is seen is irrelevant. I cannot see 17.5kHz PWM. Using the Lightsaver tailcap (for incan), I generally cannot see the PWM in the lower modes. This is kind of a red herring bit of evidence trying to support the idea that PWM isn't bad. You can't see CO2, so it's not killing you. You can't see that cavity, so it must not be causing you any pain.


Consider that incandescent lightbulbs in your house all "flicker" at 120Hz, because the alternating current power supply oscillates at 60Hz. Power goes one direction through the filament for 1/120th of a second, then stops, then goes back the other way for 1/120th of a second. If you can't see the flickering from incandescent lightbulbs operating on what is effectively 120Hz PWM, then you definitely can't see the flickering from 17,500Hz PWM. But again, you CAN hear 17,500Hz, because that is within the range of human hearing, and that may be causing you discomfort. I have a couple flashlights with audible high-frequency PWM and they are definitely more irritating to use for long periods of time.


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## fyrstormer (Mar 12, 2017)

bykfixer said:


> So pwm does not mean automatic premature death sentence to the light bulb?
> Cool!!!


No, certainly not. If it did, household lightbulbs wouldn't be able to run on alternating current.



bykfixer said:


> It seems many manufacturers have figured out how to throttle back LED's without dramatic tint changes and being an arm chair quarterback kinda figure somebody could do it to the old edison bulb.


Not possible, unfortunately. LEDs and incans generate light in fundamentally different ways. An LED generates light the same way a radio antenna generates radio waves; it is effectively broadcasting electromagnetic radiation on a frequency that is pre-tuned by the molecular composition of the emitter. As such, it can be cycled on and off extremely quickly to reduce its power consumption without changing the frequency of the EM radiation it emits when it's powered-on, and the rest of the color spectrum is filled-in by a phosphor layer on top of the emitter. An incandescent bulb, on the other hand, emits light in a wide range of frequencies at once, and the range of frequencies is determined moment-to-moment by the temperature of the filament. ANYTHING that reduces the power consumption of the filament will also reduce its temperature, and thus also change the spectrum of light it emits.


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## bykfixer (Mar 12, 2017)

^^ Good info! Thanks! 

My mind contemplates a 3 or 4x 123 cell length light with a 2 cell operating system. Based on the above posts that is. At the tail end the cooling system for the regulator taking up room one cell does in a multi cell light. 
And perhaps a 2 stage switch to power a pair of bulbs. Like those triples etc both could be lit for high, or one be lit for low via the switching system. That way lesser output would stay pretty similar in tint. 

I have a 1aa incan with a 2aa (#222) bulb in it to provide a dimmer, more orange output. It's about the size of a Solitaire, but brighter with the magnifier tip'd #112.
In complete darkness it is surprisingly effective at my end and surprisingly unseen by someone else. I did mirror testing using a beam profile to see how it worked. 
With my hand cupped around the bezel I can see surprisingly far while sneaking up on a would-be villain inside my home. And would be villain, pre-occupied with stealing the silverware would not see me until it was too late. "Flash-bang"

I say that to point out that if regulation to reduce output changes the tint to create a better stealth mode... I'm ok with that.


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## Need a Light? (Mar 12, 2017)

So, could be completely off topic, as I read a bit, but also skimmed a bit.

I have an old 6D Incan 'Dyna-Lite' made in OH. (2 actually). It has a slider switch, that when you start sliding, turns the bulb juuuust barely on, and sliding it all the way up gives full brightness, with everything in between. Basically a dimmer switch. 

Granted, you lose some color temp as you go dimmer. But why is this the only light I know if that does this?

Is it just resistance in the switch, as you slide it it has a wider contact patch maybe? I wonder if it still pulls the same current when it's dim?

It's my only dimmable Incan and I love the light, but didn't know where to post about the dimming, this thread seemed reasonably appropriate.


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## chillinn (Mar 12, 2017)

fyrstormer said:


> ...so there would need to be a second compartment for the current-regulating electronics to sit in, and adequate heat dissipation would be difficult to provide with the electronics sitting right next to a chamber occupied by a white-hot piece of tungsten that's heating the entire body of the light. They would probably be better-positioned in the tailcap....



Unlike with LED, nearly all of the heat from the tungsten filament is shooting right out the front with the light it provides. Only a fraction of the heat from the filament is heating your entire flashlight, and most of that heat is likely coming from your cells as they provide voltage and current.

I haven't seen one first hand, and though it is an LED tower, CPF member Tana is currently offering moded LED tower SingLED for E series (at least), and somehow has stuffed his driver into the little drop-in. I have no idea if an incan driver could be made small enough to fit that size housing, but it is at least a proof of concept for a spot for an incan driver. If SingLED provides enough heat sinking for LED, where the heat is mostly NOT shooting out the front, then a similar housing should provide enough heat sinking for an incan driver. I wouldn't mind the driver in the tailcap, but as has been addressed in this thread already, it would be more ideal for the driver to be in the head than the tailcap (for the reasons, see the above posts). I have no preference, personally, just repeating the info already addressed.



fyrstormer said:


> Consider that incandescent lightbulbs in your house all "flicker" at 120Hz, because the alternating current power supply oscillates at 60Hz. Power goes one direction through the filament for 1/120th of a second, then stops, then goes back the other way for 1/120th of a second. If you can't see the flickering from incandescent lightbulbs operating on what is effectively 120Hz PWM, then you definitely can't see the flickering from 17,500Hz PWM. But again, you CAN hear 17,500Hz, because that is within the range of human hearing, and that may be causing you discomfort. I have a couple flashlights with audible high-frequency PWM and they are definitely more irritating to use for long periods of time.



This second point has also been addressed. The flickering in fixed incan lighting is not a fair comparison to PWM, as the effects are not at all similar. Fixed lighting oscillating at 120Hz is not causing any issues. The flicker is minuscule, and the change in brightness is smooth and tightly centered. PWM drops the voltage to zero, then back up to full. It has been said that PWM in incan is undetectable because the filament doesn't have time to cool enough to drop the light output. But it drops it enough in some implementations to be detectable if you look carefully (like the Lightsaver Miser), but detecting it isn't the issue. The effect it has, whether it is detectable or not, is the issue, and the effect, which is not immediate but cumulative over the exposure, is that it causes pain in some, including me. 

Again, whether PWM can be seen is a red herring, and not any sort of proof that it can't be having any painful effect. Lots of things that can't be seen can hurt you, please don't make me start listing the counter-examples again, there are so many, and I have listed them too many times, annoying the owner of the site, among others.

I'm going to carefully say that it is possible that a good implementation of something like PWM (voltage pulsing) in incan may be acceptable (but might never be acceptable with LED), if it can at least achieve what fixed incan lighting achieves with its 120Hz cycles. If the rise and fall of the brightness is so fast and tight, light doesn't dim further than what can only be detected with extremely slowed down video of incan fixed lighting, then the effect should be the same, i.e. no effect.

However, as it has already been shown (in CPF threads of the past since the availability of aftermarket PWM tailcaps such as Lightsaver Miser) that the claim that PWM in incan maintains the tint and prevents yellowing at lower modes is simply false. You lower the voltage to a lamp designed for a higher voltage, and the light is going to get warmer and yellower as the voltage drops and the light dims. Bearing this in mind, PWM doesn't live up to it's claim (for incan; PWM maintaining tint in LED is another story), I honestly can't see the point of even having it. If it isn't needed, because it doesn't provide any advantage in tint or battery capacity over a constant current solution (really, a constant voltage solution), then it is superfluous, i.e. unnecessarily adding complexity to a system without benefit. 

The incan constant current (i.e. constant voltage) solution I am requesting since my initial post should be a simpler system, and more efficient, giving better runtimes. All things being equal, the simpler solution is best, with the caveat and understanding that the lower modes provided by lower voltage will not be powering the lamp ideally, causing tint shift. Tint shift is a small price to pay for avoiding a migraine trigger.



Need a Light? said:


> I have an old 6D Incan 'Dyna-Lite' made in OH. (2 actually). It has a slider switch, that when you start sliding, turns the bulb juuuust barely on, and sliding it all the way up gives full brightness, with everything in between. Basically a dimmer switch. ... Is it just resistance in the switch, as you slide it it has a wider contact patch maybe? I wonder if it still pulls the same current when it's dim



That sounds like a potentiometer, as described above in other posts. Other suggestions to achieve the same effect include QTC or electron quantum tunneling, such as that used by Peak in their lights. I have also suggested that perhaps a Zener diode or avalanche diode could be implemented to lower voltage, sparing a drop in current. Unfortunately for me, I my electrics kung fu is weak to non-existent, and I am at the mercy of clever, knowledgable, experienced, kind, and patient CPF members to come along and explain how some of these ideas are valid, some are not, and the reasons why, and how moded incan can be implemented practically without PWM, revealing the path ahead for us. I hope someone else can address your post better.


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## Minimoog (Mar 20, 2017)

I'm not an expert in circuit design but I have a few comments as I built around 5 lights with a PWM regulator fitted to regulate the brightness. Firstly it really is good to regulate incan lights for more reasons than to just keep the beam brigher for longer. I have found that regulting lights:

Almost eliminates flicker from slightly ressitive battery contacts
Makes bulb last longer as it does not get an inrush of current nor overvoltage
Can be set very accurately with a Fluke to run bulbs as bright as possible
Batteries last longer as less load - the more batteries the better!

Prior to setting up the regulator I do testing on the bench using a regulated bench PSU. I can run bulbs through burn cycles and find out how hard I can drive them before lifetime suffers. Using a regulator I find that I can go way above the rated voltage with little penalty - as opposed to using batteries direct that will blow bulbs quite readily if not rested after recharge etc. For instance in one of my lights I use Gibraltar 1.25 Volt bulbs (big globe, single strand filament) and with a regulator I can get them up to 1.85 Volts without a problem. This gives a lovely silvery light. Same for more powerful bulbs - run them over rated with rarely any problem.

As to flicker, the filament does not flash like an LED due to heat in the filament - same as removing metal from a fire - stays glowing for a good time. As to the buzz I house all my regulators inside the light and seal with thick cell foam - or you could use epoxy and leave just the adjuster free.


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