As posted above, are regulated LED lights always preferred over non-regulated lights or are there times people here would actually prefer non-regulated LED lights? I suspect that all things considered a regulated light is always more expensive than a non-regulated light, correct?
Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashlights?
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StarHalo
Flashaholic
No regulation means nothing between the battery and the emitter for max amp draw, a better configuration for insane output lights. But regulation is better for pretty much everything else.
Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
People say current regulated lights have more tint shift at low lumens, and that PWM lights maintain more even tints, but I don't see any difference (HERE is a pix of sub-lumen and ~100 lms, and one light is PWM).
Give me current regulated any day.
People say current regulated lights have more tint shift at low lumens, and that PWM lights maintain more even tints, but I don't see any difference (HERE is a pix of sub-lumen and ~100 lms, and one light is PWM).
Give me current regulated any day.
AnAppleSnail
Flashlight Enthusiast
Re: Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
It's a pretty slight tint shift above 1% rated drive current, but it is there. You'd need a constant-current flashlight with moonlight, and a PWM-capable flashlight with equally dim settings, to see it.
But "What is regulation?" In some ways, PWM is a form of regulation. Constant current is supplied (100% drive level) and flicked on/off to create different duty cycles of constant current and off.
"Regulation" can mean closed-loop feedback (A device measures the actual current or even lumen output and adjusts parameters to reach a set level).
Regulated can also mean open-loop control (Run so that the sense resistor sees xx volts).
Regulated can be open-loop with a gain factor (PWM).
Heck, I could say that my resistor 'regulates' about 0.4v off the 3xAA pack so the LED doesn't burn out. What is regulation?
If we just go with the output: Is "Regulated" ruler-flat output until the battery is dead, then total darkness? That's great for some people. It's life-threatening for others. I have some lights that do this. It's frightening when they go flat without a warning signal aside from keeping a stopwatch running to count battery life.
Other lights of mine tail off output from the moment I turn them on. Sometimes just what I want is 5 hours of light that keeps going, even as it gets dimmer. That would certainly be 'unregulated...' Unless I programmed the controller (Or response to battery discharge) to regulate that pattern. Regulation is tricky, since it has many meanings. In other words, I can regulate a light by several mechanisms, to create several regulation profiles, with several regulation patterns. As with all things, the most important thing is that a product fills your needs, than that it has the coolest super-regulated or hyper-tapered output profile. Do you need constant video light or a lot of stretched runtime during a power outage? Purchase accordingly. Look at runtime charts (Made by CPF members) for more information about lights you're considering.
Mechanism: Drive circuit and input to driver.
Regulation profiles: Flat or tapered?
Regulation pattern: Constant-current, PWM, hybrid?
It's a pretty slight tint shift above 1% rated drive current, but it is there. You'd need a constant-current flashlight with moonlight, and a PWM-capable flashlight with equally dim settings, to see it.
But "What is regulation?" In some ways, PWM is a form of regulation. Constant current is supplied (100% drive level) and flicked on/off to create different duty cycles of constant current and off.
"Regulation" can mean closed-loop feedback (A device measures the actual current or even lumen output and adjusts parameters to reach a set level).
Regulated can also mean open-loop control (Run so that the sense resistor sees xx volts).
Regulated can be open-loop with a gain factor (PWM).
Heck, I could say that my resistor 'regulates' about 0.4v off the 3xAA pack so the LED doesn't burn out. What is regulation?
If we just go with the output: Is "Regulated" ruler-flat output until the battery is dead, then total darkness? That's great for some people. It's life-threatening for others. I have some lights that do this. It's frightening when they go flat without a warning signal aside from keeping a stopwatch running to count battery life.
Other lights of mine tail off output from the moment I turn them on. Sometimes just what I want is 5 hours of light that keeps going, even as it gets dimmer. That would certainly be 'unregulated...' Unless I programmed the controller (Or response to battery discharge) to regulate that pattern. Regulation is tricky, since it has many meanings. In other words, I can regulate a light by several mechanisms, to create several regulation profiles, with several regulation patterns. As with all things, the most important thing is that a product fills your needs, than that it has the coolest super-regulated or hyper-tapered output profile. Do you need constant video light or a lot of stretched runtime during a power outage? Purchase accordingly. Look at runtime charts (Made by CPF members) for more information about lights you're considering.
Mechanism: Drive circuit and input to driver.
Regulation profiles: Flat or tapered?
Regulation pattern: Constant-current, PWM, hybrid?
Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
Thought that's what I provided in the pix linked above, top half all moonlight, bottom half all ~ 100 lumens, one light uses PWM on ML - what do you look for?
Except for Li-ions, I check my batteries periodically (when I think they might be getting low) by comparing the two highest modes. On a well regulated light (no such thing as perfect), the voltage sag as the batt weakens will lose the highest modes one at time, leaving you with a reasonable "reserve" runtime on the lower modes to get to the battery swap. Protected Li-ions, of course, will steam ahead until they trip their circuits... I don't believe you would want see them dimming either way.
Thought that's what I provided in the pix linked above, top half all moonlight, bottom half all ~ 100 lumens, one light uses PWM on ML - what do you look for?
Except for Li-ions, I check my batteries periodically (when I think they might be getting low) by comparing the two highest modes. On a well regulated light (no such thing as perfect), the voltage sag as the batt weakens will lose the highest modes one at time, leaving you with a reasonable "reserve" runtime on the lower modes to get to the battery swap. Protected Li-ions, of course, will steam ahead until they trip their circuits... I don't believe you would want see them dimming either way.
mcnair55
Flashlight Enthusiast
Curious_character
Flashlight Enthusiast
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- 1,211
I personally strongly prefer regulated lights. But non-regulated ones have characteristics that might be useful in some applications. Because of the exponential relationship between LED voltage and current, a non-regulated light (typically one using three AAA cells or possibly one RCR123 cell) begins very bright because the LED current is limited only by the internal battery resistance. This heavy discharge lowers the battery voltage quickly. But as the battery discharges and the voltage drops, the LED current drops dramatically -- very small battery changes cause very large LED current changes. This reduces the discharge rate. The LED brightness is nearly proportional to the current, so it drops a lot, too. But the more the battery discharges, the less current the LED draws and the longer it takes for the battery to lose its remaining charge. The net result is a very, very long "tail" to the light output -- the light will seem to go on forever, however at an increasingly dim level. If, for example, you couldn't carry spare batteries and absolutely had to have some light -- even very dim light -- for a very long time, an unregulated light would be the ticket. In contrast, a tightly regulated light puts out a constant intensity light right up until the battery is exhausted, then abruptly quits. Some lights attempt to give you the best of both worlds by dropping out of regulation when the battery gets low, so you still get a "moonlight mode" -- a dim output -- for an extended time before the battery completely dies.
c_c
c_c
to give an easier explanation ...
"pros" who know their lights, and how to handle (with) them, can cope with regulated lights and they are much better,
but for the beginner ... with non regulated lights there is:
* much longer runtime (declining output is hard to see for them) and
* no sudden end of the light, like they would have with regulated ones
--> as with most anything else: matter of personal taste
"pros" who know their lights, and how to handle (with) them, can cope with regulated lights and they are much better,
but for the beginner ... with non regulated lights there is:
* much longer runtime (declining output is hard to see for them) and
* no sudden end of the light, like they would have with regulated ones
--> as with most anything else: matter of personal taste
AnAppleSnail
Flashlight Enthusiast
Re: Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
Tint shift, of course. Is the second from the left the PWM light? With fixed camera CCT and adjusted exposure, I am able to see it. Also I can see by eye if I change modes myself. The Cree LED datasheet tells you exactly how much it shifts with current and temperature.
However, brightness also affects perceived tint.
Tint shift, of course
. Is the second from the left the PWM light? With fixed camera CCT and adjusted exposure, I am able to see it. Also I can see by eye if I change modes myself. The Cree LED datasheet tells you exactly how much it shifts with current and temperature.However, brightness also affects perceived tint.
thedoc007
Flashlight Enthusiast
I'm a fan of regulation. The best type in my opinion is regulation with automatic stepdown as battery gets low. It gives you tons of runtime as well, but you have clear warnings/steps to alert you precisely when you reach certain points of battery depletion. Much better to have a clear stepdown from high, to medium, to low, to moonlight, rather than gradual dimming which leaves you guessing as to both output and remaining battery life.
RetroTechie
Flashlight Enthusiast
Re: Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
Very few lights will power their LED's with a battery directly, that's stupid.
Small cells with high internal resistance being the exception (many CR20xx keychain lights for example).
In most cases there will be a series resistor to limit LED current to reasonable levels. You get a light that gradually dims, dims, and dims... but keeps outputting some light almost 'forever'. Which WILL be the preferred behavior for some use cases, in particular where you don't ever, ever want to be in complete darkness. Cave diving comes to mind... Also note that light output for such a light is a direct indicator for battery voltage/condition.
So as much as I like regulated lights, unregulated lights have their uses.
That works with Li-ions too... even with a flat discharge curve, it's the deliver-high-current of a battery that starts to drop as it runs empty. And it's the best way to check battery condition: under load.
I'd imagine there exist very few lights (if any!) that actually measure their own light output as a means of controlling same output.
Since voltage across a resistor is linear with current through it, that's effectively the same. Taking that as control measurement, would count as "closed loop" (see for example operational amplifier circuits as to why that would be/would not be the case). Similar thing goes for PWM regulation if the "on" part of the PWM cycle is controlled that way. The other part of the equation is the LED's lumens output @ a given current, which is (more or less) a constant.
Very few lights will power their LED's with a battery directly, that's stupid.
Small cells with high internal resistance being the exception (many CR20xx keychain lights for example).In most cases there will be a series resistor to limit LED current to reasonable levels. You get a light that gradually dims, dims, and dims... but keeps outputting some light almost 'forever'. Which WILL be the preferred behavior for some use cases, in particular where you don't ever, ever want to be in complete darkness. Cave diving comes to mind...
Also note that light output for such a light is a direct indicator for battery voltage/condition.So as much as I like regulated lights, unregulated lights have their uses.
Curious_character
Flashlight Enthusiast
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Re: Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
A little clarification from a EE:
"Regulation" implies that the regulated value is caused to be held constant by a feedback mechanism. In the case of a flashlight, the brightness of an LED is very nearly proportional to the current through it, so in a regulated flashlight the LED current is regulated or held constant regardless of the battery or LED voltage. "Closed loop" in this context means that the parameter being regulated (current -- see below) is sampled and this sample is used to adjust the parameter (current). A familiar example of a closed loop regulator is the thermostat and associated circuitry that regulates the temperature of your home by sensing the temperature and using that to control the furnace.
PWM is a way of reducing the average current through the LED, and if done well it can be very efficient. Although virtually all the PWM lights I've seen are regulated (that is, the average LED current is regulated by automatic adjustment of the pulse width), it's not an inherent feature of PWM so a light could have PWM without regulation.
There's a continuum between completely regulated and completely unregulated. For example, if the battery voltage is considerably higher than the LED voltage, a simple series resistor will deliver a fairly constant current to the LED as the battery voltage declines. The disadvantage of this approach is that to improve the regulation, the battery voltage must be made increasingly greater than the LED voltage, and that reduces the efficiency. That is, a bigger fraction of the battery's energy is used in heating the resistor as opposed to creating light.
c_c
A little clarification from a EE:
"Regulation" implies that the regulated value is caused to be held constant by a feedback mechanism. In the case of a flashlight, the brightness of an LED is very nearly proportional to the current through it, so in a regulated flashlight the LED current is regulated or held constant regardless of the battery or LED voltage. "Closed loop" in this context means that the parameter being regulated (current -- see below) is sampled and this sample is used to adjust the parameter (current). A familiar example of a closed loop regulator is the thermostat and associated circuitry that regulates the temperature of your home by sensing the temperature and using that to control the furnace.
PWM is a way of reducing the average current through the LED, and if done well it can be very efficient. Although virtually all the PWM lights I've seen are regulated (that is, the average LED current is regulated by automatic adjustment of the pulse width), it's not an inherent feature of PWM so a light could have PWM without regulation.
There's a continuum between completely regulated and completely unregulated. For example, if the battery voltage is considerably higher than the LED voltage, a simple series resistor will deliver a fairly constant current to the LED as the battery voltage declines. The disadvantage of this approach is that to improve the regulation, the battery voltage must be made increasingly greater than the LED voltage, and that reduces the efficiency. That is, a bigger fraction of the battery's energy is used in heating the resistor as opposed to creating light.
c_c
Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
No, only the top right corner is PWM (1st gen H51w)
Tint shift, of course
No, only the top right corner is PWM (1st gen H51w)
Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
Maybe Petzl and Black Diamond headlamps? They definite use PWM and I also notice they steadily dim as the cells weaken.
Maybe Petzl and Black Diamond headlamps? They definite use PWM and I also notice they steadily dim as the cells weaken.
Re: Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
All of my carry lights are regulated. I do like having a few low powered direct drive lights around however. These serve as battery vampires or more often as great backup lights for long term large scale emergency situations. Combine direct drive with a simple twisty switch and you have the ultimate in dependability. Then throw in a nice long taper as the batteries weaken and lights like the original Inova X5 make a lot more sense than having a stable full of high lumen regulated lights, even if they are multi level.
All of my carry lights are regulated. I do like having a few low powered direct drive lights around however. These serve as battery vampires or more often as great backup lights for long term large scale emergency situations. Combine direct drive with a simple twisty switch and you have the ultimate in dependability. Then throw in a nice long taper as the batteries weaken and lights like the original Inova X5 make a lot more sense than having a stable full of high lumen regulated lights, even if they are multi level.
carrot
Flashaholic
Re: Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
For an EDC, I prefer fully flat regulation until the battery cannot sustain the light anymore, dropping into low output.
For a light that I bring backpacking or climbing, I want the light to be close to unregulated. I don't want to be surprised by a dead battery in the middle of the night.
For an EDC, I prefer fully flat regulation until the battery cannot sustain the light anymore, dropping into low output.
For a light that I bring backpacking or climbing, I want the light to be close to unregulated. I don't want to be surprised by a dead battery in the middle of the night.
Re: Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
Non-regulated lights are good as battery vampires. I like the idea of being able to use up every bit of the juice in primary cells that regulated lights leave behind.
Who doesn't have an ever-growing box of partially depleted batteries just sitting there, taunting you?
Non-regulated lights are good as battery vampires. I like the idea of being able to use up every bit of the juice in primary cells that regulated lights leave behind.
Who doesn't have an ever-growing box of partially depleted batteries just sitting there, taunting you?
davesc
Newly Enlightened
Re: Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
Great thread...lot's of good information!
Great thread...lot's of good information!
gravelmonkey
Enlightened
Re: Are Regulated LED Flashlights Always Preferable Over Non-Regulated LED Flashl...
Yeah, I've one of those boxes, just have to keep an eye out for the ones which decide to leak! One of those 3*5mm Niteize Maglite drop-in's can't get through them fast enough.
There was an observation in the Glo-toob AAA thread that it was (more?) regulated compared to the older versions which leaves the possibility of it 'leaving you in the dark'.
Yeah, I've one of those boxes, just have to keep an eye out for the ones which decide to leak! One of those 3*5mm Niteize Maglite drop-in's can't get through them fast enough.
There was an observation in the Glo-toob AAA thread that it was (more?) regulated compared to the older versions which leaves the possibility of it 'leaving you in the dark'.
