I thought it was the number of batteries you had in there. A light with SIX 18650’s had to be
one powerful light. Then I thought it was the number of Watts. A 100 watt light had to be
one powerful throwing or big lumen light.
But all this is wrong? It’s the driver???
Can anyone put this in terms of a powerful firearm cartridge? Like it has more to do with the amount
of powder in a cartridge or speed of the bullet, not necessarily the caliber size. Big driver = big amount of powder? or high fps of speed?
Hmm, that’s a lot of question in a little post! I’ll try my best to go one thing at a time. Let’s start with the easy one. Wattage. All led’s consume watts and spit out lumens. For the most part on average, LED’s will produce about 100 or so lumens per watt. This differs from one led to another, but a good starting place is that 100 lumen per watt number. (Especially with CREE leds)
The powerful throwing light comes from the reflector or aspheric lens. A larger reflector usually equals more throw/intensity, measured in candela. Most aspheric lens lights will also have a higher intensity rating because they can be zoomed in and focused. The smaller the LED die itself and whether the led has had its dome removed also affects the intensity of the light.
As far as batteries go, there’s a whole lot of information about those, but it basically comes down to battery arrangement, capacity and chemistry. A light with six 18650’s will produce either a lot of voltage or a lot of current depending if they are arranged in series or parallel. These arrangements will affect what driver is used to power and control the LED. A buck driver usually takes higher voltage battery configurations and drops the voltage down to a number the LED can handle while supplying a varying current. A boost driver does the opposite. It takes a smaller voltage and bumps it up to the led’s required level. A direct driver driver or a linear driver take battery voltage and send it straight to the LED. This is reserved for when you have one battery per LED, such that each LED only sees one battery’s worth of voltage. The physical size of the driver for the most part won’t affect the output of the LED unless you are talking big amps.
I hope this makes sense. Anyone, please chime in if I have missed anything!
The Power is not in the Steel. The Power is in the Hand of the one who wields it.
Sorry… Wrong movie…
I’ll put my gunsmithing hat back on for a minute…
First off, the batteries (or cells in the case of 18650s etc.) can be equated to the powder charge. Their configuration is expressed as the number of cells in Parallel and/or in Series. If you had 6*18650, you might have 3 in Series with 2 “layers” in Parallel, so that would be 3S2P. The photons Out The Front are the bullet, their terminal ballistics measured in lux, lumen, foot-lamberts, etc.
As to the rifle cartridge (battery pack), think of the brisance of the powder. Black powder burns slowly & gives the bullet (the photons of light) a shove which takes some time to get to an interesting velocity. So a 6S1P light would be like black powder, say a .45/110 Sharps cartridge. You might have a lot of voltage, but you’ll need special equipment to get the most out of it in a given amount of time; and if you use too much, you’ll blow up your barrel (LED). Here you’d use a long barrel (high-voltage LED) to the best effect.
Smokeless powder lights off in a hurry, and it’s done with its work in a moment. But it gives much more velocity in a shorter period of time. So a 6P1S pack would be more like a .416 Remington Magnum. Less voltage, but a lot more current (bang) at any given moment. You’d be more likely to erode the barrel (blue-shift the LED) than make a ‘steel banana’.
They can both put the same number of photons downrange, but 6S1P does it over a longer time with less momentary power (lumens) & 6P1S dumps huge gobs of light quickly.
Okay, that’s not the greatest metaphor, but it is an interesting question/challenge. I’m looking at it from the same perspective as the LED, in that the current (up to a point) is what matters most, voltage less so (up to a point).
Without going into the gun analogy, wattage would be a way to approximate the output of a light. We often simplify it to just amperage since most of the LEDs we use have the same voltage. The battery configuration gives “potential” energy, but must be mated with a compatible LED. The driver merely controls it all, passing the power from the batteries to the LED. Some drivers are designed for lots of lumens in short bursts, others are designed to get the most longevity from the batteries. But most of them do some of both with multiple modes.
Hopefully with ten different explanations you can find one that makes sense to you
Batteries aren’t like gunpowder unless you can control the rate of burn at will. The driver controls the release of current through the led but since the advent of direct thermal path(dtp) led stars you can basically dump all of a single cells capacity through one led and even multiple cells in parallel might only increase the run time rather than smoke the led. If you assume a maximum current of say 5A then to get more light you need to dump that 5A through more emitters, either with 5A to each of however many LEDs in parallel or by placing the cells and emitters in series to get the same 5A to flow through all the emitters at a higher voltage. Drivers don’t supply power, they regulate it, like a gas pedal. LEDs can only use what power the cells supply. High current cells usually don’t have a much capacity as those that have supply less(more internal resistance). There are trade offs everywhere and it boils down to which benefits you choose to keep and which compromises you’re willing to accept.
Comparing it to water flowing from a barrel is easier
Amount of water mAh (runtime more water longer sprinkle of plants)
Pressure how hard the water will pour out.
Opening in barrel you connect hose to determines how much water can flow bigger opening more water and lower point more water but shorter period of time)
Thickness of the hose how much water will flow (wires) with the difference that electrical wires and weak electrical conductive points will heat and thus use power where a small hose merely acts like a small opening in the barrel and does not cause loss of water
As somebody experienced with both guns and light modding, there isn’t really that much of a comparison, since in guns you have bullet weight, piston diameter (caliber) and charge pressure curve.
In lights, nearly every system will have an effect, the batteries ability to deliver current, most high quality 18650s will deliver enough juice with just 1 or 2 to smoke nearly any LED on the market, so these are not usually a weak point.
The driver is usually your biggest photon chucker choke point, the amount of current delivered to the LED is decided by this.
LED bin and thermal path, LED type. You will need the right LED, an XPG-2 will make up to 800ish lumens if you drive it hard enough with the right driver, but most manufacturers will only drive them to 400-500 lumens. Better thermal path lets you push more current and chuck more photons without overheating the LED.
Optics will control the beam, bigger diameter lens means a more concentrated spot, smaller means more flood. This is also dependent on LED die size. and XPG series is roughly half the size of an XML series, so the lens needs to be twice the size for the same concentration with the XML.
Then for full optimization you can get into the little things, like switch, contacts, battery springs, wires to the LED etc.
Sadly it’s not one magic part, it’s really a combination of nearly every part of the light will influence the light being a dud or a sun cannon. Or just buy a thrunite tn36 and call it day.
While lying in bed, I realized the gun analogy would probably not be good.
This helped, “Drivers don’t supply power, they regulate it, like a gas pedal.” by RufusDuck, to start
me out…as others probably said in a different way.
“The larger the reflector, the more powerful the throw.” by Tru3s. That helped. And the deeper the reflector, the further the throw vs shallow produces more flood, as I understand it. Probably also said by Piney. But now this Noctogon M43 confuses me, such little reflectors, albeit 12 of them, produces 6300L?
So number of watts still IS important then, via PilotDog. “wattage would be a way to approximate the output of a light.”
Thanks all for your effort in explaining this. Didn’t mean to leave anyone out, just some wording jumped out at me. I’ll have to read all that a few more times and will understand more, maybe as I go.
So what again determines the number of watts in your torch? i.e. what ‘thing’ in our torches controls the amount of watts contained therein??
BTW, I just got a NiteCore TM16 4000L and it’s awesome. And preordered that new little AstroLux S41 1600L monster. I’m feeling addiction here. ( I remember from many years ago, something called The Beast was the most powerful at around 4000L, but back then it cost $3000-$4000! Now you can get that for under $175. What a deal!)
- can a driver boost current? say a battery is rated at 3.5 amps; can the driver up it to 5 amps?
- can the LED limit current? say the driver can deliver 5 amps, is there only up to a certain current that the LED will conduct?
so is the lumens out of the LED determined by the voltage, amp, or voltage x amp (watt)?
thanks DavyKOTWF for starting this thread - it has cleared a lot of my own questions while i have been thinking of doing a mod… unfortunately it has added more questions
When talking about the lumens output of a flashlight we are talking about the total amount of light that the flashlight emits, it is directly related to the power that the flashlight uses.
The way and angle this total amount of light is then projected out of the flashlight is a result of the optics used, be it reflector, aspheric, etc… and die shape and size of the LED.
So a flashlight can give much higher lumens (total light output) than another and still throw less (projecting a certain intensity of light at a given distance) because it’s optic is less focused and the light distrubuted in a wider angle and more evenly.
As far as the Meteor M43 goes, lumens =/= intensity. It’s kinda confusing to equate the two, but lumens is total overall output while candela(intensity) it’s how focused that output is. The M43 can put out so many lumens because it has more LEDs to produce the light. It’s more of a floody light because the reflector optics are so small. It has high lumens, but a lower intensity.
Wattage is determined by the voltage and current. Volts x Amps = Watts. Do some research on Ohm’s Law when you get some time. It will really give you a solid foundation for the electrical side of things.
Batteries will deliver far more current than they are rated for, internal resistance on batteries should be well under 400 milliohms, A brand new high drain battery can push as much as 100 amps in a dead short, a used up non high drain could push as much as 10 amps in a dead short. The technical term for this happening in a sealed system such as a flash light is “Pipe Bomb”. A boost driver can up voltage, but the battery drain will always be the same depending on watts drawn, minus efficiency loss for the boosting.
The LED will not really limit current, they will happily turn blue and release the magic blue smoke, direct drive is only applicable when the battery voltage is close to proper LED voltage.
Lumens can be calculated by power applied multiplied by the LEDs lumens per watt, then you have to factor in power curve efficiency and thermal handling.
You will also want to do some basic reading on forward voltage of an led vs voltage sag of a battery, as well as the common driver types: linear, buck, and boost.
I’ll try to answer these last few questions as best I can.
The wattage of a light is determined by several things. Batteries have a maximum wattage (usually referred to around here as amperage or current because voltage is the same throughout most lights) they can provide so that could be the limiting factor. On most lights, however, the driver limits the amperage (aka current, or again, wattage at a continuous voltage).
That leads into radioshaq’s question: Most drivers cannot boost the current (without lowering voltage, which is a bad idea in most flashlights). Most of the time when you see someone refer to a “boost driver” they’re talking about boosting voltage (as in the battery’s voltage doesn’t match the needs of the LED), which lowers current. A driver can, however, easily lower current at the same voltage. That’s how most drivers work to produce different mode levels. That’s done a couple of different ways, usually by either introducing resistance into the circuit or by using PWM, which is another discussion altogether. Most drivers, at least most “factory” drivers, even limit the current on turbo in order to avoid stressing the emitter or building up too much heat.
On some lights the driver does not limit current. Those are usually called “direct drive” drivers or sometimes you see the term FET. These drivers basically provide a direct connection from the battery to the LED when they’re in turbo but can still limit current in some way to make lower modes possible. In those lights, the maximum wattage is determined by other circuit elements, often resistance throughout the rest of the light, such as in wiring or in the tail switch, but is also limited by the electrical characteristics of the emitter itself, which is also probably another discussion altogether.
I’ve tried to simplify this stuff a bit and hopefully it makes sense. Some of the smarter guys may come along and be able to correct and/or add to what I’ve said.
Gotcha Tru3. Thanks.
I’ll never know as much in detailed as most of you guys, but okay with me, I’m with
WrathBringer, and will just enjoy torches.
So in a very small nutshell, would it be fair to say, that the more Watts, the more potential
power, whether it be in throw or flood? And what do you have to know about a torch to know or
calculate the Watts in it? Say for instance that Noctigon M43, with 4300 lumens. Can you multiply something like the number of 18650 batteries, times 3400mAh (3.4) times 3.7V? Or
4 x 3.4 x 3.7 = 50 watts ? (for a good approx. of number of watts; the + or - dependent on efficiency of the driver and emitter and other things)
