# Beginner's Guide to explain simple LED flashlight.



## download

Here is a "Beginner's Guide" to explain simple LED flashlight concepts.
To show how it works.

1. Reflector or Lens - used to control beam pattern, change angle of projection. 
The reflector profile is the most important aspect in if the beam if tightly focussed or spread out to give flood light. Deep reflectors typically create a tight spot and shallower reflectors a flood beam. The reflector surface finish then goes towards smoothing out the beam (using a textured surface) or reducing losses (with a mirror finish) but potentially having artefacts in the beam. 
Flashlight Beam Patterns
http://www.youtube.com/watch?v=f4L1uIcbalQ#t=43
Reflector vs. Optics: Light Loss
http://www.candlepowerforums.com/vb/showthread.php?151836-Reflector-vs-Optics-Light-Loss


2. LED - Light-emitting diode, the modern Led is much brighter than Incan bulb and life span is much longer too. The efficiency or brightness of Led will be improved every year. 
for more details, please take a look: 
Commonly Used LED Emitter Index 
http://www.candlepowerforums.com/vb/showthread.php?270419-Commonly-Used-LED-Emitter-Index
Bin Coding: Color, Flux and Vf Charts and Links for Popular White LEDs
http://www.candlepowerforums.com/vb...or-Popular-White-LEDs&highlight=color+binning


3. Heatsink - Cooling is required to remove the waste heat produced by Led. Consequent heating according to workload. 
Brighter = Hotter. Nowaday the metal body of flashlight use as heatsink. 
easy explanation asked for aluminium/Copper/silver, pls 
http://www.candlepowerforums.com/vb...luminium-Copper-silver-pls&highlight=Heatsink
Heat Management Issues
http://www.candlepowerforums.com/vb...Management-Issues&highlight=current+regulated


4. Electronic Driver - control the power and signal to led. 
The driver play a very important role here, because the led need ~3-4V only, but the battery capacity will drop according to life. 
The driver can control the brightness by varing by current (or PWM)
eg. 1.5V AA battery boost driver (step-up) to ~3V to Led. or 2x Li-ion 8.4V battery buck driver (Step-down) to ~3V to Led.
eg. 3 diffenent power level - High, middle, low.
The basics of LED drivers 
http://www.candlepowerforums.com/vb/showthread.php?444096-The-basics-of-LED-drivers
Driver board list / regulator board list
http://www.candlepowerforums.com/vb/showthread.php?188227-Driver-board-list-regulator-board-list
Led amperage basic question 
http://www.candlepowerforums.com/vb...ge-basic-question&highlight=current+regulated
PWM - What is it, How does it work and how to detect it.
http://www.candlepowerforums.com/vb...es-it-work-and-how-to-detect-it&highlight=pwm
Constant Current vs. PWM dimming Revealed
http://www.candlepowerforums.com/vb/showthread.php?70073-Constant-Current-vs-PWM-dimming-Revealed
(PWM control) AMC7135 Specs Inside **UPDATE**
http://www.candlepowerforums.com/vb...cs-Inside-**UPDATE**&highlight=amc7135+driver


5. Battery - AA, AAA, CR123, Li-ion 18650 ....... 
Battery Shoot Out
http://www.candlepowerforums.com/vb...ronics-Batteries-Included-Threads-of-Interest
Before jumping to Lithium battery, please see: The dangerous side of batteries
http://www.candlepowerforums.com/vb...d-Close-Calls-The-dangerous-side-of-batteries


6. Switch - Control On and OFF, change power level 
Forward Clicky:
- light comes on before it clicks
- momentary on (when the light is OFF you can half press the switch to flash the light ON)
- you cannot use the switch to change mode (in certain multi-mode lights) without completely turning off the light
Reverse Clicky:
- light come on after it clicks
- momentary off (when the light is ON you can half press the switch to momentarily turn the light OFF)
- you can use the switch to change modes (in certain multi-mode lights) while the light is turned on 
Twisties:
- Turn the of head or tailcap, like MiniMag


Useful Link: 
Simple guide to using a DMM for measurements 
http://www.candlepowerforums.com/vb...-Simple-guide-to-using-a-DMM-for-measurements
Please remind me if anything can explain things more effectively. Thanks!


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## shelm

i think you have got the basics right, you seem to have a clear understanding as a beginner.
so what's your question please?


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## KILLER_K

Good job and this will help people. I like it when it is very simple and easy on the eyes. 


He is just adding it to help others out. Plus allowing others to add stuff to the help section of it.


> Here is a "Beginner's Guide" to explain simple LED flashlight concepts.
> To show how it works.





shelm said:


> i think you have got the basics right, you seem to have a clear understanding as a beginner.
> so what's your question please?


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## subwoofer

Nice looking diagram.

A couple of minor things come to mind:


In the LED section I would not compare an LED to a CPU. If anything the better computer analogy would be to compare the LED to the screen. The LED is the output device not the controlling device.


Reflectors and if they are smooth or textured are not the only factors affecting the beam. The reflector profile is the most important aspect in if the beam if tightly focussed or spread out to give flood light. Deep reflectors typically create a tight spot and shallower reflectors a flood beam. The reflector surface finish then goes towards smoothing out the beam (using a textured surface) or reducing losses (with a mirror finish) but potentially having artefacts in the beam.

The Aspheric lens creates a great deal of loss of output as it typically focuses only the directly emitted light and cannot meaningfully include light collected by a reflector. The tight pencil beam is fun and light-sabre like but is of little practical use.

Just an initial reaction. Nice idea for new CPFers to find.


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## subwoofer

Oh, one other thing, the reverse vs forward clicky thread you link to is a bit confused why not simply say:

Forward Clicky:
- light comes on before it clicks
- momentary on (when the light is OFF you can half press the switch to flash the light ON)
- you cannot use the switch to change mode (in certain multi-mode lights) without completely turning off the light
Reverse Clicky:
- light come on after it clicks
- momentary off (when the light is ON you can half press the switch to momentarily turn the light OFF)
- you can use the switch to change modes (in certain multi-mode lights) while the light is turned on


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## download

When I first saw the Led flashlight, I wanted to find how it works, but no a single post to show in simple way.
That is the reason I want to make it for a long time. Especially here CPF have millions useful posts can tell the story.



shelm said:


> i think you have got the basics right, you seem to have a clear understanding as a beginner.
> so what's your question please?


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## jabe1

download said:


> When I first saw the Led flashlight, I wanted to find how it works, but no a single post to show in simple way.
> That is the reason I want to make it for a long time. Especially here CPF have millions useful posts can tell the story.




I think Shelm missed your join date, post count, and doesn't know your [email protected] modding history.

Nice job, you show the basics very clearly. I do understand the CPU comment, both gain efficiency at about the same rate over time.


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## Norm

I've made this a sticky.

Norm


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## download

KILLER_K, subwoofer & jabe1,

Thanks for your input.
Hope we will make it even better.


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## Obijuan Kenobe

Is it something to illustrate how the body of the light is used as the negative path? 

obi


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## download

Picture added, 



Obijuan Kenobe said:


> Is it something to illustrate how the body of the light is used as the negative path?
> 
> obi


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## jabe1

Under the Electronic Driver designation, note that an LEDs intensity is varied by current (or PWM) and not voltage.


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## AZPops

Nice! Thanks for taking the time to do this!


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## T-3

Very nice of you to take the time to post this. Helps broaden the understanding of someone like myself who lurks here once in a while!


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## erikesp

This is great for those of us new to this hobby. Great visual aid helps me quickly understand the relationship between all components. Thanks for posting .


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## Mid Atlantic

Thanks big help


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## stevethumb21

That was surely a big help ! I was teaching my kids the other day and got a question about LED flashlights. I searched all over the net didint find anything easy to grasp. Got to your blog and I found the wanted piece of wisdom. Thanks again. Keep sharing .


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## ericabrinyte

I like your diagram, it helps a lot for a rookie like me:nana:


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## filb

Fantastic. Well done. Easy to understand for us new to the LED flashlight building/modding

Thank You


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## Lomandor

Norm said:


> I've made this a sticky.
> 
> Norm



What is a sticky? Is it a cpf function that allows me to easily bring this page up for reference? Cheers.


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## doceric

Thanks! This is really helpful for beginners like me..


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## siwasher

OK, now understand that I'm a true beginner, with little understanding of technical issues. That said, I have two problems with the following quote from the original post. I'll overlook the first as a mere typo, but the second I truly don't understand:

"...life spin is much longer too. The brightness of newer Led will increase ~30% per year."

INCREASE? How long until it's brighter than the sun?


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## download

Thanks for reminding. Is it better like that? 

The efficiency or brightness of Led will be improved ~30% every year.


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## Blglover96

Nice


Sent from my iPhone using Tapatalk - now Free


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## Tikiman

Great Beginner's Guide
thanks..


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## enzo thecat

This might be a stupid question but the heatsink reminded me to ask. Why do our LED flashlights emit so much heat. I thought LEDs were supposed to run cool. In fact the 100 watt bulbs I have installed in my ceiling can light fixtures are completely cool to the touch. Why such a difference between applications.


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## download

Fluorescent lamp and LED (Light-emitting diode) are different technology, just like gasoline engine car and pure electric car. 
The outlook are similar but they use two different kind of technology inside.

For more technical details, please see:
http://en.wikipedia.org/wiki/Light-emitting_diode#Physics


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## enzo thecat

download said:


> Fluorescent lamp and LED (Light-emitting diode) are different technology, just like gasoline engine car and pure electric car.
> The outlook are similar but they use two different kind of technology inside.
> 
> For more technical details, please see:
> http://en.wikipedia.org/wiki/Light-emitting_diode#Physics



How did fluorescents enter into the discussion?


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## download

Sorry enzo thecat, misunderstood your 100 watt bulbs was Fluorescent lamp. 

Heat is side product when the led is driven by more current. 
Lower current = Higher Efficacy, >0.3A will generate more light per current.
Higher current = Lower Efficacy, <1A will generate less light per current and more heat. 

eg.1 Led Christmas tree lighting, the loading of led is ~0.05A, cool to touch, right? 
eg.2 Cree XML, when the current load is 0.05A, it will be cool to touch too.
When the current load reach 3A, it will generate a lot of heat, it will kill itself without suitable heatsink.


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## jamie.91

What a good thread!


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## mikemild13

Thanks for this post. If no one minds, I would like to use the diagrams to teach my young'ns. I understand the technology but can't explain it worth a darn.


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## download

We like to share what we learn from here.


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## mikemild13

download said:


> We like to share what we learn from here.



I appreciate all of the knowledge shared here. A lot of the info is over my head but I read it anyway. This post breaks it down to the basic level which makes it a great tool for beginners.


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## dklinko3

Thanks for this, it will help me a lot in deciding which flashlight to buy as my very first high quality LED light!


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## KARADENIZ

nice thread , thank 
is there any comparison chart of pwm boards to their efficiency?


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## download

AMC7135 board 
http://www.candlepowerforums.com/vb/newreply.php?do=newreply&p=2405842




Drewfus2101 said:


> 1050mA version:
> 
> 
> 
> 
> 
> 
> 1400mA version:
> 
> 
> 
> 
> 
> Pretty good boards, as long as your in they're small voltage range. DX recommends that you stay within 3.6V to 4.5V. I read that is because between 4.6V to 6.0V (which it can take up to 6.0V) it gets very hot. In my testing I used a small fan to keep the board cool so this did not affect me.
> 
> These are a great alternative to resistors, even though resistors are cheaper. The best thing to do here is order 20 of the 1400mA version and you can remove each of the black AMC boards and each one you remove will cut down the output current by 350mA. I tested this and it does work.
> 
> Where these boards beat resistors is that these give you a semi-regulated output. If you use resistors and alkalines (for example) the flashlight will never be brighter than when you first fire it up. After that, the batteries will start to dim. If you chose your resistor based on the fresh battery voltage, as the batteries start to drain, your output will drop. With these, as long as your voltage stays above about 4.0V you get the full output. The 700mA version should need a lower voltage and the 350mA an even lower voltage. So that semi-regulation is worth the extra money to me. I can't tell you how much time and headache direct drive / resistors / alkalines have caused me.
> 
> I definitely love a good boost/buck convertor more than these, but these things are not bad little boards. I thought others could benefit from these numbers.


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## bitnick

download said:


> The efficiency or brightness of Led will be improved ~30% every year.



Well... not quite.

_(The source for the below is Do The Math, an IMO extremely interesting blog that looks at energy and physics from a mathematical perspective. Well worth a read!

The units used below are the lumen [lm], watt [W], and nanometer [nm].)_

The theoretical maximal luminous efficacy for any light source, regardless of technology, is 683 lm/W. This would be a monocromatic source emitting at 555 nm ("laser green"), and it would not get warm, no matter how bright it was or how much power it used, since all the supplied power would be converted into useful photons and "beamed away".

For a white light, the theoretical maximal efficacy is lower, since the sensitivity of our eyes gets lower the farther from 555 nm we come, and white light is a mixture of wavelengths between ca 450 nm (blue) and 660 nm (red).

To make a long story short (see the link above for details), a white light source with "ideal efficacy" and a color temperature of 5800 K could reach 310 lm/W maximum (and would have a CRI of 94). At 2800 K, we could reach 370 lm/W (and the CRI would be 87). Again, these would not even get warm, regardless of brightness, since they are 100 % efficient.


Let's look at a modern LED - the Luxeon T. At a reasonable CRI of >80, and a "typical" current of 700 mA, it has a luminous efficacy of around 100 lm/W. That's not _that_ far away from the theoretical maximum!

In fact, at 30 % improvement per year, we would hit the theoretical maximum in only 5 years! 100 [lm] * 1,30^5 = 371 lm!

It's pretty amazing really that we have light sources today whose efficacy can only be doubled twice before we hit the absolute theoretical maximum, regardless of technology!


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## KARADENIZ

@download, 

thats what I was searching for, thanks


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## download

bitnick, 

Thank for the good article, we will learn something about it. :twothumbs
It is my roughly estimation only for beginner understand the concept. 

KARADENIZ, :thumbsup:

dklinko3 & minos2013, :welcome:


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## lane478

Thank you Download. That answered about a hundred questions I had all at once. I wish there were more threads to guide newbs learning to build and mod.


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## Glenn_San

Thanks for the helpful diagrams and explanation. I'm researching prior to buying a decent LED flashlight to replace the el-cheapo units I have bought in recent years as they have all failed, probably due to "You-get-what-you-pay-for" quality issues.  

It would be so nice to have a new flashlight that will last me many years without reliability issues.


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## 1911litup

Thank you for putting this information out there. Great overview. I am trying to learn more about creating drivers that are programmable. As I know NOTHING, I have a long way to go


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## TxRobtrx

This is a great post for total beginners like me who have just bought flashlights in the past and now want to start becoming an informed consumer. Thanks


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## psycosteve

Chalk this up to a noob observation but just looking at the diagrams you could not only modify but existing lights but build them given the right materials. Thank you Download


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## Dkoi

A really useful thread, a lot of terminology on this forum was passing my by and this will help my grasp. Thank you.


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## Invasion

Thanks for all the info really appreciated. Should help me sort things out


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## Tactical Michael

Thanks for the great info, starting to really get into flashlights and this primer really helps.


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## Luke01

This helps out alot. Thank you. Does the housing material matter?


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## PFKMan23

Thanks for this. It's always good to know the basic workings of things.


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## Evan12

I really like this post .you explain really well in nice way.


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## sanjayram

company should give some important and basic things about the usage and the improvement that are to be made when someone is using the lights of these kinds


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## colight

Thnaks for sharing,I used flashlights for one year ,but I don't know it very well.


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## likevvii

Thanks for the guide! I bet the senior members of this forum know all of this stuff by heart!


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## Amy sunshine

download said:


> Here is a "Beginner's Guide" to explain simple LED flashlight concepts.
> To show how it works.
> 
> 1. Reflector or Lens - used to control beam pattern, change angle of projection.
> The reflector profile is the most important aspect in if the beam if tightly focussed or spread out to give flood light. Deep reflectors typically create a tight spot and shallower reflectors a flood beam. The reflector surface finish then goes towards smoothing out the beam (using a textured surface) or reducing losses (with a mirror finish) but potentially having artefacts in the beam.
> Flashlight Beam Patterns
> http://www.youtube.com/watch?v=f4L1uIcbalQ#t=43
> Reflector vs. Optics: Light Loss
> http://www.candlepowerforums.com/vb/showthread.php?151836-Reflector-vs-Optics-Light-Loss
> 
> 
> 2. LED - Light-emitting diode, the modern Led is much brighter than Incan bulb and life span is much longer too. The efficiency or brightness of Led will be improved ~30% every year.
> for more details, please take a look:
> Commonly Used LED Emitter Index
> http://www.candlepowerforums.com/vb/showthread.php?270419-Commonly-Used-LED-Emitter-Index
> Bin Coding: Color, Flux and Vf Charts and Links for Popular White LEDs
> http://www.candlepowerforums.com/vb...or-Popular-White-LEDs&highlight=color+binning
> 
> 
> 3. Heatsink - Cooling is required to remove the waste heat produced by Led. Consequent heating according to workload.
> Brighter = Hotter. Nowaday the metal body of flashlight use as heatsink.
> easy explanation asked for aluminium/Copper/silver, pls
> http://www.candlepowerforums.com/vb...luminium-Copper-silver-pls&highlight=Heatsink
> Heat Management Issues
> http://www.candlepowerforums.com/vb...Management-Issues&highlight=current+regulated
> 
> 4. Electronic Driver - control the power and signal to led.
> The driver play a very important role here, because the led need ~3-4V only, but the battery capacity will drop according to life.
> The driver can control the brightness by varing by current (or PWM)
> eg. 1.5V AA battery boost driver (step-up) to ~3V to Led. or 2x Li-ion 8.4V battery buck driver (Step-down) to ~3V to Led.
> eg. 3 diffenent power level - High, middle, low.
> Driver board list / regulator board list
> http://www.candlepowerforums.com/vb/showthread.php?188227-Driver-board-list-regulator-board-list
> Led amperage basic question
> http://www.candlepowerforums.com/vb...ge-basic-question&highlight=current+regulated
> PWM - What is it, How does it work and how to detect it.
> http://www.candlepowerforums.com/vb...es-it-work-and-how-to-detect-it&highlight=pwm
> Constant Current vs. PWM dimming Revealed
> http://www.candlepowerforums.com/vb/showthread.php?70073-Constant-Current-vs-PWM-dimming-Revealed
> (PWM control) AMC7135 Specs Inside **UPDATE**
> http://www.candlepowerforums.com/vb...cs-Inside-**UPDATE**&highlight=amc7135+driver
> 
> 5. Battery - AA, AAA, CR123, Li-ion 18650 .......
> Battery Shoot Out
> http://www.candlepowerforums.com/vb...ronics-Batteries-Included-Threads-of-Interest
> Before jumping to Lithium battery, please see: The dangerous side of batteries
> http://www.candlepowerforums.com/vb...d-Close-Calls-The-dangerous-side-of-batteries
> 
> 6. Switch - Control On and OFF, change power level
> Forward Clicky:
> - light comes on before it clicks
> - momentary on (when the light is OFF you can half press the switch to flash the light ON)
> - you cannot use the switch to change mode (in certain multi-mode lights) without completely turning off the light
> Reverse Clicky:
> - light come on after it clicks
> - momentary off (when the light is ON you can half press the switch to momentarily turn the light OFF)
> - you can use the switch to change modes (in certain multi-mode lights) while the light is turned on
> Twisties:
> - Turn the of head or tailcap, like MiniMag
> 
> 
> Useful Link:
> Simple guide to using a DMM for measurements
> http://www.candlepowerforums.com/vb...-Simple-guide-to-using-a-DMM-for-measurements
> Please remind me if anything can explain things more effectively. Thanks!




thanks for your information. if I don't have read your article, I will don't know a tiny torch with such specific information. in addition, it is common that a torch with replaceable battery, and there is a kind of torch with non movable battery , you can charge it after the battery runs out, and we can them when we are going to camp. do you think so?


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## Amy sunshine

thanks for you information...


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## download

:welcome: 

Amy sunshine. 
Thanks for your input, the rechargeable flashlight have extra circuit for recharging the battery.
Just like our cell phone nowadays.


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## Amy sunshine

do you have a flashlight? and where do you usually get it? from a real store or an online shop? and how do you judge a flashlight according to what factors. thank you...


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## download

Amy sunshine,

Sure I own dozens of flashlights. Got them from a real store and an online shop too.
Too many criteria to judge, like, build quality, material used, reliability, battery used, user interface, price.......... 

For beginner, Please take a look of the below posts, it is good starting.
http://www.candlepowerforums.com/vb/forumdisplay.php?135-Recommend-Me-a-Light-For

And fill the "Checklist", so we could answer your questions.
http://www.candlepowerforums.com/vb...hlight-Recommendation-Checklist-Updated-MK-II


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## feifei

How do they test the life span of the LED?Some is claimed to be 100000 hours,how to measure it?


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## download

:welcome: feifei

We have some post discuss like below: 
http://www.candlepowerforums.com/vb...n-proven-yet&highlight=has+led+longevity+been


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## sunshinemore

Great thread!!! Let me have an idea on the structure of LED flashlight. Learn a lot from this post.


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## knotgoofy

Traditional flashlights are powered by a battery and use conventional light bulbs to produce light. However, within the last ten years a new type of flashlight has hit the market. LED flashlights are increasing in popularity because they do not use as much battery energy as a flashlight with traditional light bulbs.


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## Alex W

easy to get it. help a lot for the new. thanks :thumbsup:


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## BrianHook

Well, flashlights are very handy during any emergency specially at night. Various significant aspects discussed by you about LED flashlights are genuinely helpful for people.


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## Tapis

Thanks for the explanation! Although I found the concept of a LED flashlight much easier to understand than the concept of a battery :thinking:


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## jmoyat

Thank you for explaining all this, very informative 


Sent from my iPhone using Candlepowerforums


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## bpierce

Thanks for posting! I joined this forum to learn more about LED flashlight technology, so introductions like this are great.


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## tylorjarvis32

Fantastic, I learned a lot from this Beginners Guide.
This thread is very helpful


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## AHRS-24/7

Very helpful


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## calmoptic43

Informative article


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## Garytn

Thanks. The diagrams are great and I appreciate all the other more experienced folks adding their part in to make it better.


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## michiganmade

This is all great stuff - thank you


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## Amargorojo

*Beginners Guide to explain simple LED flashlight*

Depending on light height, do you think the 6 led kit would be sufficient to quarantine sps for 3-4 weeks?


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## Amargorojo

*Beginners Guide to explain simple LED flashlight*

Depending on light height, do you think the 6 led kit would be sufficient to quarantine sps for 3-4 weeks?


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## download

Amargorojo, could you tell more about your question? 
What is the light, 6 led kit, quarantine sps? 
:thinking:


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## bng1

Thanks, this is so helpful.


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## Ironside

It might be interesting to note the different ways to direct the current from the negative terminal to the head of the light.


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## rupertsilva10

Great diagram you've got there. I have never known much about LED Flashlights, all I know is it consumes lesser energy and works more efficiently.


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## Hoekjor

This is great. Thank you for the info.


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## bykfixer

Thank you.

checkout counter flashlight addict searching for better. 

This thread helps a bunch!

This forum is great.


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## CHENONN

Thanks very much for your instruction.I will try to make it by myself.


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## Min Min

Love your work!.....Great diagram


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## gagaguu

great info..thanks..


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## vqF2i6rNci

I agree, thank you for the easy explanation of directional clicking on the tailcap. I was quite confused even after reading and trying several lights, as some nuance is different. This explained it perfectly!:thumbsup:

O


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## burkevalocks

Well this diagram will definitely help a newbie understand a led flashlight great work. :thumbsup:


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## mnm

learn something new every day thank you


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## PittsburghAndy

Posting here as a brand new member, glad to have found this forum!

Great as this thread is, it's kind of overwhelming since it's 3 pages long. I found myself thinking I had to read all 3 pages to benefit from this FAQ type of thread. Sure would be nice if it was just one post that was updated, kind of like a wiki. Believe me, I'm not overlooking the irony of my posting here and saying what I said. 

Or maybe there is such a page/wiki here that I haven't found yet (if someone could point me there?).

Just a thought. Thanks!


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## roverich

Lots of information to take in ...Great stuff in the stickies ...


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## Spaceship

jamie.91 said:


> What a good thread!


i like your diagram so much. When i was first to touch flashlight i really want to find some diagram which is posted just as you did. It helps a lots for the beginners like me.Thanks.


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## Mill321

Terrific explanation. I have come across a few other explanations that have gone over my head, but I think this struck the perfect balance of keeping it informative, but simple enough for newbies such as myself to understand. Thanks!


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## larstetens

Excellent explanation-THANK YOU VERY MUCH for taking the time to put this together mate. :twothumbs


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## 1tac

*Re: Beginner's Guide to explain simple LED flashlight*

What is the best way to tell what the quality is when it comes to the Lumins/ lens and inside components?


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## download

Good questions, 1tac

The best way maybe test it by your hand, like 
1. run it at open field at night, you would see the actual output beam pattern, 
2. check the tail cap current of battery, you will know how much it draw from battery
3. check the led current, to know exactly led current, so you can calculate the efficiency of the circuit.
4. check the temperature around led and the flashlight body, is it good for heat management.

Or read other member posts about the reviews.

:santa:


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## cjs072

which type of material should be use in heat sink ?
you have mention the material but not mention the grade of the material . like aluminium , extruded or die casting , material composition , some material has high heat tolerance power , some has less , so which grade would be better ?

please suggest .


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## download

cjs072, We will love to see if you could share you expertise here. After all this post is for general concept only. 
If you search inside cpf, you would find a lot of good post talking about it. 

:welcome:


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## scw2

Wanted to thank you for putting this together, lots of great info.


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## GusManB

Hi I am New and Have a Question about LEDs.
I am sorry if this may have been answered before.

I see a number of lights on the Market that are Tri LED or more. I know that in some applications such as needing Color Mixing this is a cool idea, much like The LEDS used in Custom Star Wars Sabers. How is it applied here and is it just preference?


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## download

I guess we just want to push it to the limit, try to make it as bright as possible in hand. :laughing:
Before, high power/low voltage small die led is not available yet, put a few more together is a alternative solution.


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## nicky_is12

Thanks OP. This thread has helped me understand the basics. I thought I had a general idea prior to reading this, and boy was I wrong.


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## Slayer1

Good thread. Very informative.

S1


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## eftpower

feel silly asking BUT I'm stumped! Was gifted a lux pro lp600 and I can NOT get the battery compartment open...have put pliers to it,but will not unscrew..............I have feeling that I am trying to unscrew it at the wrong place.., I can not tell where to unscrew.. holding the light base down where IS the division between the base and the bottom cap? There is a raised band with LP600 on it, counting from the very bottom, I count 4 "divisions' to that band and 1 directly above. All I have succeeded in doing is scratch the case with my vise grips...

Please help and old geezer out 
thank you in advance 
brian


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## download

:welcome: Brain,

Take a look this link 
https://www.youtube.com/watch?v=dGhBm_DijU0


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## OrcaTorch

very useful!


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## eftpower

Thank you so very much for the link..It wqs exactly what i needed. was able to get the light apart. There was heavy white build up on the end cap threads and on the wall of the case... but no corrosion on the internal components. did need to tap a socket thru the tube to take out the dents from the pliers.

again thank you so much of the link. 

best regards
brin


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## SuperHowl

Hi all,

new to this forum and this is a great place to start. thanks for the info!


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## CharlesFX

Good information here.
Was just wondering if there are any websites / info or news on upcoming new Cree LED models and expected outputs that are coming to market etc ??


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## Lateck

Download, THANK YOU for this post and the drawings! 
I like many just got into LED lights by accident or curiosity in wanting something better than a Maglite. 
I thought I understood it all but I never really knew the "Basics". I teach at times and always push the basics in what ever field, so students can build there knowledge. I missed the basics with LED lights, until now!
Thank you and the few who helped in the beginning of the thread (and throughout).

Lateck,


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## mortality

Thank you for this. I have had a few Coast lights in the past and am looking into getting a Fenix. This post explains a few things I was curious about.


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## stanleyzz

Thank you.
I learn something from your post


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## elidaesilva

This is the thread and why I register here. I was searching a powerful led flashlight and this thread has all information that i wanted to know.


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## Jessieliu

It is very good for beginners like me. Thank you!


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## Offgridled

elidaesilva said:


> This is the thread and why I register here. I was searching a powerful led flashlight and this thread has all information that i wanted to know.



You've come to the right place . Welcome and enjoy CPF!!


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## lumanir

Great information, very useful.
What is the max lumen for handheld flashlights:huh: (if there exist a max)?


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## stjong

Thank you for the info, good information.


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## ceramicknife

I realize that the Chip on Board (COB) leds are very similar in function to the "bulbs" but my problem has been with finding a way to use heat sinks on that long board.

I wanted to bump up a COB light from 3watts to 5 watts but am worried about overheating and damaging the leds on board.

Any suggestions are welcomb.


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## firstlighting

Great guide! Mind if I share it online?


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## download

ceramicknife, should be better if install the bigger heat sinks at the back of the Chip on Board.

firstlighting, no problem.

:welcome:


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## ixix

Always easy to appreciate a simple diagram and clear explanation. Many thanks! Any chance you happen to have a diagram for LED driver design basics as well?


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## Erik005

Very good thread, did not knew this.
Bought a flashlight last week, will help me when it brakes down.


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## Nyg3

Hello everyone,

i am also a new user here and i have been wondering one thing. I dont know, is this the right place to ask, but i'll give it a shot!  So i have couple of Olight flashlights and they have this turbo mode, which produces very high output and can be used for a few minutes, until it steps down because of heat. Does the turbo modes affect to the leds lifetime, or is it safe to use them? I can manage to come along with the regular low-med-high modes, if the turbo modes are not good for the led. Thank you for all the replies!


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## archimedes

Yes, heat can accelerate fading of LED, although (as a practical matter) your flashlight may likely be obsolete long before this occurs.

This article is several years old, but explains in somewhat greater detail ...

https://www.digikey.com/en/articles...g-the-cause-of-fading-in-high-brightness-leds


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## sbslider

ixix said:


> Always easy to appreciate a simple diagram and clear explanation. Many thanks! Any chance you happen to have a diagram for LED driver design basics as well?


The only thing I have found so far is this thread - http://budgetlightforum.com/comment/349098#comment-349098
What the schematic does not show is the input voltage is regulated to this driver somehow. Unless it is a Li-ion type battery, then maybe you could run it direct, but you likely would not use the entire voltage range capability of that battery. For Alkaline or nimh some sort of boost circuit is required to drive the driver shown.


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## TaliscaAdrian

I am using FENIX PD35 1000 LUMEN CREE XP-L LED COMPACT FLASHLIGHT . Measuring at under 5.51 inches, it can easily fit in the smallest pockets. In the practical deployment, you get up to 656 feet of beam output. If you use it in its Outdoor mode, you have a choice between six modes and its effectiveness is attested to by its use by professional law enforcement officials. The smart charger it comes with can charge two batteries at once, but it’s best used with 18650 batteries; you’d be wasting its power if you tried to use it with CR123 batteries.


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## alanowak1985

How much time do you use? Does the battery hold well for a long time?


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## sekirou

Thank you！Great Beginner's Guide！


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