Not about Lasers, but about Flashlights!

Since this forum has a lot of mambers dedicated to lasers, I thought asking a question about a flashlight is relevant enough. I want to get a new flashlight, probably from DX since it has so many cool ones, but I need to ask you:

What are the different kinds of (white) LEDs available (I'm probably going to buy a LED flashlight). I'm not asking about hwether there are green, blue, yellow or whatever, I'm asking if there are LEDs that are brighter than others. For example there is this LED (I think) called Cree Q5, that seems to be very expensive for some reason (I assume because it's very bright). Another torch uses a "SSC P7 C-Bin" LED and is said to produce 900 Lumens! I didn't have the time to research all of this, though.

I also noticed that there are also different kinds of flashlights besides those with the classic light bulb (that heats and radiates light) and those with the LEDs. I'm talking about xenon lights HID and any other kinds that may exist... Do you know in what way they differ?

The two most common brands of LEDs on dx are Cree and Seoul Semiconductors(SSC).
The best Cree LEDS are known as Q5 and SSC makes p-4 and P-7 LEDS.

HID stands for High Intensity Discharge. In a HID light you have a ballast providing around 20,000 Volts and a tube that the high voltage arcs through. HID lights are extremely powerful and can easily put out 2000+ lumens.

Xenon lights are ordinary incandescent flashlights that put out yellow light instead of the white color that Crees put out. Xenon lights have several disadvantages including massive power consumption and short bulb life.

What do you want the flashlight for and how much are you willing to spend? All of the different flashlights have their own applications and the type that you should buy depends on what you need it for.

That and cost. doggone HID lights are just wrong when it comes to price.

When you compare bulb life, run time, and size vs brightness, I think the LED's such as the Cree Q5 are hard to beat. Another thing to consider, is type of battery. Those lithium primary batteries have a shelf life of 10 to 15 years! Not that it will sit for that long, but it's nice to know that if it sits a few months, you can pick it up and know it won't be discharged. Or worse yet, batteries leaked inside...
Jay

Thanks for the response.

I just checked some videos on youtube about HID flashlights and they look so powerful! Are they the ones used in helicopters and such? Quite amazing, but I'm not willing to spend that much money..

Is each company producing LEDs of its own technology, or are there some standarized types of LEDs that every company produces? I'm asking this because I've only known one type of LED, which I assume is also the most common (like in this link: h**p://3w[dot]societyofrobots[dot]com/images/electronics_led_diagram[dot]png ), and those Q5 and P7 look quite different.
What is the name of the type of the common LEDs I see everywhere (like in the above link)?
Why aren't more than 1 such (P7 or Q5 or any other high power LED) LEDs used in flashlights? Using, say 4 could easily outperform any HID I checked, for a fraction of its price!

For my flashlight, I highly seek efficiency, but I want it to be powerfull as well (some 900 lumens are good).  So I guess I should choose between a Q5 and a P7 (better than P4 I assume) flashlight, but are those LEDs as efficient as the "common" type of LED pictured in the above link?
I was initially thinking about the 128 LEDs (!) flashlight on DX (SKU 1205), but a reviewer said this is 260 Lumens. This is kinda LOW for 128 LEDs. And DX doesn't give any real specifications to its flashlights, only dimensions! WTF! Is there any more "technical" review page that I'm missing?

Request: How much longer will I have this do-not-post-links restriction? It's messing up my posts and I have to re-write them!

If you want efficiency and power you will have a hard time beating one of the P7 lights. I would recommend the aurora or trustfire flashlights because they are more reputable companies.

http://www.dealextreme.com/details.dx/sku.12624
http://www.dealextreme.com/details.dx/sku.12588
http://www.dealextreme.com/details.dx/sku.12761
Get the trustfire if you want extra long runtime. It runs off 2 18650's and should last a couple of hours.

For the batteries and charger you should get
http://www.dealextreme.com/details.dx/sku.5790
and
http://www.dealextreme.com/details.dx/sku.936

Thanks,

1) The 2 battery version torch of those is said to use a resistor. Won't a resistor "burn" miliwatts of my power? Shouldn't I get a 1 battery version for that reason?

I don't want to sound demanding but could you elaborate a bit about:

2) Is each company producing LEDs of its own technology, or are there some standarized types of LEDs that every company produces? I'm asking this because I've only known one type of LED, which I assume is also the most common (like in this link: h**p://3w[dot]societyofrobots[dot]com/images/electronics_led_diagram[dot]png ), and those Q5 and P7 look quite different.

3) What is the name of the type of the common LEDs I see everywhere (like in the above link)?

4) Why aren't more than 1 such (P7 or Q5 or any other high power LED) LEDs used in flashlights? Is there any restriction i should know?

5) Which one is the most efficient diode? P7, P4, Q5, Q4?

6) Where can I read more technical details about those flashlights besides their dimensions?! I'm based too much on user reviews..

Thanks again!

Book said:

Thanks,

1) The 2 battery version torch of those is said to use a resistor. Won't a resistor "burn" miliwatts of my power? Shouldn't I get a 1 battery version for that reason?

I don't want to sound demanding but could you elaborate a bit about:

2) Is each company producing LEDs of its own technology, or are there some standarized types of LEDs that every company produces? I'm asking this because I've only known one type of LED, which I assume is also the most common (like in this link: h**p://3w[dot]societyofrobots[dot]com/images/electronics_led_diagram[dot]png ), and those Q5 and P7 look quite different.

3) What is the name of the type of the common LEDs I see everywhere (like in the above link)?

4) Why aren't more than 1 such (P7 or Q5 or any other high power LED) LEDs used in flashlights? Is there any restriction i should know?

5) Which one is the most efficient diode? P7, P4, Q5, Q4?

6) Where can I read more technical details about those flashlights besides their dimensions?! I'm based too much on user reviews..

Thanks again!

Click to expand...

I'm not sure about the 2 battery version. The people on dx might be idiots or they might have a point. It should have an actual driver and in that case the 2 battery version will work perfectly.

For your questions
2-The actual LEDS are made by SSC or Cree. The manufacturers like trustfire/ultrafire/others buy the LEDS and use them in their products.
3-The most common LEDS are the older 5mm leds. They aren't nearly as good as the modern versions.
Are these what you are talking about? I can't get your link to work.

4-P7 LEDS generate a lot of heat and one of them alone will cause the entire head of the flashlight to warm up. Adding a bunch of them would probably melt the head of the light and overload the batteries. The best Q5 lights usually contain 3-5 LEDS.
5-I don't know enough to give a precise answer to that question :-/ I think I heard somewhere that Q5 LEDS are the best for efficiency.
6-Your only option is to wait for more customer reviews on DX or you can also try reading about the flashlights on candepowerforums.

If you want an awesome light with long runtime and plenty of modes you should check this one out. On the lowest mode it literally lasts forever.
http://www.dealextreme.com/details.dx/sku.11917
If you want a cheap multimode light that puts out 400 lumens check this one out.
http://www.dealextreme.com/details.dx/sku.5971 Only problem is the 1 hour runtime.

If you want the most lumens per $ you should just get one of the SSC P7 lights.

I can't open the link you gave us, it gives me an error.Do you mean the standart 5mm LEDs we see everywhere? I don't think they have a special name, just 5mm LED, and I think they're made by several companies (like Nichia for example).The Q5/P7 emiters are basicly HUGE versions that (of course) require more power and heatsinking as they heat up faster, and put out more light(duh).They don't like to use more than one because the beam wouldn't be as nicely focused, but it does happen.

Btw, Razako, HID should stand for High Intensity Discharge.High Energy Discharge would be HED ;D

Switch said:

I can't open the link you gave us, it gives me an error.Do you mean the standart 5mm LEDs we see everywhere? I don't think they have a special name, just 5mm LED, and I think they're made by several companies (like Nichia for example).The Q5/P7 emiters are basicly HUGE versions that (of course) require more power and heatsinking as they heat up faster, and put out more light(duh).They don't like to use more than one because the beam wouldn't be as nicely focused, but it does happen.

Btw, Razako, HID should stand for High Intensity Discharge.High Energy Discharge would be HED ;D

Click to expand...

that's what happens when I post at 2AM :

1) If it actually has a resistor, then using only one battery will only light the LED very little, but if it's using a driver, then even with one battery it will light up to its normal brightness? If that's true then it's a good way to tell, if I actually get it.

2)Yeah, I was talking about those "5mm" LEDs (as they appear to have no other commercial name). I thought they were the only kind of LED available for flashlight applications.
So the 5mm ones are made by virtually all companies (including others, besides Cree and SSC, like Nichia), but each company also produces its own-technology LED? I see a type called "P4" that is made both by Cree and SSC.
So we have: 5mm LEDs, various Cree LEDs, various SSC LEDs, and what other LEDs are there?

3) Yes, these are the LEDs I was talking about. I've seen hundreds of flashlights that used them. Are they of lower efficiency that the new ones we've been talking about?

OK, about the first link (to the three x Q5 flashlight): Max output is specified as 700 lumens! That's quite low for 3 LEDs like that, that means each one is lower than 250 lumens! I thought they were at least comparable to the SSC P7 but the latter outputs 900 lumens !

Bottomline: If the P7 and the Q5 are of similar efficiency, I'll definately go for the P7!

Book said:

1) If it actually has a resistor, then using only one battery will only light the LED very little, but if it's using a driver, then even with one battery it will light up to its normal brightness? If that's true then it's a good way to tell, if I actually get it.

2)Yeah, I was talking about those "5mm" LEDs (as they appear to have no other commercial name). I thought they were the only kind of LED available for flashlight applications.

So the 5mm ones are made by virtually all companies (including others, besides Cree and SSC, like Nichia), but each company also produces its own-technology LED? I see a type called "P4" that is made both by Cree and SSC.
So we have: 5mm LEDs, various Cree LEDs, various SSC LEDs, and what other LEDs are there?

3) Yes, these are the LEDs I was talking about. I've seen hundreds of flashlights that used them. Are they of lower efficiency that the new ones we've been talking about?

OK, about the first link (to the three x Q5 flashlight): Max output is specified as 700 lumens! That's quite low for 3 LEDs like that, that means each one is lower than 250 lumens! I thought they were at least comparable to the SSC P7 but the latter outputs 900 lumens !

Bottomline: If the P7 and the Q5 are of similar efficiency, I'll definately go for the P7!

Click to expand...

1-The trustfire flashlight probably has a driver. Trustfire would have to be completely stupid to use a resistor. If a 1 battery P7 flashlight has a proper driver with current regulation the light will remain bright until the battery voltage drops too low and it falls out of regulation. Ideally by using 2 batteries you allow the light to stay in regulation for the entire battery life. If you but the 2battery P7 it will be easy to tell if it doesn't have a driver.
2-There are also LEDS made by Luxeon and a couple of other companies but those aren't as good/popular and aren't worth mentioning.
3-The main problem with the old 5mm LEDS is they simply don't put out much light unless you cram 20+LEDS into the same flashlight and then you get a poorly focused light with poor throw.

One Q5=approximately 1/3 of a properly driven P7. The P7 is definitely the best buy if you want to save money. I bought the 3 Q5 light shortly before P7s were released. If you want pure efficiency you can't beat a single Q5. However a single Q5 will only give you ~200~lumens and if you want more you will need more Q5s or a P7.

so what is the the best ssc flashlight on dx

No mention of the R2, or the MC-E in this thread. o.o