New yellow LED AA budget light (SmallSun ZY-C82)

Hello all, I think I found a new product from several of the lesser-known chinese distributors....

Image Courtesy of popbuying.com

http://www.focalprice.com/LF487B/C82_Super_Bright_LED_Flashlight_Black.html

http://www.popbuying.com/detail.pb/sku.SmallSun_ZY_C82_Cree_P4_60_Lumen_Yellow_Light_LED_Flashlight_Torch_-27311

It was listed in the new arrivals section for January 2010 on one of the sites. I must say, the simple, clean design of this light is exactly what appeals to me. SmallSun is a fairly popular brand in the budget market. But what do you think about this LED and its color? Any estimates about runtime? One of the sites claimes 60 lumens, the other claims 90-100. As usual, I wish this were a multi-mode. But this sure looks appealing, it could be a challenger to the Uniquefire AA-S1 and the Ultrafire C3 for the ~=$10.00 flashlight category.

I like it, kind of reminds me of my old incan lights......

Warmer colour appears to help with depth perception over the typically blue light that LEDs give. It appears to be a collimator lens so gives a pretty tight beam so might be useful for spotting stuff a bit farther away than the power would imply. This does mean that it is less likely to be useful as a general purpose illuminator. But it is cheap.

It seems to be pretty much the same size as every other single AA light.

It supposedly has a Cree P4, but all P4 emitters aren't yellow, right? So is this a yellow variation of the bin?

http://www.cree.com/products/pdf/XLamp7090XR-E_B&L.pdf

Might just be....here take a look at the pdf file on crees.....

Ah ya, thanks. These other sites don't list the series and bin like DX does.

It makes a good reference sheet to go by.....just wish they would update to include the R's.

But they tend to be less bright than the blue / white ones. If it says P4 bin it should meet the same specs as P4 white LEDs in terms of brightness - but may use more - or probably less current to do so. The highest brightness bin Cree have documented is N4 for amber XR-C LEDs. The datasheet is here. The N4 bin is of the order of 65 lumens - the N3 bin would fit the claimed output. It is just possible they were meant to be warm white emitters that got ditched as they were too yellow - if so to drive them at spec needs 350mA so battery life not that wonderful. The current spec for the amber LEDs is also 350mA but the forward voltage is half that of the white LEDs - so less power needed from the cell. 350mA at 2V is 700mW or around 500mA from an AA - should be good for about 4-5 hours on a good alkaline. Remember all of this is educated guessing and a spot of Googling so may not be even slightly accurate.

Thanks for the tips there Don, you very well might be right that these are reject LEDs. The description is: "SmallSun ZY-C82 Cree P4 60-Lumen Yellow Light LED". So if it were yellow it wouldn't say P4, right?

Normal procedure it when a given number fail, the entire batch is rejected. This saves on labour costs. I can easily see some enterprising Chinese manufacturer with minute, effectively zero by European standards, labour costs get people to test these for him, most of them will be OK, even in a condemmned batch.

The LED manufacturer wins, the torch manufacturer wins, the consumer wins. And the LEDs don't end up in landfill.

I used to get free floppy disks on the same sort of basis - the rejected batches usually had enough decent disks to make the cost of my own timein checking them and binning the bad ones worthwhile. Local companies would buy truckloads of them - if someone took away the rejects for them, it lowered their waste disposal bill. A friend had the use of a bulk floppy duplicator which would reject the bad ones. Just set it to work duplicating a good blank floppy and you soon had as many as you needed.

The peak of human visual sensitivity is in the yellow/green bit of the spectrum - this light may appear brighter to the eye than to a light meter. It might well emit usable light on clinically dead cells.

You might be right. I personally like warm, yellow lighting.

At work, the current set of regulations require daylight tubes in the lights which are hideously blue - it is like being underwater all the time. Give me the sort of incandescent bulb I can no longer buy any day. I spent quite a bit of time when younger relying on paraffin (kerosene) pressure lamps for light (Tilley lamps or Chinese clones thereof - I believe Coleman sell the same sort of thing in the US). Now that's warm light - literally. The things pump out about a kilowatt of heat each. The gentle hissing is very relaxing. The heat is a big problem if you live in a hot country.

In this part of the world there is a huge energy shortage and compact fluorescent bulbs are taking over, but unfortunately they are stark, pallid, white, and not all that bright. They give me a distinct impression of gloom, death, and squalor. I use GE or Phillips warm yellow 23W (100W equivalent) CF bulbs (not from here), and they are a million times "cheerier" and inviting that the things that most homes have installed.

The cheap cfl's have ghastly phosphors - make everyone look ill. CFL lights are basically mercury discharge tubes that produce monochromatic green light. The phosphors mix is critical in getting a decent light colour. They are still more efficient than LEDs but the best LEDS are catching up. LEDS have the same phosphor problems since all white LEDs are actually blue ones with phosphors to get the light colour to something acceptable. Which is why overheated LEDs turn blue as they burn up the phosphor.

Exactly, you get it.

They put the phosphor in the glass coating to sort of filter or tint the light, right?

Basically the phosphor mix (Usually sprayed onto the inside of the glass in CFLs) absorbs the monochromatic green light and re-emits it at a mix of more suitable colours. The yellow colour you see on the front of LEDs is the phosphor. Here's a pic of the phosphor in a really cheap CFL - came from Ikea. The whitish powdery stuff inside the glass is the phosphor.