PCC
Flashlight Enthusiast
I ordered these JELEDs because I was tired of running around the San Francisco area looking for white 5mm LEDs to build some 9V emergency lights with. When I did find LEDs they were selling for $2 for a bag of two at a commonly known electronics chain. These were rated at 7000 MCD so I was expecting the 55,000 MCD JELEDs to be quite a bit brighter. I ordered 100 of the JELEDs from eBay.
When they arrived I immediately took one and plugged it straight into my Mini-Mag and was not impressed. The spot was unevenly round shaped purple with a yellow halo around it. The brightness seemed to be about on par with the 7000 MCD LEDs that I had bought previously used in the same test. Oh, well, I bought them and the price, at about 1/3 what I paid for the other ones, was certainly much better so I might as well use them. You can read some of my initial complaints about these LEDs here and here from this thread.
My initial test of these LEDs was doomed from the start because these LEDs are rated for something like 3.3V Vf. Since I was running them on about 2.9V they were not going to be putting out any kind of lumens like I was expecting. When I used two NiMH cells with these LEDs the output was even less because they were pushing about 2.5V. When I attached 3 NiMH cells the brightness improved dramatically but that's because of the 3.7 or so volts that it was getting. Brightness did not improve by much at 5V (four NiMH cells) so the reduction of the life of the emitter is not worth the extra few MCD you would get from overdriving them this hard. Keep in mind that this was all done DD.
Now that I've had some time to actually use them and to "see the light" I can post my impressions of them with a little less bias. It helps that I bought some of those small Energizer keychain lights with Nichia LEDs in them, though I do not know which exact model they are nor the bin they used. Still, those keychain lights did open my eyes a little bit more with regards to these JELEDs. The keychain lights use three A76 button batteries and the LEDs are direct-driven.
As mentioned above, the beam pattern on these LEDs is a purplish spot with a yellow halo around it. The intensity in the middle of the spot is pretty good, about comparable to the Nichia LEDs, but the Nichias have an oval spot while the JELEDs have a more or less round spot so the bright spot from the Nichias is over a larger area. Here's a picture of the two LEDs side-by-side. I took one of the Nichias out of my keychain light and replaced it with a JELED so that both LEDs have the same voltage and (hopefully) the same resistance in the circuit. You can guess which spot is from which LED. The camera does a better job of differentiating color temperature than my eyes do.
The light output from these LEDs is actually better than my initial impression left me to believe. Mounting two of these onto a 9V battery with a 100 ohm resistor in series leaves me with a light that is great to use as an electric candle for power outage situations. They're certainly brighter than the 7000 MCD LEDs I had been buying, though not by much.
Here's a picture of three JELEDs soldered to a PR flange bulb base mounting in a 3D M*gLite. Yes, I know that I'm overdriving them but this was made as a backup to the M*gLED that is in my 2D M*g and it is a lot less bright in that light for picture taking.
The reflector is causing the light to be shaped so weirdly. It didn't help that the LEDs were pointing all over the place due to the raised rim at the bottom of the head. The PR flange bulb replacements I have made since have had the rims removed on my mill and they do a much better job of putting all three spots together, though they're not perfect.
Now that I've used them in a few projects and see just what they can do I'm actually quite happy with my purchase. So happy, in fact, that I'm no longer looking for Nichia LEDs to buy but if I can find Nichia GS LEDs for close to what I paid for these JELEDs I might be tempted to buy some.
Please note that these are my opinions, observations, and impressions and that your experience may vary. Only one 5mm LED was harmed in my testing
When they arrived I immediately took one and plugged it straight into my Mini-Mag and was not impressed. The spot was unevenly round shaped purple with a yellow halo around it. The brightness seemed to be about on par with the 7000 MCD LEDs that I had bought previously used in the same test. Oh, well, I bought them and the price, at about 1/3 what I paid for the other ones, was certainly much better so I might as well use them. You can read some of my initial complaints about these LEDs here and here from this thread.
My initial test of these LEDs was doomed from the start because these LEDs are rated for something like 3.3V Vf. Since I was running them on about 2.9V they were not going to be putting out any kind of lumens like I was expecting. When I used two NiMH cells with these LEDs the output was even less because they were pushing about 2.5V. When I attached 3 NiMH cells the brightness improved dramatically but that's because of the 3.7 or so volts that it was getting. Brightness did not improve by much at 5V (four NiMH cells) so the reduction of the life of the emitter is not worth the extra few MCD you would get from overdriving them this hard. Keep in mind that this was all done DD.
Now that I've had some time to actually use them and to "see the light" I can post my impressions of them with a little less bias. It helps that I bought some of those small Energizer keychain lights with Nichia LEDs in them, though I do not know which exact model they are nor the bin they used. Still, those keychain lights did open my eyes a little bit more with regards to these JELEDs. The keychain lights use three A76 button batteries and the LEDs are direct-driven.
As mentioned above, the beam pattern on these LEDs is a purplish spot with a yellow halo around it. The intensity in the middle of the spot is pretty good, about comparable to the Nichia LEDs, but the Nichias have an oval spot while the JELEDs have a more or less round spot so the bright spot from the Nichias is over a larger area. Here's a picture of the two LEDs side-by-side. I took one of the Nichias out of my keychain light and replaced it with a JELED so that both LEDs have the same voltage and (hopefully) the same resistance in the circuit. You can guess which spot is from which LED. The camera does a better job of differentiating color temperature than my eyes do.
The light output from these LEDs is actually better than my initial impression left me to believe. Mounting two of these onto a 9V battery with a 100 ohm resistor in series leaves me with a light that is great to use as an electric candle for power outage situations. They're certainly brighter than the 7000 MCD LEDs I had been buying, though not by much.
Here's a picture of three JELEDs soldered to a PR flange bulb base mounting in a 3D M*gLite. Yes, I know that I'm overdriving them but this was made as a backup to the M*gLED that is in my 2D M*g and it is a lot less bright in that light for picture taking.
The reflector is causing the light to be shaped so weirdly. It didn't help that the LEDs were pointing all over the place due to the raised rim at the bottom of the head. The PR flange bulb replacements I have made since have had the rims removed on my mill and they do a much better job of putting all three spots together, though they're not perfect.
Now that I've used them in a few projects and see just what they can do I'm actually quite happy with my purchase. So happy, in fact, that I'm no longer looking for Nichia LEDs to buy but if I can find Nichia GS LEDs for close to what I paid for these JELEDs I might be tempted to buy some.
Please note that these are my opinions, observations, and impressions and that your experience may vary. Only one 5mm LED was harmed in my testing
. They passed my 192 hour over drive test without the slightest fading. Most 5mm LEDs can't get through this test without some lumen depreciation. I plan to post a report on them later in this forum.
