Ledcorps PR replacement bulbs

12-29-00 LED bulb from Ledcorp. If you have a 3 cell mag (C or D) and want to turn it in to the ultimate backup flashlight here is the item to do it! This is extremely bright and unconditionally warranted by LED Corp. The lamp was pulling 65ma on 3 new C cells. One of the nice things about this LED is that it doesn't have a pre-focus like most LED's. In other words it emits light in every direction so it is great for using in existing 3 cell lights. This lamp also comes in a resistored down version for 4 cell lights. To sum up I would really recommend getting a 3 C cell Mag and this lamp, you won't regret it. This also gives you have the option of using the LED or the existing lamp (carried in tail cap) for a bright or normal light output. Using 3 C cells this light should run bright for about 4 days or over week of useable light, using 3 D cells you should get about 10 days of bright light and almost 3 weeks of useable light!

I am a newbie with all these fancy-schmancy terms

I see MCD used as output and MA used for draw (no?). I am curious about these lamps and would like to know what these are comprable to in terms of output power. I can accept "bright as a photon", or anything else like that.

Also, I have no idea how I stumbled across your wonderful forum. Really. Must be the law of random keypresses. Honest!

It is hard to say how bright it will be, it depends a lot on the light you put it in. These LEDs emit light in every direction instead of out of the front like most LED's . They both are about the same mcd initially. I would say my replacement lamp in my 3 C cell mag is brighter than my Photon, but it is using more power also.

Yes mA is miliamps, amperage, and mcd is milicalendra (sp), or light output.

Hey that quote looks like it is from my web site somebody must have read it.

Hope this helps

Brock

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>I would say my replacement lamp in my 3 C cell mag is brighter than my Photon, but it is using more power also.<HR></BLOCKQUOTE>

So, the difference would be quite noticeable, yes? The problem I have with my 3C Mag is that it is a bit underpowered for my nightime situations (I like to scan a 20 x 50 area with a nice white-light), while a 6D is worthy (yet way too uncomfortable for carrying around for an extended period of time). This could save me from buying another light, if I could just pop these suckers in and retrofit my 3C mag, which is perfectly comfortable for me.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>
Hey that quote looks like it is from my web site somebody must have read it.
<HR></BLOCKQUOTE>

Yup, really don't know how I found it Glad I did though! Thanx.

Ok, I am confused. Do you mean you want to make your 3 C cell mag brighter? If so the LED is WAY dimmer than the original lamp in the mag. It is close to a Photon, but since it is in a mag you can change the beam shape in to a tight spot making it brighter in a smaller spot.

As far as making you 3 C cell mag brighter I would suggest a higher wattage lamp. You could get a 3.6v 800ma xenon lamp (XPR103) (radio Shack # 272-1182). It is about 1.5 times brighter than the original lamp, but it will use batteries a faster. You could also get a Carley lamp which would be about twice as bright, but they are harder to come by.

Or you could get a Streamlight Scorpion. It is almost twice as bright as a 3 cell mag with a much smoother beam and about 1/3 the size and weight. But then you are getting in to lithium cells. If you like flashlights and don't have one I would really suggest getting one, you won't regret it.

Brock

Thanks a million! Also, the new posts by Telephony answered the rest of my questions.

<FONT COLOR="#000000" SIZE="1" FACE="Verdana, Arial">This message has been edited by axolotls on 02-01-2001 at 08:47 AM</font>

I got one of those LED Corp bulbs, and I must say I was disappointed in its light output. Sure, it doesn't use much power, but it doesn't put out much light either. After all, it is simply a regular single LED with its plastic lens ground down for wider light dispersion. When the beam is adjusted wide, it produces a "halo", with a dark central spot, making it almost useless. In a tight beam, its not too bad, just not very bright. I personally think its light output would be more appropriate in a 3-AA cell light. It just doesn't make any sense to lug around a huge 3-D Maglite with such a puny beam, even if it will last for many hours.
Chet

That's exactly how I feel. The $12 bulb I ordered (3 cell type), is pretty much useless. About 1/4th as bright as a photon. AND THAT'S IN A 3 D CELL LIGHT. It's sitting in my drawer with some loose change. Too Bad. I was running to the mailbox everyday for a week.

I have just taken delivery of the TurtlelteII and a Ledcorp led bulb and is quite disappointed with its light output. Judging from the favourable review of Turtlelite II, I thought that it would be brighter than the lightwave or Ledtronic. However, this is not to be so. The led bulb using 4AA batteries has a bright but tight beam and would be use to see distant object.

It is possible that other may have different result from mine because based on the lightwave I have, it is brighter than the Eternal 3. Brock has different result from mine.

3 cell/4 cell LEDcorp specially
ground replacement White led..
I got Email from them definitely
recommending the 3 cell for my
4 AA-Nimh(1650ma!) unit.
Funny,-this same led got RAVE
reviews on the Don K. page...
BTW-they said "overdriving" this
led won't hurt it a bit..
-especially if you're going for
maximum performance.
Anybody else have any experience
with this combination?
theotherDoug

-Oops....
forgot to mention that the unit I have is the Eveready ArcWhite.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by videocal:
3 cell/4 cell LEDcorp specially
ground replacement White led..
I got Email from them definitely
recommending the 3 cell for my
4 AA-Nimh(1650ma!) unit.
Funny,-this same led got RAVE
reviews on the Don K. page...
BTW-they said "overdriving" this
led won't hurt it a bit..
-especially if you're going for
maximum performance.
Anybody else have any experience
with this combination?<HR></BLOCKQUOTE>

I just tried one of these in an Arc White, and noticed the results weren't as good as they could be. The bulb was *designed* to be used in a Mag Lite or other focusable flashlight, and works best in one.

The pictures on my site should show it being used in a Mag Lite. When focused, the beam is tight, then it widens as the head is turned. At widest focus, the beam has the characteristic "doughnut" shape with the hole in the center - remember even the incandescent bulb does this as well, so no more blaming it on the LED.

http://ledmuseum.home.att.net

Having already dissed my poor LED Corp 3-D PR bulb, I tried it in a small 4-C dive light I had sitting around- a definite improvement in power, in fact totally acceptable. Current draw was about 100 milliamps using nicads. I was a little worried about meltdown, so I only ran it about a minute and checked the bulb temp- definitely warm but not hot. Not sure how hot is really acceptable, but I seem to remember overloading an LED enough to smell hot epoxy without sustaining perceptable damage(I don't recommend this!). I guess potting the LED into the bulb base must help it dissipate heat, otherwise it surely would have fried don't you think? I wonder if other builders have relied upon heat sinks to (over)extend LED power?
Chet

One other way I can tell if an
led is overloaded(driven), is to
see if White changes to Bluish
tinge as well as diminished out-
put-registered on my photocell tester.
The photocell test requires looking at the reading for at least 5 sec. If the led is being driven too hard, it will change color, as well as drop down in it's output on the G.E. meter.
This applies to all colored LEDs
as well..

IMHO dedicated led flashlights make the best use of the technology. In most cases, I don't think the LEDcorp replacement bulbs will do as well as flashlights that were specifically designed for LEDs.

However, I do have the LEDcorp 4 cell bulb. I bought it specifically for a flashlight that can go from spotlight to lantern mode by sliding the reflector section forward, exposing a clear tube around the bulb. This gives me a decent light for area lighting. When there's a blackout, or in a tent, I don't just want lights that shine a circle on the wall. So, the LEDcorp bulb serves its purpose in this application.

RonM
- Glad to see the board back up. I really missed it while it was down.

Can somebody verify if the LED Corp bulbs are indeed just plain 5mm Nichias with the dome ground down? Or are they in fact "special"? The grinding isn't all that precise, either. In fact, fairly crude!
I'm thinking of experimenting with a few(plain LEDs) to see if I can make a 4 LED module that has wide enough dispersion for focussing. Perhaps just grind the outer edges of each LED. Something like that...
Chet

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by chet:
Can somebody verify if the LED Corp bulbs are indeed just plain 5mm Nichias with the dome ground down? Or are they in fact "special"? The grinding isn't all that precise, either. In fact, fairly crude!<HR></BLOCKQUOTE>

Their LEDs are Nichia NSPW5xx series.
The LEDs are ground down "crudely" for a reason: if they grind them more precisely, they will start producing beams with ugly blue rings and other crap in there. The crude grinding nullifies these artifacts quite effectively.

http://ledmuseum.home.att.net

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by telephony:
Their LEDs are Nichia NSPW5xx series.
The LEDs are ground down "crudely" for a reason: if they grind them more precisely, they will start producing beams with ugly blue rings and other crap in there. The crude grinding nullifies these artifacts quite effectively.
<HR></BLOCKQUOTE>


So, does this mean that some of us who have, say, a fine-grit sanding belt/disc could do this ourselves, if we were so inclined, and receive similar results?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Cyclops942:

So, does this mean that some of us who have, say, a fine-grit sanding belt/disc could do this ourselves, if we were so inclined, and receive similar results?<HR></BLOCKQUOTE>

It's possible, but I don't have the equipment or the materials to try this for myself. You will have to really keep a lid on static charge. The act of grinding away the plastic lens will almost instantly generate enough static charge to murder the LED within. Wrapping both leads and the lower flange of the LED's plastic case with aluminum foil and then grounding that with a wire running to a cold water pipe should do the trick.

The stresses generated in the the plastic body during grinding can cause the LED to fracture or pull the bond wire(s) off.

Expect to lose one or two, pat yourself on the head if you succeed on the first try.

http://ledmuseum.home.att.net

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by telephony:

Expect to lose one or two, pat yourself on the head if you succeed on the first try.

<HR></BLOCKQUOTE>

Since I don't have any sanding tools (unless I put a sanding disc on my drill), I guess I'll just pay the mfr to do this for me. *sigh* Thanks anyway.

I've cut down two blue-green Nichia 20,800 mcd LEDs to get rid of the typical 'hourglass' focusing pattern. This reduces the LED's perceived brightness some since the light is diffused over a larger area, but does a great job of getting rid of the rings.

After grounding myself (wrist strap), I held the LED in my fingers and used a Dremel tool with a cutoff wheel. The advantage to holding the LED with your fingers is you can sense heat buildup (the disadvantage being you'd better be careful with the Dremel or you're gonna bleed on the LED ).

I have a variable speed footswitch, so I ran the Dremel tool fairly slowly and took my time about it. If you don't have a footpedal speed control for your Dremel and the slowest yours will run is 5,000 rpm's, I think you'd need to work slowly and take little bites to avoid overheating ... your fingers should let you know when the LED is warming up.

After cutting off the bulk, I used a small, fine burr to round the edges. A gentle touch is needed here to avoid chipping the resign.

After cutting to the shape I wanted, I hand sanded with 600 grit sandpaper on a sanding block to smooth the surface. Worked great. I stuck the cotton buffing wheel on the Dremel tool and polished the reshaped resin to improve translucence. Buffing is where the greatest heat & static concerns lie ... I double-checked my grounding here and just kept wetting the LED every few seconds to keep it cool (Best be careful here, too, lest you burn your tongue ).

On the first LED, I cut just below the dome, perpendicular to the barrel, and polished. This LED puts out a very nice diffused light without much side throw. The 'spot' is 2-3 times larger than the original size with no rings or hourglass patterns.

I cut the second LED closer to the diode and the edges are more severely rounded. This LED has much greater side-throw and does an excellent job as an area light (very similar lighting pattern to an exposed incandescent bulb like a Mini Mag's).

Both bulbs work well in my Mini Mag conversion and the flashlight now focuses using the flashlight's reflector. I would expect it to work even better if you ganged three together.

-- Random thoughts on a rainy day here in OKC.