I'm setting up a darkroom and need red safelight. LEDs would be ideal for this application because there is no chance of shorter-wavelength light escaping a color filter. I think one CREE or even luxeon LED would be fine for my small room. All the red LEDs I can find, however, are wimpy 5mm and other indicator LEDS. Any ideas?
Is there such a thing as a red Cree?
- Thread starter Daravon
- Start date
I got the red Osram's from Digi-Key. I think you can get red Luxeon's or Rebels or K2's from Future. Others can chime in for distributors for Cree and Seoul. High power red LED's are used extensively by the transportation and traffic control industry and the supply is well established.
I don't know what you plan to use to drive these but keep in mind that the Vf of these is considerably lower than blue, green or white LED's and sometimes this may dictate a different driver depending on the Vin.
I don't know what you plan to use to drive these but keep in mind that the Vf of these is considerably lower than blue, green or white LED's and sometimes this may dictate a different driver depending on the Vin.
Marduke
Flashaholic
http://www.dealextreme.com/details.dx/sku.1776
You may want several, and wire them in series to a typical DC power adapter.
You may want several, and wire them in series to a typical DC power adapter.
I ordered one of the ones from Dealextreme, but it never came. The rest of my order came and it a little slip that said the LED was backordered, but DX never emailed me a confirmation email so I can't follow up. First time DX let me down.
Edit: I found the email in my spambox; it says 'waiting on supplier'.
Edit: I found the email in my spambox; it says 'waiting on supplier'.
Last edited:
znomit
Enlightened
I have 4 of these waiting to go into my scooter.
They are much brighter than the safelight at work. I think one would be plenty!
They are about twice as bright as the no name ones from the local electronics shop.
There is XR-C at 39lm@350mA but Luxeon is more common. You can find LUXEON K2 LXK2-PD12-R00, rot, 75lm
or 45lm@350ma at www.leds.de or www.led-tech.de
(for europe).
If you ever need more of them you can also use www.ledrise.com
or 45lm@350ma at www.leds.de or www.led-tech.de
(for europe).
If you ever need more of them you can also use www.ledrise.com
blasterman
Flashlight Enthusiast
- Joined
- Jul 17, 2008
- Messages
- 1,802
LEDsupply.com has the red Lux IIIs on a star for $8.00.
http://ledsupply.com/lxhl-ld3c.php
If you're in the states, they are great people to deal with and have fast shipping.
http://ledsupply.com/lxhl-ld3c.php
If you're in the states, they are great people to deal with and have fast shipping.
DonShock
Flashlight Enthusiast
Digikey carries the red Cree LEDs, but the minimum order shown on their website is 250 for a total cost over $1000. I sent an inquiry yesterday to see if they can allow a smaller quantity, maybe with a surcharge. No answer yet.
I was at the local electronics surplus store today & saw some red Crees today. I automatically thought of this thread.
Said they had 45 of them in stock as of today. $8 ea. http://www.allelectronics.com/make-a-store/item/LED-109/1-WATT-RED-ULTRA-ULTRA-BRIGHT-LED/-/1.html
Link shows XL7090 mounted on a black MCPCB but the ones I saw on display was a XR7090 mounted on a white MCPCB. I didn't see any XLs there. I suppose you can call & ask which you would get if ordered online but I doubt the guys there will know the difference if you ask them about the package type. Or I can pick them up for you that way I can make sure you will be getting XRs. PM me if interested.
Said they had 45 of them in stock as of today. $8 ea. http://www.allelectronics.com/make-a-store/item/LED-109/1-WATT-RED-ULTRA-ULTRA-BRIGHT-LED/-/1.html
Link shows XL7090 mounted on a black MCPCB but the ones I saw on display was a XR7090 mounted on a white MCPCB. I didn't see any XLs there. I suppose you can call & ask which you would get if ordered online but I doubt the guys there will know the difference if you ask them about the package type. Or I can pick them up for you that way I can make sure you will be getting XRs. PM me if interested.
baterija
Flashlight Enthusiast
- Joined
- Feb 7, 2008
- Messages
- 1,053
Mouser carries red seouls available for individual sale.
DonShock
Flashlight Enthusiast
UPDATE: I got a response back from Digikey first thing this morning. They have the red Cree XR-C LEDs available individually. The part number is XRCRED-L1-R250-00M01CT-ND and they are $5.61 each. Here's the Digi-Key direct link to them.
Paul Baldwin
Enlightened
I've got one of the dealextreme reds that Marduke linked to. It's running at 700mA and I have just tried it in a room 14'x8'. It easily lights the room enough to work by, if anything I'd say it's brighter than I remember dark room lights being at college but that's a long time ago.
Paul.
Paul.
I just got my DX LED. It worked when I tested it with a AA battery and it worked when I tested polarity of a 12v 50mA wall wart by very very briefly touching the leads. Now it's dead. Never even got a chance to try it out full power. Do you think I killed it with the wall-wart? It's about 18v open circuit, but still, being a 50mA wallwart, I figured it would be safe for the briefest of connections.
HarryN
Flashlight Enthusiast
For some reason, I am thinking that Cree red LED die are made by Osram. I am not sure on this, but it sticks in my head. Osram makes nice LED die.
As far as the walwart - some are AC of course. In any event, there are some wierd spikes when you turn things on - maybe this is what killed it.
My recommendation is the Lux III, as it can stand a lot of abuse and current range. It is not as efficient as the K2 version, but it can take tremendous abuse and current range.
Even 2 NiMH cells or a single CR123 can be used in direct drive, or add a 2 - 5 ohm resistor as needed.
This is the star version from the primary distributor:
http://www.futureelectronics.com/en...-emitters/colour/Pages/5118849-LXHL-LD3C.aspx
As far as the walwart - some are AC of course. In any event, there are some wierd spikes when you turn things on - maybe this is what killed it.
My recommendation is the Lux III, as it can stand a lot of abuse and current range. It is not as efficient as the K2 version, but it can take tremendous abuse and current range.
Even 2 NiMH cells or a single CR123 can be used in direct drive, or add a 2 - 5 ohm resistor as needed.
This is the star version from the primary distributor:
http://www.futureelectronics.com/en...-emitters/colour/Pages/5118849-LXHL-LD3C.aspx
znomit
Enlightened
Yep, 12V will fry them every time. Wouldn't matter what LED it was.
Grrr. There was a resistor in line with it, the current was (supposedly) limited to 50ma. I never would have thought.
I'm still not sure I understand. If it's a 50ma current limited, then it's NOT actually 12v...I would have thought I could wire it straight up and it would just run at 50ma...I do understand that the inrush current could have fried my led though.
I'm still not sure I understand. If it's a 50ma current limited, then it's NOT actually 12v...I would have thought I could wire it straight up and it would just run at 50ma...I do understand that the inrush current could have fried my led though.
HarryN
Flashlight Enthusiast
I re - read your post. You mentioned that you used the LED to test the polarity of the wal wart ?
Perhaps there is one more important piece of info you need - an LED (light emitting diode) is technically a diode construction, but actually is NOT a diode electrically as we normally think of them.
When I think of a diode, I imagine that it allows current in one direction and blocks it in reverse. That is sort of true in an LED, but not the way you think. In this case, electricity is "allowed" to flow in one direction. If you reverse the polarity, the "diode" is destroyed - instantly.
Perhaps there is one more important piece of info you need - an LED (light emitting diode) is technically a diode construction, but actually is NOT a diode electrically as we normally think of them.
When I think of a diode, I imagine that it allows current in one direction and blocks it in reverse. That is sort of true in an LED, but not the way you think. In this case, electricity is "allowed" to flow in one direction. If you reverse the polarity, the "diode" is destroyed - instantly.
Marduke
Flashaholic
12V will kill any LED instantly, no matter what current you try to run.
