Red LED dive light

penguinf4

Newly Enlightened
Joined
Aug 3, 2011
Messages
5
Hi all,

I posted in the flashlight mod section about modifying a Princeton Tec Miniwave to use red Seoul P4 LEDs or Luxeon Rebels or something similar. This is because I don't want to drop the cash needed to buy a Sola 600 Photo, or even an i-Torch Pro Video. However, what I learned there was that the forward voltage for the white LEDs is higher than the forward voltage for the red LEDs, so they would probably get fried. So it sounds like there's no quick and easy solution to solder out old LEDs/stick in new LEDs with thermal paste and solder in.

Before I even consider going to an i-Torch Pro Video, are there any wide-beam lights that come with red LEDs that I might consider? I'm looking for red as many underwater creatures seem to be much less sensitive to red light and will not run away.

Thanks in advance.
 

Delphinus

Newly Enlightened
Joined
Oct 15, 2009
Messages
68
Yes red, orange and yellow use a lower voltage, you can try to use a 1 ohm resistance in series.
 

DIWdiver

Flashlight Enthusiast
Joined
Jan 27, 2010
Messages
2,706
Location
Connecticut, USA
Hi all,

I posted in the flashlight mod section about modifying a Princeton Tec Miniwave to use red Seoul P4 LEDs or Luxeon Rebels or something similar. This is because I don't want to drop the cash needed to buy a Sola 600 Photo, or even an i-Torch Pro Video. However, what I learned there was that the forward voltage for the white LEDs is higher than the forward voltage for the red LEDs, so they would probably get fried. So it sounds like there's no quick and easy solution to solder out old LEDs/stick in new LEDs with thermal paste and solder in.

Before I even consider going to an i-Torch Pro Video, are there any wide-beam lights that come with red LEDs that I might consider? I'm looking for red as many underwater creatures seem to be much less sensitive to red light and will not run away.

Thanks in advance.

There's not much demand for red lights, so you may have a hard time finding something commercial. But if you want to mod, this is the place to get help!

I've noticed that in general, the shorter the wavelength of the LED (bluer), the higher the voltage. Infrareds being the longest wavelength, have the lowest voltage. Whites are built by taking a blue die and coating it with phosphor to change the color of some of the light, making it white(ish), so whites and blues have high voltages, while ultraviolet are even higher.

Depending on how the LEDs are driven, the voltage may or may not make a difference. If they are direct drive, it will make a huge difference - you will brobably blow the LEDs, unless you use penguinf4's suggestion of adding a series resistor, or something like that. But if they are driven by a switchmode current-regulating driver (the only way to get high efficiency and constant light output), it might make no difference at all, except to double your battery life. Any idea what's in the P-Tech?

By the way, a 1-ohm resistor would be about right if the desired LED current is around 1.5A. You might need more or less depending on the current.
 

350xfire

Flashlight Enthusiast
Joined
Aug 14, 2008
Messages
1,229
Location
Texas
May want to chack AVNET.com... I think that Luminus makes a very bright red LED. Something like SST-50 or 90 but red.
 

Packhorse

Flashlight Enthusiast
Joined
Nov 29, 2007
Messages
1,912
Location
New Zealand
I guess there are a few things to consider.
If the driver is a true current regulator then it shouldn't matter that the Vf is different. But if the Vf goes up then make sure the input voltage can cope. If the Vf goes down make sure the driver can cover with a greater voltage drop.
 
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