First build: PHR-803T

Hello, i'm going to make my first build.
A 405nm (violet) extracted from PHR-803T sled.

Well i have a few questions:
1.whats good current? 120mA?
2.whats a good driver for it?
3.somebody that has a diagram for what mw at wich current?

Hope you can answer to (one of my) questions.
I also gonna place some pics in this thread when its complete,
And offcourse a little video

Sirencely, Jurre

Welcome to LPF!

1. My PHR build runs off 104ma and outputs 87mw. Personally I'd keep it to between 100-110 or less. You can go with 120 but you risk blowing the diode. Then again they're only ~$8USD so have fun if you want. :beer:

2. I would just build a linear driver (aka "DDL") for a low powered build like this. An LM317 or LM1117 would work fine. Mine uses an LM317. You can build a very basic one with only the regulator and a resistor like I did but I'd recommend using a 1N4001 or similar diode to prevent reverse polarities from frying your diode.

3. I know I've seen on here but I can't find it now.

If you've never seen a 405 laser in person you'll have fun with this build. Even though this is one of my lowest powered builds it's near the top of my favorite lasers.

Here ya go!
http://laserpointerforums.com/f42/meta-topic-pinout-performance-actual-ld-26417.html

For your first PHR803T build... I would keep the LD current
below 110mA...

Don't forget to use a Test Load to adjust your Driver...



As to the Driver.... I would also suggest you build an
LM317 (DDL style) Driver.... Read up on it here....

http://laserpointerforums.com/f42/diy-homemade-laser-diode-driver-26339.html



You will also need appropriate Laser Safety Goggles/Glasses...


Jerry

Hi, thanks for the reply's!
What does a test load do?

I Already saw LM317 drivers, but isn't that one for a 650nm diode?
Do i need some changes?

Jurre

The test load lets you check to make sure your driver is outputting stable constant current without risking frying your expensive (or in a PHR's case not so expensive) laser diode. It also lets you adjust and set your desired current, again without the danger of killing your laser.

Yes there are a few changes - firstly you need only 1 10ohm resistor and the 100 pot. This will limit your max current to 125mA instead of 250mA. This is because the voltage regulator holds a 1.25 reference voltage between the left 2 pins in the picture and thus using Ohm's Law V=IR (I is in AMPS not mA) you can solve for the current.
Secondly, the Vin might not be 7.2 volts ideally... The blue-ray diode has a higher voltage drop and may require a higher voltage in. I think anything above 7 volts should work though (don't use more than 12 though - your LM317 will get VERY hot) because the dropout across the LM317 is around 1.25V and the drop across a PHR is around 4.5 iirc.

-Alex