First build: PHR-803T

[JurrePs3]

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

 

[LtKernelPanic]

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.

 

[bobhaha]

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

 

[lasersbee]

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

 

[JurrePs3]

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

 

[awlego]

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