Building a powerful red laser

Gofilord said:

I am about to pot mod it until the brightest point, don't know the mA..

Click to expand...

that is a stupid idea, you will risk destroying the diode!

get a test load and measure the current before you hook the driver to the diode.

So what should I do?

Something like this:

1. get a test load
   
2. Solder driver to test load
   
3. Attach power source to driver
   
4. measure the current in your driver.
   
5. Set the current in your driver say 350mA? read here.
   
6. Disconnect power source from driver.
   
7. De-solder driver from test load.
   
8. Short out driver output wires.
   
9. Solder LD to driver.
   
10. Install in host
    
11. Start lasing.

This is so complicated.
in the video he just soldered the driver to the diode, pot mod it and start working!

what video?

Red laser DIY by styropro

you can do what he did but its not advised.

hes turning the driver up to max current which is 440mA for that driver.

you will definitely need heat-sinking for ~440mA.

its not recommended to adjust the pot while the driver is running either, if you slip off the pot and onto the driver with your screw driver, you can potentially kill the driver and diode, so be careful if you decide to do that.

If I don't ajust it while its running, how will I know where it is the most powerful?
and also, if I don't set it to 440mA, will it still be powerful enogh?
BTW, will an old PCU heatsink work (if it is still portable)
and, what do I set it to for it to be powerful yet working without a heatsink?

You need to do some reading, my friend. Virtually all the reading I recommend here is on this site. I'm going out to the boat today and won't be back here for another 12 hours or so but I'll answer further questions after that. In the meantime, use the search feature here at LPF to find posts. If you can't find them, I'll give you links this evening.

1. You need an inexpensive digital multimeter (DMM) to adjust the driver output. A cheapie costing less than $20 will do fine, a better DMM that can also do direct current measurement would give you the advantage of running two tests.

2. You need an inexpensive soldering pencil (12 watts is fine), solder, solder wick or solder puller and soldering flux.

3. Identify your laser diode. Is probably the LPC-815 (LOC) or similar.

4. Get the power chart for the diode. I recommend using a conservative power setting shown on Dr. Lava's 660nm Roundup. If you have the power chart you can set the output of your driver accurately with a DMM before you solder the diode to the driver. Save the chart and print a copy for your workbench.

5. Go to the rkcstr Microdrive website and download the free instruction PDF for driver adjustment.

6. If you use an inexpensive DMM for adjusting the driver via voltage measurement you will need to use an inexpensive test load (dummy load). A test load is not needed for a direct current measurement from a better quality DMM. The test load uses four diodes and a resistor soldered up in series. You can get the specs here on LPF.

7. I cover a lot of the rkcstr Microdrive adjustment procedure in the thread I linked in post #9.

Gofilord said:

This is so complicated.
in the video he just soldered the driver to the diode, pot mod it and start working!

Click to expand...

I have gotten good results setting the driver to 350-380 mA. Within that range I have found the LPC815 delivers plenty of power (more power than I really need).

You need to get yourself a multimeter that can read voltage, resistance and current as the previous poster stated. You can pick them up pretty cheap these days. You would use the meter to set your current on the driver. Very handy thing to have if you are in this hobby (or any hobby dealing with electricity,

With the multimeter I can know ma?

yup, across the 1ohm resistor on the test load 1mV =~ 1mA

Just to confirm:
BEFORE I solder the driver to the diode I hook batterys to it and set the mA to about 350-400 mA, then I solder the diode and without a heatsink for less then 30 seconds it will be good?
and also, if I put up 4*AAA batterys and set the mA for like... 360mA, what is the output voltage?
BTW, will a green laser goggles will help?
PLEASE answer

Gofilord said:

Just to confirm:
BEFORE I solder the driver to the diode I hook batterys to it and set the mA to about 350-400 mA, then I solder the diode and without a heatsink for less then 30 seconds it will be good?

Click to expand...

whats connected to the driver output at this stage? a test load i hope or you will have NO way of knowing the mA.

you must short the driver outputs together before soldering to discharge the drivers capacitor so it doesn't discharge into the laser diode and kill it the first time you turn it on.

then solder the driver to the diode, DON'T keep your soldering iron on the laser diode for more than 3 seconds at a time, to reduce the chance of thermal death!

Gofilord said:

and also, if I put up 4*AAA batterys and set the mA for like... 360mA, what is the output voltage?
PLEASE answer

Click to expand...

id say between 2.5V - 3V...why do you worry about voltage anyway?

Gofilord said:

BTW, will a green laser goggles will help?
PLEASE answer

Click to expand...

No, they don't protect against red.

OK thanks, and by output I ment mW of the laser.
Now I'm from Israel so it's kinda hard to keep it up with:
"whats connected to the driver output at this stage? a test load i hope or you will have NO way of knowing the mA.

you must short the driver outputs together before soldering to discharge the drivers capacitor so it doesn't discharge into the laser diode and kill it the first time you turn it on.

then solder the driver to the diode, DON'T keep your soldering iron on the laser diode for more than 3 seconds at a time, to reduce the chance of thermal death! "
What is a test load? If I'll just connect the driver to batterys with out a diode, shoulden't I know the mA? and in what stage to I solder the diode to the driver? please explain slowly

Gofilord said:

What is a test load? If I'll just connect the driver to batterys with out a diode, shoulden't I know the mA? and in what stage to I solder the diode to the driver? please explain slowly

Click to expand...

I am new as you are. But..I am good at explaining things that I understand, in a way that lets others understand. I hope I can help you

A test load is needed. You maybe should/could google search it. Without a "device" connected to the OUTPUT of the driver, no real "current" ..will be drawn. A test load "replaces" the laser diode, so that you may see what the real current and voltage will be *WHEN* you use your laser diode.



If I am still not clear, I will continue to be patient with you.