Help appreciated

I have already built a ~1 watt 445nm laser that used a 1.25a driver but I followed a tutorial so I never understood how the process of choosing the correct driver works.

My question is this

How do you calculated what driver is required based on the diode being used. For example if I want to make a 3 watt laser how many amps is my driver going to need to be? How is this calculated? also how do I know what batteries I need?

Thanks in advance!

R3D3Y3K1K1 said:

I have already built a ~1 watt 445nm laser that used a 1.25a driver but I followed a tutorial so I never understood how the process of choosing the correct driver works.

My question is this

How do you calculated what driver is required based on the diode being used. For example if I want to make a 3 watt laser how many amps is my driver going to need to be? How is this calculated? also how do I know what batteries I need?

Thanks in advance!

Click to expand...

The best way to determine the amp for a LD needed will of cos looking at the datasheet. If you are planning to overdrive the LD. Start with the safe (suggested) current and graduate increase the amp until the desired power is reached.

The voltage of batteries should higher than the forward voltage of the LD (see datesheet) if you are using buck/linear driver. Or lower than that if you are using boost driver. The voltage drop of the driver should also be counted.

If your tutorial has you driving it more than the laser diode (LD) spec says you should, or if you want to drive it harder, then search this forum for test results for that specific LD. Many people here routinely test LDs then graph the power out vs the drive current. From that graph you can see how much they were able to drive the LD and not fail. Make note of their host/heatsink. Again, lots of people on this forum can help you with the size and where to buy a proper heatsink for your desired application. The size and type of host is often an integral part of the overall heatsink.

And most importantly, don't forget to wear proper goggles.

HTH

OVNI

R3D3Y3K1K1 said:

I have already built a ~1 watt 445nm laser that used a 1.25a driver but I followed a tutorial so I never understood how the process of choosing the correct driver works.

My question is this

How do you calculated what driver is required based on the diode being used. For example if I want to make a 3 watt laser how many amps is my driver going to need to be? How is this calculated? also how do I know what batteries I need?

Thanks in advance!

Click to expand...

Hi R3,
the NDB 7875 3W 445nm will take a 2.4A Sxd driver with a long ramp up and a 2W diode like a PLTB450B and a M140 will take a 1.8A Xdrive driver. Both will run off 2 cells in series..

Rich

A NDB7875 with a 2.4A driver and G2 lens can get you 3 watts.

Here is a pic from DTR's site of a NDB7875 running at 2.4 amps with a G2 lens making 3 watts of blue laser light.


If you go to DTR's store, I will put the link below, you can click on each diode and see what the output is based on the current it's being driven at.
You can compare diodes and see what the current gives you with each.

https://sites.google.com/site/dtrlpf/



These are good batteries and they will power even bigger diodes if you decide to go bigger later, look for IMR or INR cells.

http://www.ebay.com/itm/2x-Panasoni...692952?hash=item35df01a258:g:8A8AAOxyQfJThVDH

I also use these:

http://www.ebay.com/itm/2-LG-INR-18...326486?hash=item5678b52b56:g:U8YAAOSw3ydVsE0b

Thanks guys! I appreciate all the quick responses from all of you!