Hello everyone. When I thought about getting a 589nm laser I was not sure about the output power. A nice bright 589nm has a truly beautiful beam (in my opinion) but is not really practical in daily use. I was thinking about getting a 5mW laser but got a 50mW because the price / power ratio.
So now I build a little circuit to adjust the input power. I is using a variable step down regulator. First I wantet to build a variable current source but I had way to much ripple on th output. Now, using a variable voltage source everything works fine. The only thing that is not perfect ist the switch of the Spartan host itself. Maybe I will modify it sometime too. I am quite happy now to have a more eye safe and more mode and output power stable laser :). If I turn the converter up to 2.25V I get the full output power and the laser is more efficient due the step down regulator.
I added some pictures in the attachments.
So now I build a little circuit to adjust the input power. I is using a variable step down regulator. First I wantet to build a variable current source but I had way to much ripple on th output. Now, using a variable voltage source everything works fine. The only thing that is not perfect ist the switch of the Spartan host itself. Maybe I will modify it sometime too. I am quite happy now to have a more eye safe and more mode and output power stable laser :). If I turn the converter up to 2.25V I get the full output power and the laser is more efficient due the step down regulator.
I added some pictures in the attachments.