I am a complete beginner in this field, so please forgive me if I write something stupid.
I have a power supply that is pretty accurate, and I have been using it to power my projects. However, I need to spin the whole circuit very fast so I need a portable constant current source for my laser diode.
So, I want to create a simple constant power source that is powered by a 9 V battery (or something else) and supplies a constant 30 mA of current. The voltage range I am expecting is 0-3 V.
First, I tried to find a commercially available product, maybe like an LED driver, but guess what. turns out LEDs user a hell lot more power than a IR laser diode, and the ones that did fit in my range didn't ship to my country.
So, I naturally tried to build one myself, and looked all over the internet, and found dozens of tutorials for 1-5 A sources. I even tried to turn them into a more lower current by changing the values of the resistors, but it didn't work.
Can somebody please help me? I'm out of my profession here :(
