I was given a broken flashlite that ran off 3 series AA batteries with 1 current liming resistor, on V+.
It has a switch between 3 edge or 24 front white LEDs in parallel. I know some will pass a lot more current than others. I want to make something using old pulled transistors with 1 overall variable resistor turning the max current up to 30mA average on LEDs that pass the most current.
I can adapt the PCB to 4 rows of 6, or even 6 rows of 3. I don't want to make 9 current mirrors(although it would be fun to solder).
I also don't want to use an LM317, I want to use my basic know how of BJT regulators and current mirrors. I have lots of adjustable voltage references like TL431 and 2.5V LM336.
I also want it to run off 9V or 12V since they are the walwarts I have. I could use a switch between 2 biasing paths or IDK yet.
I'm disappointed at the brightness of 24LEDs at 325mA Thas was with 3.1V across 24. So this won't help much as the soldering station lights vs my room lights. Oh well.
Any thoughts ?