/diy/ - Do It Yourself

>>1232208
The opamp I'll likely use is probably the LM324N, which surprised me with its 0.2mV low, but since I'll be using a 4 opamp chip it doesn't really matter whether I use it or not. I already own it, so it's just a matter of mocking-up the circuit on a breadboard to see if its necessary.

I'll actually want to use pic related LEDs, though I can't find a datasheet. Since my maximum brightness will mean a 100% duty cycle, I can't just skimp on the dropper resistor. But since the LEDs will probably be over-rated for this purpose, I doubt I'll ever run them at 100%. The website actually states "Typical: 1.7 V, Max: 2.4V" in regards to the LED's forward voltage, meaning I might be able to put three in series and still get significant brightness out of them, which leads to the question of whether three LEDs at ~1.7V would be brighter than two at 2-2.4V. I'm guessing the latter, but even if I buy them there's no easy way to quantitatively measure it, except maybe measuring the resistance of an LDR a fixed distance away from them. Actually I might try that.