I'm going to build my first LED PPM meter and I'm now ordering all the parts needed.
Well, I started browsing through a selection of LEDs available at, say, Farnell and I really don't know where to start. I know, I need leds with around 2V drop (because there are 5V and 12V leds with built in resistors), but the rest makes me scratch my head.
What luminous intensity do I need, angle of light emission, package (well, this is simple but still)?
What do you guys use for your meters? Any advices?
Ilya
Well, I started browsing through a selection of LEDs available at, say, Farnell and I really don't know where to start. I know, I need leds with around 2V drop (because there are 5V and 12V leds with built in resistors), but the rest makes me scratch my head.
What luminous intensity do I need, angle of light emission, package (well, this is simple but still)?
What do you guys use for your meters? Any advices?
Ilya