Resistance and Ohm's law with Leds
January 13, 2009
Okay, this question is based on OddBot's great build your own ir sensor tutorial.
I noticed that the schematics showed a 150R resistor inline for the 2 IRs, but 82r for the single version.
My understanding of Ohm's law is that if I increase resistance, I decrease current. Therefore, wouldn't I want less resistance for the 2 leds?
Or am I missing an important part of the equation? Is the transistor increasing current, and so more resistance = more voltage?