And two LEDs in paralell is not good, as one will "hog" the current so it lights brightly and other less bright or not at all.
And to add on to gunrunerjohn, small resistance differences won't affect light output significantly. So using a 470 or 680 changes the current somewhat, but unless you have a calibrated photometer and measure light exactly the same, the light change would be un noticeable to the eye, and certainly not in train applications!
And two LEDs in paralell is not good, as one will "hog" the current so it lights brightly and other less bright or not at all.
And two LEDs in paralell is not good, as one will "hog" the current so it lights brightly and other less bright or not at all.
