> but it turns out power requirements vary depending on wavelength of light being generated.
[pedantic]
It's actually because of the different forward voltages of the blue LED vs red, not the overall power
[/pedantic]
Clearly, I knew what you were getting at, but I made that comment because it's useful to understand that LEDs are primarily current controlled devices, not voltage controlled. Had you driven both LEDs with e.g., a 10mA constant-current driver, they would both be solidly visible.
For a regular indicator LED, this isn't really an issue (other than a too-low voltage will cause the flickering you observed), but for high-power illumination LEDs, or especially laser diodes, current management can be the difference between reliable operation or letting the smoke get out.
[pedantic]
It's actually because of the different forward voltages of the blue LED vs red, not the overall power
[/pedantic]
Clearly, I knew what you were getting at, but I made that comment because it's useful to understand that LEDs are primarily current controlled devices, not voltage controlled. Had you driven both LEDs with e.g., a 10mA constant-current driver, they would both be solidly visible.
For a regular indicator LED, this isn't really an issue (other than a too-low voltage will cause the flickering you observed), but for high-power illumination LEDs, or especially laser diodes, current management can be the difference between reliable operation or letting the smoke get out.