I have been trying to figure out how LED's achieve multiple brightnesses for the last couple days and i can't quite wrap my mind around it.
The way I understand it, white LED's have a forward voltage of about 3.7 volts.
Is this the voltage drop across the LED at a particular current? Is this then the max current that the LED can handle? Are the values for forward voltage and max allowable current always paired together?
Do higher power emitters have higher max currents associated with the same Vf of ~3.7 V?
I also understand that there is a minimum threshold voltage that must be applied to the LED before current flows (this is why AA, AAA batteries need a booster circuit so they can get above this threshold)
Are the multiple brightness modes achieved by varying the voltage applied to the LED between the threshold and the max Vf of 3.7V? What electronic devices are used to vary these values?
I don't know if this makes sense but its the best i can think of right now. Any attempt to explain this stuff will be greatly appreciated.
Thank you.
The way I understand it, white LED's have a forward voltage of about 3.7 volts.
Is this the voltage drop across the LED at a particular current? Is this then the max current that the LED can handle? Are the values for forward voltage and max allowable current always paired together?
Do higher power emitters have higher max currents associated with the same Vf of ~3.7 V?
I also understand that there is a minimum threshold voltage that must be applied to the LED before current flows (this is why AA, AAA batteries need a booster circuit so they can get above this threshold)
Are the multiple brightness modes achieved by varying the voltage applied to the LED between the threshold and the max Vf of 3.7V? What electronic devices are used to vary these values?
I don't know if this makes sense but its the best i can think of right now. Any attempt to explain this stuff will be greatly appreciated.
Thank you.
