I have a 3.7 V 18650 battery and I want to control a 3 V, 130 mA LED (high power CREE LED).
I have calculated the series resistor for the LED (0.7 V/0.130 A) = 5 Ohms (ish)
But when I apply any voltage or current to the base, I don't get the 130 mA at the collector like I want. Instead, the LED is dim and I'm getting considerable voltage drop over the transistor.
I'm just confused about how to get the transistor to become fully saturated and act like a switch.
From what I understand, the base needs at least 0.7 V and the current Ib needs to be calculated from Ic/gain.
Could someone help me out please?