I am not disagreeing with you, but am trying to learn. Would you please show the math or the reference on the datasheet that provides that resistor value?In your LED test circuit, your transistor saturates fairly well with a 100k base resistor. But a weaker (but passing) 2N2222A transistor needs a 12k base resistor.
Thanks.
ETA: Is this is it?
Ic = .0089 A
Ib = .0089 / 10
Ib = .00089A
E=IR
12.03 = .00089R
R = 13517
Last edited: