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D.A.S.
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Put the transistor back and change R =50 to 500 Ohms

We want to ensure base current = >5% of LED current. Preferably 10%. (never use Vgs(th)2~4V FETS on 3.3V logic. It needs >5V.) All IRFxxx's I think are this way, Now they make Logic level FETS with a different prefix in P/N.

Your design was (3.3V-0.6Vbe)/5k=Ib= 540 uA.

Change Rb to >= 100 Ohms and it will work off any 3.3V logic and NPN open collector. Iout=(3.3-Vbe)/(Rcmos+Rs)= (3.3-0.7)/(33+100)=20 mA so it can drive 200mA to 350mA on collector with low Vce(sat)

Adjust series Rs as required.

D.A.S.
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