Thanks for the advice! If I need to switch a 380mA motor, I can use a 500mA NPN transistor, such as MPSA06. I don't have it yet. 4.4V / (0.38A * 0.1) = ~116 ohms. Closest standard value: 100 ohms. Closest value I have: 330 ohms. I need more resistor values! To control 50mA IR LED: 4.4V / (0.05A * 0.1) = 880 ohms.