10 negative type transistors with 10 current limiting resistors (2.2kOhm). The Arduino's pins are great for switching small loads (up to 40 mA), but if you'd like to control something larger (multiple LEDs, small toy motors etc.) a transistor is required. These transistors are good for currents up to 600 mA.
- Transistor (NPN) (P2N2222A) (x10)
- Resistors (2.2k Ohm) (x10)