2N3904 (5 pcs)

The 2N3904 is a general-purpose NPN bipolar junction transistor for low-power switching and small-signal amplification, sold here in a pack of 5. It is fast, low-cost and easy to use, so it appears in countless beginner circuits, Arduino tutorials and electronics courses for driving LEDs, buzzers and small relays.

2N3904 Specifications

• Type: NPN bipolar junction transistor (BJT)
• Package: TO-92, through-hole
• Collector-emitter voltage (VCEO): 40 V
• Collector current (IC): up to 200 mA
• Power dissipation: 625 mW
• DC current gain (hFE): 100–300 at 10 mA
• Transition frequency (fT): about 300 MHz
• Pinout: E-B-C, flat side facing you, legs down
• Pack size: 5 pieces

2N3904 Applications

• Switching LEDs, buzzers and small relays from microcontroller pins
• Small-signal and audio amplifier stages
• Logic inverters and level shifting
• Oscillators, timers and sensor interfaces
• Electronics education and STEM labs

What's in the Box

• 5 × 2N3904 NPN transistors

Tip: The 2N3904 handles up to 200 mA; for heavier loads choose the 2N2222 or a logic-level MOSFET. Use a base resistor (around 1 kΩ from a 5 V pin) and a flyback diode across relay coils.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.