The 2N3904 is a widely used general-purpose NPN bipolar junction transistor designed for low-power switching and signal amplification applications. It supports a maximum collector-emitter voltage of 40V and a collector current of up to 200mA, making it ideal for control circuits, logic interfacing, driver stages, oscillator circuits, and low-frequency amplification. With stable DC gain and fast switching performance, the 2N3904 is one of the most common transistors used in embedded systems, educational electronics, and small-signal analog circuits.
