general purpose transistor

A general purpose PNP transistor is a bipolar junction transistor used for switching and amplification, especially on the high side of a circuit. It turns on when the base is driven lower than the emitter, allowing current to flow from emitter to collector. Designers choose it for simple control, compact layouts, and reliable performance in … Read more

A general-purpose NPN transistor is a ratings envelope: 40 V, 200 mA, gain 100-300. How to size the base resistor, and when a MOSFET is the better answer.