A previous Design Idea describes a circuit that uses an astable multivibrator to drive an LED (Reference 1). The circuit in Figure 1 uses a simpler alternative approach. The circuit uses a 2N3904 NPN ...

Transistors are inevitable parts of Electronic circuits. The success of a circuit design lies in the selection of proper transistor type and calculation ...

Buzzer Basics: Technologies, Drive Circuits, and Live Sound Demos The positive temperature-coefficient (PTC) thermistor in the pnp transistor’s current-control circuit prevents short-circuit damage.

The classic transistor amplifier circuit then has a pair of resistors in series between supply and ground, forming a potential divider that gives the base its bias.