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 ...

A very simple but highly efficient combination lock circuit is shown in the figure. Any type of on/off switches can be used, varying from commercially available inexpensive types to more sophisticated ...

In this lesson, students build two circuits and explore how transistors function. When Bell Labs introduced the transistor in June of 1948, a spokesman proudly announced "This cylindrical object . . .

In this lesson, students build two circuits and explore how transistors function. When Bell Labs introduced the transistor in June of 1948, a spokesman proudly announced "This cylindrical object . . .