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 ...

Circuit diagrams often show transistors in switching circuits. For an ideal NPN transistor, the switch-on voltage at the base is typically 0.6V (acceptable range is 0.6V to 0.8V).

The test voltage is raised to 13.3 V dc again, and VR1 is adjusted so that the transistor turns on. With the upper and lower levels set, the NC point is connected to the circuit (15-V dc charging ...