Fabrication practice of LED flasher circuits to learn an operation principle of transistors

摘要

Fabrication practice of LED flasher circuits is impelemented for middle school students to learn an operetion principle of transistors experimentally. After the plain explanation of circuit elements, such as resistors, capacitors, and transistors, which are compared to regulating elements of water flow, LED flasher circuits are fabricated on solderless breadboards by students themselves. By replacing resistors or capacitors with other different values, a charge and discharge behavior of the transistor circuits can be seen visually and acoustically in terms of the frequency veering of LED flashers or piezoelectric speakers. Questionnaire surveys after the lecture show that the students might experientially comprehend an operation of transistors and the role of resistors and capacitors and get more interested in electronic circuits.