An introductory discussion of electronics would be remiss without a conceptual analysis of DC voltage ( Vdc ), current ( I ), and resistance ( R ). Most students readily adapt to teaching strategies that relate new topics to familiar themes and everyday life experiences. Visual aids are of preeminent importance to new and seasoned learners alike. Additionally, painstaking efforts should be made to become familiar with scientific notation, the metric units, metric prefixes, and basic metric unit conversions. Mastery of these fundamental topics leads to the study of both analog and digital machines of immense complexity and sophistication. We will now begin our journey with a discussion that relates conservation of energy principles to the energy potential ( voltage ) that enables simple battery systems to perform work:
The water in the reservoir region of our diagram has the ability to do work on the turbine due to its high energy state. As water rolls over the dam, gravitational potential energy ( PE ) is quickly converted to kinetic energy ( KE ), which is the “ energy of motion “. According to Newton’s Laws of Motion, every force has an equal and opposite component. Thus, the potential energy contained in the reservoir is ample enough to overcome the inertia of the dam’s turbine. As a consequence, the turbine converts the linear motion of the water into rotational motion that is used to create electricity. Finally, the water reaches the stream, and due to its relatively lower energy state, it no longer has the ability to do work on the turbine. Energy was neither created nor was it destroyed during this process; it only changed forms according to the law of conservation of energy.
A hot air balloon contains rapidly vibrating molecules that repel one another and give the balloon its characteristic shape. Analogous to this are concentrations of charged particle species ( ions ) within a battery’s cathode ( – ) and anode ( + ) compartments; like charges repel one another, and opposite charges are attracted to one another. A battery exploits these characteristics with electrical conductors that provide a path for negatively charged electrons to access positively charged protons. In the process of crossing conductors, electrons in motion supply power to electrical devices whose resistance to flow causes energy losses to occur in the form of heat, noise, and on occasion, light:
Physics is still ripe with questions about the nature of charged particles. In electronics, studies are dictated by what is known about how such species behave under known circumstances. It is within this framework that subsequent lectures will be structured.
RENAISSANCE PHYSICS 