Download PDF The Resource Handbook of Electronics by Jerry C. Whitaker

Sinopsis

The atomic theory of matter specifies that each of the many chemical elements is composed of unique and identifiable particles called atoms. In ancient times only 10 were known in their pure, uncombined form; these were carbon, sulfur, copper, antimony, iron, tin, gold, silver, mercury, and lead. Of the several hundred now identified, less than 50 are found in an uncombined, or chemically free, form on earth. Each atom consists of a compact nucleus of positively and negatively charged particles (protons and electrons, respectively). Additional electrons travel in well-defined orbits around the nucleus. The electron orbits are grouped in regions called shells, and the number of electrons in each orbit increases with the increase in orbit diameter in accordance with quantum-theory laws of physics. The diameter of the outer orbiting path of electrons in an atom is in the order of one-millionth (10–6) millimeter, and the nucleus, one-millionth of that. These typical figures emphasize the minute size of the atom.

The nucleus and the free electrons for an iron atom are shown in the schematic diagram in Figure 1.1. Note that the electrons are spinning in different directions. This rotation creates a magnetic field surrounding each electron. If the number of electrons with positive spins is equal to the number with negative spins, then the net field is zero and the atom exhibits no magnetic field. In the diagram, although the electrons in the first, second, and fourth shells balance each other, in the third shell five electrons have clockwise positive spins, and one a

counterclockwise negative spin, which gives the iron atom in this particular electron configuration a cumulative magnetic effect. The parallel alignment of the electron spins over regions, known as domains, containing a large number of atoms. When a magnetic material is in a demagnetized state, the direction of magnetization in the domain is in a random order. Magnetization by an external field takes place by a change or displacement in the isolation of the domains, with the result that a large number of the atoms are aligned with their charged electrons in parallel.

Content

1. Fundamental Electrical Properties
2. International Standards and Constants
3. Electromagnetic Spectrum
4. Frequency Assignment and Allocations
5. Light, Vision, and Photometry
6. Circuit Fundamentals
7. Resistors and Resistive Materials
8. Capacitance and Capacitors
9. Inductors and Magnetic Properties
10. Filter Devices and Circuits
11. Thermal Properties
12. Semiconductor Devices
13. Analog Circuits
14. Logic Concepts and Devices
15. Amplitude Modulation
16. Frequency Modulation
17. Pulse Modulation
18. Network Communications
19. Optical Devices and Systems
20. System Reliability

Click here to download