AMPILIFIER DESIGN

Design and build awesome audio amps. Amateur and professional audiophiles alike can now design and construct superior quality amplifiers at a fraction of comparable retail prices with step-by-step instruction from the High-Power Audio Amplifier Construction Manual. Randy Slone, professional audio writer and electronics supply marketer, delivers the nuts-and-bolts know-how you need to optimize performance for any audio system--from home entertainment to musical instrument to sound stage". Build a few simple projects or delve into the physics of audio amplifier operation and design. This easy to understand guide walks you through: Building the optimum audio power supply; Audio amplifier power supplies and construction: Amplifier and loudspeaker protection methods; Stability, distortion, and performance; Audio amplifier cookbook designs; Construction techniques; Diagnostic equipment and testing procedures; Output stage configurations, classes, and device types; Crossover distortion physics; Mirror-image input stage topologies

TRANSFORMERS

The name transformers is derived from the fact that when two coils are placed in close inductive proximity to one another the lines of force from one cut across the the turns of the other inducing an ac current, energy is transformed from one winding to another and this is called transformer action. There are a great variety of transformers for a variety of applications including power transformers, audio transformers and rf transformers among others. All work on the above principle. Power transformers as the name implies a power transformer is designed to usually translate voltage from one level to another. Another type called a current transformer will not be discussed here. The schematic of a transformer is depected in figure 1 below. Consider also the topics covered under where power transformers are used.

DIGITAL BASIC OF COMPUTER

Early computer programmers needed the digital basics to some way represent the human recognised numbers 10 to 15 under the decimal system in a way which still represented one decade. They conveniently chose A - F the first six letters of the alphabet and six in latin is "HEX". Hex-Decimal was born, six alphabetical characters with ten decimal numbers comprising a set of sixteen unique settings of bits all told. The first home computers such as my old personal favourite, the Apple II, had an eight bit "data bus" which dealt in "bytes" and had a sixteen bit (65,536 or 64K) "address bus". The only changes since the 1970's has been the ever increasing speed of the digital logic blocks contained within microprocessors, repeated doubling of the number of switches, (er sorry bits!) reduced power consumption for efficiency, and expanded on board "instruction sets" of micro-code for sharp programmers to use. Dead simple really. By the way, computers and other digital devices can NOT multiply or divide, they can only add and subtract or shift a sequence of bits left or right. When a computer ostensibly multiplies 3 X 4 it actually deep down in the nitty gritty department of all those basic logic blocks shown in figure 3 above, which are buried deep within your IBM or Mac microprocessor, takes the number four, adds four again and; finally adds four again to get twelve. Anyone who tells you otherwise reveals a deep ignorance of digital basics, trust me.

DYNAMIC ELECTRONICS

When electrons are made to move, the result is dynamic electricity. "Dynamic" means movement. To produce a movement of an electron it is necessary to either have a negatively charged field "push it", a positively charged field "pull it", or, as normally occurs in an electric circuit, a negative and positive charge (a pushing and pulling of forces). There are more than one hundred different atoms or elements. The simplest and lightest is Hydrogen. An atom of Hydrogen consists of one electron whirling around one proton much like the moon revolving around the earth. The next atom in terms of weight is Helium (He) consisting two protons and two electrons. The third atom is Lithium (Li) with three protons and three electrons and so it goes on.

REBEL ELECTRONS - Sounds a bit like a teenage romance - opposites attract.

When an electron and proton are brought in close proximity to one another it is the electron which moves because the proton is 1800 times heavier. It is the electron which moves in electricity. Even though the electron is much smaller, its field is quite strong negatively and is equal to the positive field of the proton. If the field strength around an electron at a distance of 1,000,000th of a centimetre was a certain amount, then the field strength around an electron at a distance of 2,000,000th of a centimetre will be 1/4 as much. This is because the field decreases inversely with the distance squared. If an increase in one thing causes an increase in something else, these two things are said to vary directly. 2,000,000 electrons on an object produce twice the negative charge than 1,000,000 electrons would. Since the electric-field strength of an electron varies inversely with the distance squared, the field strength a centimetre away would be quite weak. The fields surrounding protons and electrons are known as electrostatic fields. "Static" means stationary or not moving

Electrons and Atoms

If you turn on a light switch for example you will see the light bulb (globe) glow and emit light into the room. So what caused this to happen? How does energy travel through copper wires to light the bulb? How does energy travel through space? What makes a motor turn, a radio play? Electron theory states all matter is comprised of molecules, which in turn are comprised of atoms, which are again comprised of protons, neutrons and electrons. A molecule is the smallest part of matter which can exist by itself and contains one or more atoms. The word matter includes almost everything. It includes copper, wood, water, air....virtually everything. If we were able to take a piece of matter such as a drop of water, divided it by two and kept dividing by two until it couldn't be divided any further while it was still water we would eventually have a molecule of water. A molecule, the smallest particle which can exist, of water comprises two atoms of Hydrogen and one atom of Oxygen - H2O. An atom is also divisible - into protons and electrons. Both are electrical particles and neither is divisible. Electrons are the smallest and lightest and are said to be negatively charged. Protons on the other hand are about 1800 times the mass of electrons and are positively charged. Each are thought to have lines of forces (electric fields) surrounding them. In theory, negative lines of force will not join other negative lines of force. In fact they tend to repel each other. Similarly positive lines of force act in the same way.

BASIC ELECTRONICS

Basic electronics chapter covers the basic electronics is the most important of all for newcomers. Without a thorough grasp of basic electronics you will never fully understand the later and much more complicated electronics tutorials. To understand these processes requires an understanding of the basic principles. For the light to glow requires energy to find a path through the light switch, through the copper wire and this movement is called electron flow. It is also called current flow in electronics. This is the first important principle to understand. Everybody knows about atoms and electrons don't they? Well we could skip this part but of course we won't because you will likely learn something new. As a suggestion start by reviewing "starting out in basic electronics" followed by some radio electronics terminology. We then cover electron theory and atoms, attenuators, capacitance, current, digital basics, impedance, inductance, integrated circuits, ohms law, power supply, Q, reactance, resistance, resonance, transformers, transistors and voltage.