A Wisdom Archive on amplitude modulation - circuits

Amplitude modulation (AM) is a form of modulation in which the amplitude of a carrier wave is varied in direct proportion to that of a modulating signal. (Contrast this with frequency modulation, in which the frequency of the carrier is varied; and phase modulation, in which the phase is varied.) AM is commonly used at radio frequencies and was the first method used to broadcast commercial radio. The term "AM" is sometimes used generically to refer to the AM broadcast (mediumwave) band (see AM radio). Ampli ... Including:

• Amplitude modulation - Applications in radio
• Amplitude modulation - AM vs. FM
• Amplitude modulation - Forms of AM
• Amplitude modulation - Example
• Amplitude modulation - A more general example
• Amplitude modulation - Modulation index
• Amplitude modulation - Amplitude modulator designs
• Amplitude modulation - Circuits
• Amplitude modulation - Low level
• Amplitude modulation - High level

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Amplitude modulation - Circuits. A wide range of different circuits have been used for AM, but one of the simplest circuits uses anode or collector modulation applied via a transformer. While it is perfectly possible to create good designs using solid-state electronics, valved (tube) circuits are shown here. In general, valves are able to easily yield RF powers far in excess of what can be achieved using solid state. Most high-power broadcast stations still use valves. Modulation circuit designs can be broadly divided into low and high l ...

Read more here: » Amplitude modulation: Encyclopedia II - Amplitude modulation - Amplitude modulator designs

Analogue Electronics refers to electronics systems with analogue signals with any continuously variable signal. It differs from digital electronics in that small fluctuations in the signal are meaningful in that they are continuously variable rather than digitally quantised. Analogue is usually thought of in an electrical context, however mechanical, pneumatic, hydraulic, and other systems may also use analogue signals. Analogue Electronics is frequently confused with other sub-divisions of the general field of Electroni ...

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An analog or analogue signal is any variable signal continuous in both time and amplitude. It differs from a digital signal in that small fluctuations in the signal are meaningful. Analog is usually thought of in an electrical context, however mechanical, pneumatic, hydraulic, and other systems may also use analog signals. The word "analog" implies an analogy between cause and effect, voltage in and voltage out, cur ...

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Automatic gain control (AGC) is an electronic system found in many types of devices. Its purpose is to control the gain of a system in order to maintain some measure of performance over a changing range of real world conditions. A very common and typical example is the AGC used in AM radio. Such a receiver is essentially linear - that is, the output is proportional to the input. This is a necessary requirement because the information content of the signal is carried by the changes of amplitude of the carrier frequency. If the c ...

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The crystal radio receiver (also known as a crystal set) was first built circa 1900 by Greenleaf Whittier Pickard, who used crystalline minerals to detect radio signals. Crystal radio receiver - History. Crystal radio receiver - Early years. People first built and used simple and inexpensive crystal radio sets without batteries or electrical power. Even though vacuum tube radios were common following World War I, crystal radios remained popular, especially among be ... Including:

• Crystal radio receiver - History
• Crystal radio receiver - Early years
• Crystal radio receiver - 1920s and 1930s
• Crystal radio receiver - 1940s
• Crystal radio receiver - Later years
• Crystal radio receiver - Composition
• Crystal radio receiver - Espionage

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A capacitor is a device that stores energy in the electric field created between a pair of conductors on which equal but opposite electric charges have been placed. A capacitor is occasionally referred to using the older term condenser. Capacitor - History. In circa 600 BC, Thales of Miletus recorded that the Ancient Greeks could generate sparks by rubbing balls of amber on spindles. This is the triboelectric effect, the mechanical separation of charge in a dielectric. This effect is th ... Including:

• Capacitor - History
• Capacitor - Physics
• Capacitor - Overview
• Capacitor - Capacitance
• Capacitor - Stored energy
• Capacitor - Hydraulic model
• Capacitor - In electric circuits
• Capacitor - Circuits with DC sources
• Capacitor - Circuits with AC sources
• Capacitor - Capacitors and displacement current
• Capacitor - Capacitor networks
• Capacitor - Capacitor/inductor duality
• Capacitor - Applications
• Capacitor - Energy storage
• Capacitor - Signal processing
• Capacitor - Power supply applications
• Capacitor - Tuned circuits
• Capacitor - Signal coupling
• Capacitor - Noise filters motor starters and snubbers
• Capacitor - Transducer applications
• Capacitor - Weapons applications
• Capacitor - Ideal and nonideal capacitors
• Capacitor - Capacitor hazards and safety

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An alternator is an electromechanical device that converts mechanical energy to alternating current electrical energy. Most alternators use a rotating magnetic field. Different geometries - such as a linear alternator for use with stirling engines - are also occasionally used. In principle any AC generator can be called an alternator, but usually the word refers to small rotating machines driven by automotive and other internal combustion engines. Alternator - History. Alternating current generating ... Including:

• Alternator - History
• Alternator - Theory of operation
• Alternator - Automotive alternators
• Alternator - Radio alternators
• Alternator - External articles and futher reading

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