Analog electronics are devices utilizing systems operating with a variable signal that continuously functions. Small changes in signal input cause small changes in signal output. Basically, the electrical signal fluctuates in both voltage and current, resulting in a proportional signal representing some original information. While the technology is intuitive, it is imprecise due to the continued nature of the signal. Analog electronics vary from digital electronics in that the digital method simply uses two pieces of information, a one and a zero, to create the signal.
One of the unique facets of analog technology is the fact that the signal never stops, it can only be discontinued. For example, a vinyl record is continually read by the needle on the turntable until it is discontinued at the end of the recording. A rudimentary example of analog information would be holding a pencil down on a piece of paper and writing a sentence without lifting up. While this conveys information, it does not produce a perfectly formed writing sample. Inversely, digital information can be represented by the pencil making contact and not making contact, giving a more precise writing sample.
Analog electronics convey information that is essentially a simulation encoded and transmitted by electrical means. Some physical form is converted to information by a transducer, a device designed to transfer one type of energy into another. This can include sound, light, pressure or any other form of phenomenon. One well-known example of a transducer is a microphone, used to transmit sound into an electrical signal.
Signals for analog electronics are presented with the methodology of ranges. Basically, each signal is broken into different levels of voltage and current, which alternate to represent the given information. This varies depending on the electronics device. For example, an analog stereo system could use seven volts to represent a specific frequency from the speakers, while 7.1 would represent a step up from that frequency. This is how the simulation of a song ultimately is presented.
However, some analog electronics use the technique of modulation to convey the signal. Amplitude modulation (AM) modifies the sinusoidal voltage waveform, while frequency modulation (FM) alters the frequency. As a result, both AM, a change in the shape of the waveform, and FM, a change in the rate of waves, operate with separate analog devices, although they are often placed together into the same electronics unit.
One drawback of analog electronics is what is known as noise. Throughout the variations of the analog signal, there are inevitably certain disturbances that result in distortions or alterations to the way the signal is interpreted. This occurs most readily in electronics from thermal vibrations of particles at the atomic level. In situations in which the information is copied, this noise becomes more prevalent with each generation.