Analog signal: Difference between revisions
see-also list, but still not merged |
(or '''analogue''', an alternative British spelling) |
||
| Line 1: | Line 1: | ||
An '''analog''' electronic signal is created by the [[continuous]] [[modulation]] of some property of the [[current]] or [[wave]]. For example, in an analog sound recording, the [[frequency]] of a [[pure tone]] striking a [[microphone]] creates a corresponding pulse in the amperage passing through it. An increase in the volume of the sound causes the fluctuation of current to increase while keeping the same rhythm. |
An '''analog''' (or '''analogue''', an alternative British spelling) electronic signal is created by the [[continuous]] [[modulation]] of some property of the [[current]] or [[wave]]. For example, in an analog sound recording, the [[frequency]] of a [[pure tone]] striking a [[microphone]] creates a corresponding pulse in the amperage passing through it. An increase in the volume of the sound causes the fluctuation of current to increase while keeping the same rhythm. |
||
The primary disadvantage of analog signalling is that any electrical system has noise in it--that is, random variations. As a signal is copied and re-copied, or transmitted over long distances, these random variations become dominant. These losses are lessened by shielding, good connections and several cable types such as coax and twisted pair. |
The primary disadvantage of analog signalling is that any electrical system has noise in it--that is, random variations. As a signal is copied and re-copied, or transmitted over long distances, these random variations become dominant. These losses are lessened by shielding, good connections and several cable types such as coax and twisted pair. |
||
Revision as of 07:52, 2 October 2002
An analog (or analogue, an alternative British spelling) electronic signal is created by the continuous modulation of some property of the current or wave. For example, in an analog sound recording, the frequency of a pure tone striking a microphone creates a corresponding pulse in the amperage passing through it. An increase in the volume of the sound causes the fluctuation of current to increase while keeping the same rhythm.
The primary disadvantage of analog signalling is that any electrical system has noise in it--that is, random variations. As a signal is copied and re-copied, or transmitted over long distances, these random variations become dominant. These losses are lessened by shielding, good connections and several cable types such as coax and twisted pair.
The effects of noise make signal loss and distortion impossible to recover, as amplifying the signal to recover attenuated parts of the signal amplifies the noise as well.
See digital for a discussion of digital vs. analog.
From 'analog circuit':
Analog circuits are those that do not involve transformations of information into digital format.
The concept being measured over the circuit, whether sound, light, pressure, temperature or an exceeded limit, remains from end to end.
Analog implies an analogy between cause and effect, voltage in and voltage, current in and current out, sound in and frequency out.
From 'analog signal':
In telecommunication, the term analog signal has the following meanings:
1. A signal that has a continuous nature rather than a pulsed or discrete nature.
Note: Electrical or physical analogies, such as continuously varying voltages, frequencies, or phases, may be used as analog signals.
2. A nominally continuous electrical signal that varies in some direct correlation with another signal impressed on a transducer.
Note: For example, an analog signal may vary in frequency, phase, or amplitude in response to changes in physical phenomena, such as sound, light, heat, position, or pressure.
Source: from Federal Standard 1037C and from MIL-STD-188
See also: