It is about anythings relevant to the topic, from hardware, software, mobile phone, and all others analog &amp; digital term such as television and radio...etcnoreply@blogger.com (Binary)Sat, 7 Sep 2024 03:32:54 +0800Blogger http://www.blogger.com2125truehttp://analog-vs-digital.blogspot.com/en-usnoIt is about anythings relevant to the topic, from hardware, software, mobile phone, and all others analog &amp; digital term such as television and radio...etcnoreply@blogger.comhttp://analog-vs-digital.blogspot.com/2006/12/introduction-to-analog-and-digital.htmlnoreply@blogger.com (Binary)Thu, 7 Dec 2006 13:35:00 +0800tag:blogger.com,1999:blog-6293800043342469882.post-8030657343457941782<p><strong><span style="font-size:130%;">Analog </span></strong></p><p>An <b>analog</b> or <b>analogue</b> <a class="extiw" title="wiktionary:signal" href="http://en.wiktionary.org/wiki/signal">signal</a> is any variable signal <a title="Continuous function" href="http://en.wikipedia.org/wiki/Continuous_function">continuous</a> in both time and amplitude. It differs from a <a title="Digital signal" href="http://en.wikipedia.org/wiki/Digital_signal">digital signal</a> in that small fluctuations in the signal are meaningful. Analog is usually thought of in an <a title="Electricity" href="http://en.wikipedia.org/wiki/Electricity">electrical</a> context, however <a title="Classical mechanics" href="http://en.wikipedia.org/wiki/Classical_mechanics">mechanical</a>, <a title="Pneumatic" href="http://en.wikipedia.org/wiki/Pneumatic">pneumatic</a>, <a title="Hydraulic" href="http://en.wikipedia.org/wiki/Hydraulic">hydraulic</a>, and other systems may also convey analog signals.</p><p>An analog signal uses some property of the medium to convey the signal's information. For example, an <a title="Aneroid barometer" href="http://en.wikipedia.org/wiki/Aneroid_barometer">aneroid barometer</a> uses rotary position as the signal to convey pressure information. Electrically, the property most commonly used is <a title="Voltage" href="http://en.wikipedia.org/wiki/Voltage">voltage</a> followed closely by <a title="Frequency" href="http://en.wikipedia.org/wiki/Frequency">frequency</a>, <a title="Current (electricity)" href="http://en.wikipedia.org/wiki/Current_%28electricity%29">current</a>, and <a title="Electric charge" href="http://en.wikipedia.org/wiki/Electric_charge">charge</a>.</p><p>Any information may be conveyed by an analog signal, often such a signal is a measured <a title="Response" href="http://en.wikipedia.org/wiki/Response">response</a> to changes in physical phenomena, such as <a title="Sound" href="http://en.wikipedia.org/wiki/Sound">sound</a>, <a title="Light" href="http://en.wikipedia.org/wiki/Light">light</a>, <a title="Temperature" href="http://en.wikipedia.org/wiki/Temperature">temperature</a>, <a title="Position" href="http://en.wikipedia.org/wiki/Position">position</a>, or <a title="Pressure" href="http://en.wikipedia.org/wiki/Pressure">pressure</a>, and is achieved using a <a title="Transducer" href="http://en.wikipedia.org/wiki/Transducer">transducer</a>.</p><p>For example, in an analog sound recording, the variation in <a title="Pressure" href="http://en.wikipedia.org/wiki/Pressure">pressure</a> of a <a title="Sound" href="http://en.wikipedia.org/wiki/Sound">sound</a> striking a <a title="Microphone" href="http://en.wikipedia.org/wiki/Microphone">microphone</a> creates a corresponding variation in the voltage amplitude of a current passing through it. An increase in the volume of the sound causes the fluctuation of the current's voltage amplitude to increase while keeping the same rhythm.</p><p><span style="font-size:180%;">Digital</span></p><p>A <b>digital</b> <a title="System" href="http://en.wikipedia.org/wiki/System">system</a> is one that uses discrete values (often electrical voltages), especially those representable as <a title="Binary numbers" href="http://en.wikipedia.org/wiki/Binary_numbers">binary numbers</a>, or non-numeric <a title="Symbol" href="http://en.wikipedia.org/wiki/Symbol">symbols</a> such as <a title="Letter" href="http://en.wikipedia.org/wiki/Letter">letters</a> or <a title="Icon" href="http://en.wikipedia.org/wiki/Icon">icons</a>, for input, processing, transmission, storage, or display, rather than a <a title="Continuum" href="http://en.wikipedia.org/wiki/Continuum">continuous</a> spectrum of values (ie, as in an <a title="Analog signal" href="http://en.wikipedia.org/wiki/Analog_signal">analog</a> system).</p><p>The distinction of "digital" versus "analog" can refer to method of input, data storage and transfer, or the internal working of an device. The word comes from the same source as the word <a title="Digit" href="http://en.wikipedia.org/wiki/Digit">digit</a> and <i>digitus</i>: the <a title="Latin" href="http://en.wikipedia.org/wiki/Latin">Latin</a> word for <i><a title="Finger" href="http://en.wikipedia.org/wiki/Finger">finger</a></i> (counting on the fingers) as these are used for discrete counting.</p><p>The word <i>digital</i> is most commonly used in <a title="Computing" href="http://en.wikipedia.org/wiki/Computing">computing</a> and <a title="Electronics" href="http://en.wikipedia.org/wiki/Electronics">electronics</a>, especially where real-world information is converted to <a title="Binary numeral system" href="http://en.wikipedia.org/wiki/Binary_numeral_system">binary</a> numeric form as in <a title="Digital audio" href="http://en.wikipedia.org/wiki/Digital_audio">digital audio</a> and <a title="Digital photography" href="http://en.wikipedia.org/wiki/Digital_photography">digital photography</a>. Such data-carrying signals carry one of two electronic or optical pulses, logic 1 (pulse present) or 0 (pulse absent). The term is often meant by the prefix "e-", as in <a title="E-mail" href="http://en.wikipedia.org/wiki/E-mail">e-mail</a> and <a title="Ebook" href="http://en.wikipedia.org/wiki/Ebook">ebook</a>, even though not all electronic systems are digital.</p>0