Digital clock - wikipedia Digital clock This article is about the appliance. For timing reference for digital audio, see Word clock. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( January 2010 ) Basic digital alarm clock without a radio. The mark in the top - left of the display indicates that the time is 4 : 00pm, not 4 : 00am. A 1969 radio alarm clock ( Sony Digimatic 8FC - 59W ) with an early mechanical - digital display A digital clock is a type of clock that displays the time digitally ( i.e. in numerals or other symbols ), as opposed to an analog clock, where the time is indicated by the positions of rotating hands. Digital clocks are often associated with electronic drives, but the `` digital '' description refers only to the display, not to the drive mechanism. ( Both analog and digital clocks can be driven either mechanically or electronically, but `` clockwork '' mechanisms with digital displays are rare. ) The biggest digital clock is the Lichtzelt Pegel ( `` Light Time Level '' ) on the television tower Rheinturm Düsseldorf, Germany. Contents 1 History 2 Construction 3 Displays 3.1 Setting 4 Uses 5 References 6 External links History The first digital pocket watch was the invention of Austrian engineer Josef Pallweber who created his `` jump - hour '' mechanism in 1883. Instead of a conventional dial, the jump - hour featured two windows in an enamel dial, through which the hours and minutes are visible on rotating discs. The second hand remained conventional. By 1885 Pallweber mechanism was already on the market in pocket watches by Cortébert and IWC ; arguably contributing to the subsequent rise and commercial success of IWC. The principles of Pallweber jump - hour movement had appeared in wristwatches by the 1920s ( Cortébert ) and are still used today ( Chronoswiss Digiteur ). While the original inventor did n't have a watch brand at the time, his name has since been resurrected by a newly established watch manufacturer. Plato clocks used a similar idea but a different layout. These spring - wound pieces consisted of a glass cylinder with a column inside, affixed to which were small digital cards with numbers printed on them, which flipped as time passed. The Plato clocks were introduced at the St. Louis World Fair in 1904, produced by Ansonia Clock Company. Eugene Fitch of New York patented the clock design in 1903. 13 years earlier Josef Pallweber had patented the same invention using digital cards ( different from his 1885 patent using moving disks ) in Germany ( DRP No. 54093 ). The German factory Aktiengesellschaft für Uhrenfabrikation Lenzkirch made such digital clocks in 1893 and 1894. The earliest patent for a digital alarm clock was registered by D.E Protzmann and others on October 23, 1956, in the United States. Protzmann and his associates also patented another digital clock in 1970, which was said to use a minimal amount of moving parts. Two side - plates held digital numerals between them, while an electric motor and cam gear outside controlled movement. In 1970, the first digital wristwatch with an LED display was mass - produced. Called the Pulsar, and produced by the Hamilton Watch Company, this watch was hinted at two years prior when the same company created a prototype digital watch for Kubrick 's 2001 : A Space Odyssey. Throughout the 1970s, despite the initial hefty cost of digital watches, the popularity of said devices steadily rose. Over the years, many different types of digital alarm clocks have been developed. In Soviet Russia, the 7 - segment digital clocks were known as Elektronika 7. Construction Digital clocks typically use the 50 or 60 hertz oscillation of AC power or a 32,768 hertz crystal oscillator as in a quartz clock to keep time. Most digital clocks display the hour of the day in 24 - hour format ; in the United States and a few other countries, a more commonly used hour sequence option is 12 - hour format ( with some indication of AM or PM ). Some timepieces, such as many digital watches, can be switched between 12 - hour and 24 - hour modes. Emulations of analog - style faces often use an LCD screen, and these are also sometimes described as `` digital ''. Displays A digital clock 's display changing numbers An LCD battery - operated clock without alarm To represent the time, most digital clocks use a seven - segment LED, VFD, or LCD for each of four digits. They generally also include other elements to indicate whether the time is AM or PM, whether or not an alarm is set, and so on. Setting A premium digital clock radio with digital tuning A basic digital clock radio with analog tuning If people find difficulty in setting the time in some designs of digital clocks in electronic devices where the clock is not a critical function, they may not be set at all, displaying the default after powered on, 00 : 00 or 12 : 00. Digital clocks that run on mains electricity and have no battery must be reset every time the power has an accident or if they are moved. Even if power is cut off for a second, most clocks will still have to be reset. This is a particular problem with alarm clocks that have no `` battery '' backup, because even a very brief power outage during the night usually results in the clock failing to trigger the alarm in the morning. To reduce the problem, many devices designed to operate on household electricity incorporate a battery backup to maintain the time during power outages and during times of disconnection from the power supply. More recently, some devices incorporate a method for automatically setting the time, such as using a broadcast radio time signal from an atomic clock, getting the time from an existing satellite television or computer connection, or by being set at the factory and then maintaining the time from then on with a quartz movement powered by an internal rechargeable battery. Commercial digital clocks are typically more reliable than consumer clocks. Multi-decade backup batteries can be used to maintain time during power loss. Uses A digital clock built into an oven Because digital clocks can be very small and inexpensive devices that enhance the popularity of product designs, they are often incorporated into all kinds of devices such as cars, radios, televisions, microwave ovens, standard ovens, computers and cell phones. Sometimes their usefulness is disputed : a common complaint is that when time has to be set to Daylight Saving Time, many household clocks have to be readjusted. The incorporation of automatic synchronisation by a radio time signal is reducing this problem ( see Radio clock ). A digital light clock that can determine room temperature References Jump up ^ `` Home page ''. JosefPallweber.com. Retrieved 2015 - 11 - 07. ^ Jump up to : Churm, Thomas M. ( November 5, 2013 ). `` A Short History of Digital Clocks and Watches ''. Alarm Clock Blog. Retrieved 2016 - 02 - 28. Jump up ^ ( in German ) Imperial Patent Office ( October 27, 1890 ). `` Patent No. 54093 '' ( PDF ). German Patent and Trademark Office. Retrieved 2015 - 11 - 07. Jump up ^ `` Is digital more precise ? ''. The German Clock Museum. April 2015. Retrieved 2015 - 11 - 07. Jump up ^ `` The History of the Digital Watch ''. h2g2. April 30, 2003. Retrieved 2015 - 11 - 07. Jump up ^ `` Radio Controlled LED Alarm Clock Instruction Manual -- SM2442 '' ( DOC ). Zeon Ltd. Retrieved 2015 - 11 - 07. Jump up ^ `` Stopped Clock ''. TV Tropes. Retrieved 2015 - 11 - 07. External links Wikimedia Commons has media related to Digital clocks. How Digital Clocks Work History of the Digital Watch Museum of Vintage Rare Digital LCD Wrist Watches Electric clock technology Powerline synchronized Synchronous Motor and the Master Clock Utility frequency Synchronous motor Electronic Quartz clock Atomic clock Radio clock GND : 4149854 - 9 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Digital_clock&oldid=805612309 '' Categories : Clock designs Austrian inventions Digital technology Hidden categories : Articles with German - language external links Articles needing additional references from January 2010 All articles needing additional references All articles with unsourced statements Articles with unsourced statements from September 2011 Wikipedia articles with GND identifiers Talk Contents About Wikipedia Català Dansk Deutsch Español Bahasa Indonesia Italiano 日本 語 Polski Português Русский Svenska اردو Tiếng Việt Edit links This page was last edited on 16 October 2017, at 14 : 39. 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Question: when was the first digital alarm clock invented
Answer: D.E Protzmann and others on October 23, 1956,