Alarm clock
An alarm clock or alarm is a clock that is designed to alert an individual or group of people at a specified time. The primary function of these clocks is to awaken people from their night's sleep or short naps; they can sometimes be used for other reminders as well. Most alarm clocks make sounds; some make light or vibration. Some have sensors to identify when a person is in a light stage of sleep, in order to avoid waking someone who is deeply asleep, which causes tiredness, even if the person has had adequate sleep. To turn off the sound or light, a button or handle on the clock is pressed; most clocks automatically turn off the alarm if left unattended long enough. A classic analog alarm clock has an extra hand or inset dial that is used to show the time at which the alarm will ring. Alarm clock functions are also used in mobile phones, watches, and computers.
Many alarm clocks have radio receivers that can be set to start playing at specified times, and are known as clock radios. Additionally, some alarm clocks can set multiple alarms. A progressive alarm clock can have different alarms for different times (see next-generation alarms) and play music of the user's choice. Most modern televisions, computers, mobile phones and digital watches have alarm functions that automatically turn on or sound alerts at a specific time.
Types
Traditional analogue clocks
Traditional mechanical alarm clocks have one or two bells that ring by means of a mainspring that powers a gear to quickly move a hammer back and forth between the two bells, or between the internal sides of a single bell. In some models, the metal cover at back of the clock itself also functions as the bell. In an electronically operated bell-type alarm clock, the bell is rung by an electromagnetic circuit with an armature that turns the circuit on and off repeatedly.[1][self-published source?]
Digital
History
The
The
In China, a striking clock was devised by the
From the 14th century, some clock towers in
User-settable mechanical alarm clocks date back at least to 15th-century Europe. These early alarm clocks had a ring of holes in the clock dial and were set by placing a pin in the appropriate hole.[9][10]
The first American alarm clock was created in 1787 by Levi Hutchins in Concord, New Hampshire. This device he made only for himself, however, and it only rang at 4 am, in order to wake him for his job.[11] The French inventor Antoine Redier was the first to patent an adjustable mechanical alarm clock, in 1847.[12]
Alarm clocks, like almost all other consumer goods in the United States, ceased production in the spring of 1942, as the factories which made them were converted over to war work during World War II, but they were one of the first consumer items to resume manufacture for civilian use, in November 1944.[13][14] By that time, a critical shortage of alarm clocks had developed due to older clocks wearing out or breaking down. Workers were late for, or missed completely, their scheduled shifts in jobs critical to the war effort.[14] In a pooling arrangement overseen by the Office of Price Administration, several clock companies were allowed to start producing new clocks, some of which were continuations of pre-war designs, and some of which were new designs, thus becoming among the first "postwar" consumer goods to be made, before the war had even ended.[15][16] The price of these "emergency" clocks was, however, still strictly regulated by the Office of Price Administration.[14]
The first radio alarm clock was invented by James F. Reynolds, in the 1940s and another design was also invented by Paul L. Schroth Sr.[17]
Clock radio
A clock radio is an alarm clock and radio receiver integrated in one device.[18] The clock may turn on the radio at a designated time to wake the user, and usually includes a buzzer alarm. Typically, clock radios are placed on the bedside stand. Some models offer dual alarm for awakening at different times and "snooze", usually a large button on the top that silences the alarm and sets it to resume sounding a few minutes later.[19] Some clock radios also have a "sleep" timer, which turns the radio on for a set amount of time (usually around one hour). This is useful for people who like to fall asleep while listening to the radio.
Newer clock radios are available with other music sources such as iPod, iPhone, and/or audio CD. When the alarm is triggered, it can play a set radio station or the music from a selected music source to awaken the sleeper. Some models come with a dock for iPod/iPhone that also charges the device while it is docked. They can play AM/FM radio, iPod/iPhone or CD like a typical music player as well (without being triggered by the alarm function). A few popular models offer "nature sounds" like rain, forest, wind, sea, waterfall etc., in place of the buzzer.
Clock radios are powered by AC power from the wall socket. In the event of a power interruption, older electronic digital models used to reset the time to midnight (00:00) and lose alarm settings. This would cause failure to trigger the alarm even if the power is restored, such as in the event of a
Alarms in technology
Computer alarms
Alarm clock software programs have been developed for
Mobile phone alarms
Many modern mobile phones feature built-in alarm clocks that do not need the phone to be switched on for the alarm to ring off.
Next-generation alarms
Scientific studies on sleep having shown that
Sleepers can become accustomed to the sound of their alarm clock if it has been used for a period of time, making it less effective.[28][29] Due to progressive alarm clocks' complex waking procedure, they can deter this adaptation due to the body needing to adapt to more stimuli than just a simple sound alert.[30][31]
Alarm signals for impaired hearing
The deaf and hard of hearing are often unable to perceive auditory alarms when asleep. They may use specialized alarms, including alarms with flashing lights instead of or in addition to noise. Alarms which can connect to vibrating devices (small ones inserted into pillows, or larger ones placed under bedposts to shake the bed) also exist.[32][33]
Time switches
Time switches can be used to turn on anything that will awaken a sleeper, and can therefore be used as alarms. Lights, bells, and radio and TV sets can easily be used.[34] More elaborate devices have also been used, such as machines that automatically prepare tea or coffee. A sound is produced when the drink is ready, so the sleeper awakes to find the freshly brewed drink waiting.[35]
See also
- Delayed sleep phase syndrome
- Digital clock
- Knocker-up
- Light therapy
- Teasmade
- Timer
- Wake-up call
References
- ^ ]
- ^ Humphrey, Oleson & Sherwood 2003, p. 522; Lewis 2000, p. 363
- ^ Landels 1979, p. 35
- ^ Brill's New Pauly, edited by: Hubert Cancik and Helmuth Schneider, 2009
- ^ Joseph Needham, Volume 4, Part 2, pp. 473–5
- ^ Joseph Needham, Volume 4, Part 2, p. 165
- S2CID 145180608
- ^ Joseph Needham, Volume 4, Part 2, p. 445
- ISBN 0-19-518948-5.
- ^ "Monastic Alarm Clocks, Italian" Archived 21 November 2008 at the Wayback Machine, entry, Clock Dictionary.
- ^ Bellis, Mary (6 February 2019). "The Development of Clocks and Watches Over Time". Archived from the original on 10 July 2012. Retrieved 2 November 2006.<!—-—->
- ^ "A 2,000-Year History of Alarm Clocks". Atlas Obscura. 21 April 2016. Retrieved 15 August 2018.
- ^ "A Rude Awakening – The History of Alarm-Clocks". Throughout History. 10 March 2014. Retrieved 15 August 2018.
- ^ a b c "The Clock that Caused a Near-Riot". The Westclox Museum. 5 November 2016. Retrieved 25 February 2021.
- ^ "Find the time to scour antique shows for vintage alarm clocks – Antique Trader". Antique Trader. 6 July 2010. Retrieved 15 August 2018.
- ^ Survey of Current Business. U.S. Department of Commerce. 1955. pp. 21–22. Retrieved 15 August 2018.
- ^ Ha, Peter (25 October 2010). "All-Time 100 Gadgets". Time. Retrieved 15 August 2018.
- ^ Del Maestro, Addison (29 May 2021). "The Clock Radio and Its Moment in Consumer Technology". The Bulwark. Retrieved 30 May 2021.
- ^ Cecil Adams (26 November 1999). "Why does the alarm clock snooze button give you nine extra minutes, not ten?". The Straight Dope. Archived from the original on 31 December 2006. Retrieved 7 January 2007.
- ^ "Use One of These Free Online Alarm Clocks to Wake Up on Time". www.lifewire.com. Lifewire. Retrieved 16 August 2018.
- ^ "Online Alarm Clock". onlinealarmkur.com. Retrieved 5 May 2020.
- ^ "Why Are Alarm Clocks Still a Thing?". Motherboard.vice.com. Motherboard. 10 April 2015. Retrieved 16 August 2018.
- ^ "Hot to Set the iPhone Alarm Clock to Use Songs". www.lifewire.com. Lifewire. Retrieved 16 August 2018.
- ^ Reuven Fenton (29 August 2007). "Bio-alarm clocks set for perfect wake-up". Reuters. Retrieved 9 June 2008.
- PMID 27223290.
- ^ "Wakey, wakey! Wake up refreshed with a brain-monitoring alarm clock". phys.org. Retrieved 17 August 2018.
- S2CID 21123296.
- ISBN 9780712308816. Retrieved 17 August 2018.
- ^ Skaggs, Ernest Burton (1933). A Text Book of Experimental and Theoretical Psychology. Edwards brothers Incorporated. p. 156. Retrieved 17 August 2018.
- ^ Orin, Andy (14 March 2014). "Does the Snooze Button Turn You into a Zombie?". Lifehacker. Retrieved 17 August 2018.
- ^ "Progressive Alarm clocks". Archived from the original on 5 December 2017. Retrieved 17 August 2018.
- ^ "Alerting devices for the hearing impaired". Healthy Hearing. Retrieved 15 August 2018.
- ^ "Vibrating alarm clocks to help deaf children wake up". NDCS.org.uk. Retrieved 15 August 2018.
- ISBN 0-470-19565-7page 1201
- ^ "Best Coffee Makers, Cool Alarm Clock Technology". Retrieved 17 August 2018.
Sources
- Humphrey, John William; ISBN 978-0-203-41325-8
- Landels, John G. (1979), "Water-Clocks and Time Measurement in Classical Antiquity", Endeavour, vol. 3, no. 1, pp. 32–37,
- Lewis, Michael (2000), "Theoretical Hydraulics, Automata, and Water Clocks", in ISBN 978-90-04-11123-3
External links
- Media related to Alarm clocks at Wikimedia Commons