Alarm Clock

Alarm clock software programs have been developed for personal computers.
There are Web-based alarm clocks, some of which may allow a virtually unlimited number of alarm times (i.e. Personal information manager) and personalized tones.

A clock radio is an alarm clock and radio receiver integrated in one device.
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.
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.

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. 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.
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.
The price of these "emergency" clocks was, however, still strictly regulated by the Office of Price Administration.

The French inventor Antoine Redier was the first to patent an adjustable mechanical alarm clock, in 1847.

This device he made only for himself however, and it only rang at 4 AM, in order to wake him for his job.

The first American alarm clock was created by Levi Hutchins, of New Hampshire, in 1787.

Traditional mechanical alarm clocks have one or two bells that ring by means of a mainspring that powers a gear to propel a hammer back and forth between the two bells or between the interior sides of a single bell. In some models, the back encasement of the clock itself acts as the bell. In an electric bell-style alarm clock, the bell is rung by an electromagnetic circuit and armature that turns the circuit on and off repeatedly.

Many alarm clocks have radio receivers that can be set to start playing at specified times, and are known as clock radios.
Some alarm clocks can set multiple alarms. A progressive alarm clock can have different alarms for different times (see Next-Generation Alarms)
and even play music of your choice. Most modern televisions, mobile phones and digital watches have alarm clock functions to turn on or make sounds at a specific time.