Timer


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Related to Timer: egg timer, timer clock

timer

a switch or regulator that causes a mechanism to operate at a specific time or at predetermined intervals

Timer

 

a control device that, after a predetermined time interval, automatically starts or stops a system, machine, or apparatus used in industry or the home. The term “timer” is also applied to a monitoring device that signals when such a system, machine, or apparatus is to be started or stopped. Depending on the principle of operation, a timer can be mechanical, hydraulic, pneumatic, or electrical. The time interval of a timer is usually predetermined in the same way as in a timing relay.

Timers are classified as single-shot, multishot, and repeat-cycle. In single-shot timers the time interval is usually set manually, for example, by moving the hand of the time indicator. In this case, the timer mechanism is simultaneously wound, and the timer will operate when the hand returns to zero. Multishot timers automatically operate several times with preset time intervals. Repeat-cycle timers operate with the same time interval (the period of the cycle) after equal periods of time. In multishot and repeat-cycle timers the sequence of time intervals, or the timer schedule, is prescribed by such means as a punched tape, a disk with pins, or a system of shaped cams.

Timers based on clocks have the highest accuracy and reliability, as well as the broadest range of time intervals. Clockworks are used mostly in single-shot and multishot timers designed for operation within a 24-hour period. Electric and electronic time measurement devices are used mostly in repeat-cycle timers that function continuously over periods of several months.

B. M. CHERNIAGIN


Timer

 

a circuit used in, for example, radar sets, television equipment, and telecommunication systems primarily for the purpose of ensuring that certain processes occur in conformity to certain time relationships.

In radar sets, for example, timers provide synchronization of such processes as the emission of radio signals by the transmitter, the blocking of the receiver during transmission, and the starting of indicator sweeps at the instant the signal is received. In telemetry systems, multichannel pulse communication systems, and other information systems, timers provide a fixed spacing between, for example, information-carrying symbols (in digital transmission) or word or address markers.

The main component of a timer is a generator of frequency-stable oscillations, such as a quartz-crystal oscillator or a maser. The oscillations are used for such purposes as synchronization or the provision of local time markers either directly—that is, in the form they are taken from the oscillator output—or after conversion to other oscillations (or pulses) that are characterized by certain altered parameters, such as frequency, phase, or amplitude. In the case of pulses, the characterizing parameters include pulse duration and shape.

A. F. BOGOMOLOV

timer

[′tīm·ər]
(computer science)
A hardware device that can interrupt a computer program after a time interval specified by the program, generally to remind the program to take some action.
(electronics)
A circuit used in radar and in electronic navigation systems to start pulse transmission and synchronize it with other actions, such as the start of a cathode-ray sweep.
(engineering)
A device for automatically starting or stopping a machine or other device.
(mechanical engineering)
A device that controls timing of the ignition spark of an internal combustion engine at the correct time.
References in periodicals archive ?
Widely adopted by roughly two dozen countries around the world, traffic signal countdown timers are not used in the U.S.
He adds that Timer's also supports schools and local teams as much as they can.
If you've made a habit of flying your approaches on course at the proper airspeeds every time and get really good at correcting that time for wind, you'll know your timer gives you an idea of where you are.
"The SPT Series represents a modern timer distribution system that is easy to deploy and easy to use, filling the hole left by vendors who no longer serve this space while evolving production timers for the network," said Reimund Baeuerle, Co-managing Director, Plura Europe GmbH, a subsidiary of Plura Broadcast.
This size difference caused us to overlook the seconds on one occasion--quickly glancing at zero minutes, we thought the timer had elapsed when there were seconds remaining.
He said the department has lately canceled the digital timers because of a technical malfunction in the system, but they are being rectified and will be installed soon.
Insignia Technologies' intelligent plastics allow the company to make fully automated timers mat can be set to time out within Wile frames ranging from a few minutes, up to several months.
The patented smart cap with a built-in LCD timer fits standard prescription vials.
ZENA SAYS: Tracking down such a large timer proved not so simple a challenge.
My old timer would give a start beep, and record the time of the last shot fired.
Data triangulation was made through seeking the opinions of different part-timers and few current full-timers (former part- timers).