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 ?
USA], Nov 1 ( ANI ): Traffic signal countdown timers are helping in keeping young drivers safe on the road, a recent study has revealed.
Plura has introduced a new range of networked production timers from its Alpermann-Velte brand of infrastructure solutions for connected studios, complete with a mobile app for advanced wireless applications.
Of course, if you push stop/reset again, it zeroes the timer.
A number of motorists expressed resentment at the move by the traffic department to remove digital timers at all traffic lights and intersections.
PACT, another pioneer, also makes a fine compact timer called the Club Timer III.
Most boilers are controlled by inefficient timers that regulate the heat, running whenever the temperature outside falls below 55 degrees.
A freephone helpline (0800 408 0048) has also been created for UK customers to contact the firm for advice and to arrange an appointment for the timer to be replaced.
A timer can remember to turn off the power so you do not have to get up.
The bomb that exploded in the Myyrmanni shopping centre in Vantaa, Finland last year was equipped with a timer, according to police information.
But there's a simpler option for small or isolated areas of the garden that can be irrigated from a single hose bibb: a battery-operated timer.
Beef filet mignons and other specialty cuts of meat can be cooked to perfection with the Pop-Up[R] Timer from Volk Enterprises, Inc.