A time switch (also called a timer switch, or simply timer) is a device that operates an

electric Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwel ...

switch In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type o ...

controlled by a

timer A timer or countdown timer is a type of clock that starts from a specified time duration and stops upon reaching 00:00. It can also usually be stopped manually before the whole duration has elapsed. An example of a simple timer is an hourglass ...

Intermatic Intermatic Incorporated is an American manufacturer of time switches headquartered in Spring Grove, Illinois. Intermatic was founded in 1891 in Chicago, Illinois as the ''International Register Company'' to produce fare registers. The company's ...

introduced its first time switch in 1945, which was used for "electric signs, store window lighting, apartment hall lights, stokers, and oil and gas burners." A consumer version was added in 1952. The switch may be connected to an

electric circuit An electrical network is an interconnection of electrical components (e.g., battery (electricity), batteries, resistors, inductors, capacitors, switches, transistors) or a model of such an interconnection, consisting of electrical elements (e. ...

operating from

mains power Mains electricity, utility power, grid power, domestic power, wall power, household current, or, in some parts of Canada, hydro, is a general-purpose alternating-current (AC) electric power supply. It is the form of electrical power that is de ...

, including via a

relay A relay Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts An automotive-style miniature relay with the dust cover taken off A relay is an electrically operated switc ...

contactor A contactor is an electrically controlled switch used for switching an electrical power circuit. A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit, such as a 24-volt coil electromagne ...

; or

low voltage In electrical engineering, low voltage is a relative term, the definition varying by context. Different definitions are used in electric power transmission and distribution, compared with electronics design. Electrical safety codes define "low vo ...

, including

battery Battery or batterie most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source * Battery indicator, a device whic ...

-operated equipment in

vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...

s. It may be built into power circuits (as with a

central heating A central heating system provides warmth to a number of spaces within a building from one main source of heat. A central heating system has a Furnace (central heating), furnace that converts fuel or electricity to heat through processes. The he ...

water heater Water heating is a heat transfer process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water include cooking, cleaning, bathing, and space heating. In industry, hot water and water heated t ...

timer), plugged into a wall outlet with equipment plugged into the timer instead of directly into the power point; or built into equipment.

Types

Sleep timer

A sleep timer is a function on many modern

television Television (TV) is a telecommunication medium for transmitting moving images and sound. Additionally, the term can refer to a physical television set rather than the medium of transmission. Television is a mass medium for advertising, ...

s and other electronic devices that shuts off the power after a preset amount of time. The setting is usually made either from the

remote control A remote control, also known colloquially as a remote or clicker, is an consumer electronics, electronic device used to operate another device from a distance, usually wirelessly. In consumer electronics, a remote control can be used to operat ...

of the device or the device's menu. They are intended to allow viewers to watch as they fall asleep. The mechanism may be mechanical (e.g.,

clockwork Clockwork refers to the inner workings of either mechanical devices called clocks and watches (where it is also called the movement (clockwork), movement) or other mechanisms that work similarly, using a series of gears driven by a spring or wei ...

; rarely used nowadays),

electromechanical Electromechanics combine processes and procedures drawn from electrical engineering and mechanical engineering. Electromechanics focus on the interaction of electrical and mechanical systems as a whole and how the two systems interact with each ...

(e.g., a slowly rotating geared motor that mechanically operates switches) or

electronic Electronic may refer to: *Electronics, the science of how to control electric energy in semiconductors * ''Electronics'' (magazine), a defunct American trade journal *Electronic storage, the storage of data using an electronic device *Electronic c ...

, with

semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...

timing circuitry and switching devices and no moving parts. The timer may switch equipment on, off, or both, at a preset time or times, after a preset interval, or cyclically. A

countdown A countdown is a sequence of backward counting to indicate the time remaining before an event is scheduled to occur. NASA commonly employs the terms "L-minus" and "T-minus" during the preparation for and anticipation of a rocket launch, and eve ...

time switch switches power, usually off, after a preset time. A cyclical timer switches equipment both on and off at preset times over a period, then repeats the cycle; the period is usually 24 hours or 7 days. For example, a central heating timer may supply heat for a specified period during the morning and evening every weekday, and all day on weekends. A timer for an unattended

slow cooker A slow cooker, (also known as a crock-pot after a trademark owned by Sunbeam Products, but sometimes used generically in the English-speaking world), is a countertop electrical cooking appliance used to simmer at a lower temperature than ...

may switch on automatically at a time and for a period suitable to have food ready at mealtime. Likewise, a

coffee maker A coffeemaker, coffee maker or coffee machine is a cooking appliance used to brew coffee. While there are many different types of coffeemakers, the two most common brewing principles use gravity or pressure to move hot water through coffee ...

may turn itself on early in the

morning Morning is either the period from sunrise to noon, or the period from midnight to noon. In the first definition it is preceded by the twilight period of dawn, and there are no exact times for when morning begins (also true of evening and nigh ...

in time for awakening residents to have fresh

coffee Coffee is a beverage brewed from roasted, ground coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content, but decaffeinated coffee is also commercially a ...

already brewed for them. Timers may do other processing or have sensors; for example, a timer may switch on lights only during hours of darkness, using a

season A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's axial tilt, tilted orbit around the Sun. In temperat ...

algorithm In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algo ...

light sensor Photodetectors, also called photosensors, are devices that detect light or other forms of electromagnetic radiation and convert it into an electrical signal. They are essential in a wide range of applications, from digital imaging and optical c ...

. Combining the two allows a light to come on at sundown and go off at midnight, for example.

Astronomical timer

An astronomical (or astronomic) timer calculates

dawn Dawn is the time that marks the beginning of twilight before sunrise. It is recognized by the diffuse sky radiation, appearance of indirect sunlight being Rayleigh scattering, scattered in Earth's atmosphere, when the centre of the Sun's disc ha ...

and

dusk Dusk occurs at the darkest stage of twilight, or at the very end of astronomical twilight after sunset and just before nightfall.''The Random House College Dictionary'', "dusk". At predusk, during early to intermediate stages of twilight, enoug ...

times (tracking the sun position) for each day of the year based on the

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

and

longitude Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lett ...

(or just north/central/south and

time zone A time zone is an area which observes a uniform standard time for legal, Commerce, commercial and social purposes. Time zones tend to follow the boundaries between Country, countries and their Administrative division, subdivisions instead of ...

on more cheaply made ones), and the day of the year (month and date), programmed by the user upon installation in addition to the usual

time of day In modern usage, civil time refers to statutory time as designated by civilian authorities. Modern civil time is generally national standard time in a time zone at a fixed offset from Coordinated Universal Time (UTC), possibly adjusted by dayligh ...

, except in the case of GPS enabled astronomic timers wherein all programming is fully automatic. This eliminates the need for a

photocell Photodetectors, also called photosensors, are devices that detect light or other forms of electromagnetic radiation and convert it into an electrical signal. They are essential in a wide range of applications, from digital imaging and optical c ...

(which may be repeatedly triggered on and off by the light which it operates) or for repeatedly re-setting a regular timer for seasonal changes in the

length of day Daytime or day as observed on Earth is the period of the day during which a given location experiences natural illumination from direct sunlight. Daytime occurs when the Sun appears above the local horizon, that is, anywhere on the globe's ...

or for

daylight-saving time Daylight saving time (DST), also referred to as daylight savings time, daylight time (United States and Canada), or summer time (United Kingdom, European Union, and others), is the practice of advancing clocks to make better use of the long ...

. This allows exterior

lighting Lighting or illumination is the deliberate use of light to achieve practical or aesthetic effects. Lighting includes the use of both artificial light sources like lamps and light fixtures, as well as natural illumination by capturing daylight. ...

like a

porch A porch (; , ) is a room or gallery located in front of an entrance to a building. A porch is placed in front of the façade of a building it commands, and forms a low front. Alternatively, it may be a vestibule (architecture), vestibule (a s ...

light fixture A light fixture (US English), light fitting (UK English), or luminaire is an electrical lighting device containing one or more light sources, such as lamps, and all the accessory components required for its operation to provide illumination to ...

to be controlled by simply replacing its indoor wall switch, or doing the same for a lamp in a dark interior corner (away from a

window A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent ma ...

) by simply plugging-in a self-adjusting lamp timer. Time switches can be used for many purposes, including saving

electric energy Electrical energy is the energy transferred as electric charges move between points with different electric potential, that is, as they move across a potential difference. As electric potential is lost or gained, work is done changing the energy o ...

by consuming it only when required, switching equipment on, off, or both at times required by some process, and

home security Home security includes both the Security alarm, security hardware placed on a property and individuals' Security of person, personal security practices. Security hardware includes doors, locks, alarm systems, lighting, motion detectors, and secu ...

(for example switching lights in a pattern that gives the impression that premises are attended) to reduce the likelihood of

burglary Burglary, also called breaking and entering (B&E) or housebreaking, is a property crime involving the illegal entry into a building or other area without permission, typically with the intention of committing a further criminal offence. Usually ...

or prowling. Among applications are

(interior, exterior, and

street light A street light, light pole, lamp pole, lamppost, streetlamp, light standard, or lamp standard is a raised source of light on the edge of a road or path. Similar lights may be found on a railway platform. When urban electric power distribution b ...

ing), cooking devices such as

oven upA double oven A ceramic oven An oven is a tool that is used to expose materials to a hot environment. Ovens contain a hollow chamber and provide a means of heating the chamber in a controlled way. In use since antiquity, they have been use ...

washing machine A washing machine (laundry machine, clothes washer, washer, or simply wash) is a machine designed to laundry, launder clothing. The term is mostly applied to machines that use water. Other ways of doing laundry include dry cleaning (which uses ...

s, and

heating and cooling Heating, ventilation, and air conditioning (HVAC ) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. H ...

of buildings and vehicles. Built-in automatic washing machine controllers are examples of very complex

and electronic timers cycles, starting and stopping many processes including

pump A pump is a device that moves fluids (liquids or gases), or sometimes Slurry, slurries, by mechanical action, typically converted from electrical energy into hydraulic or pneumatic energy. Mechanical pumps serve in a wide range of application ...

s and

valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or Slurry, slurries) by opening, closing, or partially obstructing various passageways. Valves are technically Pip ...

s to fill and empty the drum with water, heating, and rotating at different speeds, with different combinations of settings for different fabrics.

Digital timers

A digital timer switch, also known as an electronic timer switch, seamlessly integrates semiconductor components for precise timing and a digital display format to present timing information in a user-friendly manner. Typically presented as a display panel or digital readout timer, this device offers high programmability, empowering users to customize timing sequences according to their specific needs. Th
scope of applications
for digital timer switches is broad and impactful. From controlling lighting systems to overseeing the operations of various electronic and electrical devices, these devices serve as versatile automation tools. The advantages of using digital timer switches are noteworthy. The ability to automate tasks translates to increased efficiency and convenience, liberating users from repetitive actions such as toggling switches or adjusting timers. Notably, these devices promote energy conservation by allowin

thereby minimizing unnecessary power consumption. In essence, digital timer switches are essential components in modern automation and control systems. By seamlessly blending accurate timing with user-friendly digital displays, they play a pivotal role in enhancing various facets of daily life.

IoT enabled time switch

An IoT-enabled time switch is a smart device that allows users to control and automate the operation of electrical appliances or systems based on a predefined schedule. This technology combines the functionality of a traditional time switch with the connectivity and intelligence of the Internet of Things (IoT). At the core of an IoT-enabled time switch is a microcontroller or microprocessor that manages the scheduling and control of the connected devices. The time switch is connected to a local network or the internet via Wi-Fi, Ethernet, or other wireless communication protocols like Zigbee or Z-Wave. This connectivity enables the time switch to be controlled and monitored remotely through a smartphone app or web interface. The time switch can be programmed to turn on or off a connected device at specific times or according to a set schedule. For example, a user could program the time switch to turn on the lights at a certain time in the morning and turn them off at night, or to activate a heating system at a specific time before the user arrives home from work. Some advanced features of IoT-enabled time switches include the ability to monitor energy consumption, adjust schedules based on local weather conditions, and integrate with other smart home devices like smart speakers or home security systems. These features allow users to optimize their energy usage, increase comfort, and enhance the overall security of their homes. In summary, a
IoT-enabled time switch
is a smart device that combines the functionality of a traditional time switch with the connectivity and intelligence of the Internet of Things, allowing users to control and automate the operation of electrical appliances or systems based on a predefined schedule.

Gallery

References

{{Authority control Switches Energy development Appropriate technology