Remote Control

A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.
The remote control can be contracted to remote or controller. It is known by many other names as well, such as converter clicker, didge, flipper, the tuner, the changer, or the button. Commonly, remote controls are Consumer IR devices used to issue commands from a distance to televisions or other consumer electronics such as stereo systems, DVD players and dimmers. Remote controls for these devices are usually small wireless handheld objects with an array of buttons for adjusting various settings such as television channel, track number, and volume. In fact, for the majority of modern devices with this kind of control, the remote contains all the function controls while the controlled device itself only has a handful of essential primary controls. Most of these remotes communicate to their respective devices via infrared (IR) signals and a few via radio signals. Earlier remote controls in the 1970s used ultrasonic tones. Television IR signals can be mimicked by a universal remote, which is able to emulate the functionality of most major brand television remote controls. They are usually powered by small AAA or AA size batteries.

History

One of the earliest examples of remote control was developed in 1898 by Nikola Tesla, and described in his patent, U.S. Patent 613,809, named Method of an Apparatus for Controlling Mechanism of Moving Vehicle or Vehicles. In 1898, he demonstrated a radio-controlled boat to the public during an electrical exhibition at Madison Square Garden. Tesla called his boat a "teleautomaton".^[1]
In 1903, Leonardo Torres Quevedo presented the Telekino at the Paris Academy of Science, accompanied by a brief, and making an experimental demonstration. In the same time he obtained a patent in France, Spain, Great Britain, and the United States. The Telekino consisted of a robot that executed commands transmitted by electromagnetic waves. It constituted the world's first apparatus for radio control^{[citation needed]} and was a pioneer in the field of remote control. In 1906, in the presence of the king and before a great crowd, Torres successfully demonstrated the invention in the port of Bilbao, guiding a boat from the shore. Later, he would try to apply the Telekino to projectiles and torpedoes, but had to abandon the project for lack of financing.
The first remote-controlled model aeroplane flew in 1932, and the use of remote control technology for military purposes was worked intensively during the Second World War, one result of this being the German Wasserfall missile.
By the late 1930s, several radio manufacturers offered remote controls for some of their higher-end models.^[2] Most of these were connected to the set being controlled by wires, but the Philco Mystery Control (1939) was a battery-operated low-frequency radio transmitter,^[3] thus making it the first wireless remote control for a consumer electronics device.

Television remote controls

The first remote intended to control a television was developed by Zenith Radio Corporation in 1950. The remote, called "Lazy Bones", was connected to the television set by a wire. A wireless remote control, the "Flashmatic", was developed in 1955; it worked by shining a beam of light onto a photoelectric cell, but the cell did not distinguish between light from the remote and light from other sources. The Flashmatic also had to be pointed very precisely at the receiver in order to work.^[4]

In 1956, Robert Adler developed "Zenith Space Command", a wireless remote.^[5] It was mechanical and used ultrasound to change the channel and volume. When the user pushed a button on the remote control, it clicked and struck a bar, hence the term "clicker". Each bar emitted a different frequency and circuits in the television detected this sound. The invention of the transistor made possible cheaper electronic remotes that contained a piezoelectric crystal that was fed by an oscillating electric current at a frequency near or above the upper threshold of human hearing, though still audible to dogs. The receiver contained a microphone attached to a circuit that was tuned to the same frequency. Some problems with this method were that the receiver could be triggered accidentally by naturally occurring noises, and some people could hear the piercing ultrasonic signals. There was an incident in which a toy xylophone changed the channels on such sets because some of the overtones from the xylophone matched the remote's ultrasonic frequency.
The impetus for a more complex type of television remote control came in the late 1970s, with the development of the Ceefax teletext service by the BBC. Most commercial remote controls at that time had a limited number of functions, sometimes as few as three: next channel, previous channel, and volume/off. This type of control did not meet the needs of teletext sets, where pages were identified with three-digit numbers. A remote control to select teletext pages would need buttons for each numeral from zero to nine, as well as other control functions, such as switching from text to picture, and the normal television controls of volume, channel, brightness, colour intensity, etc. Early teletext sets used wired remote controls to select pages, but the continuous use of the remote control required for teletext quickly indicated the need for a wireless device. So BBC engineers began talks with one or two television manufacturers, which led to early prototypes in around 1977–1978 that could control many more functions. ITT was one of the companies and later gave its name to the ITT protocol of infrared communication.^[6]
In 1980, a Canadian company, Viewstar, Inc., was formed by engineer Paul Hrivnak and started producing a cable TV converter with an infrared remote control. The product was sold through Philips for approximately $190 CAD. At the time the most popular remote control was the Starcom of Jerrold (a division of General Instruments) which used 40-kHz sound to change channels. The Viewstar converter was an immediate success, the millionth converter being sold on March 21, 1985, with 1.6 million sold by 1989.^[7]

Technique

The opto components, circuits and mathematics

Most remote controls for electronic appliances use a near infrared diode to emit a beam of light that reaches the device. A 940 nm wavelength LED is typical. This infrared light is invisible to the human eye, but picked up by sensors on the receiving device. Video cameras see the diode as if it produces visible purple light.
With a single channel (single-function, one-button) remote control the presence of a carrier signal can be used to trigger a function. For multi-channel (normal multi-function) remote controls more sophisticated procedures are necessary: one consists of modulating the carrier with signals of different frequency. After the demodulation of the received signal, the appropriate frequency filters are applied to separate the respective signals. Nowadays digital procedures are more commonly used. One can often hear the signals being modulated on the infrared carrier by operating a remote control in very close proximity to an AM radio not tuned to a station.

Consumer electronics infrared protocols

Different manufacturers of infrared remote controls use different protocols to transmit the infrared commands. The RC-5 protocol that has its origins within Philips, uses, for instance, a total of 14 bits for each button press. The bit pattern is modulated onto a carrier frequency that, again, can be different for different manufacturers and standards, in the case of RC-5, a 36 kHz carrier is being used. Other consumer infrared protocols are, for instance, the different SIRCS versions used by Sony, the RC-6 from Philips, the Ruwido R-Step, or the NEC TC101 protocol.

Infrared, line of sight and operating angle

Since infrared (IR) remote controls use light, they require line of sight to operate the destination device. The signal can, however, be reflected by mirrors, just like any other light source.
If operation is required where no line of sight is possible, for instance when controlling equipment in another room or installed in a cabinet, many brands of IR extenders are available for this on the market. Most of these have an IR receiver, picking up the IR signal and relaying it via radio waves to the remote part, which has an IR transmitter mimicking the original IR control.
Infrared receivers also tend to have a more or less limited operating angle, which mainly depends on the optical characteristics of the phototransistor. However, it’s easy to increase the operating angle using a matte transparent object in front of the receiver.

Radio Remote Control Systems

The inner photo of commonly seen rf remote control.

Radio remote control (RF Remote Control) is a way to control distance objects using a variety of radio signals transmitted by the remote control device. By using radio remote control system, you can control a variety of mechanical or electronic devices to complete various operations, such as closing circuit, move handle, start motor, etc. As a complementary method to infrared remote control type, the radio remote control is widely used in garage door remote control, electric gate remote control, automatic barrier remote control, burglar alarm, industrial remote control and wireless home alarm systems.
A radio remote control system commonly has two parts: transmit and receive.
Transmitter part is generally divided into two types, namely, rf remote control and transmitter module, by the way of using, the rf remote control can be used independently as a whole while the transmitter module is used as a component in the circuit, the advantage of using transmitter model is it can be seamlessly connected with application circuit, and it's size is small, but users must have a knowledge of circuit to use the transmitter module, the rf remote control is much more easy to use at this point.
Receiver part also is generally divided into two types, namely, the super-regenerative receiver and the superheterodyne receiver, super-regenerative receiver is actually working like the regeneration of under intermittent oscillation detection circuit. While Superheterodyne type is working like the one in radio receiver. Superheterodyne receiver features stability, high sensitivity and the anti-interference ability is relatively good, while super-regenerative receiver features a small package and the price is also cheaper.

Fixed-code RF Remote Control DIP Switch Calculator

The tri-state dip switch calculator useful in rf remote control encoding.

Tri-state DIP switches are widely used in fixed-code RF Remote Controls to define the code of address pins, while in many circumstances, it's usually useful to calculate the dip switch settings, a calculator like the following will save you a lot of time.

Access the tri-state dip switch calculator

The RF Remote Control Tri-State DIP Switch Calculator is capable of calculating DIP switches up to 8 positions, and will convert any number from 0 to 38-1 to ternary and then display it in a visual form. Our RF Remote Control Tri-State DIP Switch Calculator will assist you working out ternary values in addressing various fixed-code RF Remote Controls, thus making the DIP switch settings for RF Remote Control addressing more efficiently.

Usage

Industry

Remote control is used for controlling substations, pump storage power stations and HVDC-plants. For these systems often PLC-systems working in the longwave range are used.

Military

Only in the military field of use of remote controls can you find the jammers and the countermeasures against the jammers.
Jammers are used to disable or sabotage the enemy's use of remote controls. IED jamming systems, Radio jamming, Electronic warfare
The distances for military remote controls also tend to be much longer, up to intercontinental distance satellite linked remote controls used by the U.S. for their unmanned airplanes (drones) in Afghanistan, Iraq and Pakistan.
Remote controls are used by insurgents in Iraq and Afghanistan to attack coalition and government troops with roadside IEDs (Improvised explosive device, Explosively formed penetrator).
The arms race and the fact that the enemy is many times closer to the receiver has made it more complicated and too expensive to build radio remote controls for roadside bombs that are immune to jammers. The simplest types of radio remote controls have been almost entirely disabled by the advanced jammers, but are still in use against unprotected Iraqi and Afghan national troops and civilian targets. One of the simplest solutions against the radio jammers is to fool the jammer itself to ignite the bomb.
Optical types of remote controls that uses light instead of radio are still immune to the jammers. The resistance in Iraq is reported in the media to use modified TV remote controls to detonate the bombs.^[16]

 Military history

In World War I, the Imperial German Navy employed FL-boats (Fernlenkboote) against coastal shipping. These were driven by internal combustion engines, and controlled remotely from a shore station through several miles of wire wound on a spool on the boat. An aircraft was used to signal directions to the shore station. EMBs carried a high explosive charge in the bow and traveled at speeds of thirty knots.^[17]
The Soviet Red Army used remotely controlled teletanks during 1930s in the Winter War against Finland and the early stages of World War II. A teletank is controlled by radio from a control tank at a distance of 500–1,500 meters, the two constituting a telemechanical group. The Red Army fielded at least two teletank battalions at the beginning of the Great Patriotic War. There were also remotely controlled cutters and experimental remotely controlled planes in the Red Army.

 Space

Remote control technology is also used in space travel, for instance the Russian Lunokhod vehicles were remote-controlled from the ground. Direct remote control of space vehicles at greater distances from the earth is not practical due to increasing signal delay times.

Video games

Video game consoles had not used wireless controllers until recently, mainly because of the difficulty involved in playing the game while keeping the infrared transmitter pointed at the console. Early wireless controllers were cumbersome and when powered on alkaline batteries, lasted only a few hours before they needed replacement. Some wireless controllers were produced by third parties, in most cases using a radio link instead of infrared. Even these were very inconsistent, and in some cases, had transmission delays, making them virtually useless. The first official wireless controller made by a first party manufacturer was the WaveBird for Nintendo Gamecube. The Wavebird changed the face of wireless technology in video game consoles. In the current generation of gaming consoles, wireless controllers have become the standard.

PC control

Existing infrared remote controls can be used to control PC applications. Any application that supports shortcut keys can be controlled via IR remote controls from other home devices (TV, VCR, AC, ...). This is widely used with multimedia applications for PC based Home Theatre systems. For this to work, you need a device that decodes IR remote control data signals and a PC application that communicates to this device connected to PC. Connection can be made via serial port, USB port or motherboard IrDA connector. Such devices are commercially available or it can be home made using low cost microcontrollers.
LIRC(Linux IR Remote control) and Win-LIRC (for Windows) software are developed for the purpose of controlling PC using TV remote and can be also used for homebrew remote with lesser modification. They support almost all TV remotes.

 

 

Refrigerator

A refrigerator (commonly called a "fridge") is a cooling apparatus. The common household appliancecomprises a thermally insulated compartment and a heat pump—chemical or mechanical means—to transfer heat from it to the external environment (i.e., the room in which it is located), cooling the contents to a temperature below ambient. Cooling is a popular food storage technique in developed countries and works by decreasing the reproduction rate of bacteria. The device is thus used to reduce the rate of spoilage of foodstuffs.

A refrigerator maintains a temperature a few degrees above the freezing point of water. Optimum temperature range for perishable food storage is 3 to 5 °C (37 to 41 °F). A similar device which maintains a temperature below the freezing point of water is called a "freezer".

The refrigerator is a relatively modern invention among kitchen appliances. It replaced the icebox, which had been a common household appliance for almost a century and a half prior. For this reason, a refrigerator is sometimes referred to as an "icebox".

Light Bulb

The incandescent light bulb, incandescent lamp or incandescent light globe makes light by heating a metal filament wire to a high temperature until it glows. The hot filament is protected from air by a glass bulb that is filled with inert gas or evacuated. In a halogen lamp, a chemical process that returns metal to the filament prevents its evaporation. The light bulb is supplied with electrical current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket (a housing giving mechanical support to the bulb, keeping its terminals in contact with the supply current terminals).

Incandescent bulbs are produced in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts. They require no external regulating equipment and have a low manufacturing cost and work equally well on either alternating current or direct current. As a result, the incandescent lamp is widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, and for decorative and advertising lighting.

Some applications of the incandescent bulb use the heat generated by the filament, such as incubators, brooding boxes forpoultry, heat lights for reptile tanks, infrared heating for industrial heating and drying processes, and the Easy-Bake Oven toy. In cold weather, the heat produced by incandescent lamps is a benefit as it contributes to building heating, but in hot climates this waste heat increases the energy required by air conditioning systems.

Incandescent light bulbs are gradually being replaced in many applications by other types of electric lights, such asfluorescent lamps, compact fluorescent lamps, cold cathode fluorescent lamps (CCFL), high-intensity discharge lamps, andlight-emitting diodes (LEDs). These newer technologies improve the ratio of visible light to heat generation. Some jurisdictions, such as the European Union, are in the process of phasing out the use of incandescent light bulbs in favor of more energy-efficient lighting. In the United States, federal law has scheduled incandescent light bulbs to be phased out by 2014, to be replaced with more energy-efficient light bulbs.^[3] In Brazil, they have already been phased out.

DVD

DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Time Warnerin 1995. DVD discs offer higher storage capacity than compact discs while having the same dimensions.

Pre-recorded DVD discs are mass-produced using molding machines that physically stamp data onto the DVD. Such discs are known as DVD-ROM, because data can only be read and not written nor erased. Blank recordable DVD discs (DVD-R and DVD+R) can be recorded once using a DVD recorder and then function as a DVD-ROM. Rewritable DVD discs (DVD-RW, DVD+RW, and DVD-RAM) can be recorded and erased multiple times.

DVD discs are used in DVD-Video consumer digital video format and in DVD-Audio consumer digital audio format, as well as for authoring AVCHD discs. DVD discs containing other types of information may be referred to as DVD data discs.

Contact Lens

A contact lens (also known simply as a contact) is a corrective, cosmetic, or therapeutic lens usually placed on thecornea of the eye. Leonardo da Vinci is credited with describing and sketching the first ideas for contact lenses in 1508, but it was more than 300 years later before contact lenses were actually fabricated and worn on the eye. Rigid ones were produced and marketed first. Modern soft contact lenses were invented by the Czech chemist Otto Wichterle and his assistant Drahoslav Lím, who also invented the first gel used for their production.

Some soft contact lenses are tinted a faint blue to make them more visible when immersed in cleaning and storage solutions. Some cosmetic lenses are deliberately colored to alter the appearance of the eye. Some lenses now have a UV protection surface treatment to reduce UV damage to the eye's natural lens.

It has been estimated that 125 million people use contact lenses worldwide (2%), including 28 to 38 million in the United States and 13 million in Japan. The types of lenses used and prescribed vary markedly among countries, with rigid lenses accounting for over 20% of currently-prescribed lenses in Japan, the Netherlands and Germany but less than 5% in Scandinavia.

People choose to wear contact lenses for many reasons, often due to their appearance and practicality. When compared with spectacles, contact lenses are less affected by wet weather, do not steam up, and provide a wider field of vision. They are more suitable for a number of sporting activities. Additionally, ophthalmological conditions such askeratoconus and aniseikonia may not be accurately corrected with glasses.

Mobile Phones

A mobile phone (also called mobile, cellular telephone, or cell phone) is an electronic device used to make mobile telephone calls across a wide geographic area. Mobile phones are different from cordless telephones, which only offer telephone service within a limited range of a fixed land line, for example within a home or an office.

A mobile phone can make and receive telephone calls to and from the public telephone network which includes other mobiles and fixed-line phones across the world. It does this by connecting to a cellular network owned by a mobile network operator.

In addition to being a telephone, modern mobile phones also support many additional services, and accessories, such as SMS (or text) messages, e-mail, Internet access, gaming, Bluetooth and infrared short range wireless communication, camera, MMS that offer more advanced computing ability are referred to as smartphones.

The first handheld mobile phone was demonstrated by Dr. Martin Cooper of Motorola in 1973, using a handset weighing 2 kg. In 1983, the DynaTAC 8000x was the first to be commercially available. In the twenty years from 1990 to 2010, worldwide mobile phone subscriptions grew from 12.4 million to over 4.6 billion, penetrating the developing economiesand reaching the bottom of the economic pyramid.

ATM

An automated teller machine (ATM), commonly called a cash point in UK English after the trademark of the same name, is a computerized telecommunications device that provides the clients of a financial institution with access to financial transactions in a public space without the need for a cashier, human clerk or bank teller. ATMs are known by various other names including automatic banking machine, cash machine, and various regional variants derived from trademarks on ATM systems held by particular banks.
Most ATMs are connected to interbank networks, enabling people to withdraw and deposit money from machines not belonging to the bank where they have their account or in the country where their accounts are held (enabling cash withdrawals in local currency). Some examples of interbank networks include PULSE, PLUS, Cirrus, Interac, Interswitch, STAR, and LINK.
ATMs rely on authorization of a financial transaction by the card issuer or other authorizing institution via the communications network. This is often performed through an ISO 8583 messaging system.

There are no hard international or government-compiled numbers totaling the complete number of ATMs in use worldwide. Estimates developed by ATMIA place the number of ATMs in use currently at over 1.8 million.
India claims to have the world's highest installed ATM at Nathu La Pass, India installed by the Union Bank of India at 4310 meters, there are higher ATMs installed in Nagchu County, Tibet at 4500 meters by Agricultural Bank of China.
Security, as it relates to ATMs, has several dimensions. ATMs also provide a practical demonstration of a number of security systems and concepts operating together and how various security concerns are dealt with.