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The electric overhead garage door opener was invented by C.G. Johnson in 1926 in Hartford City, Indiana. [1] Electric Garage Door openers did not become popular until Era Meter Company of Chicago offered one after World War II where the overhead garage door could be opened via a key pad located on a post at the end of the driveway or a switch inside the garage.
Electrically operated display devices have developed from electromechanical systems for display of text, up to all-electronic devices capable of full-motion 3D color graphic displays. Electromagnetic devices, using a solenoid coil to control a visible flag or flap, were the earliest type, and were used for text displays such as stock market ...
Electric eye for a garage door opener. An electric eye is a photodetector used for detecting obstruction of a light beam. An example is the door safety system used on garage door openers that use a light transmitter and receiver at the bottom of the door to prevent closing if there is any obstruction in the way that breaks the light beam.
Detail view of an LED display with a matrix of red, green and blue diodes The 1,500-foot (460 m) long LED display on the Fremont Street Experience in Downtown Las Vegas, Nevada, is currently the largest in the world. A LED display is a flat panel display that uses an array of light-emitting diodes (LEDs) as pixels for a video display.
OLED panels can also take the shape of a light panel, where red, green and blue light emitting materials are stacked to create a white light panel. OLED displays can also be made transparent and/or flexible and these transparent panels are available on the market and are widely used in smartphones with under-display optical fingerprint sensors.
Sectional garage door Up-and-over garage door Garage Door Hardware. A garage door is a large door to allow egress for a garage that opens either manually or by an electric motor (a garage door opener). Garage doors are frequently large enough to accommodate automobiles and other vehicles. The operating mechanism is usually spring-loaded or ...
A very successful August 1925 Philco consumer product, called the "Socket Power Battery Eliminator", was a rectifier unit which enabled users to operate radios from standard light sockets. By 1927 over a million of these units had been sold, but from that year the industry began manufacturing batteryless radios using RCA 's AC tube .
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers to display information. Liquid crystals do not emit light directly [1] but instead use a backlight or reflector to produce images in color or monochrome. [2]