What is Split-flap display?
[[File:Split-flap display, Singapore Changi, 2018 (01).jpg|thumb|357x357px]] A '''split-flap display''', or a '''flap display''', is a digital [[Electromechanics|electromechanical]] [[display device]] that shows changeable [[alphanumeric]] [[Character_(computing)|text]], and sometimes [[graphics]]. They are commonly used as [[public transport]] [[Timetable|timetables]] in [[airport]]s or [[railway station]]s. Commonly they are called '''Solari boards''' after Italian display manufacturer [[Solari di Udine]], or in Central European countries they are called '''Pragotron''' after the Czech manufacturer instead. Split-flap displays were once commonly used in consumer digital clocks known as [[flip clock]]s. == Description == Each character position or graphic position has a collection of flaps on which the [[Character_(computing)|characters]] or graphics are [[paint]]ed or [[silkscreen]]ed. These flaps are rotated to show the desired character or graphic. Sometimes the flaps are large and display whole words, and in other installations there are several smaller flaps, each displaying a single character. [[File:Split-flap display 2016-01-17.gif|thumb|144x144px]] [[Flip-dot display]]s and [[LED display]] boards may be used instead of split-flap displays in most applications. Their output can be changed by reprogramming instead of replacement of physical parts but they suffer from lower readability. They also can refresh more quickly, as a split-flap display often must cycle through many states. Advantages to these displays include: * high [[visibility]] and wide [[viewing angle]] in most [[light]]ing conditions * little or no [[Electric_power|power]] consumption while the display remains static * Distinct metallic flapping sound draws attention when the information is updated. The [[Massachusetts Bay Transportation Authority]] has designed the new LED replacements for its aging Solari boards at [[North Station]] and [[South Station]] to emit an electronically generated flapping noise to alert passengers to tra