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A simple electromagnetic door holder consists of a strong electromagnet, usually attached to a wall or mounted in a floor pedestal enclosure, next to the door it controls. The mechanism may be mounted near the floor, at the upper corner of the open door, or at any convenient height along the latch edge (away from the hinged edge).
Wireless home alarm system control panel A house alarm. A security alarm is a system designed to detect intrusions, such as unauthorized entry, into a building or other areas, such as a home or school. Security alarms protect against burglary or property damage, as well as against intruders.
A metal doorframe with a strike plate built in: in other doors this would be a metal strikeplate in a wooden doorframe. The term door security or door security gate may refer to any of a range of measures used to strengthen doors against door breaching, ram-raiding and lock picking, and prevent crimes such as burglary and home invasions.
There are 8,200 alarm sirens for civil protection throughout Switzerland. They are tested once a year, on the first Wednesday in February. [1] Sound sample ⓘ An 1860s-era siren. [2] A siren is a loud noise-making device. There are two general types: mechanical and electronic.
A magnetic keyed padlock A magnetic keyed padlock. A magnetic keyed lock or magnetic-coded lock is a locking mechanism whereby the key utilizes magnets as part of the locking and unlocking mechanism. Magnetic-coded locks encompass knob locks, cylinder locks, lever locks, and deadbolt locks as well as applications in other security devices.
The word alarm comes from the Old French a l'arme meaning "to the arms", or "to the weapons", telling armed men to pick up their weapons and get ready for action because an enemy may have suddenly appeared. [1] The word alarum is an archaic form of alarm. It was sometimes used as a call to arms in the stage directions of Elizabethan dramas. [2]
Their Modulators consisted of 5020s, 3012s, 6024s and 5020Bs. Their EOWS 612 sirens were part of their original SiraTone system and were later on upgraded to UltraVoice controls as the new system utilized them. All sirens sounded in a male voice message that says “ATTENTION! ATTENTION! THIS IS A TEST OF THE EMERGENCY SIREN SYSTEM.
The magnetic detector or Marconi magnetic detector, sometimes called the "Maggie", was an early radio wave detector used in some of the first radio receivers to receive Morse code messages during the wireless telegraphy era around the turn of the 20th century.