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A black match is a type of fuse consisting of cotton string coated with a dried slurry of black powder and glue. This acts as a simple pass-fire, and was used to fire ancient cannons. They are used today in fireworks construction. A quick match or piped match is a type of black powder fuse that burns very quickly, some hundreds of feet per ...
Utility, industrial, and commercial power systems have additional protection devices to detect relatively small but undesired currents escaping to ground. In residential wiring, electrical regulations may now require arc-fault circuit interrupters on building wiring circuits, to detect small arcs before they cause damage or a fire. For example ...
An air horn is a pneumatic device designed to create an extremely loud noise for signaling purposes. It usually consists of a source which produces compressed air, which passes into a horn through a reed or diaphragm. The stream of air causes the reed or diaphragm to vibrate, creating sound waves, then the horn amplifies the sound making it louder.
Arcing horns protecting bushings on a distribution transformer. Arcing horns form a spark gap across the insulator with a lower breakdown voltage than the air path along the insulator surface, so an overvoltage will cause the air to break down and the arc to form between the arcing horns, diverting it away from the surface of the insulator. [3]
A fuse is a common type of circuit breaker that involves direct effect of Joule-overheating. A fuse is always placed in series with the path of current it will affect. Fuses usually consist of a thin strand of wire of definite-material. When more that the rated current flows through the fuse, the wire melts and breaks the circuit.
Many fire horn systems were wired to fire pull boxes that were located around a town, and this would "blast out" a code in respect to that box's location. For example, pull box number 233, when pulled, would trigger the fire horn to sound two blasts, followed by a pause, followed by three blasts, followed by a pause, followed by three more blasts.
An artillery fuze or fuse is the type of munition fuze used with artillery munitions, typically projectiles fired by guns (field, anti-aircraft, coast and naval), howitzers and mortars. A fuze is a device that initiates an explosive function in a munition, most commonly causing it to detonate or release its contents, when its activation ...
The pattern for blowing the horn remains two long, one short, and one long. This is to be repeated or prolonged as necessary until the lead locomotive fully occupies the crossing. Locomotive engineers retain the authority to vary this pattern as necessary for crossings in close proximity, and are allowed to sound the horn in emergency ...