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A passive infrared sensor (PIR sensor) is an electronic sensor that measures infrared (IR) light radiating from objects in its field of view. They are most often used in PIR-based motion detectors . PIR sensors are commonly used in security alarms and automatic lighting applications.
A "dumb" ETD can be as simple as a red flag attached to the coupler on the last car of the train, whereas "smart" devices monitor functions such as brake line pressure and accidental separation of the train using a motion sensor, functions that were previously monitored by a crew in the caboose. [1]
A mercury switch is an electrical switch that opens and closes a circuit when a small amount of the liquid metal mercury connects metal electrodes to close the circuit. There are several different basic designs (tilt, displacement, radial, etc.) but they all share the common design strength of non-eroding switch contacts.
Electrical heaters are often used as backup or supplemental heat for heat pump systems. The heat pump gained popularity in the 1950s in Japan and the United States. [14] Heat pumps can extract heat from various sources, such as environmental air, exhaust air from a building, or from the ground. Heat pumps transfer heat from outside the ...
The contact breaker is operated by an engine-driven cam.On an engine with a distributor, the contact breaker can be found beneath the distributor cap.The position of the contact breaker is set so that it opens (and hence generates a spark) at exactly the optimum moment to ignite the fuel/air mixture.
It wasn't until Ford implemented Wilcox's idea in 1929 that car cabins reached a noticeable warm temperature in the car. [3] She also developed several stoves and housing appliances, including a combined cooking and hot-water-heating stove designed to save fuel by efficiently utilizing the wasted heat of the stove. [ 5 ]
Infrared signature, as used by defense scientists and the military, is the appearance of objects to infrared sensors. [1] An infrared signature depends on many factors, including the shape and size of the object, [2] temperature, [3] and emissivity, reflection of external sources (earthshine, sunshine, skyshine) from the object's surface, [4] the background against which it is viewed [5] and ...
There were also three Plastic Construction Kits: a Mobil Truck Station, a Howard Johnson's Truck Stop, and a 'P.I.E. Freight Terminal', each molded in several colors to be glued together. These were supplied by Pola, West Germany and were also sold for a time as part of the Tyco model railroad range, but in plain Tyco 'Brown Box' packaging ...