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An automotive wiring diagram, showing useful information such as crimp connection locations and wire colors. These details may not be so easily found on a more schematic drawing. A wiring diagram is a simplified conventional pictorial representation of an electrical circuit. It shows the components of the circuit as simplified shapes, and the ...
When the box is activated by turning a knob or pulling a hook, a spring-loaded wheel turns, tapping out a pulsed electrical signal corresponding to the box's number. [1] A receiver at fire headquarters announces the alarm through flashing lights or tones, or via a pen recorder, and the box number is matched to a list of box locations. In modern ...
The NFPA 72 standard uses the term Alarm Box, which could encompass a number of initiation mechanisms. [3] A few manual call points have been approved to UL/UL Canada standards. [4] [5] At the time of this writing, the pull station is still the most prominent design in this part of the world.
Exterior alarm bell box. If a potential intruder tries to enter into a house, she or he tests whether it is closed and locked, uses tools on openings, or/and applies pressure, creating low-frequency sound vibrations. Before the intruder breaks in, the infrasound detector automatically detects the intruder's actions.
When current was passed through the wire, the force of the magnet made the wire swing sideways, out of the mercury, which broke the current to the magnet, so the wire fell back. The modern electric bell mechanism had its origin in vibrating "contact breaker" or interrupter mechanisms devised to break the primary current in induction coils. [5]
From NFPA 72, 2002 Edition: “7.4.2.1* To ensure that audible public mode signals are clearly heard, unless otherwise permitted by 7.4.2.2 through 7.4.2.5, they shall have a sound level at least 15 dB above the average ambient sound level or 5 dB above the maximum sound level having a duration of at least 60 seconds, whichever is greater ...
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One-line diagrams represent the three or four conductors of three-phase power circuits with one line. Wiring diagrams are sometimes made. These show and name the termination points and names of each conductor. In some systems, enough information can be put onto the schematics so that wiring diagrams are not needed.