Search results
Results From The WOW.Com Content Network
In one common alarm sequence, the light in a window will flash and a bell or horn will sound to attract the operator's attention when the alarm condition is detected. The operator can silence the alarm with a button, and the window will remain lit as long as the process is in the alarm state.
In visual perception, flicker is a human-visible change in luminance of an illuminated surface or light source which can be due to fluctuations of the light source itself, or due to external causes such as due to rapid fluctuations in the voltage of the power supply (power-line flicker) or incompatibility with an external dimmer.
A Simplex-brand fire alarm bell. A fire alarm notification appliance is an active fire protection component of a fire alarm system.A notification appliance may use audible, visible, or other stimuli to alert the occupants of a fire or other emergency condition requiring action.
The pendant light at Fire Station #6 in which the bulb is installed. The Centennial Light was originally a 60-watt bulb, but has since dimmed significantly and is now as bright as a 4-watt bulb. [7] [8] [9] The hand-blown, carbon-filament common light bulb was invented by Adolphe Chaillet, a French engineer who filed a patent for this socket ...
The housing of the bell box may be manufactured from wood, metal, or plastic. The basic core component of a conventional bell box is an electromagnet and a bell or other metal piece, some of which create a repetitive sound. [1] The bell sound is normally created inside the box, although the unit may have bells mounted on the outside of the box.
In its simplest form, the user activates the alarm by pulling the handle down, which completes a circuit and locks the handle in the activated position, sending an alarm to the fire alarm control panel. After operation, most fire alarm pull stations must be restored to the ready position using a special tool or key for the panel to be reset.
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.
Fire alarm bell. Fire alarm bells are divided into two categories: vibrating, and single-stroke. On a vibrating bell, the bell will ring continuously until the power is cut off. When power is supplied to a single-stroke bell, the bell will ring once and then stop. It will not ring again until power is turned off and on again.