Search results
Results from the WOW.Com Content Network
New lighting systems have not used magnetic ballasts since the turn of the century, however some older installations still remain. Fluorescent lamps with magnetic ballasts flicker at a normally unnoticeable frequency of 100 or 120 Hz (twice of the utility frequency; the lamp is lit on both the positive and negative half-wave of a cycle).
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, to produce ultraviolet and make a phosphor coating in the lamp glow.
At night, ORNL HSL uses variable-intensity fluorescent lighting electronic control ballasts. As the sunlight gradually decreases at sunset, the fluorescent fixture is gradually turned up to give a near-constant level of interior lighting from daylight until after it becomes dark outside. HSL may soon become an option for commercial interior ...
So far, two lighting methods have been shown to improve nighttime sleep in AD patients: (1) exposure to bright white light (at least 2500 lx and as high as 8000 lx at the cornea) for at least one hour in the morning, for two weeks and (2) exposure to 30 lx of blue light from LEDs, peaking at 470 nm at the eye for two hours.
To house this device, he decided on a 2-inch round device with one end capable of being screwed into a light bulb socket and the other end able to receive a light bulb. [ 4 ] When solid-state dimmers came into use, analogue remote control systems (such as 0-10 V lighting control systems) became feasible.
Here's a pro trick: Lighten a dark room by hanging a mirror across from a window or electric light source. Available in other sizes and finishes, too, this mirror shines in the bathroom, boudoir ...
Light pollution is the presence of any unwanted, inappropriate, or excessive artificial lighting. [1] [2] In a descriptive sense, the term light pollution refers to the effects of any poorly implemented lighting sources, during the day or night. Light pollution can be understood not only as a phenomenon resulting from a specific source or kind ...
Discover the best free online games at AOL.com - Play board, card, casino, puzzle and many more online games while chatting with others in real-time.