lamp ballast

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1. Coarse stone, gravel, slag, etc., used as an underlayer for poured concrete.
2. A device used to provide the required starting voltage and operating current for fluorescent, mercury, or other electric-discharge lamps.
3. Class P: A ballast for a fluorescent lamp which meets the requirements of the Underwriters’ Laboratories, Inc.; includes an automatic resetting thermal protector to remove the ballast from the circuit if its temperature exceeds a specified value.
References in periodicals archive ?
Many, but not all, "non-linear" lighting loads such as those resulting from the installation of certain common electronic lighting ballasts (typically electronic fluorescent lamp ballasts for straight-linear--or U-shaped T8 and T5 lamps), often exhibit some varying combination of both types of displacement and distortion power factors, simultaneously.
In November 2011, The Department of Energy (DOE) issued new rules regulating the efficiency of fluorescent lamp ballasts, which take effect on November 14, 2014.
For example, HPS lamps for use on mercury vapor lamp ballasts that operate at 10 percent lower power have been described in the literature (Ravi and others 1993).