ballast

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ballast

1. any dense heavy material, such as lead or iron pigs, used to stabilize a vessel, esp one that is not carrying cargo
2. crushed rock, broken stone, etc., used for the foundation of a road or railway track
3. Electronics a device for maintaining the current in a circuit

Ballast

Power-regulating device that modifies input voltage and controls current to provide the electrical conditions necessary to start and operate gaseous discharge lamps, especially fluorescents and HID (high-intensity discharge) lamps.

ballast

[′bal·əst]
(aerospace engineering)
A relatively dense substance that is placed in the cab of a balloon and can be thrown out to reduce the load or can be shifted to change the center of gravity.
(civil engineering)
Crushed stone used in a railroad bed to support the ties, hold the track in line, and help drainage.
(electricity)
A circuit element that serves to limit an electric current or to provide a starting voltage, as in certain types of lamps, such as in fluorescent ceiling fixtures.
(materials)
Coarse gravel used as an ingredient in concrete.
(naval architecture)
A relatively heavy material such as lead, iron, or water placed in a ship to ensure stability or to maintain the proper draft or trim.
To pump seawater into empty fuel tanks of a ship to ensure its stability or suitable draft and trim for seaworthiness.

ballast

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.

ballast

Weight installed in an airplane to ensure that the center of gravity is always within the permissible limits. In some aircraft, fuel is used as a ballast. This fuel, however, cannot be burned by the aircraft.
References in periodicals archive ?
The following formula is used to calculate the efficiency of Fluorescent Lamp Sign Ballasts according to DOE standards, which is based on ballast luminous efficiency (BLE) calculations.
Take the ballasts from the previous example and assume that it takes about 30 minutes to replace each one, including set-up, rewiring, and disposal of the old ballast.
We lighting engineers on the New York Mayor's Green Task Force Lighting Subcommittee were aware of the problem back in 2008 when the committee was formed and made the following suggestion: "Fluorescent fixtures installed prior to 1981 have magnetic ballasts that contain PCBs, a hazardous material.
One of the issues around the application of CDM lamps on QMH ballasts has to due with the difference in lamp power factor (PF) between these two types.
Environmental Warning: Old ballasts may contain polychlorinated biphenyls (PCBs), a toxic substance that must be disposed of properly.
The ballast control section in the IR2167 incorporates a programmable oscillator, which enables all ballast operating frequencies and MOSFET driver output deadtime.
It begins with a brief description of both standard and energy-efficient ballasts, summarizes the state and federal policies that affected ballasts production between 1983 and 1990, and then uses historical market data to assess the cost effectiveness of efficient magnetic ballasts.
If the answer to either of these questions is "yes," then you should be concerned about the proper disposal of PCB ballasts.
Such total control makes these new ballasts ideal for scene control, daylight harvesting, occupancy sensing, light tuning, load shedding and demand response--energy-saving strategies for meeting strict energy legislation and energy efficiency goals.
The DIN-DALI-2 supports two DALI channels, enables control of up to 128 individual DALI ballasts, and provides direct, 2-way network connectivity between a Crestron control system and a DALI-compliant ballast.
DALI (Digital Addressable Lighting Interface) is the highly efficient, energy saving protocol that creates "smart" ballasts for fluorescent lighting fixtures.