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 ?
Outdoor sign ballasts must also acquire UL Type 2 rating and be designed, labelled, and marketed for use in this application.
Total material cost to replace one ballast) (Number of ballasts) = Material c:ost to replace all ballasts at the end of their rated litehrne in hours Divide by 12 for annualized cost.
Like other cities, New York was strapped for funds and was still replacing lamps and ballasts during summers and vacation periods to avoid overtime costs when possible.
3 are the raw data for lamps operated on the variety of commercial ballasts.
Buy a new ballast based on the type and number of bulbs your fixture holds, as well as on the ballast factor and the sound rating,
For decades, almost all fluorescent lamp ballasts were standard magnetic ballasts ("standard ballasts").
Some waste generators dispose of PCB ballasts along with their regular commercial garbage because it is convenient and inexpensive.
Multiple ballasts sharing a single power circuit can be independently zoned and controlled, and both ballasts and zones may be reconfigured with ease, even after a system has been installed.
Analog 0-10VDC ballasts utilize low-voltage wiring to connect to associated control devices in the system and, therefore, are easily scaled to local control or integration into centralized energy-management systems that include other devices such as scheduling panels and occupancy sensors.
Most low-priced motion-activated switches ($15) that you find at hardware stores and home centers aren't rated for electronic ballasts.
When PCBs were banned in 1979, certain manufacturers of lighting ballasts used di (2-ethylhexyl) phthalate (DEHP) as a substitute in small capacitors for a five-to-ten-year period, depending on the type of ballast.