Fluorescent lamps form an inductive load on the AC mains supply. As a result large installations of such lamps suffer a poor power factor and resultant voltage drop. Adding a capacitor to each lamp corrects the power factor bringing it back close to unity (1.0).
What does a capacitor do in a ballast?
Capacitors, available in both oil-filled and dry-film technologies, are used with some HID ballasts in order to improve their power factor, light output, and even efficiency by regulating the inrush current that occurs when the light is initially started.
What does a light capacitor do?
lighting Capacitor, a device that functions as a very small battery inside a circuit. … When the voltage is lowered, the capacitor discharges its stored electricity. Capacitors are some of the most useful electronic components and are used in everything from computer memory to automotive ignition.
Are capacitors used in lighting?
Capacitors can be for single lamps or group correction (parallel types), as well as for series use (where the choke and the capacitor are in the series). … Due to the serial connection of choke and capacitor, the voltage developed across the capacitor while the lamp is energized exceeds the line voltage.
Why capacitor is used in sodium Vapour lamp?
Metallised polypropylene film capacitors are designed to compensate the inductive idle current drawn by discharge lamps (fluorescent lamps, high-pressure mercury vapour lamps, high-pressure sodium vapour lamps and metal halide lamps with a ceramic discharge tube) in 50 Hz/60 Hz grids.
What is the purpose of a ballast?
In a fluorescent lighting system, the ballast regulates the current to the lamps and provides sufficient voltage to start the lamps. Without a ballast to limit its current, a fluorescent lamp connected directly to a high voltage power source would rapidly and uncontrollably increase its current draw.
How long do electronic ballasts last?
When your fluorescent light flickers or makes a loud and annoying hum, a degrading ballast is the cause. The ballast takes in electricity and then regulates current to the bulbs. A typical ballast will generally last about 20 years, but cold environments and bad bulbs can decrease this lifespan significantly.
When should you use a capacitor?
- Power Supply Smoothing. This is the easiest and very widely used application of a capacitor. …
- Timing. If you supply power to a capacitor through a resistor, it will take time to charge. …
- Filtering. If you pass DC through a capacitor, it will charge and then block any further current from flowing.
What is the purpose of a capacitor?
A capacitor is an electronic component that stores and releases electricity in a circuit. It also passes alternating current without passing direct current. A capacitor is an indispensible part of electronic equipment and is thus almost invariably used in an electronic circuit.
What is the job of a capacitor?
A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store energy electrostatically in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors (plates) separated by a dielectric (i.e., insulator).
Is a ballast a capacitor?
Ballasts vary greatly in complexity. They may be as simple as a resistor, inductor, or capacitor (or a combination of these) wired in series with the lamp; or as complex as the electronic ballasts used in compact fluorescent lamps (CFLs) and high-intensity discharge lamps (HID lamps).
What power factor means?
Power factor is an expression of energy efficiency. It is usually expressed as a percentage—and the lower the percentage, the less efficient power usage is. Power factor (PF) is the ratio of working power, measured in kilowatts (kW), to apparent power, measured in kilovolt amperes (kVA).
What does a capacitor do in a metal halide light?
It provides good wattage control and is cheaper than the magnetic ballast and ballast losses are average. Capacitors are used as a power factor correcting or current regulating device and provide the control necessary to ensure proper lamp and ballast operation.
Which gas is used in sodium Vapour lamp?
Sodium-vapour lamp, electric discharge lamp using ionized sodium, used for street lighting and other illumination. A low-pressure sodium-vapour (LPS) lamp contains an inner discharge tube made of borosilicate glass that is fitted with metal electrodes and filled with neon and argon gas and a little metallic sodium.
Why neon gas is used in sodium lamp?
Only low-pressure sodium lamps (the ones with the monochromatic yellow light) have neon. The neon is essentially the “starter”, the neon discharge (the red light during the initial warm-up phase) pre-heats the sodium so it forms vapour and then the sodium discharge starts. … What is neon gas?
Why does sodium Vapour emit yellow light?
A sodium light consists of an evacuated tube containing electrodes and metallic sodium. … In the vapor state, the sodium electrons are excited to higher energy levels When these electrons return to a lower energy level, light is given off. The yellow color is a product of the light emitted by the sodium electrons.