A Lighting which is used to create focal point or in other words, lighting used to draw attention to a feature, like a piece of artwork, a plant, or to highlight a unique design element, like wall texture or decorative coving.

A type of Lighting which provides an overall glow to a room or space and creates enough light for you to see and move around comfortably and safely.

As driver runs vehicle in safe way, so the ballast runs/regulates the current that flows to the tube.

To glow the tube, higher voltage (i.e:600V) is required to ionize the gas inside the tube and this is served by starter along with magnetic ballast. Once gas is ionized, the conductive path is established between two ends of the tube. After this phenomenon there is no need of starter. Starter is not required while operating the tube with Electronic Ballast.

Fluorescent ballasts use three different types of starting technologies: rapid, instant, and programmed.

Rapid start: ballasts rely on this preheating method so when the light switch is turned on, the lamp turns on right away.There are two drawbacks to rapid start ballasts:

1.Rapid start ballasts are not very energy efficient.

2.Lamps paired with rapid start ballasts will not reliably turn on if they are in sub 50-degree climates, like a freezer room or outside in cold climates.

Instant start ballasts: Instant start lamps don’t use a preheating method. Instead, they send a high amount of voltage across the lamp upon the strike. Instant start lamps also start reliably at temperatures as low as zero degrees.

Programmed start ballasts: Programmed start ballasts are typically design in such a way, as it can provide Preheat mode, Ignition mode and run mode for specific period of time. This guarantees to enhance the life of Lamp/Tube in greater extent.

THD stands for Total Harmonic Distortion. Harmonic Distortion is a result of feedback/Deviation from sinusoidal wave form & with reference to fundamental frequency.

-As per EMC standards, IEC61000-3-2, for class C equipments, Current Total Harmonic Distortion must be: 11<I-THD%<39 and for Industry Standards: Current I-THD<32% (As per ANSI C82.11, max THD% should not exceed 32% in Electronic Ballast)

-Voltage V-THD<5%. Usually in low quality magnetic ballast THD% range is 90%-120%. If I-THD is more than 150%, extreme heat is generated may result in fire. Initial 5-6 harmonics are considered very significant.

       Wattage enters in Lamp/Tube

PF= ——————————–

        Wattage enters the Ballast

-PF closer to 1 has very high efficiency, means losses are highly minimized

-PF>0.7, considered high power factor (Electronic Ballasts)

-0.5<PF<0.7, considered normal power factor (standard Magnetic Ballasts)

-PF<0.5, considered poor power factor (Magnetic Ballasts of poor quality)

       Starting Wattage consumed by Lamp/Tube with Ballast

CF= ————————————————————————-

       Wattage consumed by Lamp with ballast during normal operation

CF is normally 1.4-1.7, more than this CF range reduces life of Lamp/Tube.

        Light o/p of lamp operated by specific ballast
BF= —————————————————————-
Light o/p of lamp operated by standard reference ballast

Light is defined as the electromagnetic radiation with wavelengths between 400nm to 750 nm which is visible to the human eye.

There are primarily 3 sources of Lights:
Natural sources: Produced by the sun, stars, fire, and electricity in storms.
Bio luminescence: There are even some animals and plants that can create their own light, such as fireflies, jellyfish, and mushrooms. This is called bio luminescence.
Artificial Light: Created by human being using various types of technologies; including, Incandescent Lamps, Fluorescent Lamps/Tubes, LED Lamps/Luminaries, HID, Arc Light, Metal Halide, Halogen Light etc.

A bunch of light ray or a bundle of a ray at a point is called a beam of light.

A line drawn in the direction of propagation of light is called a ray of light.

Light is composed of particles called photons.

When light hits the retina (a light-sensitive layer of tissue at the back of the eye), special cells called photoreceptors turn the light into electrical signals. These electrical signals travel from the retina through the optic nerve to the brain. Then the brain turns the signals into the images you see.

Humphry Davy invented the first electric light in 1802. He experimented with electricity and invented an electric battery. When he connected wires to his battery and a piece of carbon, the carbon glowed, producing light.

Incandescent light bulb: Electricity runs through a wire (Tungsten) inside the bulb and heats it up. When it’s hot enough, it glows.

Fluorescent Lamp/Tube: uses gas (Inert gases, like Argon) inside the tube to light up: when electricity runs through it, it excites a mixture of gases, which are transformed into light. .It needs Ballast to control the current flowing to tube.

LED Lamp/Luminary: light is generated when electricity runs through it. For systematic working of LED light, it requires control gear/Driver.

One of the most common incandescent bulbs that is used is a 60-watt bulb. To achieve the same brightness as a 60-watt bulb, you would only need a 13-15-watt fluorescent Lamp and you will need only 6-8W IN led Lamp.

Incandescent Lamps and LED Lamps don’t contain mercury vapor. Mercury is considered as toxic element for environment. Hence Incandescent Lamps and LED Lamps are not toxic.

Fluorescent Lamps, however, contain mercury. Hence these Lamps may be toxic for environment.

When it comes to CO2 emissions, however, incandescent bulbs cause the most, because of amount of electricity they use.

A traditional incandescent light bulb usually has a life span of about 1,000 hours, while a fluorescent bulb lasts about 9,000 hours. LED light Lamps last about 50,000 hours. That means If Incandescent Lamp is turned on every night for six hours, it would take about 5 months for an to be burnt out, In case of Fluorescent Lamp, 48 months (or 4 years) and in case of LED Lamp, 269 months (or 22 years). If there is good mains supply, Quality Electronic Ballast and LED Driver respectively.

In simplest terminology we can say that Lumen is

Light output of any Light source (in another word, luminous flux) is measured in terms of Lumen. For example, Light source, i.e. T12 40-watt fluorescent lamp may have a rating of 3050 lumens. Similarly, a light fixture’s output can be expressed in lumens. As lamps and fixtures age and become dirty, their lumen output decreases (i.e., lumen depreciation occurs). Most lamp ratings are based on initial lumens (i.e., when the lamp is new)

In the simplest terminology, we can say LUMEN represents brightness of light.

Light Intensity incident on particular surface is called illuminance. This is measurement of Light level.

Illuminance is measured in terms of foot candle (Lumen/square foot) and metric unit to measure illuminance is LUX (Lumen/square meter)measured in terms of Lux or Foot candle.

1 LUX=FOOT CANDLE x 10.76

In simplest terminology, we can say that, LUX is degree of spreading of light.

When Light incident on surface, it gets reflected in particular direction and this can be perceived by our eyes is called Luminance in another word also called brightness. Luminance is measured in units of Candelas/square meter.