How does a fluorescent light bulb work?
An electric current in the gas excites mercury vapor which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the bulb to glow. A fluorescent lamp converts electrical energy into useful light much more efficiently than incandescent lamps.
What is a fluorescent tube light?
A fluorescent lamp converts electrical energy into useful light much more efficiently than incandescent lamps. The luminous efficacy of a fluorescent light bulb can exceed 100 lumens per watt, several times the efficacy of an incandescent bulb with the comparable light output. What’s Inside a Fluorescent Tube Light?
How does a choke work on a fluorescent light?
This principle of the choke is exploited in lighting a fluorescent tube light. When an AC voltage is applied to a tube light fixture, the voltage passes through the choke, the starter, and the filaments of the tube. The filaments light up and instantly warm up the tube.
How do tube light fixtures work?
When an AC voltage is applied to a tube light fixture, the voltage passes through the choke, the starter, and the filaments of the tube. The filaments light up and instantly warm up the tube. The starter is made up of a discharbe bulb with two electrodes next to it.
When were fluorescent tubes introduced?
References. In the mid-1930s when first fluorescent tube lights were introduced in the market, they were a total revelation. People were amazed to see their houses and offices lit as brightly as cool daylight. Learn how they work here.
What is a fluorescent lamp?
A fluorescent lamp basically consists of a long glass gas discharge tube. Its inner surface is coated with phosphorous and is filled with an inert gas, generally argon, with a trace of mercury. The tube is then finally sealed at low pressure with two filament electrodes each at its both ends. These electrode filaments are used to preheat ...
What is a choke in a circuit?
Please refer to the circuit diagram on the right as you read the following points: The choke is in fact a large inductor. It consists of a long copper winding over iron laminations. An inductor by nature always has a tendency to throw back the stored current in it, every time the power through it is switched OFF.
Why are electronic ballasts so efficient?
The working principle of today’s modern electronic ballasts is to avoid the use of starters for the preheating purpose. They are also very light in weight. These inhibit the initial flickering of the tube light as normally seen in the ordinary tube fixtures by changing the frequency of the mains power to a much higher 20,000 hertz or more. Moreover, electronic ballasts are very energy efficient.
Why is the electron tube coated with phosphorous?
As electrons return to their original energy level, they begin to release light. However, the light they emit is ultraviolet, and not visible to the naked eye, so another step needs to take place before we can see the light. This is why the tube was coated with phosphorous.
How does a starter work?
The starter is made up of a discharbe bulb with two electrodes next to it. When electricity passes through it an electrical arc is created between the two electrodes. This creates light, however the heat from the bulb causes one of the electrodes (a bimetallic strip) to bend, making contact with the other electrode.
Why does my AC light make a buzzing noise?
The reason for this lies in the loosely fitted choke on to the fixture which vibrates in accordance with the 50 or 60 hertz frequency of our AC mains and creates a humming sort of noise. Tightening the choke’s screws may instantly eliminate the problem.
What is the central element of a fluorescent lamp?
The central element in a fluorescent lamp is a sealed glass tube. The tube contains a small bit of mercury and an inert gas, typically argon, kept under very low pressure. The tube also contains a phosphor powder, coated along the inside of the glass.
Why does a fluorescent light emit less energy than the original?
This photon has less energy than the original photon, because some energy was lost as heat. In a fluorescent lamp, the emitted light is in the visible spectrum -- the phosphor gives off white light we can see.
What kind of light does mercury emit?
The electrons in mercury atoms are arranged in such a way that they mostly release light photons in the ultraviolet wavelength range. Our eyes don't register ultraviolet photons, so this sort of light needs to be converted into visible light to illuminate the lamp.
What is a phosphor tube?
This is where the tube's phosphor powder coating comes in. Phosphors are substances that give off light when they are exposed to light. When a photon hits a phosphor atom, one of the phosphor's electrons jumps to a higher energy level and the atom heats up.
How does mercury change from liquid to gas?
As electrons and charged atoms move through the tube, some of them will collide with the gaseous mercury atoms. These collisions excite the atoms, bumping electrons up to higher energy levels.
Do fluorescent lights emit ultraviolet light?
Conventional incandescent light bulbs also emit a good bit of ultraviolet light, but they do not convert any of it to visible light. Consequently, a lot of the energy used to power an incandescent lamp is wasted. A fluorescent lamp puts this invisible light to work, and so is more efficient.
Do incandescent lights lose energy?
Incandescent lamps also lose more energy through heat emission than do fluorescent lamps. Overall, a typical fluorescent lamp is four to six times more efficient than an incandescent lamp. People generally use incandescent lights in the home, however, since they emit a "warmer" light -- a light with more red and less blue.
How does a fluorescent lamp work?
The fluorescent lamp also works on this principle. The low-pressure vapor tube has fluorescence material covered in the inner wall of the glass tube, which emits light once after absorbing UV light which generates by a chemical reaction when current flows through it. We will discuss below that how does it work…!!
What is Fluorescent light?
To know it right from the basic you need to know “ What does the word Fluorescent mean“? And before falling for the word fluorescent, I’ll discuss in short about luminescence, incandescence.
How does a metallic flip switch work?
The metallic flip switch gets opened, or it does not connect the path. But when we switch on the Fluorescent light, a potential difference generates across both the glass tube ( Tube of the fluorescent light and the tube of the starter ). But the distance between the two electrodes of the Fluorescent light is much higher than the distance between the two terminals of the stater. So the gas inside the stater get heated immediately by the potential difference across it and because of this heat, the metallic strip expands and touch the other end, or it closes the path. As a result, current flows through the starter and not through the Fluorescent lamp Tube.
Why won't my fluorescent light start?
Without the Starter the Fluorescent Lamp will not start, or even it started by chance, it will flicker or fail to provide a continuous flow of light. Without a Ballast also the light won’t start as it provides the higher voltage to the light to start. Ballast also control the current through the tube to protect it from short-circuiting.
How does mercury change from liquid to vapor?
The small amount of mercury which is present there in the glass tube changes from liquid to vapor due to the higher temperature and the charge inside the tube. As the ions of inert gas move inside the tube from one electrode to another, some of those collide with the gaseous mercury atom. This collision produces some energies and those energies get released and become a radiation UltraViolet rays. The frequency of UV light is very high, and the wavelength is so small that it can not be visible by the human eyes.
Why is the inner wall of a glass tube white?
The inner wall of the glass tube is coated with phosphor powder which is a fluorescent material and white, That is why the tube looks white to us.
Why were fluorescent lamps invented?
Fluorescent Lamps are invented to overcome the disadvantages of Incandescent lights which are
What are the elements of a fluorescent tube?
Here we discuss the internal elements in a fluorescent tube light. A fluorescent lamp basically consists of a long glass gas discharge tube. Its inner surface is coated with phosphorous and is filled with inert gas, generally argon, with a trace of mercury. The tube is then finally sealed at low pressure with two filament electrodes each ...
How does a fluorescent lamp convert electrical energy into radiant energy?
The fundamental means for conversion of electrical energy into radiant energy in a fluorescent lamp relies on inelastic scattering of electrons when an incident electron collides with an atom in the gas.
How does an AC light fixture work?
When an AC voltage is applied to a tube light fixture, the voltage passes through the choke, the starter, and the filaments of the tube. The filaments light up and instantly warm up the tube. The starter is made up of a discharge bulb with two electrodes next to it.
What is fluorescent light?
A fluorescent lamp or a fluorescent tube is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the bulb to glow.
How do ultraviolet light rays get absorbed?
Ultraviolet photons are absorbed by electrons in the atoms of the lamp’s interior fluorescent coating , causing a similar energy jump, then drop, with the emission of a further photon. The photon that is emitted from this second interaction has lower energy than the one that caused it.
How does avalanche ionization affect the conductivity of a fluorescent bulb?
As a result of avalanche ionization, the conductivity of the ionized gas rapidly rises, allowing higher currents to flow through the fluorescent lamp.
What happens when conduction of electrons between electrodes is complete?
Once the conduction of electrons between the electrodes is complete, no more heating of the filaments is required and the whole system works at a much lower current.
