They contain a small amount of mercury and are filled with. What is the importance of starter and choke in fluorescent. Fluorescent lamps work by ionizing mercury vapor in a glass tube. To make the fluorescent lamp work on dc supply, a resistance is connected in addition to the usual choke as shown in the following figure. Simple bulb swap works with any t5 fluorescent fixture. Lamp requirements a fluorescent lamp requires preheating of the filaments, a high ignition voltage to strike, current or power control for dimming, and additional filament heating during low dimming levels. In this post, let us discuss about how to make tube light works on dc supply. When the lamp first turns on, the path of least resistance is through the. If a lampballast combination meets the guidelines for these parameters as shown in the table, the lighting system is likely to start reliably. A fluorescent lamp basically consists of a long glass gas discharge tube. Fluorescent lamps contain a small amount of mercury. The fluorescent light is the most prolific type of lamp in the world. How to design a dimming fluorescent electronic ballast. A fluorescent lamp is a low weight mercury vapour lamp that uses fluorescence to deliver visible light.
These processes ensure that the fluorescent lamp is treated in an environmentally sound manner as required by the minamata convention. Fluorescent lamp, electric discharge lamp, cooler and more efficient than incandescent lamps, that produces light by the fluorescence of a phosphor coating. Figure 1 shows a driving circuit for a fluorescent lamp operated from the 220240v mains. Start it up how fluorescent lamps work howstuffworks. A t12 lamp on the left in the figure below is therefore twelveeighths of an inch, or oneandonehalf inches 3. Electronic fluorescent lamp ballast stmicroelectronics. The fluorescent lamps which is commonly known as tube light can be operated on dc supply. Fluorescent lamps are made of a glass tube filled with a low pressure mixture of gases, specifically mercury and noble gases like argon, neon, xenon and krypton.
Tube shaped fluorescent lamp is termed as tube light. One of the best accessible description of how the lamps work is in wikipedia. The circuit demonstrates proper fluorescent lamp control with conducted emi below the allowed limits using only a singlewinding filter inductor. A fluorescent tube has a filament at each end, just like the filament in an incandescent bulb but very. I 3000k 82 f032830eco 2950 20000 philips 3000k 78 f32t8tl730alto 2850 20000. An electric current in the gas energizes mercury vapor which delivers ultraviolet radiation through discharge process and the ultraviolet radiation causes the phosphor coating of the lamp inner wall to radiate visible light. Since the fluorescent power is used in the tube, it is called as fluorescent tube. Tube light is a lamp that works on low pressure mercury vapor discharge phenomenon and converts ultra violate ray into visible ray with the help of phosphor coated inside glass tube material used inside the tube light. Fluorescent systems can be used with occupancy sensors to provide instant onoff capabilities to maximize energy savings. The tube also contains a phosphor powder, coated along the inside of the glass. Simple control circuits for electronic ballast design. The fluorescent lamp how it works inventors youtube.
Distribution transformers are affected in two ways. They work much the same way as an incandescent, but the filament is. See how the ballast and starting switch work to strike an arc in the lamp. Fluorescent lamps are cylindrical glass tubes that are coated on the inside with phosphors. When the current is switched on, the starting mechanisms at each end of the lamp produce electrons that excite the gases inside the tube and make them release ultraviolet uv radiation. An electric current in the gas excites mercury vapor, which produces shortwave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. In the mid1930s when first fluorescent tube lights were introduced in the market, they were a total revelation. Wear gloves if picking up broken fluorescent lamp fragments. The materials used to build a tube light are given below. When using t8 lamps and occupancy sensors, cooper lighting industrial fluorescent luminaires use only softer starting program start ballasts to minimize damage to the lamp. Fluorescent lamp simple english wikipedia, the free. A fluorescent lamp consists of a glass tube filled with a mixture of argon and mercury vapour.
As electricity is supplied to the tube through the electrodes, the current passes through the gas conductor, in form of free electrons and ions and vaporizes the mercury. The n side injects electrons into the p side and the p side injects holes into the n side. As electricity is supplied to the tube through the electrodes, the current passes through the gas conductor, in form of free. How it works an electric current is applied to mercury vapor inside the tube, causing it to emit ultraviolet uv. The central element in a fluorescent lamp is a sealed glass tube. Commercially it is available in 10, 20, 40 and 80 watts. As the electrons collide with the gaseous atoms of mercury, they give away free electrons which jump to higher levels and. Fluorescence microscopy how light microscopes work. The tube is then finally sealed at low pressure with two filament electrodes each at its both ends. Some lamps have the tube bent into a circle, used for table lamps or other places where a more compact light source is desired.
In this case, their maintenance work is nut limited to washing lighting fixtures, but includes floors, windows, furniture. They are widely used in domestic and street lighting. The tubes are coated on the inside with a fluorescent material, usually a compound containing phosphorous. Leds generally produce light when a current runs through them.
Most cfls are designed to replace incandescent lamps and fit into most existing light fixtures. Life 4 32w fluorescent t8 ge 3000k 78 f32t8sp30eco 2850 20000 ge 3000k 86 f32t8spx30ew 2950 20000 o. In most vacuum lamps, an active material known as a getter is applied to the filament or leads during manufacture to reduce residual gas pressure and to clear up the atmosphere when the. Fluorescent lamp and working principle of fluorescent lamp. Most can be dimmed but at a higher cost than dimming incandescent lamps. There are two general types, traditional fluorescent and compact fluorescent. When the current is switched on, the starting mechanisms at each end of the lamp produce electrons that excite the gases inside. Fluoresent lamps how does fluoresent lamp works and. Specifications thrive led t5 fluorescent t5 power consumption 30 w 54 w product lifetime 50,000 hrs 20,000 hrs warranty 5 years cfl a compact fluorescent lamp cfl, also known as a compact fluorescent light or energy saving light, is a type of fluorescent lamp. A fluorescent lamp, or fluorescent tube, is a lowpressure mercuryvapor gasdischarge lamp that uses fluorescence to produce visible light. The purchase price of a fluorescent lamp is often much higher than an incandescent lamp of the same output, and the. Fluorescent lamps have a longer rated life and use less energy than an incandescent lamp of the same brightness.
Conventional lamp ballast the simplest form of ballast is an inductor. The t designation in fluorescent lamp nomenclature stands for tubular the shape of the lamp. A fluorescence microscope uses a mercury or xenon lamp to produce ultraviolet light. Down the tubes how fluorescent lamps work howstuffworks.
Its inner surface is coated with phosphorous and is filled with an inert gas, generally argon, with a trace of mercury. Animation shows the circuit of the first kind of fluorescent lamp called the preheat. A fluorescent lamp, or fluorescent tube, is a lowpressure mercuryvapor gasdischarge lamp. The cfl was initially designed to replace the incandescent lamp in terms of its compactness as well as energy efficiency. How fluorescent lamp tube light works on dc supply.
You can see how this system works in the diagram below. Well also find out why fluorescent lamps are more efficient than incandescent lighting, and see how this technology is used in other sorts of lamps. This uv radiation hits the fluorescent coating, which. The starter is a switch that is normally open, that closes a few seconds after power is applied.
Rk primer of school lighting lamps and maintenance. Fluorescent lamp how does a fluorescent lamp works. Halogen lights are sometimes referred to as energysaving, incandescent bulbs. The normal luminous viability of fluorescent lighting frameworks is 50 to100 lumens per watt, which is a few times the adequacy of incandescent lamps with equivalent light yield. A fluorescent lamp, is a type of electric light lamp that uses ultraviolet emitted by mercury vapor to excite a phosphor, which emits visible light. The lowpressure 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. This occurs when specific types of semiconductor materials are used to create pn diodes.
Magnetic trapping you may have noticed in the drawing reproduced here that the circuit of the fluorescent light fixture included a ballast coil. How a fluorescent light works schematic animation youtube. To understand how a dimming fluorescent lamp works, a simple resistive model for. Special dimming ballasts and dimming controls are required.
The classic fluorescent lamp design, which has fallen mostly by the wayside, used a special starter switch mechanism to light up the tube. A fluorescent lamp has changed over electrical energy into useful light energy to a great deal more proficiently than incandescent lamps. A fluorescent lamp converts electrical energy into useful light much more efficiently. See how the ballast and starting switch work to strike an arc. This causes electrons in the gas to emit photons at uv frequencies. The tube contains a small bit of mercury and an inert gas, typically argon, kept under very low pressure. Lamp operation once a lamp has started, a ballast maintains the lamp current. People were amazed to see their houses and offices lit as brightly as cool daylight.
The number immediately following the t gives the diameter of the lamp in eighths of an inch. Lamp current green trace and lamp voltage yellow trace during normal preheat ignition and run modes. The light comes into the microscope and hits a dichroic mirror a mirror that reflects one range of wavelengths and allows another range to pass through. The dichroic mirror reflects the ultraviolet light up to the specimen. The basic principles of the most commonly used lamp types. Fluorescent lamp tubes are often straight and range in length from about 100 millimeters 3. A fluorescent lamp, or fluorescent tube, is a lowpressure mercuryvapor gas discharge lamp. This article is about traditional fluorescent lamps.
The basic construction of a cfl consists a tube which is curvedspiraled to fit into the space of an incandescent bulb, and a compact electronic ballast in the base of the lamp. Fluorescent lamps are made of a glass tube containing a low pressure mixture of gases including mercury. In this article, well find out how fluorescent lamps emit such a bright glow without getting scalding hot like an ordinary light bulb. Pdf impact of compact fluorescent lamp on power quality.