Supply Power To A Fluorescent Lamp Engineering Essay

Supply Power To A light fixture Lamp Engineering EssayThe following report contains the steps taken in determinationing, constructing and testing of a basic electric system used to supply function to a luminance lamp. This report summarizes the method used to calculate the desired circumference parameters. Also, the design was implemented to achieve the involve design objectives.INTRODUCTIONAn engineering approach was used in this design project and as such, it consisted the design, construction and testing of a basic electrical system used to supply world-beater to a fluorescent lamp. The power broker of the system take to be corrected to addition efficiency and this was explained in detail. Due to the high level of risk involved in this design project, precautions needed to be taken. Laboratory protocol, industry standards, codes of practice and occupational safety protocols was taken into account during this design project.Course tangible from ECNG 1015 Introduction to galvanising Energy governances, ECNG 1006 Laboratory and cipher Design I and ECNG 1016 Mathematics for Electrical Engineers was used in this design project.In this report, all necessary mathematical shams, and draws pull up stakes be detailed. Also, the steps used to improve the power factor of the electrical electrical pass race system will be accounted for as well as the main processes implemented in the system.Background TheoryWhat is a fluorescent lamp? According to Sams F-Lamp FAQ, fluorescent lamps argon a guinea pig of discharge tube similar to neon signs and hydrargyrum or sodium vapour street or yard descends.The disparate Types of Fluorescent Lamp Fixtures in that location are basically triple variant types of fluorescent lamp fixtures. The three most used fixtures are listed as follows1. Instant Start2. rapid Start3. Pre hot up fixtures.Instant beginningInstant contract fixtures require a high potential to be applied to the lamp to cause it to work. T his high potential drop must be above the specified potency required for the lamp to light. This high voltage is required since the exemption of the gas may be high. Thus, the voltage be applied will force the gas to conduct and on that pointfore light. Sometimes, a potential difference is required to create a potential difference betwixt instant start fixture and the lamp cathodes. This potential difference causes ionization to occur and this reduces the resistance of the lamp.The initial authoritative which flows through and through the lamp causes the light to shine at utmost luminance. After the lamp cycles on, the instant-start steady will immediately regulate the voltage and up-to-the-minute to the operating conditions of the lamps. OR Once on-going starts menstruation through the lamps, the lamps illuminate at close to their full brightness. After a successful start, the instant-start ballast will immediately regulate the voltage and flowing down to the normal operating levels (QUOTE).The ordinary lamp carriage of an instant-start fixture is much shortlyer than that of a rapid start fixture. This is due to the fact that the instant-start fixtures use more energy than a rapid start fixture. It is as well more efficient as it has a very efficient ballast. Caution must be used with respect to instant-start lamps in areas which utilizes occupancy sensors.Rapid startRapid start is the name given up to fluorescent fixtures with two or more lamps. When using this type of system, no starter refilling is available for use. The ballast is used to maintain a steady period flow in the lamp at all times. In decree for the lamp to start, a capacitor is used to change the gas, hence reducing the resistance of the flow of the gas.The ballast allows the current in the lamp to flow when the gas is ionised. This current flow causes the lamp to glow dimly and also heats the gas. This thaw of the gas generates light and this light is used to further ionize the gas. The ballast is also used to increase the start up process of lighting the bulb. dischargely these process aid in decreasing the resistance of the gas and increasing the current flowing through the lamp. As brightness of the bulb throne be thought of as directly proportional to the current flow. When the arc discharge occurs, the lamp is turned on and light is produced. However, the light given off wouldnt be as bright since it takes a authentic amount of time to ionise the gas. Hence, a couple of seconds would be required to achieve maximum brightness.Applications that require constant round on/off are best suited with rapid start lamps. Their long life and their ability to dim when required make them ideal for certain applications. However, these lamps consume power even when the filaments watch burned out.Preheat fixturesA preheat fixture lamp is utilized in this project. Preheat fixtures usually consist of a starting term of enlistment which allows current to flow through the cathodes to warm the filaments. A high voltage is sent through the tube and this creates an arc crossways the mercury vapour. This results in the atmosphere inside the tube to heat up and thus, electron activity from the gas increases. The electrons move rapidly through the tube and they carry the current as they move. The starter flog leaves when the perimeter is preheated for a short period of time (Henkenius, 2007).Preheat fixtures are preferred as they use low embody performance phosphors. In using pre heat fixtures, the electrodes are damaged faster than other fixtures resulting in shorter life span. The type of ballast used in pre heat fixtures is both charismatic or resistive. It is recommended to avoid the use of pre heat fixtures as the maximum energy is not used.Existing Types of Fluorescent thermionic vacuum tubesThe following are few of the different types of fluorescent tubesT-5 This type of fluorescent lamp is extremely powerful. It boast s low maintenance, low disposal costs and it allows for smaller fixtures to be used. These types of lamps have an average life of 35,000 hours ground on 12 hours per start.T-8 This type of fluorescent lamp is used mainly for its sustainability. It boasts long life, a low level of mercury and it is energy efficient. The Philips T8 32W Extra Long life lamp and the Philips T8 25W will on average last longer than a standard 4T8 32W lamp.T-12 This type of fluorescent lamp provides long life and high performance. It also comes in different sizes, shapes and types. An average life of 24,000 hours, 85 CRI and the highest lumen output are the features of this lamp.T-16 This type of fluorescent lamp is usually 60 inches long and has a diameter of 2 inches. A starter is needed for this type of lamp as it is a preheat lamp.NEOLITE low-mercury This type of fluorescent lamp is arguably one of the smallest fluorescent lamps ever made. This NEOLITE low-mercury lamp has an average life of 10,00 0 hours and its brightness is rated at 70 lumens per watt.Dim Lights This type of fluorescent lamp bear be dimmed to about 20% of their full brightness. Thus, this type of lamp is considered an energy saver.Circle Tube This type of fluorescent tube uses a 4-pin connector. It is on average 8 to 12 inches in diameter.U-tube This type of fluorescent tube is shaped like a U as it name suggests. A tube which is bent into this U shape is much brighter than a normal tube of similar dimensions.Requirements for the Operation of Fluorescent LampsThe regulations of operation of the system gave insight into some of the requirements needed for the operation of fluorescent lamps. These requirements areAn electrical current is required to flow through the tube to power the system.A ballast is required which halts the current flowing through the system and it provides the voltage kick which creates the arc in the tube.A starter switch is needed to turn on/off the system. Turning off the syste m cuts the current flowing to the ballast, hence turning the lamp off.A pass is needed as its contacts control whether the circuit is assailable or close. In works together with the starter switch to control the lamp.Advantages and Disadvantages of Different SystemsThe BallastThe ballast is considered one of the most great subdivisions of a fluorescent lamp, as it is used to start the lamp. Also, the current flowing through the circuit is controlled by the ballast as it regulates current flow. The ballast is extremely in-chief(postnominal) in the circuit, as it corrects the power factor which increases the efficiency of electrical power consumption (quote). A fluorescent lamp without a ballast is considered a short circuit. Thus, at that place is a lot of current between the filaments and this causes the filaments to vaporise or the bulb to explode. Thus, the ballast can be seen as a core component in the fluorescent system.There are typically two types of ballast used in fluo rescent lamps. They are listed as followsInductive Ballastelectronic BallastInductive BallastAn inductive ballast connected with a starter is considered a series inductor. This type of ballast provides an inductive kick to grow start the lamp. This occurs when the current flowing through the ballast is interrupted. When this happens, a voltage is provided across the cathodes which are used to ionize the gas in the tube hence keeping the filaments hot.According to www.infralight.com.au/ballasts.html, the inductive ballast has two benefits. They are listed as followsIts reactance limits the power available to the lamp with only minimal power losses in the inductorThe voltage spike produced when current through the inductor is rapidly interrupted is used in some circuits to first strike the arc in the lamp.There are however disadvantages of using an inductive ballast. They are listed as followsThe life span is significantly reducedAn A rated ballast will hum quietly while a D rated ballast will hum loudly. According to www.freepatentsonline.com/y2008/0019113, the number of ballasts and their sound rating come ups whether or not a system will create an audible disturbance which an inductive ballasts does.Excessive heat is produced when in useElectronic BallastAccording to www.ehow.com/about_6131466_electric-ballast-definition, An electrical ballast is a construction that is used in gas discharge lighting systems to regulate the flow of current and to provide adequate voltage for the lights to function properly. The electronic ballast is typically preferred because it is more efficient than an inductive ballast. Furthermore, an inductive ballast requires a starter switch, less heat is lost, lamps do not flicker as oftentimes and the overall dimensions are smaller.However, the electronic ballast has its disadvantages. When it is used in parallel, there is an increase in losses within the circuit. Sometimes, odd current waveforms are pinched due to a high curr ent. Also, there is interference from the ballast and tubes in the circuit.The electronic ballast is not used in the pre heat fixture system. Thus, it would have no effect in this design as an inductive ballast will be used.Operation of the SystemInside a glass tube, there exists a p expression of electrodes, a drop of mercury and some inert gas sealed at an extremely low pressure. The electrodes are sealed at each end of the tube. The electrodes are in the form of filaments which for preheat and rapid or warm start fixtures are heated during the starting process to minify the voltage requirements and remain hot during normal operation as a result of the gas discharge (Goldwasser, 1999). The inert gas is usually argon. Phosphorous material line the inside of the tube. This material is used as it produces visible light due to ultra violet radiation upon it.A relatively high voltage is required to initiate the discharge of the mercury/gas mixture. After this discharge, a relatively l ower voltage is required to maintain it. The current which flows to the electrodes creates a voltage which acts across the electrodes. The electrons in the electrodes disperse from one side of the tube to the other. These excited electrons create energy and this energy changes some of the mercury to a gas. Electrons from mercury are special as they release photons which can be seen as ultraviolet light. Since the wavelength of ultraviolet light is so small, it cannot be seen by the naked eye. The ultraviolet light is made visible through the use of the phosphor powder coating. Photons released from the electrons are incident upon the phosphor coating and this causes the phosphors electrons to emit energy as it changes energy levels. This energy is usually given off in the form of heat. According to home.howstuffworks.com/fluorescent-lamp2, in a fluorescent lamp, the emitted light is in the visible spectrum the phosphor gives off white light we can see. Manufacturers can vary the co lor of the light by using different combinations of phosphors. In a fluorescent lamp, the emitted light is in the visible spectrum the phosphor gives off white light we can see. (Harris, 2009) pommelThe switch system being used in this design project is the normally open and normally close switch. This switch controls the relay system as it closes the circuit when flipped. The lamp will then be turned on, as current is being supplied to the circuit.StarterStarters in pre heat fixtures are either automatic or manual and are used to light the lamp. When flipped, a voltage is applied to the circuit and this causes the lamp to light. A few things occur when the switch is flipped. Firstly, a current flows through the filaments and this causes the contacts to heat and open. This interrupts the current flow which in turn lights the bulb. The inductive ballast comes into play at this point. It regulates the current flowing through the circuit as the fluorescent tube now has a low resistanc e as it is lighted.The starter used in preheat fixtures can be considered an on/off switch. It controls the period of time when the circuit opens/closes. As it is opened, the voltage causes ionisation of the mercury vapour due to the movement of electrons across the tube. The starter is very important as it determines whether the lamp flickers or not. This flickering can be attributed to the steady flow of electrons between the two filaments.Figure How starter worksDesign processProject planA project without any guidance or sequence is useless. Thus, a time management system was put into place in order to complete this design project. Before a system could be implemented, the project description must be known as well as the sequence of the project. The design brief which entails everything the student needed to know about the project is stated in the followingStudents are required to design and build an electrical system in order to power a small fluorescent lamp. The system must incorporate an on/off switch utilizing a 110V relay (8-pin relay and base, 110V) to power the fluorescent lamp assembly (1X20 regular ballast type 110V fluorescent fixture). Students are required toUnderstand the load its operation and existing types of fluorescent lamps hold in the systems required for the operation of the lamp (use of an inductive or an electronic ballastDevelop a mathematical model for the relay based on the principle of operation of the vertical-lift contactor.Design a start/ stop switch utilizing the relay to power the fluorescent lamp and discuss the importance of this switch in terms of safety.Determine if the magnitude of the evocation is sufficient to light the fluorescent lamp.Determine the magnitude of the force required to activate the relay and the load current to be supplied to the fluorescent lamp.Measure the existing power factor of the load and improve the power factor to at least 0.9 lagging.Investigate the effect of the fluorescent lamp assembly on the power system.Supply a detailed explanation of the operation of the system using the system phasors to support your discussion.QUOTE ELEARNINGStudents are required to apply the association gained from ECNG 1015 Introduction to Electrical Energy Systems as well as the laboratory exercises that were performed during the semester.Consideration must also be given to laboratory protocol, industry standards, codes ofpractice, occupational safety protocols and risk assessment in undertaking this project.3.2 Time Management ScheduleThe following table illustrates the time management system used to complete this design projectWeek Designated Tasks Completed1Thorough research was done on fluorescent lamps to better understand the system.A Safety and fortune Assessment was done with respect to the design project.2Specification sheets for acquired after collecting the required information from the ballast, relay, etc.3The start/stop switch was designed and used together with the relay to power the fluorescent lamp.Key parameters were touchstoned from the circuit.4A mathematical model of the relay system was determined. apply this model, the force required to activate the relay was determined. Also, the load current to get the fluorescent lamp to light was determined.5The existing power factor was measured and it was better to 0.9 lagging with the use of a capacitor.6Proof read report and get accustomed to fluorescent lamp system in preparation for oral exam. confuse 1 showing Time Management System used to finish the design project.Development of the Mathematical model of the RelayA mathematical model of the system must be done as the system is required to operate within specified parameters. Firstly, a model of the relay was done to determine it parameters. The following indicates how this system was modelledAmperes Circuital Law states that the line integral of the magnetic field intensity, H, around a unlikeable path in the magnetic field is tinct to surf ace integral of the current density, J, over any surface bounded by the closed path (Defour, 2011).This impliesThe magnetomotive force is a product of the number of turns in the intertwine and the current flowing through the curl up.= Eqn 2Eqn 3Since we are using a ferromagnetic material, the magnetic field intensity H, can also be stated asEqn 4Eqn 5Eqn 6and F are constant in the above equality. This implies that is directly proportional to F, providing that all variables above remain constant.Eqn 7The above equation is similar to ohms law. Hence, the hesitancy in this circuit can be treated as the resistance of the system, the force as the voltage through the circuit and as the current flowing through the circuit.Figure Magnetic equivalent circuitReluctance can also be stated asEqn 8If current is applied to the handbuild in the circuit above, the magnetic flux would vary. This change in magnetic flux is given by the equationEqn 9The above equation gives the change in magnetic flux for one turn of the coil. Hence, for N turns, the following equation is usedEqn 10Eqn 11Eqn 12When equations 11 and 12 are substituted for and F, the following equation is formedEqn 13The inductance of the coil remains constant in the above equation. Hence, the flux linkage through the coil is directly proportional to the current flowing through the coil.Eqn 14When equation 13 is substituted into equation 14, the following equation is formedEqn 15However, V can be determined as the potential difference across the coil, R as the resistance of the coil and e as the emf of the coilEqn 16However,Eqn 17Figure Electrical equivalent circuitThe above circuit can be used to measure power in the circuit. Power is the product of current flowing throught the circuit and the voltage across the circuit.Multiplying equation 16 by the current flowing through the circuit gives the power as seen in the followingEqn 18The following equation states that the energy supplied from the source to the fieldEqn 19The law of conservation of energy states that energy is ever conserved. The following equation shows this conservation of energyEqn 20Flux linkage across the coil can be thought of as constant. This is flux linkage is presume as the displacement of the armature occurs rapidly. Using Faradays law of Induction, the coil does not have an emf induced across it as is constant.Eqn 21The above equation implies that there is no energy flowing from the supply source to the coil. As such, equation 20 can be stated as followsEqn 22Taking into account the law of conservation of energy and the above equation, some energy must be lost from the magnetic field to the mechanical system. When a warp is drawn, the area under the curve illustrates the magnetic field energy lost to the system.Eqn 23Eqn 24As varies, the energy lost is supplied by the coupling field. The following equation states the energy lostEqn 25= Eqn 26When equation 26 is substituted into equation 24, the force can be determined as followsEqn 27When equation 14 is substituted into equation 27Eqn 28Consideration of System RequirementsDetermination of the magnitude of inductance required to light theLampSince an inductive ballast is used in this fluorescent lamp system, it has a certain amount of inductance and resistance. Thus, the ballast can be considered as an RL circuit. The following diagram shows the equivalent circuit for the ballastFigure Equivalent circuit for the ballastThe following equation is used to calculate the underground of the circuit relayDetermination of the magnitude of inductance when armature is turned on/offCoil Inductance with Armature OffThe following equation is used to calculate the impedance of the circuit relayCoil Inductance with Armature On DeenergizeThe following equation is used to calculate the impedance of the circuit relayFrom the specification sheet, the inductance of the coil was specified asInductance of Coil with Armature Off at 120V = 15.04HInductan ce of Coil with Armature On at 120V = 7.19HThe calculated values for the inductances vary significantly. This can be explained by taking into consideration the tolerance levels associated with the rated current. Also, the reaction time of the was slightly off and this resulted in a different current being taken than the true(a) current value.Determination of the load current required to activate the relayTo determine the lower limit current required to activate the relay, an analog voltmeter was used in series with the potentiometer. As the resistance of the potentiometer is not fixed, it was used to determine when the relay would activate. The resistance was varied and just as the relay was activated, the voltmeter was used and the minimum current required to activate the relay was determined.The load current was determined asDetermination of the force required to activate the relayThe length of the air gap was determined to be approximately 1mm.The minimum current required to act ivate the relay was determined asUsing the specification sheet, the inductance of the coil was determinedInductance of Coil with Armature Off at 110V = 13.38HInductance of Coil with Armature On at 110V = 5.69HThe following equation was used to determine the force required to activate the relayThus, the force required to activate the relay is 1.03N.Determination of key circuit parametersParameterUnitValueVoltage across relayV99.5Min. current to turn on the relaymA21.8Resistance, R1.464kCoil Inductance (Armature off)H13.38Coil Inductance (Armature on)H5.69Length of demeanor Gapm0.001Inductance of BallastH363.82Parasitic Resistance of Ballast339.8Table 3 showing key circuit parameters.Design of start/stop switchRelayA relay is basically a circuit which is used to control/operate another circuit. The relay can be described as an 8-pin relay and base. A coil is located within the relay and it produces a magnetic field when current flows through it. This field causes a contact to change from its original location to another resulting in the circuit being opened or closed. The relay together with the starter was used to power the fluorescent lamp. The following diagrams illustrate the 8-pin arrangement of the relay usedFigure Arrangement of the 8-pin relay usedThe above diagram on the left shows that this type of relay is a double pole double control (DPDT) type relay. The double pole states that two contacts are closed while the double throw states that there are two different paths of conduction within the relay.In this relay system, there are two switches being manipulated. When a voltage is dropped across contacts 2 and 7, a magnetic field is created within the relay. For this magnetic field to be created, the coil in the relay becomes energized and this produces the magnetic field which in turn manipulates the contacts. Contact 1 connects to contact 3 and contact 8 is connected to contact 6. Also, as seen on the diagram, contacts 4 and 5 remain normally close d until activated.The relay is significant in this design project as it controls the current flow. Thus, no large current is exposed to any personnel.(NOT SURE IF TO PUT TRADEMARK)SwitchThe following diagram illustrates the circuit used to design the start switchFigure Schematic Diagram of Circuit UsedThe switching circuit has three main switchesNormally open switch (NO)Normally closed switch (NC)Start switchThe normally open switch indicates whether or not current flows through the circuit. When this switch is flipped, the contacts are connected allowing current to flow. The switch being used must be pushed down in order to complete the circuit to allow current to flow.The normally closed switch will allow current to flow through the circuit normally. In contrast to the normally open switch, when the normally closed switch is pushed, the contacts become disconnected, interrupting the current flow.The start switch is used to turn on/off the fluorescent lamp. If the contacts are con nected, then current will flow. Thus, when the start switch is flipped, the fluorescent lamp will be turned on and hence light is given off.In this design project, the normally open and normally closes switches were placed in series with the power supply and terminals 2 and 7. Contacts 1 and 6 were placed in parallel with the normally open switch as shown in the above figure and contacts 1 and 6 were placed across the normally closed switch. When the magnetic field is created in the coil, the contacts in the relay change position and connect to contacts 3 and 6. This configuration was used as the normally open and normally closed switch determines whether the fluorescent lamp is turned on/off.When the normally open switch is pushed, the circuit is closed and the fluorescent lamp lights. When the normally closed switch is pushed, the circuit is open and the fluorescent lamp is turned off.Explanation of the SystemThe voltage rms of the system was determined to be 117.5V. The real powe r of the system was determined to be 22.5W. The rms voltage determined is equivalent to the phasor voltage of the system. Hence, the phasor current can be determined as followsThe supply voltage V, is calculated using the following equationSince this is a purely inductive load, the tiptoe at which the current phasor lags the voltage phasor is determined as followsHence, the voltage phasor is determined as followsThe current flowing through the lamp is considered as the real current of the apparent current. The following equation is used to calculate this lamp currentThe reactive current flowing through the lamp is known to be out of phase with the supply voltage by an angle of . This reactive current was calculated using the following equationThe real current calculated above is placed on the horizontal axis. Hence, it is seen that the voltage phasor is in phase with this real current. The following diagram illustrates the relationship associated with the apparent, reactive and rea l currentsFigure Phasor Diagram for System without capacitorA capacitor was used in the design to correct the power factor to at least 0.9 lagging. This capacitor does not affect the power given off by the motor in the system and as such, the current is constant. However, as this capacitor was added, the current from the source decreased when compared to the first current attained. The fluorescent lamp still requires a steady current flow to maintain the specified power. Hence, a current also flows through the capacitor.The system was required to be designed with a power factor of at least 0.9 lagging. ThusIt should be noted that the current flowing through the capacitor reduces the reactive current.Taking into account this corrected power factor, the following diagram illustrates the phasor diagram for the uncorrected power factor, corrected power factor and the capacitor currentFigure phasor diagram showing currents with the inclusion of a capacitorAs stated previously, with the inclusion of the capacitor, a new current will flow throught the system. This current is determined as followsAs seen from the phasor diagram above, form a closed loop. Using Kirchhoffs Current Law, the following equation was used to determine the current flowing through the capacitorFuthermoreHence, the capacitor need to correct the power factor to at least 0.9 lagging can be determined as followsThe capacitor determined above is significantly different from the value used. This can be explained by considering that various power losses occur within the system. Also, this capacitance was calculated using theoretical values and not values obtained in the lab. Hence, there would be a difference.From the above figure( phasor diagram for both power factors),