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Supply Power To A Fluorescent Light fixture Engineering Essay

The following record contains the steps taken in designing, building and examining of a basic electric powered system used to supply capacity to a fluorescent lamp. This statement summarizes the method used to calculate the desired circuit parameters. Also, the look was implemented to attain the required design goals.


An engineering procedure was used in this design job and as such, it consisted the design, construction and assessment of a simple electric system used to provide power to a fluorescent light fixture. The power factor of the machine needed to be corrected to increase efficiency and this was explained in detail. Due to the higher level of risk involved with this design job, precautions would have to be taken. Laboratory protocol, industry standards, rules of practice and occupational protection protocols was considered during this design project.

Course materials from ECNG 1015 - Intro to ELECTRICITY Systems, ECNG 1006 - Laboratory and Job Design I and ECNG 1016 - Mathematics for Electrical Engineers was found in this design project.

In this record, all necessary mathematical models, and diagrams will be complete. Also, the steps used to increase the electric power factor of the relay system will be accounted for as well as the main processes integrated in the system.

Background Theory

What is a fluorescent light fixture? Corresponding to Sam's F-Lamp FAQ, fluorescent bulbs are a kind of discharge tube very much like neon symptoms and mercury or sodium vapour neighborhood or yard lamps.

The Various kinds of Fluorescent Lamp fixture Fixtures

There are basically three different kinds of fluorescent light fittings. The three most used fixtures are listed the following;

1. Instant Start

2. Swift Start

3. Preheat fixtures.

Instant start

Instant start accessories require a high voltage to be employed to the lamp to cause it to work. This high voltage must be above the specified voltage necessary for the light to light. This high voltage is required since the amount of resistance of the gas may be high. Thus, the voltage being applied will drive the gas to execute and hence light. Sometimes, a potential difference is required to make a potential difference between instant start fixture and the light fixture cathodes. This potential difference causes ionization that occurs which reduces the resistance of the light.

The first current which flows through the light fixture causes the light to shine at maximum lighting. After the light becomes on, the instant-start ballast will immediately regulate the voltage and current to the operating conditions of the lighting fixtures. OR Once current starts streaming through the lights, the lamps light up at near their full brightness. After an effective start, the instant-start ballast will immediately regulate the voltage and current right down to the standard operating levels (QUOTE).

The average light life associated with an instant-start fixture is a lot shorter than that of an instant start fixture. That is because of the fact that the instant-start fittings use more energy when compared to a quick start fixture. Additionally it is more efficient as it offers a very reliable ballast. Caution must be used with respect to instant-start bulbs in areas which utilizes occupancy detectors.

Rapid start

Rapid start is the name directed at fluorescent accessories with several lamps. When using this kind of system, no beginner switch is designed for use. The ballast can be used to maintain a steady current move in the lamp all the time. For the lamp to start, a capacitor can be used to ionize the gas, hence minimizing the amount of resistance of the circulation of the gas.

The ballast allows the current in the light fixture to move when the gas is ionised. This current flow causes the lamp to glow dimly and also heats the gas. This home heating of the gas generates light and this light can be used to help expand ionize the gas. The ballast is also used to boost the start up procedure for lighting the light. Each one of these process assist in decreasing the level of resistance of the gas and increasing the current streaming through the lamp. As brightness of the light can be regarded as directly proportional to the present flow. When the arc discharge occurs, the light is fired up and light is produced. However, the light given off wouldn't be as excellent since it requires a degree of time to ionise the gas. Hence, several seconds would be asked to achieve maximum brightness.

Applications that require constant making on/off are suitable with fast start lights. Their long life and their capacity to dim when required make them ideal for certain applications. However, these lighting fixtures consume power even when the filaments have burned out.

Preheat fixtures

A preheat fixture light is employed in this job. Preheat accessories usually contain a starting circuit which allows current to flow through the cathodes to warm the filaments. A high voltage is directed through the pipe and this creates an arc over the mercury vapour. This ends up with the atmosphere inside the tube to heat up and therefore, electron activity from the gas boosts. The electrons move rapidly through the pipe and they carry the existing as they move. The basic switch starts when the circuit is preheated for a short time frame (Henkenius, 2007).

Preheat accessories are preferred as they use low priced performance phosphors. In using pre heating accessories, the electrodes are destroyed faster than other fittings leading to shorter life span. The sort of ballast used in pre heat accessories is either magnetic or resistive. It is strongly recommended to avoid the use of pre heating fixtures as the maximum energy is not used.

Existing Types of Fluorescent Tubes

The pursuing are some of the various types of fluorescent pipes;

T-5 - This sort of fluorescent lamp is incredibly powerful. It offers zero-maintenance, low disposal costs and it permits smaller accessories to be used. These kinds of lamps have the average life of 35, 000 hours predicated on 12 hours per start.

T-8 - This type of fluorescent lamp is employed mainly because of its sustainability. It boasts long life, a low degree of mercury and it is energy conserving. The Philips T8 32W Extra Long life light fixture and the Philips T8 25W will typically last longer than a standard 4'T8 32W light.

T-12 - This type of fluorescent light provides extended life and high performance. It also comes in several sizes, shapes and types. The average life of 24, 000 time, 85 CRI and the highest lumen output will be the features of this lamp.

T-16 - This sort of fluorescent light is usually 60 ins long and has a diameter of 2 inches. A beginner is needed for this type of light as it is a preheat light.

NEOLITE low-mercury - This type of fluorescent light fixture is probably one of the smallest fluorescent lamps ever made. This NEOLITE low-mercury lamp comes with an average life of 10, 000 hours and its lighting is scored at 70 lumens per watt.

Dim Lights - This type of fluorescent light can be dimmed to about 20% of their full lighting. Thus, this kind of lamp is known as a power saver.

Circle Pipe - This sort of fluorescent tube uses a 4-pin connector. It is on average 8 to 12 ins in diameter.

U-tube - This sort of fluorescent pipe is shaped such as a "U" as it name suggests. A pipe which is bent into this U condition is a lot brighter when compared to a normal pipe of similar proportions.

Requirements for the Procedure of Fluorescent Lamps

The guidelines of procedure of the system gave perception into some of the requirements needed for the procedure of fluorescent bulbs. These requirements are;

An electric current must flow through the tube to power the system.

A ballast is necessary which controls the existing flowing through the machine and it offers the 'voltage kick' which creates the arc in the pipe.

A starter change is required to turn on/off the machine. Turning off the machine cuts the current flowing to the ballast, hence turning the lamp off.

A relay is needed as its contacts control whether the circuit is available or close. In works together the starter transition to control the light.

Advantages and Down sides of Different Systems

The Ballast

The ballast is known as one of the most important components of a fluorescent light, as it is utilized to start out the lamp fixture. Also, the existing moving through the circuit is managed by the ballast as it regulates current circulation. The ballast is extremely important in the circuit, as it corrects the energy factor which escalates the efficiency of electrical power usage (quote). A fluorescent light with out a ballast is considered a brief circuit. Thus, there is a whole lot of current between your filaments and this causes the filaments to vaporise or the light to explode. Thus, the ballast is seen as a central aspect in the fluorescent system.

There are usually two types of ballast used in fluorescent lamps. They are really listed as follows;

Inductive Ballast

Electronic Ballast

Inductive Ballast

An inductive ballast linked with a beginner is considered a string inductor. This sort of ballast has an inductive kick to hop start the light. This occurs when the current streaming through the ballast is interrupted. When this happens, a voltage is provided over 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 simply listed as follows;

Its reactance restricts the power open to the lamp fixture with only little power loss in the inductor

The voltage spike produced when current through the inductor is swiftly interrupted can be used in some circuits to first punch the arc in the light.

There are however cons of using an inductive ballast. They are listed as follows;

The life time is significantly reduced

An "A" rated ballast will hum softly while a "D" ranked ballast will hum loudly. Regarding to www. freepatentsonline. com/y2008/0019113, the number of ballasts and their audio rating determines whether or not a system will create an audible disruption which an inductive ballasts does indeed.

Excessive heating is produced when in use

Electronic Ballast

According to www. ehow. com/about_6131466_electric-ballast-definition, A power ballast is a tool that can be used in gas release lighting systems to modify the circulation of current and provide enough voltage for the lamps to function properly. The digital ballast is normally preferred since it is more efficient than an inductive ballast. Furthermore, an inductive ballast requires a starter change, less heating is lost, bulbs do not flicker normally and the overall proportions are smaller.

However, the electronic ballast has its cons. When it is used in parallel, there is an increase in loss within the circuit. Sometimes, unusual current waveforms are drawn due to a higher current. Also, there may be interference from the ballast and pipes in the circuit.

The electric ballast is not found in the pre heat fixture system. Thus, it could have no impact in this design as an inductive ballast will be used.

Operation of the System

Inside a glass tube, there is a pair of electrodes, a drop of mercury and some inert gas sealed at an extremely low pressure. The electrodes are covered at each end of the pipe. The electrodes are by means of filaments which for preheat and quick or warm start accessories are heated during the starting process to diminish the voltage requirements and continue to be hot during normal procedure consequently of the gas discharge (Goldwasser, 1999). The inert gas is usually argon. Phosphorous material line the inside of the tube. This material is utilized as it produces obvious light scheduled to super violet radiation after it.

A relatively high voltage is required to initiate the discharge of the mercury/gas blend. After this release, a comparatively lower voltage is required to maintain it. The current which flows to the electrodes creates a voltage which operates across the electrodes. The electrons in the electrodes disperse from one aspect of the tube to the other. These fired up electrons create energy which energy changes some of the mercury to a gas. Electrons from mercury are special as they release photons which can be viewed as ultraviolet light. Because 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 event after the phosphor coating and this triggers the phosphor's electrons to produce energy as it changes energy. This energy is usually given off by means of heat. According to home. howstuffworks. com/fluorescent-lamp2, in a fluorescent light fixture, the emitted light is in the obvious range -- the phosphor produces white light we can easily see. Manufacturers can vary the color of the light by using different mixtures of phosphors. Within a fluorescent lamp, the emitted light is in the obvious variety -- the phosphor gives off white light we can see. (Harris, 2009)


The switch system being found in this design project is the normally open up and normally close turn. This switch handles the relay system as it closes the circuit when flipped. The light fixture will then be turned on, as current is being provided to the circuit.


Starters in pre heat accessories are either automatic or manual and are being used to light the lamp. When flipped, a voltage is put on the circuit and this causes the lamp to light. A couple of things happen when the move is flipped. First of all, a current flows through the filaments and this causes the associates to heat up and open. This interrupts the existing flow which lights the light bulb. The inductive ballast is necessary at this point. It regulates the existing moving through the circuit as the fluorescent tube now has a minimal resistance as it is lighted.

The starter used in preheat fixtures can be viewed as an on/off swap. It control buttons the time frame when the circuit opens/closes. Since it is opened up, the voltage causes ionisation of the mercury vapour due to the activity of electrons over the tube. The basic is vital as it establishes whether the lamp fixture flickers or not. This flickering can be attributed to the steady flow of electrons between your two filaments.

Figure :How basic works

Design process

Project plan

A project without any guidance or series is unproductive. Thus, a period management system was placed into place in order to complete this design project. Before something could be put in place, the project description must be known as well as the length of the job. The design quick which entails everything the scholar needed to know about the project is explained in the following;

Students must design and build an electrical system in order to power a small fluorescent lamp. The machine must include an on/off switch utilizing a 110V relay (8-pin relay and foundation, 110V) to power the fluorescent lamp assembly (1X20 regular ballast type 110V fluorescent fixture). Students are required to;

Understand the load: its operation and existing types of fluorescent lamps

Determine the systems necessary for the operation of the light fixture (use of an inductive or an electronic ballast

Develop a mathematical model for the relay based on the theory of operation of the vertical-lift contactor.

Design a start/ stop switch using the relay to force the fluorescent lamp fixture and discuss the importance of this change in terms of protection.

Determine if the magnitude of the inductance is sufficient to light the fluorescent lamp fixture.

Determine the magnitude of the force required to activate the relay and the load current to be provided to the fluorescent lamp fixture.

Measure the prevailing ability factor of the strain and enhance the electricity factor to at least 0. 9 lagging.

Investigate the effect of the fluorescent light fixture assembly on the power system.

Supply an in depth description of the operation of the system using the machine phasors to support your debate.


Students must apply the knowledge gained from ECNG 1015 - Advantages to ELECTRICITY Systems as well as the laboratory exercises which were performed during the semester.

Consideration must also get to laboratory standard protocol, industry standards, codes of

practice, occupational safety protocols and risk evaluation in undertaking this task.

3. 2 Time Management Schedule

The following table illustrates enough time management system used to complete this design project;

Week #

Designated Jobs Completed


Thorough research was done on fluorescent lamps to raised understand the machine.

A Safety and Risk Assessment was finished with respect to the design project.


Specification bedding for purchased after collecting the required information from the ballast, relay, etc.


The start/stop change was designed and used together with the relay to force the fluorescent lamp fixture.

Key parameters were assessed from the circuit.


A mathematical style of the relay system was determined. By using this model, the force required to switch on the relay was identified. Also, the strain current to receive the fluorescent light fixture to light was motivated.


The existing power factor was assessed and it was increased to 0. 9 lagging by using a capacitor.


Proof read article and become accustomed to fluorescent light system in prep for dental exam.

Table 1 showing Time Management System used to complete the design project.

Development of the Numerical model of the Relay

A mathematical model of the system must be done as the system must operate within specified parameters. First of all, a style of the relay was done to determine it guidelines. The following implies how this system was modelled;

Ampere's Circuital Regulation says that the series integral of the magnetic field strength, H, around a shut down way in the magnetic field is equal to surface essential of the existing density, J, over any surface bounded by the closed down route (Defour, 2011).

This implies;

The magnetomotive push is a product of the number of turns in the coil and the current moving through the coil.

=> [Eqn 2]

[Eqn 3]

Since we have been utilizing a ferromagnetic material, the magnetic field level H, may also be stated as;

[Eqn 4]

[Eqn 5]

[Eqn 6]

and F are continuous in the above mentioned equation. Therefore that is directly proportional to F, providing that all variables above remain constant.

[Eqn 7]

The above formula is similar to ohm's law. Hence, the reluctance in this circuit can be cared for as the level of resistance of the machine, the drive as the voltage through the circuit as the current moving through the circuit.

Figure : Magnetic equal circuit

Reluctance can also be stated as;

[Eqn 8]

If current is put on the coil in the circuit above, the magnetic flux would differ. This change in magnetic flux is given by the formula;

[Eqn 9]

The above equation gives the change in magnetic flux for one turn of the coil. Hence, for N becomes, the following equation is used;

[Eqn 10]

[Eqn 11]

[Eqn 12]

When equations 11 and 12 are substituted for and F, the next equation is developed;

[Eqn 13]

The inductance of the coil remains frequent in these formula. Hence, the flux linkage through the coil is immediately proportional to the current streaming through the coil.

[Eqn 14]

When equation 13 is substituted into formula 14, the next equation is made;

[Eqn 15]

However, V can be established as the difference over the coil, R as the amount of resistance of the coil and e as the emf of the coil;

[Eqn 16]


[Eqn 17]

Figure : Electrical equivalent circuit

The above circuit can be used to measure electricity in the circuit. Electric power is the product of current streaming throught the circuit and the voltage across the circuit.

Multiplying equation 16 by the existing streaming through the circuit gives the power as seen in the following;

[Eqn 18]

The following equation states that the vitality supplied from the source to the field;

[Eqn 19]

The law of conservation of energy expresses that energy is actually conserved. The next formula shows this conservation of energy;

[Eqn 20]

Flux linkage across the coil can be thought of as constant. This is flux linkage is assumed as the displacement of the armature occurs speedily. Using Faraday's rules of Induction, the coil does not have an emf induced across it as » is constant.

[Eqn 21]

The above formula implies that there is no energy moving from the supply source to the coil. As a result, equation 20 can be explained the following;

[Eqn 22]

Taking into account regulations of conservation of energy and the above formula, some energy must be lost from the magnetic field to the mechanised system. When a curve is attracted, the area under the curve illustrates the magnetic field energy lost to the system.

[Eqn 23]

[Eqn 24]

As varies, the power lost is supplied by the coupling field. The following equation states the energy lost;

[Eqn 25]

=> [Eqn 26]

When formula 26 is substituted into formula 24, the push can be motivated as follows;

[Eqn 27]

When formula 14 is substituted into equation 27;

[Eqn 28]

Consideration of System Requirements

Determination of the magnitude of inductance necessary to light the


Since an inductive ballast is used in this fluorescent lamp fixture system, it includes a certain amount of inductance and level of resistance. Thus, the ballast can be viewed as as an RL circuit. The following diagram shows the equivalent circuit for the ballast;

Figure : Equivalent circuit for the ballast

The following formula is employed to assess the impedance of the circuit relay;

Determination of the magnitude of inductance when armature is changed on/off

Coil Inductance with Armature Off

The following formula is utilized to calculate the impedance of the circuit relay;

Coil Inductance with Armature On - Deenergize

The following formula is used to estimate the impedance of the circuit relay;

From the specs sheet, the inductance of the coil was given as;

Inductance of Coil with Armature Off at 120V = 15. 04H

Inductance of Coil with Armature On at 120V = 7. 19H

The calculated values for the inductances change significantly. This can be explained by taking into consideration the tolerance levels associated with the ranked current. Also, the effect time of the was just a bit off which resulted in a different current being taken than the actual current value.

Determination of the load current required to trigger the relay

To determine the bare minimum current required to trigger the relay, an analog voltmeter was used in series with the potentiometer. As the resistance of the potentiometer is not set, it was used to find out when the relay would activate. The resistance was varied and just as the relay was triggered, the voltmeter was used and the minimum amount current required to stimulate the relay was established.

The insert current was motivated as

Determination of the force required to switch on the relay

The amount of the air distance was identified to be about 1mm.

The minimal current required to switch on the relay was established as

Using the specification sheet, the inductance of the coil was driven;

Inductance of Coil with Armature Off at 110V = 13. 38H

Inductance of Coil with Armature On at 110V = 5. 69H

The following formula was used to determine the force required to stimulate the relay;

Thus, the make required to stimulate the relay is 1. 03N.

Determination of key circuit parameters




Voltage across relay


99. 5

Min. current to carefully turn on the relay


21. 8

Resistance, R

1. 464k

Coil Inductance (Armature off)


13. 38

Coil Inductance (Armature on)


5. 69

Length of Air Gap


0. 001

Inductance of Ballast


363. 82

Parasitic Amount of resistance of Ballast

339. 8

Table 3 exhibiting key circuit parameters.

Design of start/stop switch


A relay is basically a circuit which is used to control/operate another circuit. The relay can be described as an 8-pin relay and foundation. A coil is situated within the relay and it produces a magnetic field when current moves through it. This field triggers a contact to change from its original location to another resulting in the circuit being opened or shut. The relay together with the basic was used to power the fluorescent light. The next diagrams demonstrate the 8-pin set up of the relay used;

Figure : Design of the 8-pin relay used

The above diagram on the left shows that this type of relay is a dual pole double put (DPDT) type relay. The dual pole state governments that two contacts are closed while the double throw states that we now have two different pathways of conduction within the relay.

In this relay system, there are two switches being manipulated. Whenever a voltage is slipped across associates 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 which produces the magnetic field which manipulates the associates. Contact 1 connects to contact 3 and contact 8 is linked to get hold of 6. Also, as seen on the diagram, associates 4 and 5 remain normally shut until triggered.

The relay is significant in this design task as it manages the current movement. Thus, no large current is subjected to any personnel.



The following diagram illustrates the circuit used to create the start switch;

Figure : Schematic Diagram of Circuit Used

The moving over circuit has three main switches;

Normally open turn (NO)

Normally closed move (NC)

Start switch

The normally open up switch indicates if current moves through the circuit. When this swap is flipped, the connections are connected allowing current to movement. The switch getting used must be forced down in order to complete the circuit to allow current to circulation.

The normally sealed switch will allow current to move through the circuit normally. In contrast to the normally available swap, when the normally closed down switch is pushed, the contacts become disconnected, interrupting the current flow.

The start switch is used to carefully turn on/off the fluorescent light. If the contacts are connected, then current will move. Thus, when the start switch is flipped, the fluorescent lamp fixture will be turned on and therefore light is given off.

In this design job, the normally open and normally closes switches were positioned in series with the energy supply and terminals 2 and 7. Associates 1 and 6 were located in parallel with the normally wide open swap as shown in the aforementioned figure and connections 1 and 6 were positioned across the normally closed turn. When the magnetic field is created in the coil, the contacts in the relay change position and connect to connections 3 and 6. This settings was used as the normally open and normally shut down switch determines if the fluorescent light is flipped on/off.

When the normally available switch is forced, the circuit is shut and the fluorescent lamp lights. If the normally closed change is forced, the circuit is available and the fluorescent lamp fixture is turned off.

Explanation of the System

The voltage rms of the machine was driven to be 117. 5V. The true power of the system was motivated to be 22. 5W. The rms voltage driven is the same as the phasor voltage of the system. Hence, the phasor current can be motivated as follows;

The resource voltage V, is calculated using the next equation;

Since this is a simply inductive load, the angle at which the existing phasor lags the voltage phasor is set as follows;

Hence, the voltage phasor is determined the following;

The current flowing through the lamp fixture is recognized as the real current of the clear current. The next equation can be used to compute this light current;

The reactive current flowing through the lamp may be out of phase with the resource voltage by an position of. This reactive current was calculated using the next equation;

The real current determined above is located on the horizontal axis. Hence, it is seen that the voltage phasor is within phase with this real current. The following diagram illustrates the relationship associated with the evident, reactive and real currents;

Figure : Phasor Diagram for System without capacitor

A capacitor was found in the design to improve the energy factor to at least 0. 9 lagging. This capacitor does not affect the power given off by the motor in the system and therefore, the current is constant. However, as this capacitor was added, the current from the source decreased in comparison with the first current accomplished. The fluorescent light fixture still takes a steady current stream to maintain the specified vitality. Hence, a present-day also moves through the capacitor.

The system was required to be designed with a power factor of at least 0. 9 lagging. Thus;

It should be noted that the current moving through the capacitor reduces the reactive current.

Taking into consideration this corrected electricity factor, the following diagram illustrates the phasor diagram for the uncorrected ability factor, corrected electric power factor and the capacitor current;

Figure; phasor diagram showing currents with the inclusion of a capacitor

As stated recently, with the addition of the capacitor, a new current will flow throught the machine. This current is determined as follows;

As seen from the phasor diagram above, form a shut down loop. Using Kirchhoff's Current Laws, the following equation was used to look for the current streaming through the capacitor;


Hence, the capacitor need to correct the energy factor to at least 0. 9 lagging can be motivated as follows;

The capacitor motivated above is significantly different from the worthiness used. This is explained by due to the fact various power loss occur within the machine. Also, this capacitance was determined using theoretical ideals and not principles obtained in the lab. Hence, there will be a difference.

From the above mentioned figure( phasor diagram for both ability factors), the power factor is reduced following the capacitor is put in place parallel with the strain. It is shown that the phase position is reduced significantly, thus increasing the energy factor to a workable value. The capacitor used corrected the energy factor to 0. 92 lagging which is within the suitable value.

Power lost in something is distributed by the equation Systems which may have a low power factor generally have more energy losses taking place. This is so due to the high currents moving through the system. Hence, as stated under ability factor correction, the power factor must be as close to unity as is feasible to limit the losses.

The longer the light was kept on, the hotter the ballast became. This can be explained by taking into account the power losses for eddy currents and hysteresis. Utilizing a capacitor in parallel with the strain would correct the energy factor thus reducing the energy losses further reducing the heat of the ballast. Once the capacitor was put in parallel, the current flowing through the capacitor was out of period by with the current flowing through the load.

Power Factor

The ability factor of an AC electric power system is defined as the ratio of the real vitality to the clear power. Electricity factor is important in circuits just because a low ability factor will have higher currents to transfer a given quantity of power when compared to a circuit with a higher power factor (Quote website). . Reactive tons like capacitors and inductors may sometimes be there in a circuit. Where present, a period difference between your current and voltage waveforms prevails where energy storage space occurs.

The ability factor is computed using the period sides through either the capacitive fill or inductive weight. On this design project, an inductive weight is used and therefore, the energy factor will be lagging. The cosine of the existing phase viewpoint to the voltage stage angle is utilized to find the power factor.

Reactive loads mentioned previously dissipate zero vitality. However, voltages are dropped across them and they draw current giving the impression that electric power is dissipated from these tons. This imaginable ability is called reactive power and its own unit is Volt-Amps-Reactive (VAR). True electric power is the actual electricity dissipated by these reactive loads and is assessed in watts. Obvious vitality is a combination of reactive ability and true ability. This apparent electricity is found by using the product of the voltage and current of your circuit, with no phase angle. It really is measured in Volt-Amps (VA). Furthermore, the relationship between your three types of capabilities and the phase angle associated with it can be seen in the next figure;

Calculated Solution to Determine Electricity Factor

Certain circuit guidelines were assessed as they were had a need to determine the power factor of the circuit so that it can be corrected to 0. 9 lagging. The analog voltmeter, wattmeter and ammeter were used to measure the following guidelines;

0. 27A

22. 5W

Oscilloscope Method to Determine Vitality Factor

Using the variable resistor, the least possible amount of resistance was located in series with the lamp.

The electric power factor above mixed from the main one calculated previously. This is explained by understanding of the internal level of resistance of the oscilloscope. The oscilloscope generally has a higher internal resistance in comparison with the internal amount of resistance of your wattmeter. Thus, the power factor identified using the oscilloscope will be utilized as it is more appropriate than the prior method.

Power Factor Correction

A electric power factor of just one or "unity power factor" is the purpose of any electric tool company since if the energy factor is significantly less than one, they have to source more current to the user for a given amount of vitality use. By doing this, they incur more line loss (Price). Hence, for the system designed above, the energy factor must be corrected so that you will see fewer energy loss in the system.

A ability factor of 0. 9 lagging is considered acceptable as efficiency does not are present.

Kirchhoff's Current Regulation will be utilized to assist in the correction of the energy factor. Kirchhoff's Current Legislation states that the algebraic total of most currents going into and exiting a node must equal zero (Estimate).

Using Kirchhoff's Current Legislation again;

0. 71

0. 70 0. 435

A capacitive reactive power resulting from the bond of a appropriately sized capacitor can make up for the inductive reactive vitality required by the electrical power insert. This ensures a reduction in the reactive ability attracted from the source and is named Power Factor Modification (Offer). Hence, a capacitor will be used to correct the power factor to at least 0. 9 lagging. The following computations were done;

Thus, a capacitor of is required to correct the energy factor to at least 0. 9 lagging.

Since there wasn't a capacitor available, a 2 capacitor was used to improve the machine.

The pursuing diagram illustrates the circuit used with the capacitor.

After the capacitor was positioned in the circuit as shown above, the existing through the load, the voltage over the load and the true electric power of the light was measured the following;

Considerations USED Planning and Realizing Job Objectives

Laboratory Protocol

All personnel using the lab must wear proper defensive clothing all the time.

All loosely dangling jewellery must be removed before doing any work.

All emergency exits were known as well as evacuation procedures.

A risk diagnosis of the look project must be achieved before joining the lab.

A technical helper was always in the lab to ensure that everyone and everything was maintained in balance.

Industry Standards

Fluorescent Lamp fixture used was a Phillips F20T12/D graded at 20Watt.

The ballast used was a JADCO J1/20PH120-S pre heat ballast. This ballast was made specifically lamp mentioned above and based on the manufacturer's standards sheet, the ballast is to be operated between 110V -120V at 60Hz.

The relay used was a SOKE MK2P-1 double-pole, double-throw normally exposed electromagnetic relay.

All connections made were done to manufacturer specifications.

Exposure to reside in wires was avoided by using insulation.

Shocking currents from electric powered systems and tools were prevented by grounding them.

Electric shock or arc blast was avoided by using PPE and protective tools.

Codes of Practice

All exposed cables were protected with caps.

The connection to the power source was cut when the circuit was being modified.

All workspace was held clear and uncluttered at all times.


Measurements of Key System Variable and Parameters




Voltage across the lamp


117. 5

Current through the lamp


0. 28

Minimum current necessary to switch on the relay


16. 4

Force necessary to switch on the relay


Inductance Required to light the lamp


Power factor

0. 71

Corrected vitality factor

0. 92

Capacitance required for electricity factor correction


2. 19

Capacitor used



Result of electric power factor correction

Initial vitality factor - 0. 71

Acceptable power factor - 0. 9

Capacitor used to improve electricity factor -

New ability factor - 0. 92


Under ideal conditions, the load dissipates no power. The inductive fill or ballast dissipates pointless power by means of heating and magnetic field energy. On top of that, the copper line has a amount of resistance and this amount of resistance can't be considered negligible as thin copper wire was used. Also, the resistance of this cable is inversely proportional to the mix sectional section of the copper wire.

By adding a capacitor in parallel with the power supply, the energy factor is corrected to a value closer to 1. The reactance of the capacitor would preferably cancel out the reactance of the inductor.

The fluorescent light is the load and it generally does not give off ability linearly. Thus, the voltage over the tube is shown as a square influx. This theoretically limits the power factor to around 0. 9 lagging. Thus, this vitality factor is known as acceptable to work with.

Achievement of Project Objectives

Certain objectives needed to be done to be able to complete this design job. They were explained in the design brief stated earlier. They are stated again the following;

Understand the strain: its operation and existing types of fluorescent lamps

Determine the systems necessary for the operation of the lamp fixture (use of an inductive or an electronic ballast

Develop a mathematical model for the relay based on the rule of procedure of the vertical-lift contactor.

Design a start/ stop move utilizing the relay to force the fluorescent light fixture and discuss the importance of this swap in conditions of safe practices.

Determine if the magnitude of the inductance is enough to light the fluorescent light fixture.

Determine the magnitude of the push required to trigger the relay and the strain current to be supplied to the fluorescent light.

Measure the existing electricity factor of the strain and increase the vitality factor to at least 0. 9 lagging.

Investigate the effect of the fluorescent light assembly on the energy system.

Supply a detailed description of the procedure of the system using the machine phasors to support your talk.

The specified parts details the targets in the above list.


An electric powered system used to force a fluorescent light was designed and examined. A mathematical model of the relay to be used was done and used to estimate the magnitude of the drive required to activate the relay. The minimum amount current needed to turn on this relay was also determined. This design task was completed within the allotted timeframe.

The designed system possessed a electricity factor of 0. 71. This was considered undesirable and needed to be advanced to 0. 9 lagging. A capacitor was used to do this.

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