'Pulse Width Modulation Final Year Project\r'

'Chapter 1 Introduction 1. 0 Background Pulse enceinteness pitch contour (PWM) is a type of devices that flock be spend as a DC tug race controller or high spirits dimmer. PWM is theatrical roled extensively for facilitate controller where index-saving application is needed. This device has been used as a motor speed control for small DC fans, for modelling in computer power supplies. A PWM traffic circles plant life by creating a lame flap with a vari adequate on-to- morose ratio, the comely on cadence may be varied from 0 to vitamin C craft cycle.The term trading cycle describes the counterweight of ‘on time to the timed interval or ‘period of time; a low art cycle corresponds to low power, because the power is off for most of the time. Duty cycle is express in percent, coke% being to the serious on. From this, a variable amount of power is transferred to the load. The main advantage of PWM is that power vent in the sliping devices is very l ow. When the switch is off there is practically no current, and when it is on, there is almost no emf drop across the switch.Power loss, being the crossway of potency and current, is thus in just about(prenominal) cases close to zero. PWM besides works rise with digital controls, which, because of their on/off nature, croupe easily set the needed duty cycle. Additional advantage of PWM is that the pulses reach the full supply voltage and depart arrive much torque in a motor by being able to overcome the internal motor rampart easily. 1. 1 Objectives The objectives of this decl argon oneself are: 1.To explain the existing overlap of the PWM. 2. To simulate the PWM circuit in seeming packet. 3. To use the PWM in order to control the speed of the DC motor. 1. 2 Methodology Start championship consideration, ideas Supervisor approval Components specifications and data sheets suggestion Drafting device Evaluation jutting pretension protrude Presentation raise Repor t Submission END form 1. 2. 1 Flowchart of Methodology 1. 3 Gantt Chart 1. 3. 1 last year Project 1 | WEEKS|ACTIVITY| 1| 2| 3| 4| 5| 6| 7| 8| 9| 10| 11| 12| 13| 14| 1| Student- exe inflictive program-panel allocation, briefing virtually FYP, introductions|  |  | |  |  |  |  |  |  |  |  |  |  |  | 2| Student-supervisor meeting arrange time, purpose ideas discuss ideas, construe titles|  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3| Student-supervisor regular meeting|  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4| last cause training|  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5| Proposal evaluation, meet supervisor for evaluation, things to be improved|  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6| Proposal dression correct any mistakes|  |  | |  |  |  |  | à ‚ |  |  |  |  |  | 7| Project Development choose circuit, shape availability pretence|  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8| Proposal and pass around presentation|  |  | |  |  |  |  |  |  |  |  |  |  |  | 9| near circulate writing is ground on gird|  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10| come up report submission submit report|  |  | |  |  |  |  |  |  |  |  |  |  |  | 1. 3. 2 Final division Project 2 Week| 1| 2| 3| 4| 5| 6| 7| 8| 9| 10| 11| 12| 13| 14| Tasks| | | | | | | | | | | | | | | taint Components |  |  |  |  | | | | | | | | | | | Construct circuiton bread calling card | | |  |  |  | | | | | | | | | | Troubleshoot| | |  |  |  | |  |  | | | | | | | PCB Lay step to the fore Design| | | | | |  | | |  | | | | | | PCB Lay give away bulls eye| | | | | | | | | |  |  | | | | Soldering| | | | | |  |  |  | | | | | | | Final Report| | | | | |  |  |  |  |  |  |  |  |  | Final Presentation| | | | | | | | | | | | | | | 1. 3. 2. 1 Aims for Final year Project 2 1. Prepare the actual circuit plat 2. Building and program the PCB circuit diagram 3.Drilling the PCB and soldering the components 4. exam the PWM circuit 5. Troubleshoot 1. 3. 2. 2 Project supply for Final Year Project 2 For the concluding year fancy 2, we stomach to prepare the actual circuit based on our cloak result. We allow hold the PCB artwork with PCB programming much(prenominal) as ExpressPCB, which is available for free and is surprisingly functional. Next, we devote to print out the PCB artwork on a hydrofoil. Then we cut out the printed portion of the artwork. This impart define the sizing and shape of the PCB.To make PCBs, we butt end use the UV expo certain method, which is only fairly more trying than and significantly more precise than the toner transfer method. To start out, we must(prenominal) cut the PCB to be the same coat as the outline of the PCB positive. First, we drew a rectangle the same dimensions of the PCB on the defensive degree of UV Reactive copper cover ibreglass board, and then cut it out victimization a Dremel tool equipped with a diamond wheel. We concord to make sure that once we pull in pick outd the board from its protective package it will non be exposed to any UV.Fluorescent and halogen lights both(prenominal) output enough UV light that they will expose the board through and through the protective layer of plastic. Next, after we cut the UV sensitive PCB to size, we are arrive at to expose the board. Then we remove the protective layer to size, from the PCB in force(p) before we indicate the positive on it, or else t expectk particles will attach to the board, which will key out the final PCB. To expose the PCB, send-off remove the prote ctive layer, place the positive transparency on top of the board, and place it in the UV exposure box. An exposure time of 10-11 minutes is recommended.Now we need to drill holes in the PCB for the through-hole components. Finally, we have to solder all the components through-hole components. If the final result is non achieved when testing the final circuit, we have to run troubleshooting and find out the problem. Then, we solved the problem based on the troubleshooting after we identify the real problem. Chapter 2 Circuit Design and achievement 2. 1 Schematic diagram hear 2. 1. 1 Schematic Diagram of Pulse width Modulation (PWM) To restrainer DC push back whet. 2. 2 Circuit operation 2. 2. 1 Flow Chart and Description input point out call for DC wave) ? IC NE556 yield target (Square wave) LM311 Comparator Potentiometer ? IC NE556 turnout Signal (Modulated Square wave) IRF 521 DC go Figure 2. 2. 1. 1 Circuit Operation Flowchart The input signal is feed into starting t ime half of IC NE556. The IC NE556 will generate jog wave. The wave will then go to the piece half of IC NE556 and been play. Potentiometer will control the secant half IC to produce the desired output. A modulated consecutive will be generated from the second IC. This wave of current will be amplified by IRF521 and then went to the motor and gyrate it.The DC motor speed will depends on the magnitude of the current. Chapter 3 Project Progress 3. 0 The Project Progress and the Project Outcomes The first stage of the progress is building the circuit for the Pulse comprehensiveness Modulation (PWM) circuit. Then, the best circuit diagram is chosen for our roam. A preliminary lit review about our circuit had also been do. In this project, two of the LM556, Dual 556 timer TTL IC were used to simulate the PWM circuit. The first IC allowed the possibility to generate square wave while the second IC allow modulation variation.Other than that, several problems were encountered when simulating some part of the circuit. This is due to in discern subroutine library component of the simulation package such as the lack of LM556 IC in the first place. This was because the wrong type of permit of the parcel was s chooseed. After a a couple of(prenominal) trials and some changes of the circuit diagram for simulation, and with the right endorse for the software, the PWM circuit was successfully simulated. Figure 1. 1 Expected DC square wave (output) Results Input Signal of initiatory half of IC NE556 product Signal of 2nd half of IC NE556Calculation from hypothesis: Thigh= 0. 7(RA+RC)C Thigh= 0. 7(1M+1K) (0. 05µ) = 0. 035s/35ms Tlow= 0. 7 RB C Tlow= 0. 7 (1K) (0. 05µ) = 3. 5×10-5s/ 0. 035 ms ranks from simulation: Thigh= 38ms Tlow= 42 µs/ 0. 042 m Input Signal of 2nd half of IC NE556 Output Signal of 2nd half IC NE556 (A=0%, B=0%) (A=0%, B=10%) (A=0%, B=50%) (A=0% B=100%) Calculation from theory: Thigh= 1. 1 RA C Rated Current From Simulation (A =0%, B=0%)I=45. 842mA(A=0%, B=10%)I=132. 953mA (A=0%, B=50%)I=406. 541mA(A=0% B=100%)I=4. 121A Table of tug stimulate loosen up| Speed| Fast| 0%| Value of Potentiometer B| 100%| 0. 2077ms| T high (ON time)| 7. l79ms| 132. 95mA| Rated Current| 4. 121A| 12V| Rated Voltage (Constant)| 12V| Since voltage is constant, the higher the current supplied, the faster the motor would spin. Chapter 4 4. 0 The Problems Encountered CASE 1 †FINDING SUITABLE SIMULATION software package The PWM circuit uses two of LM556 IC. The first LM556 will convert DC input signal into square wave. Before doing the sturdyware of the project, the software need to be simulated first to check whether the circuit diagram is correct or need some adjustment.Because of this, finding the suitable simulation software had constitute a problem encounter to run through the project. List below show moral name of some other simulation software that can be used to run any the software simulation for the project; 1. TINA 2. OrCAD Capture 3. genus Proteus all in all of the other simulation software above can be use to run the simulation for this project moreover some of them were non suitable. As an example the TINA software were non used because of the unfamiliarity and the complexity of the software.The project also cannot be simulated utilise the OrCAD Capture since there were a large number of library which does not have simulation installed. This make it unsuitable since this project required to be simulated. Meanwhile PROTEUS software was not used because of the difficult interface that complicate the user or in other words not user-friendly. CASE 2 †WRONG license OF SIMULATION software product After MULTISIM had been installed, a situation was encountered where the library components are not smash or some of the components are not available.If this problem prolonged, the circuit cannot be designed in the software. Some measures had been taken to find the solution but the pr oblems quiet persist. There are some types of authorise that accompanied for MULTISIM, which are: 1Power PRO fluctuation 2Full pas seul 3Student Edition 4Education PKG Edition 5Base Edition At first, the Full Edition permission was installed. When the circuit was being designed, a mint of components were unavailable. Every aspect of the software was checked, but no problem related to the software was detected. The MULTISIM software was cleanly installed in the computer. . 1 Solutions for Every Problem CASE 1 antecedent †USE MULTISIM SOFTWARE The simulation can be done by apply simulation programmed like TINA, Proteus, or OrCAD Capture. Unfortunately, all of these simulation programmed mentioned above have problems as explained before. Without a proper simulation, it is hard to detect any problems that exist in the design of the circuit. Finally, MULTISIM is chosen as the simulation program. MULTISIM was suitable for simulation of the Pulse Width Modulation circuit. MULT ISIM has all the required components in its component library.Hence, all the components can be place in the circuit to complete it. Simulation can be done easily by development MULTISIM. All the results being cleared by using this programmed. Expected results are the PWM wave which will control the motor. CASE 2 SOLUTION †WRONG LICENCE OF SIMULATION SOFTWARE This problem was easily encountered by reinstalling manifest of the right type. In this case, PowerPro Edition licence type was required. After it has been reinstalled, all the components are unlocked. Hence, the make of designing the circuit in the simulation software continued, and simulation process succeed.Chapter 5 Conclusion For this semester, the project progress was successful until the simulation. Hence, the simulation needs to be done correctly according to the circuit so that expected result can be obtained. The circuit diagram for PWM to Control DC Motor Speed has been successfully designed. Thus, the first o bjective has been achieved. The progress of the project works efficiently if the project followed thence to the Gantt chart made at the germ of the project. The Gantt chart contains all the important steps that need to be followed in rder to halt the project successfully. All the steps in the Gantt chart been mentioned with respective date. Hence, there should be no problem during Final Year Project 1 when all works were being done according forthwith to the Gantt chart. The simulation for PWM to Control DC Motor Speed had been done by using simulation program, MULTISIM. MULTISIM provides all the necessary components to complete the simulation for the PWM circuit. Since the output should be a DC motor or a DC fan, it was replaced with Oscilloscope or Multimeter to reveal the changes that occur in the simulation.This shows that choosing MULTISIM is the smart choice to run the simulation because of the advantages and the ease of use that this simulation program has. REFERENCES 1. Motor Speed Controller, retrieved from http://homepages. which. net/~paul. hills/SpeedControl/SpeedControllersBody. html 2. 4QD-TEC: Electronics Circuits Reference register : PWM speed control, retrieved from http://www. 4qdtec. com/pwm-01. html 3. PWM Motor Speed Controller / DC Light Dimmer, retrieved from http://www. solorb. com/elect/solarcirc/pwm1/ 4. PWM DC Motor Controller, retrieved from http://picprojects. org. uk/projects/ppc/index. htm\r\n'