multiple-output, variable-output dc power supply - phase 2 may 04-08
TRANSCRIPT
Multiple-Output, Variable-Output Multiple-Output, Variable-Output DC Power Supply - Phase 2DC Power Supply - Phase 2
May 04-08 May 04-08
http://seniord.ee.iastate.edu/may0408/
Multiple-Output, Variable-Output DC Power SupplyMultiple-Output, Variable-Output DC Power Supply
ClientClient Senior DesignSenior Design
Dr. LamontDr. Lamont Prof PattersonProf Patterson
AdvisorsAdvisors Dr. PotterDr. Potter Dr. AjjarapuDr. Ajjarapu
Team MembersTeam Members Benjamin Voetberg, EEBenjamin Voetberg, EE Fares Karadsheh, EEFares Karadsheh, EE Trung Nguyen, EETrung Nguyen, EE Darrell Long, EEDarrell Long, EE
Senior Design :: May 04-08Senior Design :: May 04-08
OverviewOverview Project objectives & guidelinesProject objectives & guidelines
Create low cost dc power supplyCreate low cost dc power supply Range of voltagesRange of voltages
Design ApproachDesign Approach ac to dcac to dc
End ResultEnd Result What the team accomplishedWhat the team accomplished
BudgetBudget Price comparisonPrice comparison Layout of costLayout of cost
ScheduleSchedule Project EvaluationProject Evaluation Risk and Risk ManagementRisk and Risk Management
Senior Design Senior Design :::: May 04-08 May 04-08
Project Objectives & GuidelinesProject Objectives & Guidelines
The project is to design a DC power supply that provides The project is to design a DC power supply that provides
power at various voltagespower at various voltages
+/- voltages will include 5V, 6V, 12V, 18V+/- voltages will include 5V, 6V, 12V, 18V
+/common voltages will include 1.5V, 3.0V, 3.2V, 3.3V, +/common voltages will include 1.5V, 3.0V, 3.2V, 3.3V,
4.5V, 5V, 6V, 7.5V, 9V, 12V, 15V, 18V, 24V 4.5V, 5V, 6V, 7.5V, 9V, 12V, 15V, 18V, 24V
Voltmeter and Ammeter to display output valuesVoltmeter and Ammeter to display output values
Between 2 to 4 output terminals.Between 2 to 4 output terminals.
Senior Design Senior Design :::: May 04-08 May 04-08
Project Objectives and Project Objectives and Guidelines Cont.Guidelines Cont.
Operating EnvironmentOperating Environment Indoor use for senior design projectsIndoor use for senior design projects
Intended users/usesIntended users/uses Students enrolled in EE/CprE senior designStudents enrolled in EE/CprE senior design Possibility for use in freshman and sophomore level Possibility for use in freshman and sophomore level
labslabs Used to test senior design projects that require DC Used to test senior design projects that require DC
voltagevoltage Assumptions/LimitationsAssumptions/Limitations
Powered by a 120V, 60Hz wall outletPowered by a 120V, 60Hz wall outlet +/- 1% ripple output voltage+/- 1% ripple output voltage Function with +/- 5% of wall outlet voltageFunction with +/- 5% of wall outlet voltage Output current not to exceed 1A on each terminal Output current not to exceed 1A on each terminal
Senior Design Senior Design :::: May 04-08 May 04-08
Design Approach Definitions Design Approach Definitions
PWM : Pulse Width Modulation PWM : Pulse Width Modulation
Duty Ratio (D) : Time ON divided Duty Ratio (D) : Time ON divided by the total time by the total time
Lm : Magnetizing Inductance of a Lm : Magnetizing Inductance of a transformer transformer
For the simulation, 2 choice:For the simulation, 2 choice:
Pspice: Available and have a lot of Pspice: Available and have a lot of partsparts
Electronic Work Bench : Easy and Electronic Work Bench : Easy and more visual more visual
Senior Design Senior Design :::: May 04-08 May 04-08
Sample from the simulation
Electronic Work Bench was used to simulate the design
Design Approach Buck ConverterDesign Approach Buck Converter
Convert ac to dc using Convert ac to dc using bridge rectifierbridge rectifier
Buck converter is used to Buck converter is used to vary the voltage to get vary the voltage to get desired voltage outputdesired voltage output
Buck converter outputBuck converter outputVo=Vs*DVo=Vs*D
Buck converter diagram
Simple ac/dc conversion
Design Approach Flyback Design Approach Flyback ConverterConverter
Not able to make 1.5-24 Not able to make 1.5-24 volts directly from 120 Vvolts directly from 120 V
Use a flyback converterUse a flyback converter
Flyback converter output Flyback converter output equationequation
Vo=Vs(D/(1-D)) N2/N1Vo=Vs(D/(1-D)) N2/N1
Senior Design Senior Design :::: May 04-08 May 04-08
Design Approach PWMDesign Approach PWM Output equations:Output equations:
Vo=Vs(D/(1-D)) N2/N1 Vo=Vs(D/(1-D)) N2/N1 (Flyback)(Flyback)
Vo=Vs*D ( Buck )Vo=Vs*D ( Buck )
PWM : Generate a PWM : Generate a square wave. square wave. (see figure)(see figure)
Trig.sourceComparator
Senior Design Senior Design :::: May 04-08 May 04-08
The Reason behind using Flyback then a The Reason behind using Flyback then a ____buck converter is to create an buck converter is to create an isolation.isolation.
Design Approach TakenDesign Approach Taken
A commercial power supply to replaceA commercial power supply to replace bridge rectifierbridge rectifier flyback converter.flyback converter.
Power supply eliminates problemsPower supply eliminates problems Current and the voltage regulationCurrent and the voltage regulation Difficulty finding transformerDifficulty finding transformer Saved timeSaved time
Even with changes still functions as the Even with changes still functions as the simulationsimulation
Buck converter still used to vary voltage to get Buck converter still used to vary voltage to get desired outputdesired output
Senior Design Senior Design :::: May 04-08 May 04-08
The new design The new design
Senior Design Senior Design :::: May 04-08 May 04-08
Power Supply
120 VAC
Wall outlet 48VDC
Fixed Buck Converter
High Freq. Switch
TL499ACD
25VDCVariable Outputs
Variable Buck Converter
End Product OptionsEnd Product Options
# of +/- terminals
# of + terminals
Meters
Option #1 1 1AmmeterVoltmeter
Option #2 1 2AmmeterVoltmeter
Option #3 2 2AmmeterVoltmeter
Client wants for power supply
Low cost system
Useful to senior design teams
Portable Power Supply
Senior Design Senior Design :::: May 04-08 May 04-08
Commercial Power SupplyCommercial Power Supply
Astrodyne ® Power SupplyAstrodyne ® Power Supply Regulated OutputRegulated Output 85-265 VAC input85-265 VAC input Overload Voltage protectionOverload Voltage protection Short Circuit ProtectionShort Circuit Protection EMI FilterEMI Filter
Senior Design Senior Design :::: May 04-08 May 04-08
Fixed Buck ConverterFixed Buck Converter Switch componentsSwitch components
Motorola SG3527A Pulse Width Modulator Control CircuitMotorola SG3527A Pulse Width Modulator Control Circuit
Fixed duty ratio, 44 VDC to 25 VDCFixed duty ratio, 44 VDC to 25 VDC
Sends square wave to MOSFET DRIVERSends square wave to MOSFET DRIVER
Maxim MA4428 Dual High-speed 1.5A MOSFET DriverMaxim MA4428 Dual High-speed 1.5A MOSFET Driver Drivers both a N-channel and P-channel MOSFET to achieve Drivers both a N-channel and P-channel MOSFET to achieve
the desired switching speedthe desired switching speed
Texas Instruments TL499A circuitTexas Instruments TL499A circuitWide-Range Power-Supply Controllers
R1, R2, R3 create a R1, R2, R3 create a comparison voltagecomparison voltage
Voltage varied by changing Voltage varied by changing potentiometerpotentiometer
Minimum output voltage is Minimum output voltage is 2.5 volts.2.5 volts.
Maximum output voltage is Maximum output voltage is 24 volts24 volts
Digital DisplayDigital Display
Maxim ICL7107 3 1/2 Maxim ICL7107 3 1/2 Digit A/D Converter Digit A/D Converter
Connected across the Connected across the outputoutput
Displays output Displays output voltage to 1/10 voltage to 1/10 accuracyaccuracy
2 double digit 7 2 double digit 7 segment LED displayssegment LED displays
Future Work RecommendationsFuture Work Recommendations
A phase to finalize the projectA phase to finalize the project Necessary future workNecessary future work
Negative voltagesNegative voltages Voltage regulationVoltage regulation Circuit protectionCircuit protection
Other future workOther future work Variable currentVariable current Voltage zero at start upVoltage zero at start up Auto zeroing voltmeterAuto zeroing voltmeter
Senior Design Senior Design :::: May 04-08 May 04-08
Financial ComparisonFinancial Comparison
Senior Design Senior Design :::: May 04-08 May 04-08
Agilent 3631a triple output power supplyAgilent 3631a triple output power supply 80 watts80 watts ++ 25 V at 1 A 25 V at 1 A +6 V at 6 A+6 V at 6 A $ 1200$ 1200
Proam universal ac-dc adaptorProam universal ac-dc adaptor 9 watts9 watts + 1.5, 3, 4.5, 6, 7.5, 9, 12 V at .5 A+ 1.5, 3, 4.5, 6, 7.5, 9, 12 V at .5 A $ 9.00$ 9.00
Our design nowOur design now 24 watts24 watts 2.5 to 24 V at 1 A2.5 to 24 V at 1 A $ 120$ 120
Personal Time CommitmentPersonal Time Commitment
Senior Design Senior Design :::: May 04-08 May 04-08
Paper work
Research Design Construction Total
Darrel Long 25 41 42 24 134
Fares Karadsheh
20 48 47 14 131
Trung Nguyen
22 41 43 24 132
Benjamin Voetberg
25 51 45 14 137
Total 90 184 195 65 534
Second Semester ScheduleSecond Semester Schedule
Senior Design Senior Design :::: May 04-08 May 04-08
Project EvaluationProject Evaluation Identify possible designs to implement, completed Identify possible designs to implement, completed and choose one and choose one
Design hardwareDesign hardware completed completed
Hardware specificationsHardware specifications completed completed
Circuit simulationsCircuit simulations completed completed
Test hardwareTest hardware almost almost complete complete
DocumentationDocumentation completed completed
Senior Design Senior Design :::: May 04-08 May 04-08
Lessons LearnedLessons Learned What went wellWhat went well
CommunicationCommunication Within the teamWithin the team With company representativesWith company representatives
TeamworkTeamwork What didn’t go wellWhat didn’t go well
Unspecific project, time constraint for meeting with Unspecific project, time constraint for meeting with clientsclients
Simulation of the circuitSimulation of the circuit Hardware implementationHardware implementation
Technical knowledge gainedTechnical knowledge gained Simulation experienced gainedSimulation experienced gained Power electronics knowledgePower electronics knowledge
Senior Design Senior Design :::: May 04-08 May 04-08
Risk and Risk ManagementRisk and Risk Management Anticipated risksAnticipated risks
Team schedulingTeam scheduling Loss of team member, advisor, or clientsLoss of team member, advisor, or clients
Unanticipated risksUnanticipated risks Simulation complicationsSimulation complications Hardware implementationHardware implementation Unable to use certain designs because of costUnable to use certain designs because of cost
Senior Design Senior Design :::: May 04-08 May 04-08
Closing SummaryClosing Summary Variable dc output of 2.5 to 24 voltsVariable dc output of 2.5 to 24 volts
Meets client specificsMeets client specifics Provides extra voltage valuesProvides extra voltage values
Digital voltmeterDigital voltmeter Accurately provides output voltageAccurately provides output voltage
Design is a solid base to further expandDesign is a solid base to further expand Negative voltagesNegative voltages Circuit protectionCircuit protection Voltage regulationVoltage regulation
Senior Design Senior Design :::: May 04-08 May 04-08