1. Bike Cellphone Charger Chris Battaglia (ME) Ajeetesh Govrineni (EE) Kellen Warriner (IE)

2. Project Summary and Background Create a system that harvests human waste energy and converts it into electricity in order to charge a cell phone To be used in Haiti – Collect energy from riding a bicycle Previous team designed a system (upper right) but proved expensive, unappealing, difficult to manufacture, etc. – Includes generator and cell phone holder Current plan is to optimize old design and achieve better results – Using MIT’s design (lower right) as the standard to meet/exceed

3. Customer Needs Must be able to charge Nokia cell phones (250mA, 3.5V) – Ability to charge Blackberries (750mA, 5V) desirable but not strictly necessary Design should be adaptable and fit a variety of bicycle frames – Easy installation (little to no tool use) – User feedback is important, user wants to see the phone charging Total material costs should be <$15 with <1hr labor – MIT design is $11 but lacks phone housing – Willing to ship materials and more complicated components (breadboard, generator, etc) but main assembly should be done on-sight with minimal supervision – Should not use any machining equipment more complicated/expensive than hand tools Forgiving tolerances – Design should be simple enough to repair and/or cheap enough to replace if broken

4. Customer Specifications Cust. Needs Spec NoSpecification Directi on UnitsMarginalIdealNotes CN1S1 Percent of tested phones that can be charged with the devicemax%80% 90% + charges Blackberr y Nokia common in Haiti CN1, CN2S2Output voltagetargetV4.7-5.34.8-5.2 Standard cell phone requirements CN1S3 Current output at sustainable (specify) biking speed (15-17 mph?) or cadence (60-80 rpm)maxmA>250>750 need to research blackberry needs, seems like 750 mA needed, what is a sustainable biking speed? CN1, CN5S4Maximum current outputtargetmA15001000 came from previous team, not sure why this is max. CN1, CN2S5Uses standard connectorsyesNAnoyes i.e.. Usb CN3S6 Range of bike tires accommodatedmaxcm 40.6 - 71.1 (kids and adult bikes) 60.6 -71.1 (adult bikes only) CN9S7 People required to install the devicemin # of people21 CN9S8 Number of tools required to install the devicemin # of tools2<=1 tools should be standard hand tools or supplied with device CN9S9Time to installmin <10<5 CN8, CN9S10 Increased effort for bicyclist over biking with no device (heart rate or VO2)min%<10%<5% CN12S11 Noise reduction over MIT devicemax% (db) >10% (db)>20% (db) CN4, CN13S12 Cost (parts + machining & assembly labor + shipping estimate)min$<25<15 Assuming parts purchased and imported or made in Haiti at $2/hr, lots of 100 CN4S13Cost of installationmin$<30 Cust. Needs Spec NoSpecification Directi on UnitsMarginalIdealNotes CN4S14 Estimated maintenance/replacemen t part costs per year of lifemin <5<1 CN4, CN7S15 Manufacturing time reduction from previous device% >10%>25% CN4, CN7S16Number of partsmin# same as current design 3 less than current CN4, CN6S17 Number of expensive/specialized machine tools required for manufacturingmin# less than current0 mill, lathe, drill press, specialized machines, etc. CN5S18 Increased temperature to bike partsmin oCoC105 CN10S19Resists impacts/crashesmax IEC6052 9* Level 1-9 >5>7 CN10S20Resists dustmax IEC6052 9* digit 1 Level 0-6 >46 CN10S21Resists watermax IEC6052 9* digit 2 Level 0-8 >4>7 CN11S22Rough road test? not sure how to test… CN13S23Weightminkg <current CN14S24 % of people rating it 4 or above on a scale of 1-5 for aesthetically pleasingmax%>50>70 CN14S25 % of people rating the device as more aesthetically pleasing than the previous versionmax%>60>75 CN15S26 Reduced environmental impact (embodied energy) over previous device (estimated)max%>0%>10% not sure what value to put on this as it is not a main requirement CN15S27 Reduced environmental impact (embodied energy) over MIT device (estimated)max%>0%>10% not sure what value to put on this as it is not a main requirement

5. Test Plan

6. Project Risk Assessment IDRisk ItemEffectCause Likelihood Severity Importance Action to Minimize RiskOwner Describe the risk briefly What is the effect on any or all of the project deliverables if the cause actually happens? What are the possible cause(s) of this risk? L*S What action(s) will you take (and by when) to prevent, reduce the impact of, or transfer the risk of this occurring? Who is responsible for following through on mitigation? 1 Long lead time on partsMake the project latereal world scenario 9981 Order long lead parts at end of first quarter Kellen 2 Running out of budget Unable to complete project mismanagement of team funds 3927 Completion of budget to manage costs Kellen 3 Design Malfunctions Push project schedule potentially making the project late Poor equipment or design 3927 Accurate analysis of working system AJ and Chris 4 Poor Team Dynamics Unable to Complete quality team work Reduce quality of team project 199 Communication and even distribution of tasks team 5 Miss team deadlines Unhappy client/Lower grade in course Poor management of team time 199 Complete team project timeline team 6 Team Scheduling Conflicts Unable to complete team work/discussion Flexibility of group members 339 Create fix schedules to meet every week team

7. Technical Risk Assessment IDID Risk ItemEffectCause Likelihood Severity Importance Action to Minimize RiskOwner 7 Motor Housing Rotates on Bike Frame Generator housing is not held in place allowing the generator to turn to produce current Fixture to hold generator is not robust/stron g enough 3927 Create generator housing with strong clamp with rubber lining to prevent slippage Chris 8 End of Motor shaft does not press firmly against bike wheel Generator is unable to spin at rated speed to produce current Clamp to hold generator housing moves or bike tire is bent 3927 Design a spring to help hold generator shaft against the bike wheel Chris 9 Bread Board/PCB does not output correct voltage/curre nt Phone is unable to charge Circuits of Breadboard/ PCB are not correct 3927 Create simulation of Breadboard/PCB to observe the voltage/current outputs AJ

8. Technical Risk Assessment ID Risk ItemEffectCause Likelihood Severity Importance Action to Minimize Risk Owner 10 Generator Produces too much heat Generator burns up Generator spins too fast, Housing does not dissipate heat, or phone requires too much electric load for specified generator 199 End of generator shaft has correct size wheel to run at rated speed Chris 11 Bike Charger damages phone Burn the phone up or phone won't charge Circuit design does not protect phone 3927 A voltage regulator is used to prevent the phone from receiving too much voltage AJ 12 Bread Board produces to much heat inside housing Bread board malfunctio ns Enclosed Housing does not dissipate heat 9981 Heat Transfer Analysis to determine heat sync required Chris/AJ

9. Generator Housing Design Same general design but with a few modifications – Housing is made of cut stock PVC pipe – End caps are glued along the inner diameter of the PVC and are made of cut Plexiglas Opted for simplicity and low cost over complexity and utility (details in next slide) Not shown: – Weather stripping around generator for cushioning – Small spring acting against generator inside the housing Shaft for generator rod has twice the diameter in clearance Will hopefully be enough to hold generator shaft against any bike wheel. May need adjustments.

10. Generator Housing CAD Drawing

11. Generator Housing Concept Selection The need to machine metal (even just drilling) made choices undesirable Most of the options seemed too flimsy or expensive Ultimately needed to “step back” and return to the simplest solution for this project – Kept the “wiggle shaft” idea and made it internal

12. Frame Attachment Needs to support 4+ times the housing’s weight under rough road conditions (-Prof. Lam) Lack of machining equipment in Haiti prompts a purchased pre-manufactured component Generator can be removed by hand later, but only with added cost (clamps, wing nuts, etc – all more expensive) No sure way to determine which options (See below) would be best. Luckily options are easily interchangeable so we can experiment during testing Will be used both on the frame and the generator housing – No need to machine into the housing – Shouldn’t need an arm to bridge the two, but one can be made from plastic if necessary $2.00 - $2.50$2.50 - $2.75 (Current Design) $0.75 - $1.50$0.10 - $0.50

13. Circuit Board Housing Design Decided to use a breadboard over PCB – Cost Heat generation is the biggest concern mechanically – Analyzed under very conservative conditions (no convection whatsoever) – Nokia (3.75W) setup passes, Blackberry (10W) does not (see right) Current design is to place the breadboard in a separate housing – Made of same materials as generator housing – Thermal testing may show that it can be safely placed in the generator housing Generator shaft and any metal fasteners may dissipate enough heat

14. Heat Transfer Calculations

15. Phone Housing Design Alternative Design to the purchased phone holder More expensive More labor intensive Not necessarily a bad thing Can be manufactured in Haiti Made out of cut sheet stock, glue, and one metal dowel

16. Phone Holder CAD Drawing

17. Material Selection Material CharacteristicsMetalWoodRubberAluminumPlastic Durability0-0+0 Stability0--00 Waterproofing0-+0+ Corrosion Resistances00+++ Longevity0-0++ Availability/Different Sizes0000+ Cost0++-+ Processing Tools0++-+ Sum (+)02436 Sum (-)04120 Sum (0)02332 Sum Net Score0-2316 Rank35241

18. Manufacturing Goal of project was to make device as cheap as possible Use of mass produced product – PVC pipe – Plexiglass – Steel rod and tubes Tools Used: – Handsaws, Cordless drill

19. Manufacturing User Assembled – Cheaper – Create jobs – Slow assembly time Learning curve Incorrect assembly results in device not working Preassembly – Costs more (labor in U.S.) – Lower risk of assembly mistakes

20. Circuit Selection

21. Circuit Simulation

22. Bill of Materials Generator Housing PartPart SupplierPricePrice EachLeadtimeNotes 2 in Stock PVCLowes$6.67$0.10Purchase in 10 foot Sections.25" PlexiglassLowes$25/sheet$0.182'X4' Sections (sheets) 14 gauge wireTractor Supply$19.95$0.02Spool Rubber ConnectorsN/A$.10ea$0.20Estimated, Unsure where to get Loctite Rubber CementLowes$4.67$0.2510.2 oz tube for caulk gun GeneratorOnline$2.50 1 weekShipping costs reduce for large quantities Cost Per Unit:$3.25 Phone Housing PartPart SupplierPricePrice EachLeadtimeNotes.125" PlexiglassLowes$25.50$2.50Purchase in 2'X4' Sections Loctite Rubber CementLowes$4.67$0.5010.2 oz tube for caulk gun.125"X8" metal dowelLowes$6.08$0.75Rod is 6 feet long Cost Per Unit: $3.25

23. Bill of Materials Part ManufacturerDistributer Serial NumberNamePart nameLevelRevision Make/Bu yNamePart #NamePart #Unit CostQuantity Total Cost 15 V Voltage RegulatorIC11ABuy National SemiconductorLM2940Jameco8375051.391 2USB A ConnectorSL3 and SL42ABuyAdam TechUSB-A-S-RAJameco20961810.4920.98 32 Pin Connector MaleSL1 and SL22ABuyTE Connectivity 440055-2 DigikeyA100043-ND0.1620.32 410 µ F CapacitorC1 and C33ABuyJameco ValueProR10/50Jameco298910.0920.18 50.1 µ F CapacitorC23ABuyJameco ValueProR0.1/51Jameco21519700.071 615 Ω ResistorR13ABuyYago FMP200JR-52- 15R Digikey15ZTR-ND0.021 7 2 Pin Connector Female 2ABuyTE Connectivity 440129-2 DigikeyA100011-ND0.120.2 8Connector Pins 3ABuyTE Connectivity 1735801-1 DigikeyA103922CT-ND0.140.4 Total 3.56 Part ManufacturerDistributer Serial NumberNamePart nameLevelRevision Make/Bu yNamePart #NamePart #Unit CostQuantity Total Cost 1Bread Board 1ABuyJameco ValueProPCB-594Jameco20659411.951 222 AWG red wire 2ABuyJameco ValuePro820-2*Jameco12579510.951 323 AWG black wire 2ABuyJameco ValuePro820-0*Jameco12584010.951 424 AWG white wire 2ABuyJameco ValuePro820-9*Jameco12583110.951 Total 44.8

24. Moving Forward

25. MSD II Project Plan Address Issues in Detail Design Review Purchase components with long lead times