Pedal Powered Generator for Mobile Charging Haiying Lu (ECE) │ Jason Xu (ECE) │ Kimo Spector (MEMS) │ Norman Pai (ECE) │ Tiffany Kuo (ECE) Specifications Objective Design a portable and fast charging device harnessing human-generated power Provide a reliable source of energy for charging mobile phones. Market device for sale to vendors (NGOs, entrepreneurs) in developing countries. Vendors can charge using a per-use model Less than $0.05 each time a customer charges a phone Mobile Phone = Life Line Two-thirds of the world’s five billion plus mobile phone users live in developing countries. Over 2 billion of them are in areas without reliable electricity sources. Cell-phones are critical communication tools: Trade – Buy and sell crops, obtain price quotes Healthcare – Connect remotely to health professionals Banking – Conduct transactions like deposits and withdrawals Acknowledgments Project funds provided by Rice Electrical and Computer Engineering (ECE) Department and Oshman Engineering Design Kitchen (OEDK). Thanks to our mentors: Gary Woods (ECE), Richard Gerhold (Consultant), and J.D. Wise (ECE). Results User pedaling outputs (depending on effort): Easy-moderate pace: 30 watts Charge 1 cell phone in less than 15 minutes Strenuous pace: 65 watts (max) Belt slippage occurs when faster G-Ped System User pedals for 30 minutes Turns motor-generator (5.9:1 gear reduction) 1. Pedal System Boost or limit motor output voltage 0-30 V input to 14 V output for battery intake Buck-boost switching regulator (LTC3780) 2. Input Board Microcontroller – TI MSP430 I 2 C Protocol for slave devices Measure battery input current Current-sense amplifier (MAX9611) 3. Control Board (Part I) 12 V Lead-Acid Kept between 40-70% capacity Avoid overcharge and deep discharge Large storage capacity: 15 Ah (17 full charges) 4. Battery System Measure battery output current Current-sense amplifier (MAX9611) Determine state of charge Calculating I/O difference in battery charge 5. Control Board (Part II) High efficiency power division Switching regulator (TPS54040) Three outputs with 5 V, 1 A Multiple cell phone models supported 6. Output Board Up to 3 phones simultaneously charged Energy provided for 3 full charges* 7. Cell Phones Existing Chargers Datexx Super-Battery A portable hand crank phone charging device. NameCharge Time per phone # Phones Supplied Storage Capacity G-Ped10-15 min.315 Ah Datexx Superbattery ~72 min.11.7 Ah BioLogic ReeCharge ~80 min.1N/A Nokia Bike Dynamo ~60 min.1N/A CriteriaValue Size3.0 x 2.16 x 1.16 ft Cost$300 Output Devices3 phones Output Specs3 x (5V, 1A) Battery Storage15 Ah EncasingWeather proof Weight36 lbs incl. battery Pedal Time40 minutes Solution G-Ped is specifically designed for cell phone users in developing countries. Independent system Rigid structure Weather and dust proof User friendly Easy to maintain G-Ped is adaptable to the Universal Charging Solution (UCS) that will be used by virtually all mobiles made after * = Typical 860 mAh cell phone battery Pedal System Energy Conversion Input Board Energy Regulation Control Board Energy Readings Battery System Energy Storage Output Board Energy Division Cell Phones Energy Recipient Side view of system Isometric view of system 27.6% charged 13.6% charged Area = Total Energy Generated in 2 minutes User display LEDs Green Green – Battery charged Yellow Yellow – Charging (sufficient RPM) Red Red – Battery empty