A Novel Foot Power Generator

1. A Novel Foot Power Generator EE4013 Presented by: Paul Lennox Martin Robichaud Supervised by: Dr. Sharaf

2. Presentation Layout • Summary • History & Background • Moving Platform • Generator • Charging Circuit & Source • Future Recommendations • Questions

3. Summary • Purpose is to generate electrical energy from a foot step. Courtesy: www.3dcharacter.com

4. History & Background • Our project is based on a foot generator designed by a group of 2nd year mechanical engineering students. • Foot platform had already been assembled. • A DC generator was their method of producing electrical energy.

5. Platform & Generator Courtesy: Floor Generator manual, ME2332, Winter 2004

6. Functional Diagram • Generator • Charger circuit • Source • Utility circuit

7. Moving Platform • Redesign or Reuse • Tested the prototype design with pre-established requirements • We decided to build our own

8. Moving Platform Testing

9. Goals: 15 mm displacement and sturdy Moving Platform Design Red = Frame Welding Design Green = Moving Platform

10. Moving Platform Construction • The frame was welded by Mr. Oscar Robichaud. • The main construction was performed by Paul and I.

11. Generator • Three methods were suggested by our advisor. • Piezoelectric ceramics • DC generators • Variable reluctance coils • Secondary generator

12. DC Generator Design • Decision: DC Generator • Two main concerns: • Gear Ratio • Total Voltage Rating of 9V • Restrictions: • Small Linear Vertical Movement • Upward and Downward Motion

13. DC Generator 1 • Tamiya 72005 6-Speed Gearbox • Specifications: • RPM: 5040-6300 • Rated: 3V • Amperage: 0.64A

14. DC Generator 2 • Tamiya 70097 Twin-Motor Gearbox • Specifications: • RPM: 6990-9100 • Rated: 3V • Amperage: 0.66A

15. Generator Mechanisms • 3 Attempted Mechanisms • Air Pressure • Mechanical Arm • Mechanical Arm + One-Way Bearing

16. Mechanical Arm Design • Objectives: • Increase Linear Motion • Interact with Shaft • Easy to adjust Red = Frame Green = Moving Platform

17. Mechanical Arm • Problems: • Quick change in direction, hard on gears • Change in direction of current, requires H-Bridge • Unusable voltage in the upward motion • Counterweights required due to motor torque

18. One-Way Bearing • Solution: Add a one-way bearing • Benefits: • Eliminate H-Bridge requirement • Decrease Plate Resistance • Easier on Gears

19. Generator System

20. Generator Results • We do not have a digital photo of the output yet. The output current and maximum power will also be noted. Tuesday afternoon. • Currently between 7-8Vpeak per step

21. Generator Results • Peak Voltage = 8.20 Volts

22. Generator Results • Max Current = 1.20A • Max Power = 9.84W • Assumptions for plot: • Constant Velocity • No time delay from plate movement to generator output

23. Charging Circuit & Source • Two methods were suggested by our advisor. • Sealed lead gel batteries • Not Expensive(5$) • Requires Charging Circuit • Super capacitor • Expensive(100$+) • No Charging Circuit Required

24. Sealed Lead Gel Battery • Specifications: • 6V, 4Amp-Hours • Charging Voltage • 6.7-7.3 Volts

25. Charging Circuit Design

26. Charging Circuit Result • 1.10 Voltage drop across the regulator

27. Charging Circuit Modification • Voltage Regulator LM317T will be replaced • An LDO Voltage Regulator, LM1117 will be used in its place • Expected results: • 0.5 Volt drop across the Voltage Regulator, instead of the current 2.0 Volt drop

28. Future Recommendations • Generator: • Piezoelectric Ceramics • Variable reluctance coils • Source: • Super Capacitor

29. Piezoelectric Generator • Benefits: • Implementation • Pressure Dependant • Reliability/Durability

30. Possible Future Applications Wave Generator

31. Conclusion • Our prototype demonstrates that a floor generator can be done • A DC generator can illustrate the concept, but the reliability and durability are questionable • Methods to increase output Power: • Increase Displacement • Increase Applied Force

32. Questions

33. Extra: Current Measurement