The Treadmill-a-volt is a device that converts human kinetic energy into electric potential energy. The energy exerted to turn a belt on the treadmill is transferred via a generator into a simple circuit that charges a small battery. The battery can then be used to charge small electrical devices. This "give a volt-take a volt" system demonstrates that human power converted to energy and then back into power is not cheap, it takes work, whether it's from burning coal or from running on the treadmill. So please check out our design and try making one yourself. You may never need to go to the gym again.
Video[edit | edit source]
Check out how this things works...
Background[edit | edit source]
Our goal is to harness human kinetic energy through common gym equipment and convert it into useful applications. Our human powered electric generator is used to charge a battery which can then be used to charge small electronic devices such as cell phones, iPods, cameras, or laptops.
The project is an assignment for ENGR 305 (Appropriate Technology) at Cal Poly Humboldt, Arcata, CA. We will be in collaboration with our client, The Humboldt Bay Center for Sustainable Living who operates the new Humboldt Bay Eco-Hostel located in Manila, CA.
The device will be operational by the end of the semester so that it can be a useful and educational part of the Eco-Hostel. We hope to emphasize that energy is not cheap and that it takes work to make electricity used to power even the smallest electronic devices in our lives.
Literature Review[edit | edit source]
This is a review of the literature acquired in the beginning stages of our research on Human powered devices and a means to build them.
Human Power Basics[edit | edit source]
With the utilization of mechanical/electrical devices, human energy can be transferred from the body into almost any small or moderate sized household device. With human power, small kitchen appliances such as blenders, food processors, and juicers are simple and effective for construction, but are not limited to just those ideas. Lawnmowers, sewing machines, and even electricity generation are all possible destinations of the energy that is generated by humans..
Construction Concerns[edit | edit source]
A limited knowledge of electricity and mechanical construction is our main obstacle. We plan to build on others' past accomplishments, learning from their experiences and adding our own to the base of knowledge. Research into basic wiring and electricity will be vital for a successful project.Other construction concerns involve the design. We want to harness the maximum potential a person can produce. By evaluating arm and hand vs. leg and foot devices we can narrow our design possibilities. Another concern will be in the cost and time to complete the project.
Types of Devices[edit | edit source]
Most devices are foot pedaled rotary mechanisms, either attached directly to a mechanical device or connected to an electrical generator, which will then operate an electrical motor, or charge a battery bank.
Mechanical Devices[edit | edit source]
The energy harnessed can be maintained as mechanical energy. This type of device uses belts, chains, or shafts to carry the energy and pulleys or gears can change speed, magnitude, and direction of a force. Mechanical force can be applied using a hand crack with such devices as; pencil sharpener, juicer, drill, or ice cream maker. Pedal power has been applied to such devices as blenders, pumps, saws, sewing machines, even a dentist's drill.
Electrical Devices[edit | edit source]
The device could also incorporate a generator and create electricity. The generated electricity can be used immediately to power electrical appliances such as TVsor radios. The energy can also be stored in batteries to power devices at another time. Bart Orlando built the Human Energy Converter or HEC which connected 14 pedal powered bikes to a battery and generated just over a kilo-Watt to power sound stages at festivals.The power stored can be used to charge small portable electronic devices such as MP3 players, cameras, cell phones, and laptops.In a much larger project, human power could be used to generate enough electricity to power an entire facility, like the one in Hong Kong, This is a spectacular design with an outstanding budget, one that we can learn from, but not duplicate.
Designing interpretive materials[edit | edit source]
According to our client Sean Armstrong, Director of the the Humboldt Bay Center for Sustainable Living, interpretive materials for the human powered gym should include a way of measuring the amount of energy created and stored in our electrical generating device. The energy created should be compared to energy usage for other common devices such as a computer, light bulb, or hair dryer.
Costs[edit | edit source]
Humboldt Bay Treadmill-a-Volt[edit | edit source]
The device converts kinetic energy into electrical to charge a battery good for charging small electronic devices. The generator was graciously donated by Lonny Grafman. In addition a special thanks to Eco-Groovy Abundance for providing a great deal on the treadmill.
|Quantity||Material||Source||Cost ($)||Total ($)|
|1||Nordic Trak Walk-Fit 5000 Treadmill||Eco-Groovy Abundance||30.00||30.00|
|1||Gel Cell Battery||Interstate Battery||28.95||28.95|
|1||Mounting brackets||Ace Hardware Store||10.00||10.00|
|1||Generator pulley wheel||McMaster.car (online)||9.00||9.00|
|1||Pulley Wheel Belt (old bicycle tube)||trash||0.00||0.00|
|1||Power Meter||Harbor Freight||4.00||4.00|
|1||Wiring Components||Ace Hardware||30.00||30.00|
|1||Shipping and Handling||Carrier||5.00||5.00|
Criteria[edit | edit source]
To help us with the difficult task of making important decisions with our project we developed a list of criteria that we and our client feel are important. Each criteria has constraints and a given weight of importance (1 being the least important and 10 being the most). The following is for both devices.
|Size||The device should fit within a 4' x 6' area||3|
|Functionality||Device should be be useful to hostel guests, accommodating all ages||10|
|Educational||Hostel guests should experience some educational value||6|
|Maintainability||Device should not require technical maintenance||6|
|Aesthetic||Device should look fun and inviting||7|
|Noise||Operation should not be intolerable to Hostel guests||3|
|Structural Integrity||2-3 years of operation should be expected||8|
|Time to construct||Devices should be fully constructed and operating with 1 semester and possibly some extra time||9|
|Number of devices||Devices built should meet all criteria||1|
|Versatility||Should be able to provide power to multiple smaller devices||5|
|Cost||The device should not exceed $150 (cost/benefit exceeds)||7|
Proposed time line[edit | edit source]
|1||Decide on project|
|2||Research, Start Appropedia page, and meet with Sean Armstrong|
|3||Search for equipment|
|4||Search for equipment|
|5||Add Criteria List to Appropedia|
|6||Add Proposed Time Line to Appropedia and meet with Sean Armstrong|
|7||Test motor output, determine belt speed and gear ratio, and test batteries|
|8||Search for Proper Size Pulley Wheel, and possibly look for battery|
|9||Build motor mount assembly, search for inverter, charge regulator|
|10||Assemble electrical components|
Parts of the Treadmill-a-volt[edit | edit source]
Check out some of the basic parts used in constructing this device.
Conclusion[edit | edit source]
The idea, design, construction, and testing of the treadmill-a-volt was a great learning experience that had its challenges and rewards. Some of the challenges we had were finding an appropriate piece of gym equipment that would meet our objectives. We kept an open mind as we searched the county and beyond for affordable equipment. Flexibility from any preconceived ideas is an important aspect to the designing phase.What works on paper doesn't necessarily translate well in reality. Our original idea to attach a gear, "the power sled", to the transmission actually provided to many RPMs to the generator. Its efficiency would have converted our exercise machine into a relaxation machine as the generator only required a very slow walking pace on the belt. This is not to say that pre-design on paper is not important. Its application with sketches, diagrams, models, and prototypes bring out problems and ideas that you may not have thought about. These extra steps can save time and money on parts and labor. We wanted to offset the use of new products such as the battery, inverter, and multimeter by using as much recyclable parts as possible. This led us to the tire tube drive belt. Many different things were used before we were satisfied with the rubber. The simplification of the electronics was also important to us. We wanted to create an effective circuit without spending a lot on parts. All in all this was a successful project. We hope that The Eco-Hostel in Manila appreciates it as much as we do, and that it educates and inspires all who use it.
Next Step[edit | edit source]
We have a whole host of ideas that others can take and run with.
- Include an educational panel can be constructed to illustrate how it works and highlight some of the basic concepts included in the design.
- Mount the electrical components onto a dedicated circuit board. Basic soldering and some time could enhance the aesthetics of the circuit box.
- Add a toggle switch to engage and disengage the battery from the system. At the moment a manual disconnection of the fuse, eliminates the battery from the system which directs power directly to the inverter.
- Construct or purchase a more robust drive belt.
- Mount an iPod and beverage holder to console.
- Extra ambitious people may want to look into the idea of using the power sled and working in a de-railer system to shift gears and drive the belt at different speeds.
References[edit | edit source]
- Dean, Tamara.2008. The Human Powered Home, choosing muscle over motors. Gabriola Canada. New Society Publishers.
- Shelden, J, Linda. 1977. Basic Home Wiring, illustrated. Menlo Park California. Sunset Books and Magazines.
- Jones, Calvin. 2005. Big Blue Book of bicycle repair. Saint Paul MN. Park Tool Company.
- Dean, Tamara. The Human-Powered Home; Choosing Muscles Over Motors. New Society Publishers, 2008.
- Walton, Harry. How and Why of Mechanical Movements. New York, NY: Popular Science Pub. Co., 1968.
- Public Health Bike Blender
- Dean, Tamara. The Human-Powered Home; Choosing Muscles Over Motors. New Society Publishers, 2008.
- Samoa Hostel Pain in the Axle
- WaterPod Bicycle Energy Generator
- WaterPod Tour de Volts
- Dean, Tamara. The Human-Powered Home; Choosing Muscles Over Motors. New Society Publishers, 2008
- Thad Starner, Joseph A. Paradiso. Human Generated Power for Mobile Electronics. Atlanta: Georgia Tech, 2 13, 2011.
- Levesque, Tylene. 2007. Human Powered Gyms in Hong Kong. http://inhabitat.com/human-powered-gyms-in-hong-kong/.