Amitabh Shrivastava’s ‘human-powered generator’ turns old exercise equipment into power sources
In the face of rising energy bills globally, manufacturer Amitabh Shrivastava put an old treadmill to work, turning it into a current-powered generator capable of producing a useful amount of energy, while working on an even more powerful bike version.
“It’s very easy to convert that old, disused treadmill into a human-powered generator that can easily produce 25 watts or more,” Shrivastava says of the project. “A spin-off project could be to convert the treadmill motor into a bicycle-powered generator, which can probably generate 100 watts easily.”
The goal of Shrivastava’s project is to show how old exercise equipment can have a new purpose in life by offering you not only the chance to lose a few pounds or improve your fitness, but also to fuel real-world electronics at zero cost – and how the conversion can, he says, be done “with minimal electronics experience and very basic tools”.
To prove the concept, Shrivastava adapted an old treadmill with a built-in direct current (DC) motor – which, when operated by the user while running on the treadmill, acts as a generator. An inverter and DC-DC converter complete the build, which proved to be enough to drive a TV, provided i.e. you don’t stop running. “I liked the concept even more when I realized that in a system without a battery, if you stopped operating the TV, it would turn off and it would take a minute for it to restart,” explains the manufacturer. “Thus, the device encourages you to maintain a steady pace.”
A more powerful bike-based version offers up to 100W of sustained power. (📷: Amitabh Shrivastava)
The treadmill version is fully functional, but took more effort than expected to drive the TV. The solution: a bicycle version. “Since I was a road cyclist having done a few [of] 100,000 rides, I know very well that cycling is one of the most efficient forms of extracting energy from humans,” says Shrivastava. “So I took the motor out of the treadmill and made a training bike with the same electronics. “
Now Shrivastava is focusing on hardware longevity: the bike generator’s higher power output proved too much for a pair of low-cost DC-DC converters used in the treadmill version, which burned out; proposed solutions include using a more expensive converter, siphoning excess power into a battery, or burning it in an LED strip light or heater.
More details on the project, which aims to publish a DIY guide that anyone can follow, are available. on Shrivastava’s Hackaday.io page.