I'm planning on building a Human-Electric Hybrid Bicycle. What is the difference between my project and an electrically assisted bike?
Well, on a normal e-assist setup the motor is in parallel with the standard drivetrain. In other words, the connection from the pedals to the wheel is the same as a regular bike with the motor hooked up somehow to provide help.
In my idea, the driver will pedal a generator, the output from the generator will be connected to a set of batteries and then through a motor controller to the main drive motor. My current plans are for a three wheeled recumbent trike (Tadpole arrangement).
There are several advantages to this idea:
You can pedal while stopped and "bank" energy to be used while moving.
Pedal at a steady output level regardless of speed.
Capable of much higher speeds than unassisted (at least for a little while)
In stop and go traffic (such as a downtown area) this vehicle could travel at 30mph between stoplights. Since you would be able to keep up with traffic this should be safer than riding a standard bicycle. The range in this mode is set by the driver (how long can you pedal?)
When driving non-stop, using just pedal power and a full charge in the main batteries, this vehicle should be capable of 30-40mph for 1 hour (1.5 hours with a solar array, 40 minutes on batteries alone).
Rather than spend a lot of money buying components and hoping they will do what I want, I decided to run a series of experiments. There are two main objectives to these experiments.
The first is educational. I hope to learn more about how electric motors work (and don't work) than what I've been able to pick up from books.
The second objective is to establish the minimum specifications required to succesfully implement my ideas.
Working towards these goal I have divided the project up into 4 phases:
- I learn about using PMDC motors as generators. I also get an idea of total system efficiency.
Phase II - I mount the drive motor on my racing bike. From this I learn if the motor is powerful enough and measure current draw in a real work application.
Phase III - I will build a prototype. Well, just the frame actually. Goal is to determine the proper dimensions for optimum handling. I also hope to determine if the whole concept is workable or not.
Phase IV - I take lessons learned from earlier phases, make any needed adjustments and built the fully-faired vehicle. I will also determine if the extra power from a solar array will offset the additional drag on the vehicle.
I have a seperate page describing the Pros and Cons of my concept.
Soon I will add a page with drawings of the vehicle as well as a more detailed description.