Introduction:

Exercise “spinning bikes” and bicycle training stands are common ways to maintain fitness and train for cycling. This exercise necessitates the user putting work into the machine by means of pedaling. In many instances the work put into exercise bikes and training stands is not taken advantage of.

The objective of this project is an attempt to make use of some of the energy that a person would usually expend during exercise by building a generator that interfaces with multiple spinning bikes and training stands. It uses a synchronous pulley system to interface with the exercise machine and spin a DC motor. The motor charges a battery which can be used to charge small electronic devices that are compatible with 12V DC power. Adjustable legs and straps secure the generator to different machines.

The design for the generator was developed by measuring the geometry of several training stands and exercise bikes. The drive train was designed to function within the range of a natural human exercise cadence and spin the motor at sufficient rpms to charge the battery. The generator was designed for easy attachment, detachment, and transportation. The generator can produce a voltage between 12 and 13.4 volts in order to charge a battery. It is able to adapt to no less than two spinning bikes and two training stands. The generator is capable of accommodating more than 6 different tire diameters and thicknesses. The setup time for the generator is less than 7 minutes.