A power generating element is provided. The power generating element includes a piezoelectric body and a pair of electrodes. The piezoelectric body is expandable and contractible in response to a movement of a moving body. The piezoelectric body undergoes a deformation when expanding or contracting and generates power when undergoing the deformation. The pair of electrodes extracts the power generated as the piezoelectric body undergoes the deformation.

A motor-less leg-powered curved treadmill produced that allows people to walk, jog, run, and sprint without making any adjustments to the treadmill other than shifting the user's center of gravity forward and backwards. A closed loop treadmill belt running between front and rear pulley rollers is formed with a low friction running surface of transverse aluminum, wooden, plastic, rubber or carbon fiber slats attached to each other in a resilient fashion. An essential feature of treadmill is the concave shape of the upper portion of the belt running surface, the treadmill configurations ensure that this shape is maintained during actual use. These configurations prevent the concave upper running surface portion from being pulled taut into a flat shape between the front and rear pulley rollers. The slats of the treadmill each have an end view crossectional I-beam shape, for strength and stability of the slat positioned upon the treadmill belt.

A motor-less leg-powered curved treadmill produced that allows people to walk, jog, run, and sprint without making any adjustments to the treadmill other than shifting the user's center of gravity forward and backwards. A closed loop treadmill belt running between front and rear pulley rollers is formed with a low friction running surface of transverse aluminum, wooden, plastic, rubber or carbon fiber slats attached to each other in a resilient fashion. An essential feature of treadmill is the concave shape of the upper portion of the belt running surface, the treadmill configurations ensure that this shape is maintained during actual use. These configurations prevent the concave upper running surface portion from being pulled taut into a flat shape between the front and rear pulley rollers. The slats of the treadmill each have an end view crossectional I-beam shape, for strength and stability of the slat positioned upon the treadmill belt.

A mechanism has four connected links to mimic the motion of a knee joint. A lower link is oriented towards the vertical. A leverage ratio between flexion of the knee and relative angular displacement of certain links in the mechanism remains fairly steady over much of the range of motion of the mechanism. The mechanism may be used to drive an energy harvesting gearbox with steadier and more efficient energy harvesting at deep flexion, as well as with quieter operation.

Methods and apparatus to power an exercise machine are disclosed herein. An example method includes measuring a power supply current produced by a user of the exercise machine. A rotations per minute of the exercise machine is measured. A power supply reference current is determined, the power supply reference current based on a user selected wattage and the rotations per minute. A differential power supply current is calculated based on the power supply reference current and a measured current of a power supply of the exercise machine. A power supply duty cycle is calculated based on a previous power supply duty cycle, a time constant, the differential power supply current, and a previous differential power supply current, the power supply duty cycle to control power supplied to a console of the exercise machine. The power supply duty cycle is output to a power output controller.

The present invention relates to a self-power generating apparatus that can generate power by converting an external force that alternately acts in a forward and reverse direction into a unidirectional force, and can generate power by winding a wire around a pulley axially coupled to a drive shaft and applying, by a user, an external force to the wire with his/her hands to rotate the pulley in a forward and reverse direction, thereby enhancing power generation efficiency. To this end, the self-power generating apparatus comprises: a drive shaft alternately rotated by an external force in a forward and reverse direction; a forward power transmission part that transmits only the forward rotating force of the drive shaft to a power generating shaft; a reverse power transmission part that transmits only the reverse rotating force of the drive shaft to the power generating shaft; and a power generator that generates power using a unidirectional rotating force of the power generating shaft.

Disclosed herein is a self-generation shoe using magnetic induction. The self-generation shoe includes a self-generation unit which is configured to generate electromotive force using magnetic induction, a rectifier circuit which converts electromotive force generated from the self-generation unit into constant voltage, and a charging circuit which charges the constant voltage output from the rectifier circuit. The self-generation unit includes a coil bobbin and a permanent magnet. The coil bobbin has a hollow pipe structure and protrudes downward from an upper surface of the chamber. A coil is wound around the outer surface of the coil bobbin. The permanent magnet protrudes upward from the lower surface of the chamber and is inserted into or removed from the coil bobbin depending on contraction or expansion of the chamber.

Disclosed herein is a self-generation shoe using magnetic induction. The self-generation shoe includes a self-generation unit which is configured to generate electromotive force using magnetic induction, a rectifier circuit which converts electromotive force generated from the self-generation unit into constant voltage, and a charging circuit which charges the constant voltage output from the rectifier circuit. The self-generation unit includes a coil bobbin and a permanent magnet. The coil bobbin has a hollow pipe structure and protrudes downward from an upper surface of the chamber. A coil is wound around the outer surface of the coil bobbin. The permanent magnet protrudes upward from the lower surface of the chamber and is inserted into or removed from the coil bobbin depending on contraction or expansion of the chamber.

The present invention is able to extract significant amounts of energy from a user who is walking or running while remaining discreetly hidden near an area of the body where many people already carry things (e.g. wallet, smartphone, keys). The user benefits by keeping their device(s) charged for a longer period of time without the need for external batteries. In addition, the present invention encourages an active lifestyle, which has been shown to promote good health and reduce the risk of many diseases.