Methods and apparatus to power an exercise machine are disclosed herein. An example exercise machine includes a generator to convert movement of a moveable part of the exercise machine into electric power. The example exercise machine includes a generator power receiver to measure the power output by the generator, and to calculate a rotations per minute of the moveable part. A mode controller is to calculate a power supply duty cycle based on the power output by the generator, the rotations per minute of the moveable part, and a user selected wattage. A power output controller is to control power provided to a console of the exercise machine based on the power supply duty cycle.

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.

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.