Methods and apparatus to power an exercise machine

1. An apparatus for use with an exercise machine, the apparatus comprising:

a power receiver to measure a power output by a generator that is to convert movement of a moveable part into electric power, the power receiver to calculate a rotations per minute of the moveable part;

a mode controller 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; and

a power output controller to control power provided to a console of the exercise machine based on the power supply duty cycle.

2. The apparatus of claim 1 , further including the console.

3. The apparatus of claim 1 , further including a power supply to receive power from a commercial power source, wherein the power output controller includes a first rectifier and a second rectifier in a wired-OR configuration, the first rectifier coupled to the power supply and the console, the second rectifier coupled to the generator and the console.

4. The apparatus of claim 3 , wherein the first rectifier is a diode.

5. The apparatus of claim 3 , wherein the first rectifier is a controlled switch.

6. The apparatus of claim 3 , wherein the power supply duty cycle is a pulse width modulated signal, and further including a converter intermediate the second rectifier and the generator, the converter to receive the pulse width modulated signal.

7. The apparatus of claim 6 , wherein the converter is an isolated flyback converter.

8. The apparatus of claim 6 , wherein the converter is a switch.

9. The apparatus of claim 1 , wherein the generator includes an electromagnetic brake controlled by a resistive load.

10. The apparatus of claim 1 , wherein the generator is loaded by a controlled resistive load.

11. An apparatus for use with an exercise machine, the apparatus comprising:

means for measuring a power output by a generator that is to generate electricity based on a user input;

first means for calculating a rotations per minute of a moveable part;

second means for calculating 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; and

means for controlling power provided to a console of the exercise machine based on the power supply duty cycle.

12. The apparatus of claim 11 , further including the console.

13. The apparatus of claim 11 , further including power supply means to receive power from a commercial power source, the means for controlling including a first rectifying means and a second rectifying means arranged in a wired-OR configuration, the first rectifying means coupled to the power supply means and the console, the second rectifying means coupled to the generator and the console.

14. The apparatus of claim 13 , wherein the first rectifying means is a diode.

15. The apparatus of claim 13 , wherein the first rectifying means is a controlled switch.

16. The apparatus of claim 13 , wherein the power supply duty cycle is a pulse width modulated signal, and further including converting means intermediate the second rectifying means and the generator, the converting means to receive the pulse width modulated signal.

17. The apparatus of claim 16 , wherein the converting means is an isolated flyback converter.

18. The apparatus of claim 16 , wherein the converting means is a switch.

19. The apparatus of claim 11 , wherein the generator includes an electromagnetic brake controlled by a resistive load.

20. The apparatus of claim 11 , wherein the generator is loaded by a controlled resistive load.