Abstract: An exercise machine is described which is entirely self-contained without any source of outside power. A rechargeable battery is used to maintain the exercise system operative for a time-out period. At all other times the machine is powered by the user. The machine is compact, light, rigid and sized to fit through a standard doorway. The entire exercise machine is provided with a wrap-around handrail into which a display input/output unit has been integrally provided. The exercise machine or stepper utilizes a dynamically controllable load or alternator which is controlled by a computer circuit to maintain the power input into the exercise machine or to maintain metabolically energy consumption rate within a user of the exercise machine at a predetermined, approximately constant level, regardless of the speed of stepping or the actual or effective weight of the user. The alternator is dynamically controlled by pulse width modulating its field coils.

Abstract: An exercise machine is described which is entirely self-contained without any source of outside power. A rechargeable battery is used to maintain the exercise system operative for a time-out period. At all other times the machine is powered by the user. The machine is compact, light, rigid and sized to fit through a standard doorway. The entire exercise machine is provided with a wrap-around handrail into which a display input/output unit has been integrally provided. The exercise machine or stepper utilizes a dynamically controllable load or alternator which is controlled by a computer circuit to maintain the power input into the exercise machine or to maintain metabolically energy consumption rate within a user of the exercise machine at a predetermined, approximately constant level, regardless of the speed of stepping or the actual or effective weight of the user. The alternator is dynamically controlled by pulse width modulating its field coils.

Abstract: An exercise machine is described which is entirely self-contained without any source of outside power. A rechargeable battery is used to maintain the exercise system operative for a time-out period. At all other times the machine is powered by the user. The machine is compact, light, rigid and sized to fit through a standard doorway. The entire exercise machine is provided with a wrap-around handrail into which a display input/output unit has been integrally provided. The exercise machine or stepper utilizes a dynamically controllable load or alternator which is controlled by a computer circuit to maintain the power input into the exercise machine or to maintain metabolically energy consumption rate within a user of the exercise machine at a predetermined, approximately constant level, regardless of the speed of stepping or the actual or effective weight of the user. The alternator is dynamically controlled by pulse width modulating its field coils.

Abstract: A motor-driven exercise apparatus is disclosed, which incorporates a plurality of runaway-preventing features, thus reducing the chance of injury to the user. A motor control circuit is effectively controlled by pulse width modulated commands from a CPU, and by frequency-variable feedback information. These data are converted to voltages and input to a differential amplifier. A relay switch is used to cause immediate power turn off at both speed and elevation motors if any of the following occurs: (a) loss of feedback signal from the speed feedback at the CPU, (b) too rapid speed change sensed by the CPU, (c) failure of the motor control circuit to receive a signal from the CPU within a certain period, or (d) an elevation motor runaway sensed by the CPU.

Abstract: The disclosure provides an electronic motor control circuit which switches and amplifies to control a bi-directional electric motor, using a symmetrical circuit, each half of which consists of five transistors. The circuit has a logic level input and motor driving power output using, for control in each direction: an input transistor; a control transistor turned on and off by the input transistor; two matched, complementary motor drive transistors (at opposite terminals of the motor) turned on and off simultaneously by the control transistor; and a lockout transistor, also actuated by the control transistor, which is operatively connected to one of the motor drive transistors in the other half of the system to prevent short circuiting.