Abstract: A pole for use in a magnetic circuit includes a flux-passing portion for passing magnetic flux and a cap. The flux-passing portion has a face through which at least some of the magnetic flux passes and to which the cap is fixed. The cap is made of a permeable material and is formed to impede eddy currents in the cap. The cap may have a top and bottom surface joined by a shoulder to provide a distribution of magnetic flux through the shoulder that is less concentrated than the flux distribution through a 90-degree corner. The pole may be incorporated into a generator, a motor, a linear motor, or a portable engine-driven generator to increase the efficiency thereof.

Abstract: A power conversion system includes an engine coupled to drive an alternator, a rectifier circuit, and an ignition controller. The alternator includes a stator and a rotor that cooperate when driven to provide a current supplied to the rectifier circuit. The rectifier circuit provides output power having a voltage. The ignition controller supplies energy to the spark plug of the engine. If the voltage exceeds a predetermined limit, the ignition controller supplies less energy to the spark plug to decrease engine drive. The stator may include several windings (or a tapped winding) and the system further includes an engine throttle controller and a winding control circuit. The winding control circuit selectively couples one or more windings of the plurality (or one or more turns of a tapped winding) to the rectifier circuit. The winding control circuit cooperates with a throttle controller to facilitate provision of a predetermined output power with a relatively low engine RPM for noise abatement.

Abstract: A pole for use in a magnetic circuit includes a shaft for passing magnetic flux and a cap. The shaft has a face through which at least some of the magnetic flux passes and to which the cap is fixed. The cap is made of a permeable material and is formed to impede eddy currents in the cap. The cap may have a top and bottom surface joined by a shoulder to provide a distribution of magnetic flux through the shoulder that is less concentrated than the flux distribution through a 90-degree corner. The pole may be incorporated into a generator, a motor, a linear motor, or a portable engine-driven generator to increase the efficiency thereof.

Abstract: An improved three-phase bridge inverter DC link converter power circuit for a portable generator, preferably the generator system described in U.S. Pat. No. 5,625,276 to Scott et al. Dual voltage and variable frequency inverter designs and improved converter designs are disclosed. Embodiments of the present invention avoid a capacitor induced center voltage drift problem found in certain prior art inverter designs.

Abstract: The throttle of an engine in an engine driven generator system operating under an intermittently heavy load, as in supplying current to a welder, is controlled such that successive control signals sent to a throttle actuator for adjusting the engine throttle position are inhibited until at least a predetermined time has elapsed since the last preceding adjustment to the throttle. This procedure ensures that, as to each incremental adjustment to the throttle, the engine has sufficient time to respond, thereby preventing over-speeding or stalling the engine. The throttle actuator may be a stepper motor which is stepped by throttle position change signals from a processor which monitors engine speed and generator load to determine whether the throttle should be adjusted and, if so, in which direct. Alternatively, the throttle actuator may be a solenoid pulling against a spring in accordance with the average current through the solenoid coil.

Abstract: A lightweight engine-driven generator set including a stator having at least first and second windings (preferably three-phase) and a rotor having a soft magnetic core and a plurality of high energy product permanent magnets, separated by consequence poles, disposed proximate the stator such that relative motion of the rotor and stator causes magnetic flux from the rotor to interact with and induce current in the stator windings. The first winding includes a predetermined number of turns corresponding to a first predetermined voltage output; and the second winding includes a predetermined number of turns corresponding to a second predetermined voltage output, the respective windings being grouped together as a unit and wound about the core such that the respective winding coils are wound in continuous close thermal contact with each other.

Abstract: The throttle of an engine in an engine driven generator system operating subject to a wide and rapidly variable load, as in supplying current to a welder, is operated such that control signals are sent to a throttle actuator for adjusting the engine throttle position in response to load changes. The throttle actuator may be a solenoid pulling against a spring in accordance with the average current through the solenoid coil. In this embodiment, the processor causes pulse width modulated signals to be applied across the solenoid coil with throttle position changes being reflected in changes to the width of the pulses, such changes in the pulse width being delayed for at least the predetermined time since the last preceding adjustment to the throttle.

Abstract: A lightweight engine-driven generator set including a stator having at least first and second windings (preferably three-phase) and a rotor having a soft magnetic core and a plurality of high energy product permanent magnets, separated by consequence poles, disposed proximate the stator such that relative motion of the rotor and stator causes magnetic flux from the rotor to interact with and induce current in the stator windings. The first winding includes a predetermined number of turns corresponding to a first predetermined voltage output; and the second winding includes a predetermined number of turns corresponding to a second predetermined voltage output, the respective windings being grouped together as a unit and wound about the core such that the respective winding coils are wound in continuous close thermal contact with each other.

Abstract: A particularly advantageous power converter, suitable for use in an engine powered generator system. A signal simulating a desired AC waveform is produced by a converter circuit at first and second converter output terminals. The converter circuit, responsive to respective switching signals applied thereto, selectively effects current paths between a juncture node and one of the first and second converter output terminals and between a common rail and the other of the first and second converter output terminals. A controller selectively generates control signals to the converter circuit and to a mechanism for varying the magnitude of the juncture node voltage, to create a predetermined waveform at the converter output terminals simulating the desired AC waveform. A number of alternative embodiments for producing a simulated sine wave are described, as well as accommodations for inductive loads, and mechanisms for minimizing power dissipation during the switching interval.

Abstract: An improved method and system of increasing the effective electrical load capacity of a power converter is disclosed. Potential damage due to current surges from variation in load is avoided by sensing an impending over-current condition, decreasing the system output by a predetermined amount or to a predetermined level, and then gradually increasing the output to bring the system back to desired operating conditions. Such control can be affected by varying the throttle setting to adjust rotor speed, controlling the DC rail level, or a combination of both methods.

Abstract: A particularly advantageous power converter, suitable for use in an engine powered generator system. A signal simulating a desired AC waveform is produced by a converter circuit at first and second converter output terminals. The converter circuit, responsive to respective switching signals applied thereto, selectively effects current paths between a juncture node and one of the first and second converter output terminals and between a common rail and the other of the first and second converter output terminals. A controller selectively generates control signals to the converter circuit and to a mechanism for varying the magnitude of the juncture node voltage, to create a predetermined waveform at the converter output terminals simulating the desired AC waveform. A number of alternative embodiments for producing a simulated sine wave are described, as well as accommodations for inductive loads, and mechanisms for minimizing power dissipation during the switching interval.

Abstract: A mechanically and electrically efficient, lightweight, portable motor-generator includes a stator having a plurality of windings and a rotor with a body of soft-magnetic material carrying a plurality of permanent, high energy product magnets in a surface near the stator such that relative motion of the rotor and stator causes magnetic flux from the permanent magnets to interact with and induce current in the stator windings. The magnets are mounted in insets formed in the rotor surface which includes portions between the insets to form respective consequence poles. The rotor is a hollow cylinder with the magnets mounted on an internal surface, and the stator is concentrically disposed within the cylinder. The stator includes first and second windings.

Abstract: A generator according to the disclosure includes a control system for regulating the output of the generator. The generator, such as a permanent magnet generator, includes multiple windings. For high current applications, the windings are connected in parallel. For high voltage applications, each three-phase set of windings is connected in series. The various windings may be selectively and individually activated by the control system to achieve a desired output current or voltage.

Abstract: An electric machine according to various aspects of the invention includes a transformer having a rotating component for transmitting power from a stationary portion of the machine to a rotating portion of the machine, or vice versa. Both the rotating component and a stationary component of the transformer includes a winding, wherein the windings are disposed to be magnetically coupled. Current provided to the winding of the stationary component generates a magnetic field, which induces current in the winding of the rotating component.

Abstract: A self propelled vehicle which provides a trailer compartment for transporting horses and other animals and living quarters for humans. A cab has a frame which is connected with the trailer frame by a special connection system that enhances the strength and rigidity of the frame. The cab body and trailer body are welded together with flat steel plates. The vehicle provides a low elevation for the trailer floor to facilitate loading and unloading of animals. Front wheel drive propulsion eliminates the need for a drive line to the rear wheels which would interfere with the low to the ground floor.