Abstract: An auxiliary winding for use in an engine-driven generator system is disclosed. The auxiliary winding is separate from but resides with the main winding in the stator slots of an alternator in the generator system. The auxiliary winding is configured to utilize the fundamental component of the flux in the airgap of the alternator along with selected spatial harmonic components to provide power to an automatic voltage regulator during all operating conditions.

Abstract: An auxiliary winding for use in an engine-driven generator system is disclosed. The auxiliary winding is separate from but resides with the main winding in the stator slots of an alternator in the generator system. The auxiliary winding is configured to utilize the fundamental component of the flux in the airgap of the alternator along with selected spatial harmonic components to provide power to an automatic voltage regulator during all operating conditions.

Abstract: A method of controlling an engine-driven, electrical generator is provided. The generator generates an output voltage at a frequency with the engine running at an operating speed. The method includes the steps of connecting the generator to a load and varying the operating speed of the engine to optimize fuel consumption in response to the load. Thereafter, the frequency of the output voltage is modified to a predetermined level.

Abstract: A method of controlling an engine-driven, electrical generator is provided. The generator generates an output voltage at a frequency with the engine running at an operating speed. The method includes the steps of connecting the generator to a load and varying the operating speed of the engine to optimize fuel consumption in response to the load. Thereafter, the frequency of the output voltage is modified to a predetermined level.

Abstract: A "hot start" method for arc welding includes selecting a first weld current, setting a time interval, striking an arc, flowing a second, higher weld current through the welding rod and then, after a brief time interval, reducing the current through the rod to the value of the first weld current. Also disclosed is a new arc welder stator having two groups of slots around a core. The group of larger slots contains the weld current windings and slots in the group of smaller slots contain windings for timing, gate voltage, battery charging, auxiliary power and the like. A new cooling apparatus for an arc welder has an air duct and a "double-bladed" fan for flowing air along several paths and cooling both the welder control section and the generating section. A new method for electronically controlling engine speed in an engine-driven arc welder is also disclosed.

Abstract: An engine-driven generator having a battery powered starter motor includes a permanent magnet battery charger/pre-exciter for charging the starting battery and for exciting the main alternator field winding of an AC synchronous alternator included in the engine-driven generator. A first winding in the permanent magnet battery charger/pre-exciter provides power to a first voltage regulator that, in turn, maintains a desired load voltage substantially independently of alternator loading. A second winding within the permanent magnet battery charger/pre-exciter supplies power to a second voltage regulator that maintains a desired battery charging voltage substantially independently of the alternator loading. Use of the permanent magnet battery charger/pre-exciter maintains a desired battery charge current and a desired main alternator field excitation substantially independently of the load current supplied by the alternator.

Abstract: An engine-driven generator includes an internal combustion engine, a permanent magnet alternator and an AC to AC converter. The output frequency and voltage of the permanent magnet alternator are largely dependent on engine speed and the alternator load. The AC to AC converter converts the speed-dependent alternating potential developed by the alternator to another alternating potential whose frequency and voltage are largely independent of engine speed. Voltage regulation is provided by varying the engine speed in accordance with the load current. Frequency regulation is provided by frequency dividing the alternator output by an integer divisor that varies in accordance with engine speed. Additional voltage regulation is provided by deleting selected cycles of the alternator output current as needed to maintain the RMS output voltage within predetermined limits.

Abstract: A variable-speed, leading power factor AC machine which may be supplied through a line-commutated inverter.

Abstract: An electromagnetic machine (particularly an electric motor) based on the design described in British Patent Application No. 48794/74.Iron losses in this type of machine are reduced by laminating the rotor backing plate (2,4). Although a spiral lamination (FIG. 3) is preferred, an axial stack of insulated plates (FIG. 2) may be employed.Interpolar flux leakage is reduced by radially staggering the U-shaped pole pieces around the stator coil (FIG. 4). In addition or alternatively differently shaped pole pieces may be employed, alternately, around the stator assembly (FIG. 5).Eddy current losses are reduced by replacing the backing plates (2,4) and separate magnets (1,1a,3,3a) with plates (12,14) of sintered magnetic material, permanently magnetized to present alternate North and South poles, therearound.