Abstract: A system and method is provided for overload and fault current protection of a permanent magnet generator. The system comprises a permanent magnet machine, a DC link, an inverter, coupled between the permanent magnet machine and the DC link, and a controller adapted to provide a linear decrease in voltage for the DC link when the permanent magnet machine is in at least one of an overload and fault current condition.

Abstract: In a power generator, a start of rotor rotation is detected by utilizing a small AC voltage in a stator winding generated by a remaining magnetic flux. A leak current which flows to the power generator from a battery is passed to a negative terminal of the battery through a resistor temporarily connected in series so that a small amplitude of the AC voltage will not be masked by DC drifting component arising from the leak current. Further, periodically connecting the resistor to the negative terminal upon an increase in the leak current reduces an amplitude of the AC voltage.

Abstract: A laser device incorporates a rectangular multi-mode beamsplitter waveguide connected at one end to a retro-reflecting mirror. The beamsplitter waveguide is connected at a second end to an output coupling waveguide and a reflection coupling waveguide. The reflection coupling waveguide is terminated by a second retro-reflecting mirror. Radiation produced within the device is reflected by the mirror and coupled to the two coupling waveguides in a manner such that a partially reflecting mirror is not required at an output to the device.

Abstract: An inductor generator for welding in which: a plurality of generator elements are combined and incorporated in a single generator and respectively provided with excitation windings to render the generator elements self excitable; a constant-current control circuit is inserted between each excitation winding and corresponding field winding in order to stabilize the field current which has been once set. The constant-current control circuits are so mutually connected that compensation operation is possible so that, when the field current of any of the generator elements is varied, fluctuations of the output values of the other generator elements are prevented, these fluctuations otherwise being due to various effects acting mutually between the generator elements, particularly magnetic effect, in spite of the fact that the field currents of the other generator elements are being maintained at their set values. As a result the above described problems of the prior art are overcome.

Abstract: A system for supplying power to a field winding to maintain excitation of an alternating current generator during excessive output current conditions, the generator having a plurality of output lines for supplying power to a load and the field winding being supplied during normal operating conditions by a shunt type voltage regulator responsive to the output voltage of the generator. The system includes a current transformer having a primary winding in series with an output line of the generator, a secondary winding, and a tertiary winding shunted by a capacitance. A rectifier circuit rectifies the voltage supplied by the secondary winding, the output terminals of the rectifier circuit being connected in series with the regulator output terminals to supply power to the field winding. A control circuit, connected to the output of the generator and responsive to output current conditions enables the rectifier circuit output during excessive output conditions.

Abstract: The present invention is directed to a novel frequency regulator which controls a generator output frequency for variations in both the input power to the generator and the power supplied to an uncontrolled external load. The present invention further includes over current and current balance protection devices which are relatively inexpensive to manufacture, which may be encapsulated to provide protection from the operating environment and which respond more quickly than previously known electromechanical devices.