Abstract: A control circuit (microcomputer) is provided in each of two inverter portions. Magnitude of a target waveform signal corresponding to a voltage to be output by each of the inverter portions is varied according to an operation state. The number of revolution of the engine is adjusted according to the larger one of the effective powers output from the two inverter portions. To cope with a temporary output shortage from the AC generator, the output voltage is temporarily lowered and then the output voltage is restored after waiting for the number of revolution of the engine increases.

Abstract: A process for producing highly pure 6,13-dihydroquinacridone, which is a suitable intermediate for effectively producing a quinacridone pigment, for a short period of time at high yields, the process comprising providing a cylindrical reactor, providing an atmosphere free of oxygen in the cylindrical reactor, heating the cylindrical reactor so that the temperature of at least a surface of an inner wall of a cylinder of the cylindrical reactor is in the range of from 250.degree. to 400.degree. C.

Abstract: A self-holding type solenoid valve has an exciting coil 1 and an exciting circuit that switches the direction of flow of exciting current passing through the coil. When a positive exciting current flows through the coil, a movable iron core is attracted to a stationary iron core and held in the attracted position by a self-contained permanent magnet. When a reversed current flows through the coil, a return spring releases the movable iron core away from the stationary iron core.

Abstract: A process for producing a metal phthalocyanine pigment which comprises the steps of: reacting phthalic anhydride or a derivative thereof with urea or a derivative thereof with heating in the presence of a catalyst either in the presence or absence of an organic solvent; adding to the reaction mixture of the preceding step a metal or its compound capable of constituting the core of the metal phthalocyanine either alone or together with urea or a derivative thereof, without isolating the reaction product from the reaction mixture of the preceding step; and allowing the reaction mixture to react while simultaneously applying a mechanical grinding force in the presence or absence of a grinding agent.