Abstract: An optical device for the spectral analysis of a light source which comprises a spectrograph assembly including a dispersive element, and a classical collimator. The spectrograph assembly supplies a complete intermediate spectrum at the object focus of the classical collimator and the classical collimator reforms, at its image focus, an image of the dispersive element. The spectrograph assembly is preferably a Czerny-Turner or other type of spectrograph comprising an entry slit, two juxtaposed concave mirrors of the same focal length and a dispersive element placed strictly in the common focal plane of the two mirrors. Most preferably, the classical collimator is the first mirror of the second, similar spectrograph assembly. The device is most advantageous in that it is readily useable for both simultaneous and sequential spectroscopy.

Abstract: An inverter arrangement for converting DC to AC having a first inverter with an input for receiving DC and an output for providing a first inverter output, a second inverter having an input for receiving DC and an output for providing a second inverter output, an AC output circuit having a first input for receiving the first inverter output, a second input for receiving the second inverter output, and an AC output for providing AC based upon the first inverter output and the second inverter output, and a controller for controlling the first inverter to minimize DC content in a first inverter output, and for controlling the second inverter output based upon DC content between the first inverter output and the second inverter output to minimize DC content in the second inverter output.

Abstract: A valve member comprising a lower support portion and an upper seal portion. The support portion is made of a relatively rigid plastic and the seal portion is made of a relatively soft plastic. The two plastic portions are integrally merged to form a single piece valve member. The valve member may further include an upper support portion which is formed of a relatively rigid plastic and is integrally merged with the seal portion. The method of making the valve member using a mold in the shape of the valve member, comprises pouring the material forming one of the portions into the mold while in a liquid or molten state, and then pouring the material forming another of the portions into the mold in a liquid state onto the first portion. The two portions merge or diffuse along the interface between them and, when cured, form an integral unit.

Abstract: This disclosure relates to an air cleaner for use in an air-cooled engine including a cooling fan within a fan housing. The cleaner is connected to draw air from the housing, and includes a casing having a side wall, an air inlet opening in the fan housing, an air passage formed within the casing and extending from the inlet along the wall, the passage including a curved portion, and a narrow opening formed in the wall adjacent the curved portion. The curved passage causes dust particles to move by reason of inertia to the radially outer side of the passage and the particles are removed through the narrow opening.