Abstract: A method of generating a color wheel index signal for use in a display system (10) that uses a spatial light modulator (14) and a color wheel (15). The index signal is compared to a reference signal associated with an input image signal so that the color wheel and the data being displayed can be synchronized (FIG. 2). The index signal is generated by placing a color-sensitive photodetector (14a) in close proximity to the spatial light modulator (14). Light filtered through the color wheel (15) illuminates both the spatial light modulator (14) and the photodetector (14a). The photodetector (14a) responds to color transitions in the filtered light, generating a pulse in response to each transition to the color to which it is sensitive.

Abstract: Apparatus for controlling the air-fuel ratio in an internal combustion engine to substantially maintain the ratio at a predetermined value while the engine is operating under various load conditions. The engine has a carburetor with an air passageway through which air is drawn into the engine. Fuel is supplied to the carburetor through a fuel system and mixed with air passing through the carburetor. The presence of oxygen in the combustion products, which is a function of the air-fuel ratio of the mixture, is sensed and a first electrical signal representative of the oxygen content is supplied. The first electrical signal is compared with a predetermined reference level which is a function of the predetermined value to produce a second electrical signal having first and second signal elements, a first signal element being produced when the air-fuel ratio of the mixture is greater than the predetermined level and a second signal element being produced when the ratio is less than the level.

Abstract: A combustible mixture of air and minute fuel droplets is produced for supply to the cylinders of an internal combustion engine. The engine includes a carburetor having a main air passageway in it, and an intake manifold interposed between the engine and the carburetor. The intake manifold includes at least one wall defining a plurality of fluid passageways operatively connected to the carburetor and to the combustion chambers of the engine. A throttle structure is mounted in the intake manifold. The combustible mixture is formed by introducing liquid fuel into a stream of intake air and uniformly distributing the fuel in the air by passing the air and fuel mixture through a constriction to increase the velocity of the mixture to sonic speed. The constriction occurs at the throttle structure in the manifold. The area of the constriction and the amount of fuel entering the air stream are adjustable for correlation with engine demand.