Astropower, Inc.

Astrosystems, Inc.

James B McNeely

Allen M Barnett

Paul E Sims

The disclosure describes a high-temperature optical transducer capable of acquiring input variables for closed-loop control of combustion systems. The key components of the innovation are a high-temperature, embedded photodiode, the use of low-cost, integral absorption filters; and the use of an embedded high-temperature preamplifier circuit. These components are combined in an optical-to-electrical signal transducer deployed in the high-temperature combustion environment, thus avoiding the high costs of optical signal transmission. The optical signals to the transducer are employed to recognize events in real-time such as the ignition spark, the start of combustion, end of combustion, misfires, and knocking. The outputs from the transducer may be used in a statistical fashion to control engine roughness and cyclic stability. By resolving specific colors in the flame, the optical sensors may also be used to determine the temperature and the emission production in the combustion chamber.

High-temperature optical combustion chamber sensor

An improved tandem solar cell includes a gallium arsenide phosphide top solar cell and silicon bottom solar cell. The gallium arsenide phosphide solar cell is fabricated on a transparent gallium phosphide substrate and either placed in series with the silicon solar cell for a two terminal device or wired separately for a four terminal device. The top solar cell should have an energy gap between 1.77 and 2.09 eV for optimum energy conversion efficiency. A compositionally graded transition layer between the gallium phosphide substrate and the active semiconductor layers reduces dislocations in the active region. A gallium phosphide cap layer over the gallium arsenide phosphide solar cell reduces surface recombination losses.

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Newark, DE, United States of America

James B McNeely