Abstract: The present invention provides a method and apparatus for generating refrigeration in a process operating at sub-ambient temperatures in which the refrigeration is generated by a turboexpander. The turboexpander is coupled to a generator controlled so that its speed is maintained at a setpoint through electromagnetic braking and its power output is maintained at line matching voltage and frequency. The speed control of the generator therefore, also controls the speed of the turboexpander. The setpoint is calculated to be equal to a product of an operational efficiency parameter, U/Co, and a square root of twice the enthalpy drop in the flow passing through the turboexpander divided by a product of pi and a diameter of an impeller employed within the turboexpander.

Abstract: The present invention provides a method and apparatus for generating refrigeration in a process operating at sub-ambient temperatures in which the refrigeration is generated by a turboexpander. The turboexpander is coupled to a generator controlled so that its speed is maintained at a setpoint through electromagnetic braking and its power output is maintained at line matching voltage and frequency. The speed control of the generator therefore, also controls the speed of the turboexpander. The setpoint is calculated to be equal to a product of an operational efficiency parameter, U/Co, and a square root of twice the enthalpy drop in the flow passing through the turboexpander divided by a product of pi and a diameter of an impeller employed within the turboexpander.

Abstract: A digital color camera for converting an input optical image to a standard color television signal by using digital signal processing techniques includes: an image sensor for converting optical signals to a series of pixel signals; an analog to digital converting circuit for producing digital pixel signals; a digital signal detecting circuit for separating the digital pixel signals into a digital luminance signal and a digital chrominance difference signal; a digital chrominance signal processing circuit for producing two independent digital chrominance difference signals; a digital luminance signal correction circuit for making a gamma correction on the digital luminance signal; a color television signal encoding circuit for producing an analog standard color television signal from the two independent digital chrominance difference signals and the gamma corrected luminance signal. These circuits are controlled by timing pulses produced by a control timing generating circuit driven by a driving circuit.

Abstract: A digital color TV camera includes an image sensor for receiving optical signals so as to produce two alternately different pixel signals and an analog to digital converter for receiving the two alternately different signals so as to produce a multiplexed digital pixel signal. The camera also includes a digital chrominance signal processor for receiving the multiplexed digital pixel signal so as to produce two independent digital chrominance difference signals and the camera further includes a digital luminance signal processor for receiving the multiplexed digital pixel signal to produce a digital luminance signal.

Abstract: An RF amplifier stage of an AM broadcast tuner is disclosed wherein, depending upon the power level of the received input signal, said input signal is amplified by a high gain radio frequency amplifier, or by a low gain radio frequency amplifier, or by a combination of both the high and low gain radio frequency amplifiers at intermediate levels. This system provides wide dynamic range and low distortion in that it prevents amplifier saturation and reduces intermodulation product signal levels.

Abstract: This invention discloses a versatile gain circuit for use as a combination AM and FM intermediate frequency amplifier. The uniqueness of the circuit is large FM gain and large AM dynamic range.