Importance

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Abstract

A turbine/air vent reeling machine for use in aerial towed target applications and the like disclosed characterized by use of a novel turbine head/air vent design which extracts ram air energy from the wind stream impinging upon a moving aircraft for the purpose of driving and braking the reeling machine for pay-in and pay-out of a towed target. Control of the turbine rotational speed is achieved through plural variable opening vents located aft of the turbine head which are driven through an open and closed orientation by a servo-motor to throttle the air mass flow through the turbine head. Turbine speed is sensed by a tachometer which is coupled to a shaft driven by the turbine. The tachometer output voltage is introduced into a closed loop control circuit including processing electronics which compares the tachometer voltage to a pre-selected set point voltage corresponding to the desired rotational speed of the turbine. The difference between the desired and actual tachometer voltage and its derivative and integral values with respect to time are mixed and amplified to drive the servo-motor to adjust the vent opening in a direction that will cause the turbine to accelerate or decelerate to a desired operational speed. The servo-motor rotation is converted to vent door movement via an actuation mechanism which ensures the vent doors will remain in a closed position in the event that power is removed from the servo-motor.

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First Claim