Ltv Aerospace & Defense Company

Ltv Aerospace Corporation

Homer W Heinzman

Albert J Marek

A planar thermal radiator for use in outer space is disclosed. The radiator is adapted to rotate on two mutually perpendicular x and y axes which are in x and y planes respectively that are perpendicular to each other and to the planar surfaces of the radiator. It utilizes a plurality of pairs of heat sensors wherein each heat sensor provides a value of electrical resistance which is representative of the incident heat energy along the sensitive axis of that heat sensor. A common heat sensor pair detects incident heat energy which is perpendicular to the radiator. A first plurality of heat sensor pairs is used to detect incident heat energy along sensitive axes that are parallel to the x-plane and a second plurality of heat sensor pairs is used to detect incident heat energy along sensitive axes that are parallel to the y-plane. One sensor of each heat sensor pair is mounted on the opposite surface of the radiator. Each heat sensor pair has an associated heat sensor pair in its respective plurality. Each heat sensor pair and its associated heat sensor pair is mounted to detect incident thermal energy which is impinging at equal but opposite angles with respect to the axis that is perpendicular to the radiator. Each pair is electrically connected in series. During operation, the series resistance of each heat sensor pair is measured and the sensitive axis of the common heat sensor pair is oriented in the direction of the sensitive axis of the sensor pair that has the least series resistance value. The radiator is then rotated until the difference between the value of the series resistance of each heat sensor pair and its associated heat sensor pair is nearly zero.

Minimum thermal environment sensor

Optical communication system having repeater amplifiers cascaded with plurality of optical star couplers wherein each star coupler is coupled to an associated set of terminals. Each star coupler has two mixing sections serially disposed between its input and output terminal ports. Star couplers receive optical signals from their associated terminals, mix the received signals and retransmit the mixed signals to each terminal in its associated set and to each of the repeater amplifiers. Star couplers also receive amplified signals from the repeater amplifiers, mix the received amplified signal and retransmit the mixed optical signals only to their associated terminals. Star couplers, thus, enable optical signals transmitted by their associated terminals to be transmitted to each terminal in the system without permitting the same signal to be returned to the same star coupler, thereby avoiding the formation of continuous optical loops and hence avoiding the problem of optical lockup.

Optical communication systems using star couplers

Disclosed is an apparatus for protecting a three-phase power transmission line, having three power conductors, from intermembral electrical faults. First, second, and third sensing and rectifying means are inductively associated with respective ones of the three power conductors of the power transmission line for generating respective DC signals corresponding to the current flow through the respective, associated power conductors. A first switching means is provided for disconnecting the power transmission line from a power source upon the occurrence of a voltage imbalance between the sensing and rectifying means. Another switching means is provided for temporarily interconnecting the outputs of the sensing and rectifying means before operation of the first switching means, for preventing spurious tripping of the first switching means during sharp increases in power which do not occur as a result of a fault. In the preferred embodiment, the response time of the second switching means is shortened in the event of an increase in power involving a fault.

Apparatus for protecting a multiphase power transmission line from

A power controller for transmitting alternating current from a power input circuit to a load, the controller being a master silicon controlled rectifier, hereinafter the 'master rectifier,' and a slave silicon controlled rectifier, hereinafter the 'slave rectifier,' connectible in parallel with the load across the input circuit, a capacitor chargeable during positive half cycles for discharging at the zero voltage crossover between half cycles of positive and negative input voltage to render the master capacitor conductive and a second capacitor chargeable When the master controlled rectifier is conductive whose discharge renders the slave rectifier conductive at the instant of zero voltage crossover between half cycles of negative and positive input voltage. The controller may also include a light sensitive diode connected in series between the control gate of the master rectifier and the first capacitor which is conductive only as long as a light emissive diode is energized and an overload responsive circuit for deenergizing the light emissive diode upon the occurrence of an overload. The controller may also additionally include a shunting transistor for shunting the discharge from the first capacitor from the light sensitive diode during half cycles of negative input voltage to prevent initiation of conduction of the master rectifier at times other than at the instant of zero voltage crossover between half cycles of positive and negative input voltage. Another form of the power controller may include a DC to DC converter for supplying the power for turning on the master rectifier and for supplying substantially a large proportion of the current for turning on the slave rectifier. In this second form of controller a single capacitor is charged during the periods of conduction of the master rectifier and discharged through an amplifying transistor to the gate of the master rectifier.

Growing community of inventors

Arlington, TX, United States of America

Homer W Heinzman