Abstract: A microprocessor-controlled airfield series lighting circuit communications system and method allows bi-directional communication between the controlling microprocessor and the airfield lamps. The bi-directional communications signals are formed by using a modulated radio-frequency signal that is transmitted through a circuit containing many transformers having their primary windings connected in series. Respective secondary windings of the transformers are connected to various devices, such as lamps or sensors. A high frequency signal is imposed on the series-connected primary windings to control the lamps. The frequency of this signal is selected to be able to be detected on the secondary side of the transformer. A remote controller is connected to the secondary of each transformer to receive the control signal and selectively switch power obtained from the transformer secondary to the respective connected device.

Abstract: The present invention includes a method for separating AC and DC components of a composite waveform, and an inductive device capable of performing the method. The present invention also includes a ground fault condition monitoring system containing an inductive device of the present invention, and an electrical distribution system containing such a ground fault condition monitoring system, such as one for a lighting system.

Abstract: A method for changing the inductance of a multiple-tap transformer in a circuit having a current regulator and the transformer, including the steps of comparing the current regulator's duty-cycle to a duty-cycle setpoint, increasing the turns ratio of the transformer when the duty-cycle is less than the setpoint. An apparatus for switching the taps of a multiple-tap transformer connected to a power supply and a load circuit, including a load regulator for generating a desired duty-cycle signal, and an inductance controller having a first reference signal generator, a comparator for comparing the reference signal to the desired duty-cycle, and relays connected to the transformer taps that are responsive to the comparator.

Abstract: The present invention includes a method for separating AC and DC components of a composite waveform, and an inductive device capable of performing the method. The present invention also includes a ground fault condition monitoring system containing an inductive device of the present invention, and an electrical distribution system containing such a ground fault condition monitoring system, such as one for a lighting system.

Abstract: The present invention includes an airfield lighting and control system for energizing at least one airfield control device and containing a ground fault detection system, comprising: (1) at least one airfield control device; (2) an AC electrical circuit conducting an AC signal and connected to said at least one airfield control device; (3) an inductive device, in electrical contact with said AC electrical circuit, which comprises (a) an inductive coil having an input pole and an output pole, and being loaded by a capacitor; (b) a driver winding for the inductive coil, the driver winding adapted to sense AC current flow through the inductor coil; (c) a sampling resistor connected to the driver winding and adapted to detect AC current in the form of a voltage across the sampling resistor; (d) signal processing circuitry comprising: (1) an inverting amplifier adapted to amplify the voltage; and (2) a phase shifter adapted to shift the phase of the voltage; and (e) a power amplifier connected to the signal proces

Abstract: A microprocessor-controlled airfield lighting control and monitoring system having bi-directional communication between the controlling microprocessor and the airfield lights and/or sensors. The system also includes a metal container for the remote control microprocessor and an improved attachment arrangement for the power transistor associated therewith. A DC power supply is connected to the remote controller microprocessor and has an integrated circuit adapted to sense a threshold voltage, which causes the power transistor to short around the associated power source.

Abstract: A light base and transformer housing to house an isolation transformer and to be used as a mounting base for airport mavigational lights comprising a unitary housing made from a noncorrosive material provided with external vertically extending fluted indentations so that said housing will have greater compressive strength and will resist movement in the ground when installed therein and after concrete or bitumen has been poured around said housing.

Abstract: A modular high-intensity elevated runway edge or threshold light having a glass outer dome containing two oppositely disposed prisms therein, sealed to said cover and fixedly positioned with respect to two complementary inner prisms surrounding a light source. The entire assemblage may be easily removed by loosening two wing nuts for bulb replacement and, if necessary, the inner prisms may be readily replaced by removing three screws and when reinserted will be in exact alignment with the outer prisms.

Abstract: An adustable light base and transformer housing to house an isolation transformer and to be used as a mounting base for in pavement airport navigational lights comprising an adjustable upper portion adapted to receive said light fixture and maintain and position it at the proper elevation with respect to the surface of the airport runway.