Imperial Chemical Industries Limited

Terrafix Limited

Andrew Stratton

Ian John Kirby

Michael I Mitchell

Eric Lowe

Martin C Poppe

Three fixed reference stations having known positions comprise Omega receivers. Phase measurements made at all three stations are assembled at a master station, utilizing landlines or radio links and, using the known positions of the stations, a central processing unit calculates not merely the offset of the master station as measured from the true position but also the errors in the azimuths of the propagation directions of the received signals. The position measurement of a vehicle with an Omega receiver is corrected on the basis of the offset and also the errors in the said azimuths. Sufficient accuracy is achieved for finding the position of land based vehicles whose position may be calculated subject to the corrections in the master station on the basis of raw data transmitted to the master station over a link. Alternatively the azimuth corrections may be transmitted to the vehicle over the link. Two fixed stations suffice if they can measure absolute phase.

Position finding system

Separate electrical timing and load activation devices are provided for each of plural electrical loads and each device is connected to receive reference timing signals from a central unit. Each of the separate timing and load activation devices measures a reference time interval accurately defined by the reference timing signals and subsequently activates its associated electrical load after a respectively corresponding predetermined time delay which is determined as a function of the locally measured reference time interval.

Apparatus and method for selectively activating plural electrical loads

Apparatus & method for selectively activating plural electrical loads at

An electrically ignited load such as a fusehead is connected to the secondary winding of a transformer. The secondary winding is magnetically linked to a primary winding through a magnetic circuit and the transformer is constructed so as to provide a substantial leakage inductance associated with the secondary winding and effectively connected in series with the load to be ignited. The structure selectively passes electrical ignition energy to the load only in response to input electrical energy having predetermined magnitude and frequency characteristics.

Growing community of inventors

Farnborough, United Kingdom

Andrew Stratton