Heading system

Claim 1

A SONAR SYSTEM COMPRISING IN COMBINATION: A VESSEL; A BODY FOR TOWING BEHIND SAID VESSEL; A DIRECTIONAL TRANSDUCER MOUNTED WITHIN SAID BODY; A SYNCHRO CONTROL TRANSMITTER WITHIN SAID BODY AND CONNECTED WITH SAID TRANSDUCER FOR GENERATING AN ELECTRICAL FUNCTION PROPORTIONAL TO THE ANGULAR DIFFERENCES BETWEEN THE BEARING OF SAID TRANSDUCER AND THE BEARING OF SAID BODY; A MAGNETIC COMPASS FIXEDLY MOUNTED WITHIN SAID BODY HAVING A MECHANICAL OUTPUT WHICH IS PROPORTIONAL TO THE RELATIVE BEARING OF SAID BODY TO MAGNETIC NORTH; A FIRST SERVO AMPLIFIER WITHIN SAID BODY AND MECHANICALLY CONNECTED TO SAID COMPASS FOR PRODUCING A MECHANICAL OUTPUT WHICH IS PROPORTIONAL TO THE OUTPUT FROM SAID COMPASS; A SYNCHRO DIFFERENTIAL TRANSFORMER WITHIN SAID BODY, ELECTRICALLY CONNECTED TO SAID TRANSMITTER, AND FURTHER CONNECTED WITH SAID FIRST SERVO AMPLIFIER, RESPONSIVE TO THE MECHANICAL OUTPUT FROM SAID FIRST SERVO AMPLIFIER AND TO THE OUTPUT FROM SAID TRANSMITTER, AND HAVING AND OUTPUT PROPORTIONAL TO THE SUM OF THE ELECTRICAL OUTPUT FROM SAID TRANSMITTER AND THE MECHANICAL OUTPUT FROM SAID FIRST SERVO AMPLIFIER; A SYNCHRO CONTROL TRANSFORMER ABOARD SAID VESSEL, ELECTRICALLY CONNECTED TO SAID SYNCHRO DIFFERENTIAL TRANSFORMER AND INCLUDING MANUAL ADJUSTING MEANS FOR FEEDING A DESIRED HEADING THEREINTO, SAID CONTROL TRANSFORMER PRODUCING AN ELECTRICAL OUTPUT PROPORTIONAL TO THE DIFFERENCE BETWEEN THE TERRESTRIAL HEADING OF THE TRANSDUCER AND THE DESIRED HEADING; A SECOND SERVO AMPLIFIER ABOARD SAID VESSEL ELECTRICALLY CONNECTED TO SAID CONTROL TRANSFORMER FOR PRODUCING AN ELECTRICAL OUTPUT PROPORTIONAL TO THE OUTPUT OF SAID CONTROL TRANSFORMER; AN ELECTRIC MOTOR WITHIN SAID BODY, ASSOCIATED WITH SAID TRANSMITTER AND SAID TRANSDUCER AND ELECTRICALLY CONNECTED TO SAID SECOND SERVO AMPLIFIER FOR POSITIONING SAID TRANSDUCER IN ACCORDANCE WITH THE DESIRED HEADING; AND A SECOND SYNCHRO DIFFERENTIAL TRANSFORMER CONNECTED BETWEEN SAID SYNCHRO DIFFERENTIAL TRANSFORMER ASSOCIATED WITH SAID FIRST SERVO AMPLIFIER AND SAID SYNCHRO CONTROL TRANSFORMER, SAID SECOND SYNCHRO DIFFERENTIAL TRANSFORMER BEING EFFECTIVE TO MODIFY THE BEARING OF SAID TRANSDUCER RELATIVE TO TRUE NORTH.