Digital communication system

Claim 1

A SYSTEM FOR CONVERTING DIGITAL INFORMATION INTO EQUIVALENT ANALOG INFORMATION INCLUDING IN COMBINATION: INPUT CIRCUIT MEANS FOR RECEIVING A REFERENCE INPUT SIGNAL, OUTPUT CIRCUIT MEANS FOR PRODUCING AN OUTPUT SIGNAL IN RESPONSE TO SUCH INPUT SIGNAL AND INCLUDING A FIRST PATH AND A SECOND PATH, SAID FIRST PATH INCLUDING MEANS FHIFTING THE PHASE OF THE CURRENT THEREIN RELATIVE TO THE PHASE OF THE CURRENT IN SAID SECOND PATH, MEANS FOR COMBINING THE CURRENTS IN SAID FIRST AND SECOND PARTS TO FORM AN OUTPUT SIGNAL HAVING A PHASE RELATIVE TO SAID INPUT SIGNAL DETERMINED BY THE RELATIVE MAGNITUDES OF THE CURRENT FLOW IN SAID FIRST AND SECOND PATHS, A PLURALITY OF RESISTORS CONNECTED TO A COMMON INPU TTERMINAL WHICH IS COINNECTED TO SAID INPUT CIRCUIT MEANS, SAID RESISTORS EACH HAVING AN OUTPUT TERMINAL WITH THE VALUES OF RESISTANCE BETWEEN SAID INPUT TGERMINAL AND SAID OUTPUT TERMINALS VARYING IN ACCORDANCE WITH A BINARY CODE, CONTROL MEANS COUPLED TO SAID OUTPUT TERMINALS OF SAID REISSTORS AND ACTUABLE FOR SELECTIVELY CONNECTING SAID OUTPUT TERMINALS TO SAID FIRST PATH AND TO SAID SECOND PATH OF SAID OUTPUT CIRCUIT MEANS, SAID CONTROL MEANS APPLYING CURRENT FROM SAID RESISTORS TO SAID FIRST AND SECOND PATHS AND CONTROLLING THE RELATIVE MAGNITUDES OF THE CURRENT FLOW IN SAID FIRST AND SECOND PATHS, AND MEANS FOR RECEIVING DIGITAL INFORMATION COUPLED TO SAID CONTROL MEANS TO ACTUATE SAID CONTROL MEANS IN ACCORDANCE WITH THE MAGNITUDE OF THE BINARY NUMBER REPRESENTED BY THE RECEIVED DIGITAL INFORMATION AT ANY INSTANT.

Claim 2

A SYSTEM FOR CONVERTING DIGITAL INFORMATION INTO EQUIVALENT ANALOG INFORMATION INCLUDING IN COMBINATION: INPUT CIRCUIT MEANS FOR RECEIVING A REFERENCE INPUT SIGNAL, OUTPUT CIRCUIT MEANS FOR PRODUCING AN OUTPUT SIGNAL IN RESPONSE TO SUCH INPUT SIGNAL AND INCLUDING A FIRST PATH AND A SECOND PATH, SAID FIRST PATH INCLUDING MEANS FHIFTING THE PHASE OF THE CURRENT THEREIN RELATIVE TO THE PHASE OF THE CURRENT IN SAID SECOND PATH, MEANS FOR COMBINING THE CURRENTS IN SAID FIRST AND SECOND PARTS TO FORM AN OUTPUT SIGNAL HAVING A PHASE RELATIVE TO SAID INPUT SIGNAL DETERMINED BY THE RELATIVE MAGNITUDES OF THE CURRENT FLOW IN SAID FIRST AND SECOND PATHS, A PLURALITY OF RESISTORS CONNECTED TO A COMMON INPU TTERMINAL WHICH IS COINNECTED TO SAID INPUT CIRCUIT MEANS, SAID RESISTORS EACH HAVING AN OUTPUT TERMINAL WITH THE VALUES OF RESISTANCE BETWEEN SAID INPUT TGERMINAL AND SAID OUTPUT TERMINALS VARYING IN ACCORDANCE WITH A BINARY CODE, CONTROL MEANS COUPLED TO SAID OUTPUT TERMINALS OF SAID REISSTORS AND ACTUABLE FOR SELECTIVELY CONNECTING SAID OUTPUT TERMINALS TO SAID FIRST PATH AND TO SAID SECOND PATH OF SAID OUTPUT CIRCUIT MEANS, SAID CONTROL MEANS APPLYING CURRENT FROM SAID RESISTORS TO SAID FIRST AND SECOND PATHS AND CONTROLLING THE RELATIVE MAGNITUDES OF THE CURRENT FLOW IN SAID FIRST AND SECOND PATHS, AND MEANS FOR RECEIVING DIGITAL INFORMATION COUPLED TO SAID CONTROL MEANS TO ACTUATE SAID CONTROL MEANS IN ACCORDANCE WITH THE MAGNITUDE OF THE BINARY NUMBER REPRESENTED BY THE RECEIVED DIGITAL INFORMATION AT ANY INSTANT.