Digital to analogue decade converter

Claim 1

A DECADE CONVERTER COMPRISING, IN COMBINATION, A VOLTAGE SOURCE HAVING FIRST AND SECOND TERMINALS, A VOLTAGE DIVIDER CONNECTED ACROSS SAID SOURCE AND PROVIDING A PLURALITY OF POINTS RESIDING AT RESPECTIVELY DIFFERENT VOLTAGE VALUES RELATIVE TO SAID SECOND TERMINAL, A PLURALITY OF N DECADES OF DIGIT SELECTOR SWITCHES WITH EACH SWITCH ADAPTED TO RESIDE IN EITHER A FIRST STATE OR A SECOND STATE, MEANS CONNECTING ONE SIDE OF EAH SWITCH IN ANY DECADE TO A RESPECTIVE ONE OF SAID POINTS, MEANS CONNECTING THE OPPOSITE SIDE OF ALL SWITCHES IN A GIVEN DECADE TO A COMMON JUNCTION SO THAT THERE ARE N COMMON JUNCTIONS CORRESPONDING TO RESPECTIVE ONES OF SAID N DECADES, A SUMMING RESISTOR, N CURRENT LIMITING MEANS CONNECTED BETWEEN RESPECTIVE ONES OF SAID N JUNCTIONS AND ONE END OF SAID SUMMING RESISTOR, THE OPPOSITE END OF SAID SUMMING RESISTOR BEING CONNECTED TO SAID SECOND TERMINAL OF SAID VOLTAGE SOURCE, MEANS RESPONSIVE TO A CHANGE OF ANY ONE OF SAID SWITCHES IN A GIVEN DECADE FROM SAID FIRST TO SAID SECOND STATE FOR INCREASING BY A PREDETERMINED AMOUNT THE EFFECTIVE VALUE OF THE CURRENT LIMITING MEANS WHICH CORRESPONDS TO THAT DECADE, AND MEANS CONNECTED ACROSS SAID SUMMING RESISTOR TO SENSE THE VOLTAGE DROP THEREACROSS AND THEREBY SENSE THE DIGITAL VALUE REPRESENTED BY THE PARTICULAR ONES OF SAID SWITCHES WHICH ARE IN SAID SECOND STATE.