Error checking circuit for electronic counters

Claim 1

APPARATUS FOR CHECKING AN ELECTRONIC COUNTER OF ELECTRICAL PULSES WHICH OPERATES ON A SCALE N OVER AT LEAST TWO POWERS OF N AND HAS FOR EACH POPOWER OF N TO THE LIMIT REQUIRED AN ARRAY OF N DIGIT-REPRESENTING STAGES INCLUDING (A) A FIRST SCALE-OF-M RESIDUE COMPUTER, WHERE M IS AN INTEGER SUCH THAT THE RESIDUE OF N TO MODULUS M IS UNITY, FOR PRODUCING AT ANY GIVEN MOMENT A FIRST COMPUTED SIGNAL TO RESPENSENT THE RESIDUE TO MODULUS M OF THE ALGEBRAIC TOTAL OF PULSES DELIVERED TO THE COUNTER UP TO THAT MOMENT, (B) EACH ARRAY OF THE COUNTER INCLUDING A RESIDUE NETWORK ARRANGED TO PRODUCE AT ANY GIVEN MOMENT AN ARRAY RESIDUE SIGNAL TO REPRESENT THE RESIDUE TO MODULUS M OF THE DIGIT HELD IN THAT ARRAY AT THAT MOMENT, (C) A SECOND SCALE-OF-M RESIDUE COMPUTER TO WHICH THE ARRAY RESIDUE SIGNALS ARE SUPPLIED BY SAID RESIDUE NETWORKS FOR PRODUCING AT ANY GIVEN MOMENT A SECOND COMPUTED SIGNAL TO RESIDUE TO MODULUS M OF THE ALGEBRAIC SUM OF THE RESIDUES REPRESENTED BY THE ARRAY RESIDUE SIGNALS AT THAT MOVEMENT, THE SIGN OF THE RESIDUE DERIVED FROM EACH ARRAY OF AN ODDNUMBERED POWER OF N BEING NEGATIVE WHERE THE SAID UNITY RESIDUE IS NEGATIVE, AND (D) A COMPARATOR TO WHICH THE FIRST AND SECOND COMPUTED SIGNALS ARE SUPPLIED BY SAID COMPUTERS, SAID COMPARTOR BEING OPERATIVE TO COMPARE SAID SIGNALS AND TO DERIVE A RESPONSE WHEN THE RESIDUES REPRESENTED BY THEM ARE UNEQUAL.