Signal transfer apparatus incorporating means to suppress spurious interference signals

Claim 1

A SIGNAL TRANSFER APPARATUS FOR APPLYING TO A VOLTAGE RESPONSIVE MEANS A POTENTIAL DIFFERENCE REPRESENTATIVE OF THE OUTPUT OF A VOLTAGE GENERATING MEANS, SAID APPARATUS COMPRISING: (A) A FIRST PAIR OF TERMINALS TO WHICH IS APPLIED SAID POTENTIAL DIFFERENCE REPRESENTATIVE OF THE OUTPUT OF THE VOLTAGE GENERATING MEANS; (B) A SECOND PAIR OF TERMINALS BETWEEN WHICH THE VOLTAGE RESPONSIVE MEANS IS CONNECTED; (C) AN IMPEDANCE PATH INCLUDING A CAPACITATIVE ELEMENT; AND (D) A FIRST SWITCH MEANS HAVING A SET OF CONTACTS WHICH, IN A FIRST CONDITION OF THE SWITCH MEANS SERVES TO CONNECT SAID IMPEDANCE PATH BETWEEN THE FIRST PAIR OF TERMINALS, AND IN A SECOND CONDITION OF SAID SWITCH MEANS, SERVES TO CONNECT SAID IMPEDANCE PATH BETWEEN THE SECOND PAIR OF TERMINALS, (I) SAID SET OF CONTACTS PROVIDING STRAY CAPACITANCES BETWEEN THE FIRST PAIR OF TERMINALS AND THE SECOND PAIR OF TERMINALS, AND (E) A SECOND SWITCH MEANS HAVING A SET OF CONTACTS WHICH SERVES TO CONNECT ONE OF SAID FIRST PAIR OF TERMINALS TO A POINT OF FIXED POTENTIAL WHEN SAID FIRST SWITCH MEANS IS IN ITS SECOND CONDITION AND TO DISCONNECT SAID ONE OF THE FIRST PAIR OF TERMINALS FROM SAID POINT WHEN SAID FIRST SWITCH MEANS IS IN ITS FIRST CONDITION; AND (F) MEANS CONNECTING THE ONE OF THE SECOND PAIR OF TERMINALS CORRESPONDING TO THE OTHER OF SAID FIRST PAIR OF TERMINALS TO A POINT OF FIXED POTENTIAL WHEN SAID FIRST WHICH MEANS IS IN ITS SECOND CONDITION, (G) WHEREBY ONE END OF EACH STRAY CAPACITANCE IS MAINTAINED AT A FIXED POTENTIAL AT LEAST WHEN TE FIRST SWITCH MEANS IS IN ITS SECOND CONDITION.