Electronic multiplexer with signal offset means for high speed communication of low level signals

Claim 1

A MULTIPLEX SYSTEM COMPRISING MEANS HAVING INPUT MEANS AND OUTPUT MEANS TO PROVIDE A SIGNAL RELATED TO THE DIFFERENCE BETWEEN A FIRST AND SECOND INPUT SIGNAL, A PLURALITY OF INPUT SIGNAL CHANNELS, EACH CHANNEL INCLUDING COUPLING MEANS TO COUPLE SAID INPUT MEANS FOR PROVIDING A CHOPPED INPUT SIGNAL AT A PREDETERMINED CHOPPING FREQUENCY, ADJUSTABLE MEANS COUPLED TO SAID INPUT MEANS FOR PROVIDING AN INPSUT SIGNAL IN SYNCHRONISM WITH SAID CHOPPED SIGNAL AND AT SAID CHOPPING FREQUENCY, AND MEANS FOR SEQUENTIALLY COUPLING EACH OF SAID COUPLING MEANS FOR PROVIDING CHOPPED INPUT SIGNALS TO SAID INPUT MEANS WHEREBY AN INDICATION OF THE DIFFERENCE BETWEEN SAID CHOPPED SIGNALS IS PROVIDED AT SAID OUTPUT MEANS, SAID ADJUSTABLE MEANS COMPRISING A VARIABLE IMPEDANCE, A SWITCH OPERATING IN SYNCHRONISM WITH SAID CHOPPED SIGNAL AND AT SAID CHOPPING FREQUENCY CONNECTED ACROSS SAID VARIABLE IMPEDANCE, SAID SWITCH COMPRISING A PAIR OF TRANSISTORS, EACH TRANSISTOR HAVING AN INPUT ELECTRODE AND AN OUTPUT ELECTRODE AND MEANS COUPLED TO EACH OF SAID INPSUT ELECTRODE