Threshold circuit utilizing field effect transistors

Claim 1

A THRESHOLD CIRCUIT COMPRISING, IN COMBINATION, A PAIR OF FIELD-EFFECT TRANSISTORS OF OPPOSITE CONDUCTIVITY TYPES WITH EACH HAVING FIRST AND SECOND ELECTRODES SEPARATED BY A CHANNEL DEFINING A CONDUCTIVE PATH FOR SAID TRANSISTORS, AND A CONTROL ELECTRODE FOR CONTROLLING THE CONDUCTANCE OF SAID CHANNEL, MEANS FOR DIRECTLY TOGETHER THE CONTROL ELECTRODES OF SAID TRANSISTORS, MEANS FOR SERIALLY CONNECTING TOGETHER THE FIRST-TOSECOND ELECTRODE CONDUCTIVE PATHS OF SAID TRANSISTORS SO THAT ONE TRANSISTOR FUNCTIONS AS A LOAD ON THE OTHER, MEANS FOR CAPACITIVELY COUPLING INPUT SIGNALS TO THE JUNCTION OF THE CONTROL ELECTRODES OF SAID PAIR OF TRANSISTORS, AND MEANS FOR DERIVING OUTPUT SIGNALS FROM THE JUNCTION OF SAID FIRST-TO-SECOND ELECTRODES CONDUCTIVE PATHS OF SAID PAIR OF TRANSISTOR, SAID OUTPUT SIGNALS EXHIBITING AN ABRUPUT CHANGE FROM ONE SIGNAL LEVEL TO ANOTHER WHEN SAID INPUT SIGNALS EXCEED A PREDETERMINED THRESHOLD SIGNAL LEVEL.