Transistor switch having impedance means effecting negligible drop between emitter and collector

Claim 1

AN ELECTRONIC SWITCHING CIRCUIT HAVING A SIGNAL TERMINAL AND AN OUTPUT TERMINAL, SAID CIRCUIT BEING OPERABLE UPON APPLICATION OF A CONTROL VOLTAGE VARYING IN POLARITY TO APPLY AND DISCONNECT ELECTRICALLY SAID SIGNAL TERMINAL TO AND FROM SAID OUTPUT TERMINAL, COMPRISING IN COMBINATION; A TRANSISTOR HAVING A BASE TERMINAL AND EMITTER AND COLLECTOR ELECTRODES, ONE OF SAID ELECTRODES BEING CONNECTED TO SAID SIGNAL TERMINAL AND THE OTHER OF SAID ELECTRODES BEING CONNECTED TO SAID OUTPUT TERMINAL; CIRCUIT MEANS FOR APPLYING SAID CONTROL VOLTAGE BETWEEN SAID BASE TERMINAL AND A FOURTH TERMINAL; A FIRST CIRCUIT INCLUDING A FIRST DIODE AND A FIRST RESISTANCE CONNECTED IN SERIES BETWEEN SAID FOURTH TERMINAL AND SAID COLLECTOR ELECTRODE; A SECOND CIRCUIT INCLUDING A SECOND DIODE AND A SECOND RESISTANCE CONNECTED IN SERIES BETWEEN SAID FOURTH TERMINAL AND SAID EMITTER ELECTRODE; WHEREIN THE SUM OF THE IMPEDANCE OF SAID FIRST RESISTANCE, THE FORWARD IMPEDANCE OF SAID FIRST DIODE AND THE COLLECTOR-BASE JUNCTION FORWARD IMPEDANCE OF SAID TRANSISTOR IS MADE SUBSTANTIALLY EQUAL TO THE SUM OF SAID SECOND RESISTANCE, THE FORWARD IMPEDANCE OF SAID SECOND DIODE AND THE BASE-EMITTER JUNCTION FORWARD IMPEDANCE OF SAID TRANSISTOR, WHEREBY THE VOLTAGE DROP ACROSS THE COLLECTOR-BASE JUNCTION SUBSTANTIALLY EQUALS THE VOLTAGE DROP ACROSS THE BASE-EMITTER JUNCTION, SUBSTANTIALLY TO ELIMINATE ANY VOLTAGE DROP BETWEEN SAID COLLECTOR AND SAID EMITTER WHEN SAID TRANSISTOR CONDUCTS.