Transistor switch utilizing a control transistor and zener diode

Claim 1

A TRANSISTOR SWITCH COMPRISING A SWITCHING TRANSISTOR, MEANS CONNECTED TO THE COLLECTOR OF SAID SWITCHING TRANSISTOR FOR MAINTAINING THE COLLECTOR POTENTIAL WITHIN PREDETERMINED LIMITS, MEANS CONNECTED TO THE EMITTER OF SAID SWITCHING TRANSISTOR FOR MAINTAINING THE EMITTER POTENTIAL CONSTANT OUTSIDE SAID LIMITS, MEANS FOR MAINTAINING THE BASE POTENTIAL BETWEEN THE EMITTER AND COLLECTOR POTENTIALS WHEREBY SAID TRANSISTOR IS FORWARD BIASED AND CONDUCTING, MEANS COUPLED TO SAID LAST-MENTIONED MEANS AND RESPONSIVE TO AN INPUT SIGNAL FOR ALTERING THE BASE POTENTIAL SO THAT SAID TRANSISTOR IS NO LONGER FORWARD BIASED, AN OUTPUT CONNECTION TO THE COLLECTOR WHEREBY, WHEN SAID TRANSISTOR IS FORWARD BIASED AS IT IS IN ITS NORMAL CONDITION, THE OUTPUT IS SUBSTANTIALLY THE EMITTER POTENTIAL, AND WHEN SAID TRANSISTOR IS CUT OFF, THE OUTPUT IS THE COLLECTOR POTENTIAL, SAID MEANS FOR MAINTAINING THE BASE POTENTIAL COMPRISING A VOLTAGE DIVIDER, THE BASE LEAD BEING CONNECTED TO A TAPPING POINT ON SAID VOLTAGE DIVIDER, SAID MEANS RESPONSIVE TO AN INPUT SIGNAL COMPRISING A FURTHER DIODE CONNECTED ON ONE END TO THE BASE OF SAID SWITCHING TRANSISTOR AND POLARIZED TO BE CONNECTED THROUGH TO THE BASE WHEN THE POTENTIAL ON IT EXCEEDS THE BASE POTENTIAL IN THE DIRECTION OF THE EMITTER POTENTIAL, A CONTROL TRANSISTOR, A ZENER DIODE CONNECTED TO THE EMITTER OF SAID CONTROL TRANSISTOR, AND A RESISTOR IN SERIES WITH SAID ZENER DIODE, THE FREE END OF SAID RESISTOR BEING CONNECTED TO SAID VOLTAGE DIVIDER, AND THE FREE END SAID FURTHER DIODE BEING CONNECTED TO THE JUNCTION OF SAID ZENER DIODE WITH SAID LAST NAMED RESISTOR.