High voltage ramp waveform generator utilizing capacitor discharge through a constant current pentode

Claim 1

A SWEEP GENERATOR CIRCUIT COMPRISING: AN ELECTRON DISCHARGE TUBE INCLUDING A CATHODE, A CONTROL GRID, A SCREEN GRID, AND AN ANODE; MEANS CONNECTED BETWEEN SAID ANODE AND SAID CATHODE FOR SUPPLYING AN INITIAL POSITIVE POTENTIAL TO SAID ANODE RELATIVE TO SAID CATHODE THAT IS AN ORDER OF MAGNITUDE GREATER THAN THE NORMAL RATED VALUE; MEANS CONNECTED BETWEEN SAID SCREN GRID AND SAID CATHODE FOR SUPPLYING AN INTIAL POSITIVE POTENTIAL TO SAID SCREEN GRID RELATIVE TO SAID CATHODE, SAID MEANS CONSTITUTING THE SOLE POTENTIAL SUPPLY FOR SAID SCREEN GRID; MEANS FOR APPLYING A BIAS TO SAID CONTROL GRID TO RENDER SAID DISCHARGE TUBE INITIALLY NONCONDUCTING; A CAPACITOR CONNECTED IN SHUNT BETWEEN SAID ANODE AND SAID CATHODE; A TRANSISTOR INCLUDING A BASE, A COLLECTOR, AND AN EMITTER; A RELATIVELY NEGATIVE VOLTAGE SUPPLY CONNECTED TO SAID COLLECTOR; A RELATIVELY LOW VOLTAGE SUPPLY CONNECTED TO SAID EMITTER; MEANS CONNECTING SAID COLLECTOR TO THE CONTROL GRID OF SAID ELECTRON DISCHARGE TUBE; SAID TRANSISTOR BEING NORMALLY NONCONDUCTING, WHEREBY THE CONTROL GRID OF SAID ELECTRON DISCHARGE TUBE IS NORMALLY BELOW CUTOFF POTENTIAL; MEANS FOR PRODUCING A NEGATIVE CURRENT STEP OF SUFFICIENT MAGNITUDE TO RENDER SAID TRANSISTOR CONDUCTING; AND MEANS FOR COUPLING SAID NEGATIVE CURRENT STEP TO THE BASE OF SAID TRANSISTOR THEREBY TO RENDER THE SAID TUBE TER-COLLECTOR CIRCUIT THEREOF CONDUCTING, WHEREUPON THE CONTROL GRID VOLTAGE OF SAID ELECTRON DISCHARGE TUBE IS RAPIDLY RAISED ABOVE CUTOFF TO RENDER SAID TUBE CONDUCTING AND TO CAUSE SAID CAPACITOR TO DISCHARGE THROUGH SAID TUBE; SAID TUBE BEING CHARACTERIZED IN THAT ITS PLATE CURRENT IS CONSTANT WITHIN ABOUT 5% OVER A RANGE OF ANODE VOLTAGE BETWEEN 3000 AND 1000 VOLTS UNDER FIXED CONTROL GRID AND SCREEN GRID VOLTAGE, WHEREBY THE VOLTAGE ON SAID CAPACITOR DISCHARGES, AT A CONSTANT RATE TO PRODUCE A LINEAR RAMP VOLTAGE THEREACROSS.