Emission current regulator for ion gauge

Claim 1

IN A POWER SUPPLY FOR THE FILAMENT OF AN ION GAUGE HAVING A THERMIONIC ELECTRON-EMISSIVE FILAMENT AND AN ELECTRON COLLECTOR, SAID SUPPLY INCLUDING CAPACITIVE MEANS IN THE CONTROL CIRCUIT THEREOF AND MEANS FOR APPLYING POWER TO SAID FILAMENT DURING A PORTION OF AN ALTERNATING CURRENT POWER CYCLE THAT VARIES IN THE OPPOSITE DIRECTION AS CHANGES IN THE RATE OF CHARGING OF SAID CAPACITIVE MEANS, THE IMPROVEMENT OF MEANS FOR VARYING SAID RATE OF CHARGING TO EFFECT SUBSTANTIALLY CONSTANT ELECTRON EMISSION FROM SAID FILAMENT COMPRISING: A SOURCE OF SUBSTANTIALLY CONSTANT CHARGING VOLTAGE CONNECTED TO SAID CAPACITIVE MEANS; A TRANSISTOR HAVING BASE, COLLECTOR AND EMITTER ELECTRODES; MEANS CONNECTING SAID TRANSISTOR COLLECTOR AND EMITTER ELECTRODES IN SHUNT WITH SAID CAPACITIVE MEANS; A SERIES LOOP NETWORK INCLUDING SAID ELECTRON COLLECTOR, A SOURCE OF UNIDIRECTIONAL VOLTAGE ENERGIZING SAID ELECTRON COLLECTOR TO A VOLTAGE RELATIVE TO SAID FILAMENT AT WHICH IT COLLECTS SUBSTANTIALLY ALL OF THE ELECTRONS FROM SAID FILAMENT, A RESISTOR, AND ONE TERMINAL OF SAID FILAMENT; AND CONDUCTIVE MEANS CONNECTING SAID RESISTOR AND A SOURCE OF CONSTANT VOLTAGE IN SERIES VOLTAGE-OPPOSING RELATIONSHIP IN THE BASE-EMITTER CIRCUIT OF SAID TRANSISTOR, SAID SOURCE OF CONSTANT VOLTAGE BEING CONNECTED TO CAUSE DECREASED CONDUCTION OF SAID TRANSISTOR AND SAID RESISTOR BEING CONNECTED SUCH THAT THE VOLTAGE GENERATED THEREIN BY THE FLOW OF EMISSION CURRENT THERETHROUGH INCREASES CONDUCTION OF SAID TRANSISTOR.