nelson

Claim 1

A FUEL CONTROL AMPLIFIER FOR CONTROLLING THE FUEL SUPPLIED TO A GAS TURBINE ENGINE IN ACCORDANCE WITH TURBINE AIR INLET TEMPERATURE COMPRISING, THERMOCOUPLE MEANS POSITIONED TO RESPOND TO TURBINE AIR INLET TEMPERATURE AND PROVIDING AN OUTPUT VOLTAGE THAT IS PROPORTIONAL TO SAID AIR INLET TEMPERATURE, VOLTAGE REFERENCE MEANS INCLUDING A ZENER DIODE PROVIDING A SOURCE OF CONSTANT POTENTIAL DIRECT CURRENT VOLTAGE, MEANS PROVIDING A CONTROL VOLTAGE THAT IS PROPORTIONAL TO THE DIFFERENCE IN VOLTAGE DEVELOPED BY SAID VOLTAGE REFERENCE MEANS AND SAID THERMOCOUPLE MEANS, FUEL CONTROL MEANS CONNECTED WITH SAID ENGINE INCLUDING A SHIFTABLE ELEMENT FOR VARYING THE AMOUNT OF FUEL SUPPLIED TO SAID ENGINE, AN A.C. ELECTRIC MOTOR CONNECTED WITH THE SHIFTABLE ELEMENT OF SAID FUEL CONTROL MEANS FOR SHIFTING THE SAME, A SATURABLE REACTOR MOTOR DRIVE CIRCUIT CONNECTED WITH SAID A.C. MOTOR FOR ENERGIZING THE SAME, A PLURALITY OF MAGNETIC AMPLIFIERS CONNECTED IN SERIES, ONE OF SAID MAGNETIC AMPLIFIERS BEING CONNECTED WITH SAID CONTROL VOLTAGE AND ONE OF THEM BEING CONNECTED WITH SAID SATURABLE REACTOR MOTOR DRIVE CIRCUIT, A TACHOMETER GENERATOR HAVING AN A.C. OUTPUT DRIVEN BY SAID MOTOR, A SOURCE OF A.C. VOLTAGE, A PHASE RESPONSIVE CIRCUIT CONNECTED WITH SAID A.C. TACHOMETER GENERATOR AND WITH SAID SOURCE OF A.C. VOLTAGE, SAID PHASE RESPONSIVE CIRCUIT INCLUDING A PAIR OF TRANSISTORS AND A PAIR OF DIODES, A VOLTAGE DEVELOPING CIRCUIT ELEMENT FORMING A PART OF SAID PHASE RESPONSIVE CIRCUIT AND DEVELOPING A D.C. VOLTAGE WHICH IS APPLIED TO THE INPUT OF SAID MAGNETIC AMPLIFIERS, A FIRST CIRCUIT CONNECTED ACROSS SAID SOURCE OF A.C. VOLTAGE INCLUDING IN A SERIES CONNECTION THE EMITTER-COLLECTOR CIRCUIT OF ONE OF SAID TRANSISTORS, ONE OF SAID DIODES AND SAID VOLTAGE DEVELOPING CIRCUIT ELEMENT, A SECOND CIRCUIT CONNECTED ACROSS SAID SOURCE OF A.C. VOLTAGE INCLUDING IN A SERIES CONNECTION THE EMITTER-COLLECTOR CIRCUIT OF SAID OTHER TRANSISTOR, SAID OTHER DIODE AND SAID VOLTAGE DEVELOPING CIRCUIT ELEMENT, THE OUTPUT VOLTAGE OF SAID A.C. TACHOMETER GENERATOR BEING CONNECTED WITH THE BASE ELECTRODES OF SAID TRANSISTORS, AN ELECTRICALLY CONTROLLED BRAKE FOR HOLDING THE SHIFTABLE ELEMENT OF SAID FUEL CONTROL MEANS IN A PREDETERMINED POSITION, AND MEANS INCLUDING A MAGNETIC AMPLIFIER CAUSING SAID BRAKE TO BE RELEASED WHEN THE OUTPUT OF SAID SERIES CONNECTED MAGNETIC AMPLIFIERS IS OF A PREDETERMINED VALUE, THE MAGNETIC AMPLIFIER CONTROLLING SAID ELECTRICALLY OPERATED BRAKE INCLUDING POSITIVE AND NEGATIVE FEEDBACK WINDINGS AND A ZENER DIODE CONNECTED WITH THE NEGATIVE FEEDBACK WINDING.