Push-pull amplifier circuit having an inductive load and method for obtaining a symmetrical gain

Claim 1

A SINGLE ENDED PUSH-PULL AMPLIFIER CIRCUIT FOR DRIVING AN INDUCTIVE LOAD COMPRISING: A FIRST AND SECOND TRANSISTOR OF LIKE TYPE EACH HAVING A COLLECTOR, EMITTER, AND BASE; AN INDUCTIVE LOAD CONNECTED TO THE COLLECTOR OF SAID FIRST AND SECOND TRANSISTOR; A SUPPLY VOLTAGE SOURCE CONNECTED AT THE MIDPOINT OF SAID INDUCTIVE LOAD; A THIRD TRANSISTOR HAVING A COLLECTOR, EMITTER AND BASE FOR INVERTING ONE HALF OF THE INDUCTIVE LOAD, ONE HALF OF THE INDUCTIVE LOAD BEING CONNECTED TO THE THIRD RESISTOR IN A COMMON EMITTER CONFIGURATION AND THE OTHER HALF BEING CONNECTED IN A COMMON BASE CONFIGURATON WITH THE EMITTER AND BASE BEING RESISTIVELY CONNECTED TO THE COLLECTORS OF THE FIRST END SECOND TRANSISTORS; AND A LOAD RESISTOR CONNECTED TO THE MIDPOINT OF SAID LOAD AND TO SAID THIRD TRANSISTOR FOR DEVELOPING A SINGLE ENDED OUTPUT.

Claim 3

A METHOD OF PRODUCING A SYMMETRICAL GAIN FROM A PUSH-PULL AMPLIFIER HAVING A SINGLE ENDED FORM WHILE OBTAINING A FEEDBACK SIGNAL FOR DRIVING AN INDUCTIVE LOAD COMPRISING: CONNECTING AN INDUCTIVE LOAD TO THE COLLECTORS OF THE PUSH-PULL TRANSISTORS WITH A SUPPLY VOLTAGE SOURCE AT THE MIDPOINT OF THE INDUCTIVE LOAD; CONNECTING A LOAD RESISTOR BETWEEN THE SUPPLY VOLTAGE SOURCE AND THE COLLECTOR OF AN INVERTING TRANSISTOR ONE HALF OF THE INDUCTIVE LOAD BEING CONNECTED TO THE INVERTER TRANSISTOR IN A COMMON EMITTER CONFIGURATION AND THE OTHER HALF BEING CONNECTED IN A COMMON BASE CONFIGURATION; CONNECTING BIASING RESISTORS TO THE EMITTER AND BASE OF THE INVERTER TRANSISTOR ONE BIASING RESISTOR BEING VARIABLE AND THE OTHER BEING FIXED; AND BALANCING THE AMPLIFIER CIRCUIT TO OBTAIN A SYMMETRICAL GAIN BY DISCONNECTING THE FIXED BIASING RESISTOR AT ONE END OF THE INDUCTIVE LOAD, CONNECTING THE FIXED BIASING RESISTOR TO THE OPPOSITE END OF THE INDUCTIVE LOAD, AND ADJUSTING A VARIABLE BIASING RESISTOR TO CREATE A NULL VALUE AT THE LOAD RESISTOR.

Claim 4

A METHOD OF PRODUCING A SYMMETRICAL GAIN FROM A PUSH-PULL AMPLIFIER HAVING A SINGLE ENDED FORM WHILE OBTAINING A FEEDBACK SIGNAL FOR DRIVING AN INDUCTIVE LOAD COMPRISING: CONNECTING AN INDUCTIVE LOAD TO THE COLLECTORS OF THE PUSH-PULL TRANSISTORS WITH A SUPPLY VOLTAGE SOURCE AT THE MIDPOINT OF THE INDUCTIVE LOAD; CONNECTING A LOAD RESISTOR BETWEEN THE SUPPLY VOLTAGE SOURCE AND THE COLLECTOR OF AN INVERTING TRANSISTOR ONE HALF OF THE INDUCTIVE LOAD BEING CONNECTED TO THE INVERTER TRANSISTOR IN A COMMON EMITTER CONFIGURATION AND THE OTHER HALF BEING CONNECTED IN A COMMON BASE CONFIGURATION; CONNECTING BIASING RESISTORS TO THE EMITTER AND BASE OF THE INVERTER TRANSISTOR ONE BIASING RESISTOR BEING VARIABLE AND THE OTHER BEING FIXED; AND BALANCING THE AMPLIFIER CIRCUIT TO OBTAIN A SYMMETRICAL GAIN BY DISCONNECTING THE FIXED BIASING RESISTOR AT ONE END OF THE INDUCTIVE LOAD, CONNECTING THE FIXED BIASING RESISTOR TO THE OPPOSITE END OF THE INDUCTIVE LOAD, AND ADJUSTING A VARIABLE BIASING RESISTOR TO CREATE A NULL VALUE AT THE LOAD RESISTOR.