Temperature controlled microcircuits

Claim 2

A substrate temperature stabilizing circuit comprising: a temperature sensor means comprised of a resistance bridge at least one arm of which includes a negative resistance coefficient element and having first and second pairs of diagonal bridge points; an electrical power source connected across said first pair of points; an operational amplifier connected to sense said second pair of points; a feedback circuit comprising a plurality of base-emitter circuits of a plurality of transistors connected across said operational amplifier, said transistors comprising a high current gain amplifier, and having collector-emitter circuits connected across said electrical power source, at least one of said transistors comprising a heater for said substrate.

Claim 3

A substrate temperature stabilizing circuit as recited in claim 1 wherein said temperature sensor means and said feedback circuit are mounted in close thermal conductivity with said substrate and said operational amplifier is mounted away from said substrate.

Claim 4

A substrate temperature stabilizing circuit comprising: a resistance bridge including at least one thermistor and having first and second bridge diagonal points; high current gain means comprising oppositely poled first and second transistors having commonly connected emitter electrodes, and base electrodes connecting said transistors across said first bridge diagonal points, each said transistor having collector electrodes; and, a heater comprising a third transistor having a collector electrode and an emitter electrode comprising a collector-emitter circuit connected across said second bridge diagonal points, said third transistor collector electrode being connected to said first transistor collector electrode, and a third transistor base electrode connected to said second transistor collector electrode, and including an electrical power source connected across said second bridge diagonal points.

Claim 5

A substrate temperature stabilizing circuit comprising: a resistance bridge including at least one thermistor and having first and second bridge diagonal points; high current gain means comprising oppositely poled first and second transistors having commonly connected emitter electrodes, and base electrodes connecting said transistors across said first bridge diagonal points, each said transistor having collector electrodes; and, a heater comprising a third transistor having a collector electrode and an emitter electrode comprising a collector-emitter circuit connected across said second bridge diagonal points, said third transistor collector electrode being connected to said first transistor collector electrode, and a third transistor base electrode connected to said second transistor collector electrode, and including an electrical power source connected across said second bridge diagonal points.

Claim 6

A substrate temperature stabilizing circuit as recited in claim 3 with additionally nonlinear current limiting means connected in series with said third transistor collector-emitter circuit.

Claim 7

A substrate temperature stabilizing circuit as recited in claim 4 wherein said nonlinear current limiting means comprises a field effect transistor having a drain-source circuit serially connected with said third transistor collector-emitter circuit and a gate electrode connected to a common terminal of said field effect transistor and said third transistor.

Claim 8

A substrate temperature stabilizing circuit as recited in claim 3 wherein said resistance bridge comprises a first thermistor arm and second, third and fourth resistor arms with additionally a first diode connected in said thermistor arm and a second diode connected in one of said resistor arms.

Claim 9

A substrate temperature stabilizing circuit comprising a bridge having at least a thermistor arm and additionally having first and third bridge junction points comprising a first bridge diagonal and second and fourth bridge junction points comprising a second bridge diagonal and including at least a first diode connected in one of said bridge arms; high current gain means comprising oppositely poled first and second transistors having commonly connected emitter electrodes, and base electrodes connecting said transistors across said second bridge diagonal, said first transistor having a collector electrode connected to said first bridge junction point, said second transistor having a collector electrode; and, a third transistor having a base electrode connected to said second transistor collector electrode, and a collector-emitter circuit connected between said third bridge junction point and a junction of said first diode with said one bridge arm, said circuit including a power supply connected across said first and third bridge junction points.

Claim 10

A substrate temperature stabilizing circuit comprising a bridge having at least a thermistor arm and additionally having first and third bridge junction points comprising a first bridge diagonal and second and fourth bridge junction points comprising a second bridge diagonal and including at least a first diode connected in one of said bridge arms; high current gain means comprising oppositely poled first and second transistors having commonly connected emitter electrodes, and base electrodes connecting said transistors across said second bridge diagonal, said first transistor having a collector electrode connected to said first bridge junction point, said second transistor having a collector electrode; and, a third transistor having a base electrode connected to said second transistor collector electrode, and a collector-emitter circuit connected between said third bridge junction point and a junction of said first diode with said one bridge arm, said circuit including a power supply connected across said first and third bridge junction points.

Claim 11

A substrate temperature stabilizing circuit as recited in claim 7 with additionally nonlinear current limiting means connected in series with said third transistor collector-emitter circuit.

Claim 12

A substrate temperature stabilizing circuit as recited in claim 8 wherein said nonlinear current limiting means comprises a field effect transistor having a drain-source circuit serially connected with said third transistor collector-emitter circuit and a gate electrode connected to a common terminal of said field effect transistor and said third transistor.

Claim 13

A microcircuit for automatically stabilizing the temperature of a microcircuit substrate comprising: an electrical power source; a resistance bridge having first and second pairs of bridge diagonal points, said power source being connected across said first pair of bridge diagonal points; an operational amplifier having first and second input ports connected across said second pair of bridge diagonal points, and an output tap; a first transistor having a base electrode connected to one of said first pair of bridge diagonal points and collector and emitter electrodes; a second transistor having a base electrode connected to said first transistor emitter electrode, a collector electrode connected to said first transistor collector electrode, and an emitter electrode; and, a third transistor having a base electrode connected to said output tap, an emitter electrode connected to said second transistor emitter electrode, and a collector electrode, said first, second and third transistors being connected between said first transistor collector electrode and said third transistor collector electrode across said power source.

Claim 14

A microcircuit for automatically stabilizing the temperature of a microcircuit substrate comprising: an electrical power source; a resistance bridge having first and second pairs of bridge diagonal points, said power source being connected across said first pair of bridge diagonal points; an operational amplifier having first and second input ports connected across said second pair of bridge diagonal points, and an output tap; a first transistor having a base electrode connected to one of said first pair of bridge diagonal points and collector and emitter electrodes; a second transistor having a base electrode connected to said first transistor emitter electrode, a collector electrode connected to said first transistor collector electrode, and an emitter electrode; and, a third transistor having a base electrode connected to said output tap, an emitter electrode connected to said second transistor emitter electrode, and a collector electrode, said first, second and third transistors being connected between said first transistor collector electrode and said third transistor collector electrode across said power source.

Claim 15

A substrate temperature stabilizing circuit as recited in claim 10 with additionally nonlinear current limiting means connected in series with at least one of said first, second and third transistor collector-emitter circuits.

Claim 16

A substrate temperature stabilizing circuit as recited in claim 11 wherein said nonlinear current limiting means comprises a field effect transistor having a drain-source circuit serially connected with said first transistor collector-emitter circuit and a gate electrode connected to a common terminal of said field effect transistor and said first transistor.

Claim 17

A substrate temperature stabilizing circuit comprising: temperature sensor means for generating an electrical signal proportional to the deviation of said substrate temperature from a predetermined temperature; a power source; and, an operational amplifier means responsive to said electrical signal for generating a control signal, said operational amplifier means including a feedback circuit comprised of a plurality of base-emitter circuits of a plurality of transistors and having collector-emitter circuits connected across said power source, at least one of said transistors being responsive to said control signal for heating said substrate.

Claim 18

A substrate temperature stabilizing circuit comprising: temperature sensor means for generating an electrical signal proportional to the deviation of said substrate temperature from a predetermined temperature; a power source; and, an operational amplifier means responsive to said electrical signal for generating a control signal, said operational amplifier means including a feedback circuit comprised of a plurality of base-emitter circuits of a plurality of transistors and having collector-emitter circuits connected across said power source, at least one of said transistors being responsive to said control signal for heating said substrate.

Claim 19

A substrate temperature stabilizing circuit as recited in claim 13 with additionally nonlinear current limiting means for limiting the maximum current in said substrate heating transistor.