Self-balancing bridge network

A self-balancing bridge network comprising:

• first and second terminals defining an input port for connection to an energizing supply;
• third and fourth terminals defining an output port;
• first and second conductive means connecting said first terminal respectively to said third terminal and to said fourth terminal and having conductances in 1:G ratio, G being a positive number;
• first and second transistors of a first conductivity type, each of them having respective first and second electrodes defining the ends of its principal current conduction path and having a respective third electrode, the conduction of its principal current conduction path being controlled by potential appearing between its first and third electrodes, the conduction of the principal current conduction path of said first transistor being H times that of said second transistor for any given value of first-to-third electrode potential, H being a positive number which multiplied by G exceeds unity, the second electrodes of said first and second transistors being galvanically connected respectively to said third terminal and to said fourth terminal;
• a resistor having a first end connected to the first electrode of said first transistor and having a second end connected to the first electrode of said second transistor and to said second terminal;
• third and fourth current-amplifying transistors of said first conductivity type, each of said transistors having first and second electrodes defining the ends of its principal current conduction path and having a respective third electrode, the conduction of its principal current conduction path being controlled by current applied to its third electrode, the current amplification between the third electrode and the principal current conduction path of each of said third and fourth transistors being substantially equal to that of the other;
• means direct coupling the first electrode of said third transistor to an interconnection between the third electrodes of said first and second transistors;
• means for galvanically connecting the second electrode of said third transistor to the first electrode of said fourth transistor;
• means for applying operating potential to the second electrode of said fourth transistor;
• current mirror amplifier means having an input connection to the third electrode of said fourth transistor and having an output connection for supplying a current G+1 times as great as the current demanded at its input connection;
• fifth and sixth transistors of a second conductivity type complementary to said first conductivity type, each of these transistors having respective first and second electrodes defining the ends of its principal current conduction path and having a respective third electrode, the conduction of its principal current conduction path being controlled by potential appearing between its first and third electrodes, the conduction of the principal current conduction path of said sixth transistor being G times as large as that of said fifth transistor for any given value of first-to-third electrode potential, the first electrodes of said fifth and sixth transistors being connected together at an interconnection to receive current from the output connection of said current mirror amplifier means, the third electrodes of said fifth and sixth transistors respectively being at said third terminal and at said fourth terminal;
• means for applying operating potential to the second electrode of said sixth transistor;
• such that current through that electrode does not flow to affect voltage at, or current to, the third electrode of said third transistor;
• and
• means for galvanically connecting the second electrode of said fifth transistor to the third electrode of said third transistor, so the currents flowing through these electrodes are the same.

A self-balancing bridge network comprising:

• first and second terminals defining an input port for connection to an energizing supply;
• third and fourth terminals defining an output port;
• first and second transistors of a first conductivity type and third and fourth transistors of a second conductivity type complementary to the first conductivity type, each of said transistors having respective first and second electrodes defining the ends of its principal current conduction path and having a respective third electrode, the conduction of its principal current path being controlled by potential appearing between its first and third electrodes;
• means for connecting said first and second transistors as a first current amplifier having an input connection at said third terminal, having a common connection at said first terminal, and having an output connection at said fourth terminal, said means including
• first and second galvanic connecting means between said first terminal and the first electrodes respectively of said first transistor and of said second transistor,
• third galvanic connecting means between the second electrode of said first transistor and said third terminal,
• fourth galvanic connecting means between the second electrode of said second transistor and said fourth terminal, and
• means exclusive of said fourth galvanic connecting means, directly responsive to the potential at said third terminal for controlling the potentials at the third electrodes of said first and second transistors, thereby completing a direct coupled voltage feedback connection between the second and third electrodes of said first transistor;
• means for connecting said third and fourth transistors as a second current amplifier having an input connection at said fourth terminal, having a common connection at said second terminal, and having an output connection at said third terminal, including
• fifth and sixth galvanic connecting means between said second terminal and the first electrodes respectively of said third transistor and of said fourth transistor,
• seventh galvanic connecting means between the second electrode of said third transistor and said fourth terminal,
• eighth galvanic connecting means between the second electrode of said fourth transistor and said third terminal, and
• differential-input amplifier means having inverting and non-inverting input connections respectively at said third and fourth terminals and having an output connection for directly controlling the potentials at the third electrodes of said third and fourth transistors;
• and
• current feedback means included in at least the second of said first and second current amplifiers to differentially degenerate the gains of its said transistors for reducing the product of the current gains of said first and second current amplifiers.

A self-balancing bridge network comprising:

• first and second terminals defining an input port for connection to an energizing supply;
• third and fourth terminals defining an output port;
• first and second transistors of a first conductivity type and third and fourth transistors of a second conductivity type complementary to the first conductivity type, each of said transistors having respective first and second electrodes
• fifth and sixth galvanic connecting means between said second terminal and the first electrodes respectively of said third transistor and of said fourth transistor,
• seventh galvanic connecting means between the second electrode of said third transistor and said fourth terminal,
• eighth galvanic connecting means between the second electrode of said fourth transistor and said third terminal,
• fifth and sixth transistors of a conductivity type complementary to said first conductivity type, each having respective first and second electrodes defining the ends of its principal current conduction path and having a respective third electrode, the conduction of its principal current conduction path being controlled by potential appearing between its first and third electrodes, the third electrode of said fifth transistor having said third terminal connected thereto the third electrode of said sixth transistor having said fourth terminal connected thereto, and the second electrode of said fifth transistor being direct coupled to the third electrodes of said third and fourth transistors for controlling their potentials, and
• means for completing connection of said fifth and sixth transistors in long-tailed-pair configuration including means for connecting the second electrode of said sixth transistor to said first terminal and
• means for applying tail current to an interconnection of the first electrodes of said fifth and sixth transistors;
• and
• current feedback means included in at least one of said first and second current amplifiers to differentially degenerate the gains of its said transistors for reducing the product of the current gains of said first and second current amplifiers.

A self-balancing bridge network comprising:

• first and second terminals defining an input port for connection to an energizing supply;
• third and fourth terminals defining an output port;
• first and second transistors of a first conductivity type and third and fourth transistors of a second conductivity type complementary to the first conductivity type, each of said transistors having respective first and second electrodes defining the ends of its principal current conduction path and having a respective third electrode, the conduction of its principal current path being controlled by potential appearing between its first and third electrodes;
• means for connecting said first and second transistors as a first current amplifier having an input connection at said third terminal, having a common connection at said first terminal, and having an output connection at said fourth terminal, said means including
• first and second galvanic connecting means between said first terminal and the first electrodes respectively of said first transistor and of said second transistor,
• third galvanic connecting means between the second electrode of said first transistor and said third terminal,
• fourth galvanic connecting means between the second electrode of said second transistor and said fourth terminal, and
• means exclusive of said fourth galvanic connecting means, directly responsive to the potential at said third terminal for controlling the potentials at the third electrodes of said first and second transistors, thereby completing a direct-coupled voltage feedback connection between the second and third electrodes of said first transistor;
• means for connecting said third and fourth transistors as a second current amplifier having an input connection at said fourth terminal, having a common connection at said second terminal, and having an output connection at said third terminal, including
• fifth and sixth galvanic connecting means between said second terminal and the first electrodes respectively of said third transistor and of said fourth transistor,
• seventh galvanic connecting means between the second electrode of said third transistor and said fourth terminal,
• eighth galvanic connecting means between the second electrode of said fourth transistor and said third terminal, and
• differential-input amplifier means having inverting and non-inverting input connections respectively at said third and fourth terminals and having an output connection for directly controlling the potentials at the third electrodes of said third and fourth transistors;
• and
• current feedback means included in at least one of said first and second current amplifiers to differentially degenerate the gains of its said transistors for reducing the product of the current gains of said first and second current amplifiers--said self-balancing bridge network being improved in that said differential-input amplifier means includes:
• fifth and sixth transistors, each having respective first and second electrodes defining the ends of its principal current conduction path and having a respective third electrode, the conduction of its principal current conduction path being controlled by potential appearing between its first and third electrodes, the inverting and non-inverting input connections of said differential-input amplifier respectively being at the third electrode of said fifth transistor and at the third electrode of said sixth transistor;
• and
• means for completing connection of said fifth and sixth transistors in long-tailed-pair configuration including
• means for applying tail current to an interconnection of the first electrodes of said fifth and sixth transistors, and including
• a current mirror amplifier having an input connection to which the second electrode of said sixth transistor connects and having an output connection to the output connection of said differential input amplifier.

A self-balancing bridge network comprising:

• first and second terminals defining an input port for connection to an energizing supply;
• third and fourth terminals defining an output port;
• first and second transistors of a first conductivity type and third and fourth transistors of a second conductivity type complementary to the first conductivity type, each of said transistors having respective first and second electrodes defining the ends of its principal current conduction path and having a respective third electrode, the conduction of its principal current path being controlled by potential appearing between its first and third electrodes;
• means for connecting said first and second transistors as a first current amplifier having an input connection at said third terminal, having a common connection at said first terminal, and having an output connection at said fourth terminal, said means including
• first and second galvanic connecting means between said first terminal and the first electrodes respectively of said first transistor and of said second transistor,
• third galvanic connecting means between the second electrode of said first transistor and said third terminal,
• fourth galvanic connecting means between the second electrode of said second transistor and said fourth terminal, and
• means directly responsive to the potential at said third terminal for controlling the potentials at the third electrodes of said first and second transistors, thereby completing a direct coupled voltage feedback connection between the second and third electrodes of said first transistor;
• means for connecting said third and fourth transistors as a second current amplifier having an input connection at said fourth terminal, having a common connection at said second terminal, and having an output connection at said third terminal, including
• fifth and sixth galvanic connecting means between said second terminal and the first electrodes respectively of said third transistor and of said fourth transistor,
• seventh galvanic connecting means between the second electrode of said third transistor and said fourth terminal,
• eighth galvanic connecting means between the second electrode of said fourth transistor and said third terminal, and
• differential-input amplifier means having inverting and non-inverting input connections respectively at said third and fourth terminals and having an output connection for directly controlling the potentials at the third electrodes of said third and fourth transistors;
• and
• current feedback means included in at least one of said first and second current amplifiers to differentially degenerate the gains of its said transistors for reducing the product of the current gains of said first and second current amplifiers, said self-balancing bridge network being improved in that
• said differential-input amplifier means includes
• fifth and sixth transistors of a conductivity type complementary to said first conductivity type, each having respective first and second electrodes defining the ends of its principal current conduction path and having a respective third electrode, the conduction of its principal current conduction path being controlled by potential appearing between its first and third electrodes, the inverting and non-inverting input connections of said differential-input amplifier respectively being at the third electrode of said fifth transistor and at the third electrode of said sixth transistor,
• means for completing connection of said fifth and sixth transistors in long-tailed-pair configuration including
• means for applying tail current to an interconnection of the first electrodes of said fifth and sixth transistors;
• a seventh transistor of said first conductivity type having first and second electrodes defining the ends of its principal current conduction path and having a third electrode, the conduction of its principal current conduction path being controlled by potential appearing between its first and third electrodes;
• means connecting said seventh transistor in common first electrode amplifier configuration, including
• means for direct coupling the second electrode of said seventh transistor to the output connection of said differential-input amplifier;
• and
• means differentially combining the current flowing through the second electrode of said fifth transistor with the current flowing through the second electrode of said sixth transistor for applying current to a node to which the third electrode of said seventh transistor connects.