Current proportioning circuit

Claim 2

In combination: first and second transistors, each having base and emitter electrodes with a base emitter junction therebetween and each having a collector electrode, their emitter electrodes being joined at a first interconnection; first and second conductive paths connecting respective ones of the base electrodes of said first and said second transistors to a second interconnection; 2n semiconductor diodes, n of which are included in said first conductive path without other substantial intervening elements and poled for serial forward conduction with said first transistor base-emitter junction, and n others of which are included in said second conductive path without other substantial intervening elements and poled for serial conduction with said second transistor base-emitter junction, n being a positive integer; a first current supply coupled in circuit with said first conductive path to forward bias each semiconductor junction therein; a second current supply; and means connecting said second current supply between said first interconnection and each of the collector electrodes of said first and said second transistors, including: a first current utilization means in the connection of said second current supply to said first transistor collector electrode, the base current flow of said second transistor resulting from the aforesaid connections of the aforesaid elements providing the sole means to forward bias each said semiconductor junction in said second conductive path.

Claim 3

The combination set forth in claim 1 having: 2n further transistors, each having a base and an emitter electrodes with a semiconductor junction therebetween, each having a collector electrode to which its said base electrode is connected and each providing between its said collector and said emitter electrodes one of said 2n semiconductor diodes.

Claim 4

The combination set forth in claim 1 having: a third and a fourth transistors, each having a base and an emitter electrodes with an emitter-base junction therebetween, each having a collector electrode, their base electrodes being connected to said second interconnection and their respective base-emitter junctions providing one of the diodes in said first and in said second conductive paths, respectively; and means connected to each of the collector electrodes of said third and said fourth transistors for biasing them for normal transistor operation.

Claim 5

The combination set forth in claim 3, wherein n exceeds 1, having: 2n-2 further transistors each having a base and an emitter electrodes with a semiconductor junction therebetween, each having a collector electrode to which its base electrode is connector and each providing between its collector and emitter electrodes one of said 2n semiconductor diodes not provided by the base-emitter junctions of said third and said fourth transistors.

Claim 6

The combination set forth in claim 1 having: first and second current amplifiers each having an input circuit and an output circuit, the input circuit of said first current amplifier having said first transistor collector electrode connected thereto, and corresponding to said first current utilization means, the input circuit of said second current amplifier connecting said second transistor collector electrode to said second current supply, the input circuit of said second transistor also being included in said means connecting said second current supply between said first interconnection and each of the collector electrodes of said first and said second transistors, as a second current utilization means.

Claim 7

The combination set forth in claim 5 wherein said first current supply comprises means for additively combining the output currents from the output circuits of said first and said second current amplifiers to which it is connected, to obtain said first current.

Claim 8

The combination of: first and second transistors, each having base, emitter and collector electrodes, connected emitter electrode-to-emitter electrode, and a current source coupled between the emitter electrodes and the respective collector electrodes of said transistors for supplying the collector-to-emitter currents of said transistors; a third transistor having base, emitter, and collector electrodes; means connecting said third transistor emitter electrode to said second transistor base electrode and serving as the principal path for the base current flow of said second transistor, whereby the emitter current of said third transistor and the base current of said second transistor substantially equal each other; means supplying a current via the emitter-to-collector path of said third transistor to the base electrode of said second transistor; a common connection; two paths, the first between said common connection and the base electrode of said first transistor, and the second between said common connection and the base electrode of said second transistor, said second path including at least one diode comprising the base-emitter diode of the third transistor, and said first path including the same number of diodes as said second path, said diodes being connected to conduct current in the forward direction relative to the base-emitter diodes of the first and second transistors; and means connected between said common connection and the emitter electrodes of said first and said second transistors for applying currents in the forward direction through the first and second paths, the former of which currents is larger than the latter.

Claim 9

The combination of: first and second transistors, each having base, emitter and collector electrodes, connected emitter electrode-to-emitter electrode, and a current source coupled between the emitter electrodes and the respective collector electrodes of said transistors for supplying the collector-to-emitter currents of said transistors; a third transistor having base, emitter, and collector electrodes; means connecting said third transistor emitter electrode to said second transistor base electrode and serving as the principal path for the base current flow of said second transistor, whereby the emitter current of said third transistor and the base current of said second transistor substantially equal each other; means supplying a current via the emitter-to-collector path of said third transistor to the base electrode of said second transistor; a common connection; two paths, the first between said common connection and the base electrode of said first transistor, and the second between said common connection and the base electrode of said second transistor, said second path including at least one diode comprising the base-emitter diode of the third transistor, and said first path including the same number of diodes as said second path, said diodes being connected to conduct current in the forward direction relative to the base-emitter diodes of the first and second transistors; and means connected between said common connection and the emitter electrodes of said first and said second transistors for applying currents in the forward direction through the first and second paths, the former of which currents is larger than the latter.