Transistor control apparatus

Claim 2

Control apparatus, comprising a. transistor means having collector, base, and emitter electrodes and a collector-base junction; b. means for connecting a turn-on source to provide a driving signal to said base electrode having a magnitude sufficient to drive said transistor into a saturated condition; and c. means for establishing current flow through said collectorbase junction to reverse bias said junction to enable said transistor to turn off quickly; d. said reverse bias establishing means including transformer means having primary and secondary winding means, an isolating rectifier means, and means for connecting a reverse bias source to said primary winding; e. secondary winding means of said transformer means being connected in a circuit with said collector-base junction to enable current from secondary winding means to flow through said collector-base junction in a reverse bias direction; f. said isolating rectifier means being connected in a circuit between said collector and base electrodes which includes at least one of said primary and secondary winding means to prevent current flow between said collector and base electrodes through said winding means in response to potential differences between said collector and base electrodes which establish a forward bias on said collector-base junction; g. primary winding means of said transformer means being connected to receive current from a reverse bias source which will induce a potential on the secondary winding means connected in circuit with said collector-base junction to cause current flow through said collector-base junction in a direction to reverse bias said collector-base junction and discharge the minority carriers from said junction if saturated to enable said transistor to turn off quickly.

Claim 3

Apparatus as defined in claim 1 which further includes means responsive to saturation of said transistor for enabling current flow in winding means of said transformer means.

Claim 4

Apparatus as defined in claim 1 which further includes means responsive to removal of a driving signal to said base electrode for enabling current flow in winding means of said transformer means.

Claim 5

Apparatus as defined in claim 1 which further includes means responsive to a coincidence of a removal of a driving signal to said base electrode and to saturation of said transistor for enabling current flow in winding means of said transformer means.

Claim 6

Apparatus as defined in claim 2 in which said saturation responsive means includes means connecting winding means of said transformer means in a series circuit with said isolating rectifying means wherein said isolating rectifying means is reverse biased until saturation of said transistor means occurs.

Claim 7

Apparatus as defined in claim 1 in which said means for connecting a revErse bias source to said primary winding means includes switching means, interposed between the reverse bias source and primary winding means of said transformer means, which is responsive to a turn-off signal to connect said reverse bias source to said primary winding.

Claim 8

Apparatus as defined in claim 6 in which said switching means includes a. second transistor means responsive to a turn-off signal to supply driving current to said pressure winding means, and b. feedback means responsive to the driving current required by said primary winding means for regulating the output of said second transistor means.

Claim 9

Apparatus as defined in claim 6 which further includes means for also connecting said primary winding means driving current to the base electrode of said first-mentioned transistor means, thereby enabling said feedback means to control the driving of said first-mentioned transistor means to maintain the first-mentioned transistor means near saturation as current flow through the collector-emitter circuit thereof varies.

Claim 10

Apparatus as defined in claim 1 which further includes means for preventing drive current at the base electrode of said transistor means from flowing through said primary winding means.

Claim 11

Apparatus as defined in claim 6 in which one end of said primary winding means and the side of the reverse bias switching means opposite from the reverse bias source is connected to said base electrode.

Claim 12

Apparatus as defined in claim 10 which further includes rectifier means connected between a connection of the reverse bias source to said base electrode and said one end of said primary winding to prevent current flow from a turn-on source through said primary winding.

Claim 13

Apparatus as defined in claim 1 in which a. a first switching means is interposed between a turn-on source and said base electrode and is responsive to a turn-on signal to connect said turn-on source to said base electrode, b. a second switching means is interposed between said reverse bias source and said primary winding and is responsive to a turn-off signal to connect said reverse bias source to said primary winding.

Claim 14

Control apparatus, comprising a. transistor means having collector, base, and emitter electrodes with collector-base and base-emitter junctions between said electrodes; b. means for connecting a turn-on source to provide a driving signal to said base electrode having a magnitude sufficient to turn said transistor on and drive said transistor into a saturated condition; and c. means for establishing current flow through said collector-base junction to reverse bias said junction to enable said transistor to turn off quickly; d. said reverse bias establishing means including a transformer having primary and secondary windings, an isolating rectifier means, and means for connecting a reverse bias source to said primary winding; e. at least one of said primary and secondary windings being connected in a circuit across said collector-base junction with said isolating rectifier means, said isolating rectifier means being connected to prevent current flow between said collector electrode and said base electrode through windings of said transformer in response to potential differences establishing a forward bias across said collector-base junction; f. said primary winding being connected to receive current from a reverse bias source which will induce a potential on said secondary winding to cause current flow through said isolating rectifier means in the forward direction and through said collector-base junction in a direction to reverse bias said collector-base junction and discharge the minority carriers from the saturated junction to enable said transistor to turn off quickly.

Claim 15

Control apparatus, comprising a. transistor means having collector, base, and emitter electrodes with collector-base and base-emitter junctions between said electrodes; b. means for connecting a turn-on source to provide a driving signal to said base electrode having a magnitude sufficient to turn said transistor on and drive said transistor into a saturated condition; and c. means for establishing current flow through said collector-base junction to reverse bias said junction to enable said transistor to turn off quickly; d. said reverse bias establishing means including a transformer having primary and secondary windings, an isolating rectifier means, and means for connecting a reverse bias source to said primary winding; e. at least one of said primary and secondary windings being connected in a circuit across said collector-base junction with said isolating rectifier means, said isolating rectifier means being connected to prevent current flow between said collector electrode and said base electrode through windings of said transformer in response to potential differences establishing a forward bias across said collector-base junction; f. said primary winding being connected to receive current from a reverse bias source which will induce a potential on said secondary winding to cause current flow through said isolating rectifier means in the forward direction and through said collector-base junction in a direction to reverse bias said collector-base junction and discharge the minority carriers from the saturated junction to enable said transistor to turn off quickly.

Claim 16

Apparatus as defined in claim 13 which further includes means responsive to saturation of said transistor for enabling current flow in primary winding means of said transformer.

Claim 17

Apparatus as defined in cliam 14 in which sAid saturation responsive means includes means for connecting said primary winding to receive a reverse bias source potential from said turn-on source, and means for connecting said secondary winding across said collector and base electrodes so that flow therethrough is prevented until saturation of said transistor thereby reflecting a high impedance back to said primary winding and preventing current flow therethrough.

Claim 18

Apparatus as defined in cliam 14 in which sAid saturation responsive means includes means for connecting said primary winding to receive a reverse bias source potential from said turn-on source, and means for connecting said secondary winding across said collector and base electrodes so that flow therethrough is prevented until saturation of said transistor thereby reflecting a high impedance back to said primary winding and preventing current flow therethrough.

Claim 19

Apparatus as defined in claim 14 in which said saturation responsive means includes connecting one end of said primary winding to said base electrode and one side of said turn-on source and the other end of said primary winding to the other side of said turn-on source, while connecting said secondary winding between said base and collector electrodes via said isolating rectifier means.

Claim 20

Apparatus as defined in claim 13 which further includes means responsive to removal of a driving signal to said base electrode for enabling current flow in primary winding means of said transformer means.

Claim 21

Apparatus as defined in claim 13 in which said secondary winding and said isolating rectifier means are connected between said base electrode and said collector electrode.

Claim 22

Apparatus as defined in claim 18 in which one end of said primary winding is connected to said base electrode.

Claim 23

Apparatus as defined in claim 19 in which said reverse bias source for said primary winding is derived from said driving current for said transistor means.

Claim 24

Apparatus as defined in claim 19 which further includes rectifier means connected between said base electrode and said primary winding to prevent the flow of transistor driving current through said primary winding.

Claim 25

Apparatus as defined in claim 18 in which said means for connecting a reverse bias source to said primary winding includes second and third transistors, said second transistor being responsive to a turn-off signal to enable said third transistor to connect a reverse bias source to supply driving current to said primary winding.

Claim 26

Apparatus as defined in claim 22 which further includes feedback means responsive to the driving current supplied to said primary winding for regulating the output of said second transistor means.

Claim 27

Apparatus as defined in claim 23 in which the end of said primary winding receiving driving current from said reverse bias source is also connected to said base electrode of said first-mentioned transistor means, thereby enabling said feedback means to maintain said first-mentioned transistor means near saturation as the current flow through the collector-emitter circuit varies and thus also varies the current flow through said secondary winding connected to the collector electrode of said first-mentioned transistor means.

Claim 28

Apparatus as defined in claim 18 in which said primary winding has one end connected to said base electrode and derives the reverse bias source from the driving current for said transistor.

Claim 29

In a system for supplying operating potential to a load device wherein at least two transversely oriented conductors are dielectrically isolated from a gas discharge medium between said two conductors, comprising a. voltage wave form generating means adapted to be connected to a transverse conductor; b. said wave form generating means including at least one transistor means operating as a switching means between an operating potential and a transverse conductor, said transistor means having collector, base, and emitter electrodes and a collector-base junction; c. means for applying a turn-on signal to said base electrode having a magnitude sufficient to turn said transistor on and drive said transistor into a saturated condition; and d. means for selectively establishing current flow through said collector-base junction to reverse bias said junction; e. secondary winding means of said transformer means being connected in a circuit with said collector-base junction to enable current from secondary winding means to Flow through said collector-base junction in a reverse bias direction; f. said isolating rectifier means being connected in a circuit between said collector and base electrodes which includes at least one of said primary and secondary winding means to prevent current flow between said collector and base electrodes through said winding means in response to potential differences between said collector and base electrodes which establish a forward bias on said collector-base junction; g. primary winding means of said transformer means being connected to receive current from a reverse bias source which will induce a potential on the secondary winding means connected in circuit with said collector-base junction to cause current flow through said collector-base junction in a direction to reverse bias said collector-base junction and discharge the minority carriers from said junction if saturated to enable said transistor to turn off quickly.

Claim 30

In a system for supplying operating potential to a load device wherein at least two transversely oriented conductors are dielectrically isolated from a gas discharge medium between said two conductors, comprising a. voltage wave form generating means adapted to be connected to a transverse conductor; b. said wave form generating means including at least one transistor means operating as a switching means between an operating potential and a transverse conductor, said transistor means having collector, base, and emitter electrodes and a collector-base junction; c. means for applying a turn-on signal to said base electrode having a magnitude sufficient to turn said transistor on and drive said transistor into a saturated condition; and d. means for selectively establishing current flow through said collector-base junction to reverse bias said junction; e. secondary winding means of said transformer means being connected in a circuit with said collector-base junction to enable current from secondary winding means to Flow through said collector-base junction in a reverse bias direction; f. said isolating rectifier means being connected in a circuit between said collector and base electrodes which includes at least one of said primary and secondary winding means to prevent current flow between said collector and base electrodes through said winding means in response to potential differences between said collector and base electrodes which establish a forward bias on said collector-base junction; g. primary winding means of said transformer means being connected to receive current from a reverse bias source which will induce a potential on the secondary winding means connected in circuit with said collector-base junction to cause current flow through said collector-base junction in a direction to reverse bias said collector-base junction and discharge the minority carriers from said junction if saturated to enable said transistor to turn off quickly.