Exciter apparatus for impact member solenoid

Claim 2

An excitation control circuit for a printer-actuating solenoid member of a high-speed printer mechanism, comprising: a semiconductor amplifier including a plurality of semiconductor devices, with the collector electrodes of said transistor devices being connected to a common terminal and thence to a groundable terminal of said printer-actuating solenoid member, said solenoid member having another terminal connected to a ground referenced source of direct current energy and having a voltage limiter circuit connected between said ground referenced source and said groundable terminal, said semiconductor amplifier having the emitter electrode of a prior transistor device connected to the base electrode of a succeeding transistor device, and having an input terminal connected to the base electrode of a first transistor device serving as an amplifier input terminal, with said common collector terminal serving as one amplifier output terminal and the emitter electrode of the final transistor device serving as another amplifier output terminal; a current-sensing resistance of a low value connected between the emitter electrode of the final transistor device and ground so as to have flowing therethrough the current flowing in said solenoid member and said final transistor device; a comparator transistor device having its base electrode connected to a junction point between said current-sensing resistance and the emitter electrode of said final transistor device, its emitter electrode connected to a source of reference potential, and its collector electrode connected through a diode to said amplifier input terminal; a frequency response determining capacitance element connected between the collector electrode and the base electrode of one transistor device in said semiconductor amplifier; a plurality of leakage current compensating resistances each connected with the base electrode of one transistor device so as to conduct away collector to base leakage current occurring within said transistor device; and a source of timed current signals for commanding desirable opening and closing of said actuating member, said source of signals being coupled to said amplifier input terminal.

Claim 3

Electrical apparatus for effecting intermittent mechanical actuation of a movable print hammer in a printing mechanism; the apparatus comprising; a source of direct current energy; electromagnetic transducer means having a movable member that is mechanically coupled with the movable print hammer, the transducer means being electrically connected with the source of direct current energy and including as parts thereof electrIcal windings and magnetic flux conducting structure, the transducer means providing means for converting energy from the source of direct current energy into energy that moves the print hammer; cascaded semiconductor linear amplifier means having an output port that is connected with the source of direct current energy and the electromagnetic transducer means, for controlling the flow of energy from the source of direct current energy to the electromagnetic transducer means, the amplifier means also having an input port for receiving amplifier controlling input signals, the amplifier being linearly responsive to analog signals applied to said input port; performance sensing means joined to the electromagnetic transducer means and the amplifier means for generating an analog electrical signal representative of the instantaneous magnetic performance of said electromagnetic transducer means; means for mixing the analog performance sensing means signal with two or more electromagnetic transducer means control signals, at least one of which is an intermittent control signal, and one of which is an analog transducer means current controlling signal and for supplying the mixed signals to the amplifier input port; whereby the current which excites the print hammer, and the print hammer, are time responsive to the intermittent control signal and are analog responsive to the analog transducer means current controlling signal.

Claim 4

Electrical apparatus for effecting intermittent mechanical actuation of a movable print hammer in a printing mechanism; the apparatus comprising; a source of direct current energy; electromagnetic transducer means having a movable member that is mechanically coupled with the movable print hammer, the transducer means being electrically connected with the source of direct current energy and including as parts thereof electrIcal windings and magnetic flux conducting structure, the transducer means providing means for converting energy from the source of direct current energy into energy that moves the print hammer; cascaded semiconductor linear amplifier means having an output port that is connected with the source of direct current energy and the electromagnetic transducer means, for controlling the flow of energy from the source of direct current energy to the electromagnetic transducer means, the amplifier means also having an input port for receiving amplifier controlling input signals, the amplifier being linearly responsive to analog signals applied to said input port; performance sensing means joined to the electromagnetic transducer means and the amplifier means for generating an analog electrical signal representative of the instantaneous magnetic performance of said electromagnetic transducer means; means for mixing the analog performance sensing means signal with two or more electromagnetic transducer means control signals, at least one of which is an intermittent control signal, and one of which is an analog transducer means current controlling signal and for supplying the mixed signals to the amplifier input port; whereby the current which excites the print hammer, and the print hammer, are time responsive to the intermittent control signal and are analog responsive to the analog transducer means current controlling signal.

Claim 5

Electrical circuitry in combination with a print hammer electrical solenoid structure for producing precise intermittent excitation thereof, said electrical circuitry being composed of: electrical windings magnetically coupled with said print hammer electrical solenoid structure, said electrical windings including a first terminal and a second terminal at the start and finish thereof; a source of direct current electrical energy capable of exciting said print hammer electrical solenoid electrical windings and having a first output terminal and a second output terminal; a bipolar power transistor having a base terminal, an emitter terminal, and a collector terminal; a current-sensing resistance element having electrical resistance less than one ohm and having a first electrical terminal and a second electrical terminal; means for connecting said source of direct current electrical energy, said electrical windings, said bipolar power transistor, and said current-sensing resistance element into a closed electrical circuit wherein said electrical windings first terminal is connected to said source of direct current electrical energy first output terminal, said electrical winding second terminal is connected to said bipolar power transistor collector terminal, said bipolar power transistor emitter terminal is connected with said current-sensing resistance element first electrical terminal, and said current-sensing resistance element is connected with said source of direct current electrical energy second output terminal; a transistor amplifier including a first junction transistor having collector, emitter, and base terminals and a second junction transistor having collector, emitter, and base terminals, said transistor amplifier having the collectors of the first and second junction transistors connected together and connected to the collector terminal of said bipolar power transistor and having the emitter terminal of the first junction transistor connected to the base terminal of the second junction transistor and the emitter terminal of the second junction transistor connected to the base terminal of said bipolar power transistor; whereby said transistor amplifier and said bipolar power transistor are connected into a Darlington circuit; an adjustable reference signal source capable of generating reference signals comparable with the voltage developed across said current-sensing resistance element; a junction transistor for comparing and mixing signals from said reference signal source and said current-sensing resistance element, said junction transistor for comparing and mixing signals having a base terminal that is connected to said current-sensing resistance element first electrical terminal, and an emitter terminal that is connected to said adjustable reference signal source, and a collector terminal that is connected with the base terminal of said transistor amplifier first junction transistor; and timed binary control signal source means connected with said base terminal of said transistor amplifier first junction transistor for supplying to said base terminal a binary signal capable of placing said first and second junction transistors in said transistor amplifier and said bipolar power transistor in the substantially nonconducting state and in the controlled conductivity state sequentially, thereby opening and closing said print hammer electrical solenoid structure.

Claim 6

Electrical circuitry in combination with a print hammer electrical solenoid structure for producing precise intermittent excitation thereof, said electrical circuitry being composed of: electrical windings magnetically coupled with said print hammer electrical solenoid structure, said electrical windings including a first terminal and a second terminal at the start and finish thereof; a source of direct current electrical energy capable of exciting said print hammer electrical solenoid electrical windings and having a first output terminal and a second output terminal; a bipolar power transistor having a base terminal, an emitter terminal, and a collector terminal; a current-sensing resistance element having electrical resistance less than one ohm and having a first electrical terminal and a second electrical terminal; means for connecting said source of direct current electrical energy, said electrical windings, said bipolar power transistor, and said current-sensing resistance element into a closed electrical circuit wherein said electrical windings first terminal is connected to said source of direct current electrical energy first output terminal, said electrical winding second terminal is connected to said bipolar power transistor collector terminal, said bipolar power transistor emitter terminal is connected with said current-sensing resistance element first electrical terminal, and said current-sensing resistance element is connected with said source of direct current electrical energy second output terminal; a transistor amplifier including a first junction transistor having collector, emitter, and base terminals and a second junction transistor having collector, emitter, and base terminals, said transistor amplifier having the collectors of the first and second junction transistors connected together and connected to the collector terminal of said bipolar power transistor and having the emitter terminal of the first junction transistor connected to the base terminal of the second junction transistor and the emitter terminal of the second junction transistor connected to the base terminal of said bipolar power transistor; whereby said transistor amplifier and said bipolar power transistor are connected into a Darlington circuit; an adjustable reference signal source capable of generating reference signals comparable with the voltage developed across said current-sensing resistance element; a junction transistor for comparing and mixing signals from said reference signal source and said current-sensing resistance element, said junction transistor for comparing and mixing signals having a base terminal that is connected to said current-sensing resistance element first electrical terminal, and an emitter terminal that is connected to said adjustable reference signal source, and a collector terminal that is connected with the base terminal of said transistor amplifier first junction transistor; and timed binary control signal source means connected with said base terminal of said transistor amplifier first junction transistor for supplying to said base terminal a binary signal capable of placing said first and second junction transistors in said transistor amplifier and said bipolar power transistor in the substantially nonconducting state and in the controlled conductivity state sequentially, thereby opening and closing said print hammer electrical solenoid structure.

Claim 7

Electrical circuitry in combination with a print hammer electrical solenoid structure as in claim 3 wherein said circuitry also includes energy dissipating voltage limiting means including an electrical diode and an electrical resistance element connected across said electrical windings first and second terminals for dissipating energy stored in the magnetic circuit of said electrical solenoid structure.

Claim 8

Apparatus for effecting precisely controlled intermittent contact between a printing font and media to be printed, said apparatus comprising the combination of: movable print hammer means for moving said printable media into pressured contact with said printing font; a source of direct current electrical energy; electrical solenoid means including electrical windings coupled to said source of direct current electrical energy and also including mechanical means connected with said movable print hammer means for transducing electrical energy from said source of direct current electrical energy into mechanical energy vested in said movable print hammer means; linear amplifier circuit means including an input port and cascaded variable conductivity elements the final one of which is connected electrically via an output port between said source of direct current electrical energy and said electrical windings of said electrical solenoid means for halting and for regulating the instantaneous magnitude of the flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means; current sensing means connected electrically between said source of direct current electrical energy and said electrical windings of said electrical solenoid means for generating an electrical signal representative of the instantaneous magnitude of the flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means; reference signal source means for producing an electrical signal comparable with the instantaneous magnitude of said current sensing means electrical signal at the instant when said flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means attains a desired predetermined magnitude; digital control signal source means including a source of binary electrical signals for determining the printing and the quiescent time intervals of said movable print hammer means; and signal comparing and mixing means connected with said current sensing means, said reference signal source means, and said digital control signal source means and said linear amplifier circuit means input port for comparing said current sensing means electrical signal with said reference signal source means electrical signal and generating therefrom a difference signal and for mixing said difference signal with said binary electrical signals from said digital control signal source means and for thereby generating and applying to said linear amplifier circuit means Input port a binary gated negative feedback difference signal capable of dynamically maintaining said linear amplifier circuit means variable conductivity elements in a linear operating region during the printing time interval of said digital control signal source means binary electrical signals.

Claim 9

Apparatus for effecting precisely controlled intermittent contact between a printing font and media to be printed, said apparatus comprising the combination of: movable print hammer means for moving said printable media into pressured contact with said printing font; a source of direct current electrical energy; electrical solenoid means including electrical windings coupled to said source of direct current electrical energy and also including mechanical means connected with said movable print hammer means for transducing electrical energy from said source of direct current electrical energy into mechanical energy vested in said movable print hammer means; linear amplifier circuit means including an input port and cascaded variable conductivity elements the final one of which is connected electrically via an output port between said source of direct current electrical energy and said electrical windings of said electrical solenoid means for halting and for regulating the instantaneous magnitude of the flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means; current sensing means connected electrically between said source of direct current electrical energy and said electrical windings of said electrical solenoid means for generating an electrical signal representative of the instantaneous magnitude of the flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means; reference signal source means for producing an electrical signal comparable with the instantaneous magnitude of said current sensing means electrical signal at the instant when said flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means attains a desired predetermined magnitude; digital control signal source means including a source of binary electrical signals for determining the printing and the quiescent time intervals of said movable print hammer means; and signal comparing and mixing means connected with said current sensing means, said reference signal source means, and said digital control signal source means and said linear amplifier circuit means input port for comparing said current sensing means electrical signal with said reference signal source means electrical signal and generating therefrom a difference signal and for mixing said difference signal with said binary electrical signals from said digital control signal source means and for thereby generating and applying to said linear amplifier circuit means Input port a binary gated negative feedback difference signal capable of dynamically maintaining said linear amplifier circuit means variable conductivity elements in a linear operating region during the printing time interval of said digital control signal source means binary electrical signals.

Claim 10

Apparatus for effecting precisely controlled intermittent contact as in claim 5 wherein said current sensing means includes an electrical resistance element having resistance less than one ohm.

Claim 11

Apparatus for effecting precisely controlled intermittent contact as in claim 5 wherein said final one of said variable conductivity elements in said linear amplifier circuit means includes a bipolar junction power transistor which is connected to at least one other bipolar junction transistor in a Darlington circuit configuration.

Claim 12

Apparatus for effecting precisely controlled intermittent contact as in claim 5 wherein said signal comparing and mixing means includes a bipolar transistor having a base electrode terminal which is connected with said current sensing means, an emitter electrode terminal which is connected with said reference signal source means, and a collector electrode terminal which is connected with said linear amplifier circuit means input port and to said digital control signal source means.

Claim 13

Apparatus for effecting rapid precisely controlled simultaneous pressure contact between a medium to be printed and plural locations on a continuously moving printing font, comprising the combination of: a plurality of movable print hammer means for moving said printable medium into pressure contact with said continuously moving printing font; a source of direct current electrical energy; plural electrical solenoid means each including a set of electrical windings connected with said source of direct current electrical energy and mechanical means connected with one of said print hammer means for transducing electrical energy from said source of direct current electrical energy into mechanical energy vested in said print hammer means; a plurality of linear amplifier circuit means each including an input port and cascaded variable conductivity elements at least one of which is connected electrically between said source of direct current electrical energy and said electrical windings of one of said electrical solenoid means for halting and for regulating the instantaneous magnitude of the flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means; a plurality of current sensing means each connected electrically between said source of direct current electrical energy and said electrical windings of said electrical solenoid means for generating an electrical signal representative of the instantaneous magnitude of the flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means; a single reference signal source means for producing an electrical signal comparable with the instantaneous magnitude of said current-sensing means electrical signal at the instant when said flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means attains a desired predetermined magnitude; a plurality of digital control signal source means each including a source of binary electrical signals for determining the printing and the quiescent time intervals of said movable print hammer means; and a plurality of signal comparing and mixing means each connected with said single reference signal source means, one of said current sensing means, one of said digital control signal source means, and one of said linear amplifier circuit means input ports for comparing said current sensing means electrical signal with said reference signal source means electrical signal and generating therefrom a difference signal And for mixing said difference signal with said binary electrical signals from said digital control signal source means and for thereby generating and applying to said linear amplifier circuit means input port a binary gated negative feedback difference signal capable of dynamically maintaining said linear amplifier circuit means variable conductivity elements in a linear operating region during the printing time interval of said digital control signal source means binary electrical signals.

Claim 14

Apparatus for effecting rapid precisely controlled simultaneous pressure contact between a medium to be printed and plural locations on a continuously moving printing font, comprising the combination of: a plurality of movable print hammer means for moving said printable medium into pressure contact with said continuously moving printing font; a source of direct current electrical energy; plural electrical solenoid means each including a set of electrical windings connected with said source of direct current electrical energy and mechanical means connected with one of said print hammer means for transducing electrical energy from said source of direct current electrical energy into mechanical energy vested in said print hammer means; a plurality of linear amplifier circuit means each including an input port and cascaded variable conductivity elements at least one of which is connected electrically between said source of direct current electrical energy and said electrical windings of one of said electrical solenoid means for halting and for regulating the instantaneous magnitude of the flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means; a plurality of current sensing means each connected electrically between said source of direct current electrical energy and said electrical windings of said electrical solenoid means for generating an electrical signal representative of the instantaneous magnitude of the flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means; a single reference signal source means for producing an electrical signal comparable with the instantaneous magnitude of said current-sensing means electrical signal at the instant when said flow of electrical energy between said source of direct current electrical energy and said electrical windings of said electrical solenoid means attains a desired predetermined magnitude; a plurality of digital control signal source means each including a source of binary electrical signals for determining the printing and the quiescent time intervals of said movable print hammer means; and a plurality of signal comparing and mixing means each connected with said single reference signal source means, one of said current sensing means, one of said digital control signal source means, and one of said linear amplifier circuit means input ports for comparing said current sensing means electrical signal with said reference signal source means electrical signal and generating therefrom a difference signal And for mixing said difference signal with said binary electrical signals from said digital control signal source means and for thereby generating and applying to said linear amplifier circuit means input port a binary gated negative feedback difference signal capable of dynamically maintaining said linear amplifier circuit means variable conductivity elements in a linear operating region during the printing time interval of said digital control signal source means binary electrical signals.

Claim 15

Exciter apparatus for inducing a rapid energy controlled pressure contact between imprintable paper and a continuously moving printing typefont, the exciter apparatus comprising the combination of: print hammer means including a movable ballistic print hammer for bringing said imprintable paper and said continuously moving printing typefont together in a pressured printing relationship; electrical energy to mechanical energy transducer apparatus including an electrical solenoid having electrical windings and a mechanical connection with said print hammer means for converting bursts of electrical energy into bursts of kinetic energy vested in said movable ballistic print hammer of said print hammer means; an electronic amplifier including at least two bipolar junction transistors having commonly connected collector terminals which are in turn connected to a first amplifier output terminal and having series-connected emitter and base terminals wherein an emitter terminal of a prior transistor is connected with a base terminal of a next succeeding transistor and having a base terminal of the first transistor connected to an amplifier input terminal and having an emitter terminal of the last transistor connected to a second amplifier output terminal; current-sensing means including an electrical resistance having a value less than one ohm and having one terminal thereof connected to said second amplifier output terminal for generating a voltage signal proportional in magnitude to the current flowing in said current sensing means and said electronic amplifier; direct current energy source means for exciting said electrical solenoid; connecting means for connecting said electrical solenoid of said electrical energy to mechanical energy transducer apparatus, said first and second amplifier output terminals of said electronic amplifier, said current sensing means, and said direct current energy source means into a series circuit wherein excitation current for said electrical solenoid of said electrical energy to mechanical energy transducer apparatus flows; reference potential source means for generating a voltage signal comparable with said voltage signal generated by said electrical resistance of said current-sensing means when a predetermined current flows therein; negative feedback means including a comparator transistor of the junction type having a base terminal that is connected to said second amplifier output terminal of said electronic amplifier and an emitter terminal connected to said reference potential source means and a collector terminal connected with said amplifier input terminal for comparing said current sensing means voltage signal with said reference potential source means voltage signal and for generating from said signals as a negative feedback signal capable of dynamically maintaining said electronic amplifier in a conducting but non-saturated state and maintaining said current sensing means voltage signal comparable with said reference potential source means voltage signal; frequency response determining means connected with the signal transmission path of said electronic amplifier for limiting the high-frequency response of said electronic amplifier to a frequency band wherein said amplifier is dynamically stable; leakage current compensating means connected with at least one of said bipolar junction transistors in said electronic amplifier for precluding leakage current conduction in said electronic amplifier; anD digital signal source means including a source of digital signals connected with said amplifier input and capable of overcoming said negative feedback signal generated by said comparator transistor in said negative feedback means for terminating conductivity in said electronic amplifier between actuations of said print hammer means.

Claim 16

Exciter apparatus for inducing a rapid energy controlled pressure contact between imprintable paper and a continuously moving printing typefont, the exciter apparatus comprising the combination of: print hammer means including a movable ballistic print hammer for bringing said imprintable paper and said continuously moving printing typefont together in a pressured printing relationship; electrical energy to mechanical energy transducer apparatus including an electrical solenoid having electrical windings and a mechanical connection with said print hammer means for converting bursts of electrical energy into bursts of kinetic energy vested in said movable ballistic print hammer of said print hammer means; an electronic amplifier including at least two bipolar junction transistors having commonly connected collector terminals which are in turn connected to a first amplifier output terminal and having series-connected emitter and base terminals wherein an emitter terminal of a prior transistor is connected with a base terminal of a next succeeding transistor and having a base terminal of the first transistor connected to an amplifier input terminal and having an emitter terminal of the last transistor connected to a second amplifier output terminal; current-sensing means including an electrical resistance having a value less than one ohm and having one terminal thereof connected to said second amplifier output terminal for generating a voltage signal proportional in magnitude to the current flowing in said current sensing means and said electronic amplifier; direct current energy source means for exciting said electrical solenoid; connecting means for connecting said electrical solenoid of said electrical energy to mechanical energy transducer apparatus, said first and second amplifier output terminals of said electronic amplifier, said current sensing means, and said direct current energy source means into a series circuit wherein excitation current for said electrical solenoid of said electrical energy to mechanical energy transducer apparatus flows; reference potential source means for generating a voltage signal comparable with said voltage signal generated by said electrical resistance of said current-sensing means when a predetermined current flows therein; negative feedback means including a comparator transistor of the junction type having a base terminal that is connected to said second amplifier output terminal of said electronic amplifier and an emitter terminal connected to said reference potential source means and a collector terminal connected with said amplifier input terminal for comparing said current sensing means voltage signal with said reference potential source means voltage signal and for generating from said signals as a negative feedback signal capable of dynamically maintaining said electronic amplifier in a conducting but non-saturated state and maintaining said current sensing means voltage signal comparable with said reference potential source means voltage signal; frequency response determining means connected with the signal transmission path of said electronic amplifier for limiting the high-frequency response of said electronic amplifier to a frequency band wherein said amplifier is dynamically stable; leakage current compensating means connected with at least one of said bipolar junction transistors in said electronic amplifier for precluding leakage current conduction in said electronic amplifier; anD digital signal source means including a source of digital signals connected with said amplifier input and capable of overcoming said negative feedback signal generated by said comparator transistor in said negative feedback means for terminating conductivity in said electronic amplifier between actuations of said print hammer means.

Claim 17

Apparatus for controlling the flow of electrical energy between a source of direct current energy and a print hammer magnetic actuator, said apparatus comprising: a current-sensing resistance element having electrical resistance less than one ohm; circuit means including a bipolar junction power transistor having emitter, base, and collector terminals and including the emitter-to-collector current flow path therein for completing a series electrical circuit that also includes said source of direct current energy, said print hammer magnetic actuator and said current sensing resistance; an adjustable source of reference signals capable of generating voltage signals comparable with voltage signals appearing across said current-sensing resistance when a predetermined magnitude of print hammer magnetic actuator current flows therein; a linear mode current amplifier circuit having input and output ports and including at least one linear mode amplifier transistor, said current amplifier output port being connected to said bipolar junction power transistor base terminal; a junction transistor having a base terminal connected to said current sensing resistance element, an emitter terminal connected to said adjustable source of reference signals, and a collector terminal connected via a signal path with said input port of said linear mode current amplifier circuit; and a switching transistor source of digital control signals connected with said linear mode current amplifier circuit input port for controlling the conducting and nonconducting time intervals of said bipolar junction power transistor, whereby said junction transistor, said bipolar junction power transistor, and said linear mode current amplifier circuit are contained within a linear closed loop negative feedback circuit.

Claim 18

Apparatus for controlling the flow of electrical energy between a source of direct current energy and a print hammer magnetic actuator, said apparatus comprising: a current-sensing resistance element having electrical resistance less than one ohm; circuit means including a bipolar junction power transistor having emitter, base, and collector terminals and including the emitter-to-collector current flow path therein for completing a series electrical circuit that also includes said source of direct current energy, said print hammer magnetic actuator and said current sensing resistance; an adjustable source of reference signals capable of generating voltage signals comparable with voltage signals appearing across said current-sensing resistance when a predetermined magnitude of print hammer magnetic actuator current flows therein; a linear mode current amplifier circuit having input and output ports and including at least one linear mode amplifier transistor, said current amplifier output port being connected to said bipolar junction power transistor base terminal; a junction transistor having a base terminal connected to said current sensing resistance element, an emitter terminal connected to said adjustable source of reference signals, and a collector terminal connected via a signal path with said input port of said linear mode current amplifier circuit; and a switching transistor source of digital control signals connected with said linear mode current amplifier circuit input port for controlling the conducting and nonconducting time intervals of said bipolar junction power transistor, whereby said junction transistor, said bipolar junction power transistor, and said linear mode current amplifier circuit are contained within a linear closed loop negative feedback circuit.

Claim 19

Apparatus for controlling the flow of electrical energy as in claim 11 wherein said signal path connecting said junction transistor collector terminal with said input port of said linear mode amplifier circuit includes a semiconductor diode element.

Claim 20

Apparatus for controlling the flow of electrical energy as in claim 11 wherein said linear mode current amplifier circuit includes frequency response controlling means for limiting the high-frequency response of said amplifier circuit and transistor leakage current-controlling means for nullifying the effect of transistor leakage currents in said amplifier.