Tuned oscillator circuit for providing a rotating magnetic field

Claim 2

A field drive circuit for providing a magnetic field rotating in a plane including: first and second tuned circuits, each of which provides a different one of two orthogonal magnetic field components comprising said rotating field; means for initiating and terminating said rotating field at a predetermined point in each field rotation cycle; means responsive to a first state of a binary control signal for starting first and second oscillatory field drive currents having a like frequency and a predetermined phase difference in said first and second tuned circuits, respectively; means for maintaining the amplitude envelopes of said first and second currents at a predetermined level; and means responsive to a second state of said binary control signal occurring during the last half of said cycle for terminating each of said currents at the end of an oscillation cycle without producing substantial ringing effects in said tuned circuits.

Claim 3

A field drive circuit for providing a magnetic field rotating in a plane including: first and second tuned circuits, each of which provides a different one of two orthogonal magnetic field components comprising said rotating field; means for initiating and terminating said rotating field at a predetermined point in each field rotation cycle; means responsive to a first state of a binary control signal for starting first and second oscillatory field drive currents having a like frequency and a predetermined phase difference in said first and second tuned circuits, respectively; means for maintaining the amplitude envelopes of said first and second currents at a predetermined level; and means responsive to a second state of said binary control signal occurring during the last half of said cycle for terminating each of said currents at the end of an oscillation cycle without producing substantial ringing effects in said tuned circuits.

Claim 4

A field drive circuit for providing a magnetic field rotating in a plane including: first and second tuned circuits, each of which provides a different one of two orthogonal magnetic field components comprising said rotating field; means for initiating and terminating said rotating field at a predetermined point in each field rotation cycle; means responsive to a first state of a binary control signal for starting first and second oscillatory field drive currents having a like frequency and a predetermined phase difference in said first and second tuned circuits, respectively; means for maintaining the amplitude envelopes of said first and second currents at a predetermined level; and means responsive to a second state of said binary control signal occurring during the last half of said cycle for terminating each of said currents at the end of an oscillation cycle without producing substantial ringing effects in said tuned circuits.

Claim 5

An oscillator circuit including: a series tuned circuit comprising a capacitor and at least one coil; means, connected to said series circuit, for precharging said capacitor in response to a first state of a first binary control signal; means, having first and second terminals connected across said series circuit, for switching said series circuit into a closed resonant loop and initiating an oscillatory current therein by shorting said terminals in response to the application of a second state of said binary signal to said switching means; means, connected across first and second points in said series circuit, for maintaining the envelope of said oscillatory current at full amplitude; and means, connected across said first and second terminals of said switching means, for terminating said oscillatory current at the end of any oscillation cycle without producing ringing effects in said loop in response to the application of said first state of said binary signal to said switching means at any time during the final half of such a cycle.

Claim 6

An oscillator circuit including: a series tuned circuit comprising a capacitor and at least one coil; means, connected to said series circuit, for precharging said capacitor in response to a first state of a first binary control signal; means, having first and second terminals connected across said series circuit, for switching said series circuit into a closed resonant loop and initiating an oscillatory current therein by shorting said terminals in response to the application of a second state of said binary signal to said switching means; means, connected across first and second points in said series circuit, for maintaining the envelope of said oscillatory current at full amplitude; and means, connected across said first and second terminals of said switching means, for terminating said oscillatory current at the end of any oscillation cycle without producing ringing effects in said loop in response to the application of said first state of said binary signal to said switching means at any time during the final half of such a cycle.

Claim 7

The oscillator circuit in accordance with claim 2 in which said maintaining means comprises a feedback network connected across said coil between said first and second points in said series circuit, said feedback network including means for sampling a signal representative of said oscillatory current at said first point and in response thereto coupling a proportional amount of regenerating current into said loop at said second point.

Claim 8

A field drive circuit including: first and second oscillator circuits, each of said oscillator circuits comprising, a series tuned circuit comprising a capacitor and at least one coil, means, connected to said series circuit, for precharging said capacitor in response to a first state of a first binary control signal, means, having first and second terminals connected across said series circuit, for switching said series circuit into a closed resonant loop and initiating an oscillatory current therein by shorting said terminals in response to the application of a second state of said binary signal to said switching means, means for maintaining the envelope of saId oscillatory current at a predetermined amplitude, and means, connected across said first and second terminals of said switching means, for terminating said oscillatory current at the end of any oscillation cycle without producing ringing effects in said loop in response to the application of said first state of said binary signal to said switching means at any time during the final half of such a cycle; means for coupling said binary control signal to said switching means of said first oscillator circuit and for delaying said signal by a predetermined amount and thereafter coupling the delayed signal to said switching means of said second oscillator circuit, for controlling the respective oscillations of the oscillatory currents in response thereto; a feedback network in said maintaining means of said first oscillator circuit, said network connecting between first and second circuit points in said series circuit of said first oscillator circuit; and a synchronization path in said maintaining means of said second oscillator circuit, said path connecting between said first circuit point in said series circuit of said first oscillator circuit and a third circuit point in said series circuit of said second oscillator circuit, for maintaining the envelope of said oscillatory current therein at full amplitude.

Claim 9

A field drive circuit including: first and second oscillator circuits, each of said oscillator circuits comprising, a series tuned circuit comprising a capacitor and at least one coil, means, connected to said series circuit, for precharging said capacitor in response to a first state of a first binary control signal, means, having first and second terminals connected across said series circuit, for switching said series circuit into a closed resonant loop and initiating an oscillatory current therein by shorting said terminals in response to the application of a second state of said binary signal to said switching means, means for maintaining the envelope of saId oscillatory current at a predetermined amplitude, and means, connected across said first and second terminals of said switching means, for terminating said oscillatory current at the end of any oscillation cycle without producing ringing effects in said loop in response to the application of said first state of said binary signal to said switching means at any time during the final half of such a cycle; means for coupling said binary control signal to said switching means of said first oscillator circuit and for delaying said signal by a predetermined amount and thereafter coupling the delayed signal to said switching means of said second oscillator circuit, for controlling the respective oscillations of the oscillatory currents in response thereto; a feedback network in said maintaining means of said first oscillator circuit, said network connecting between first and second circuit points in said series circuit of said first oscillator circuit; and a synchronization path in said maintaining means of said second oscillator circuit, said path connecting between said first circuit point in said series circuit of said first oscillator circuit and a third circuit point in said series circuit of said second oscillator circuit, for maintaining the envelope of said oscillatory current therein at full amplitude.

Claim 10

A field drive circuit comprising first and second oscillator circuits, each of said oscillator circuits comprising, a series tuned circuit compriring a capacitor and at least one coil, means, connected to said series circuit, for precharging said capacitor in response to a first state of a first binary control signal, means, having first and second terminals connected across said series circuit, for switching said series circuit into a closed resonant loop and initiating an oscillatory current therein by shorting said terminals in response to the application of a second state of said binary signal to said switching means, means for maintaining the envelope of said oscillatory current at full amplitude, and means, connected across said first and second terminals of said switching means, for terminating said oscillatory current at the end of any oscillation cycle without producing ringing effects in said loop in response to the application of said first state of said binary signal to said switching means at any time during the final half of such a cycle; first and second synchronization paths in the maintaining means of said first and second oscillator circuits, respectively, each of said synchronization paths interconnecting said oscillator circuits between different circuit points in said series circuits of said oscillator circuits; said first synchronization path including means for sampling a first signal representative of said oscillatory current in said first oscillator circuit and in response thereto cross-coupling a proportional amount of regenerating current into said second oscillator circuit; said second synchronization path including means for sampling a second signal representative of said oscillatory current in said second oscillator circuit and in response thereto cross-coupling a proportional amount of regenerating current into said first oscillator circuit; and means for coupling said first binary control signal to said switching means of said first oscillator circuit and for delaying said signal by a predetermined amount and thereafter coupling the delayed signal to said switching means of said second oscillator circuit, for controlling the respective oscillations of said field currents in response thereto.

Claim 11

A field drive circuit comprising first and second oscillator circuits, each of said oscillator circuits comprising, a series tuned circuit compriring a capacitor and at least one coil, means, connected to said series circuit, for precharging said capacitor in response to a first state of a first binary control signal, means, having first and second terminals connected across said series circuit, for switching said series circuit into a closed resonant loop and initiating an oscillatory current therein by shorting said terminals in response to the application of a second state of said binary signal to said switching means, means for maintaining the envelope of said oscillatory current at full amplitude, and means, connected across said first and second terminals of said switching means, for terminating said oscillatory current at the end of any oscillation cycle without producing ringing effects in said loop in response to the application of said first state of said binary signal to said switching means at any time during the final half of such a cycle; first and second synchronization paths in the maintaining means of said first and second oscillator circuits, respectively, each of said synchronization paths interconnecting said oscillator circuits between different circuit points in said series circuits of said oscillator circuits; said first synchronization path including means for sampling a first signal representative of said oscillatory current in said first oscillator circuit and in response thereto cross-coupling a proportional amount of regenerating current into said second oscillator circuit; said second synchronization path including means for sampling a second signal representative of said oscillatory current in said second oscillator circuit and in response thereto cross-coupling a proportional amount of regenerating current into said first oscillator circuit; and means for coupling said first binary control signal to said switching means of said first oscillator circuit and for delaying said signal by a predetermined amount and thereafter coupling the delayed signal to said switching means of said second oscillator circuit, for controlling the respective oscillations of said field currents in response thereto.

Claim 12

The field drive circuit in accordance with claim 5 including: means for coupling said first control signal to said switching means of said first oscillator circuit and for coupling said delayed first control signal to said switching means of said second oscillator circuit, in response to a first state of a second binary control signal; means for coupling said First control signal to said switching means of said second oscillator circuit and for coupling said delayed first control signal to said switching means of said first oscillator circuit, in response to a second state of said second control signal; and means responsive to a change in state of said second control signal for interchanging said circuit points between which said first and second synchronization paths interconnect.

Claim 13

An oscillator circuit including: a first serial conduction path comprising a current source, first and second terminals of an electronic switch which operates in response to a first binary control signal, and a point of reference potential serially connected in that order therein; a second conduction path including a diode shunting said terminals of said switch; a third conduction path connecting between said point of reference potential and said first terminal, including at least one coil and a capacitor connected therein in a tuned inductive-capacitive circuit; and a regenerative feedback path, connecting between the terminals of said coil in a path exclusive of said capacitor, for maintaining the amplitude envelope of an oscillatory current flowing therethrough at a predetermined level.

Claim 14

An oscillator circuit including: a first serial conduction path comprising a current source, first and second terminals of an electronic switch which operates in response to a first binary control signal, and a point of reference potential serially connected in that order therein; a second conduction path including a diode shunting said terminals of said switch; a third conduction path connecting between said point of reference potential and said first terminal, including at least one coil and a capacitor connected therein in a tuned inductive-capacitive circuit; and a regenerative feedback path, connecting between the terminals of said coil in a path exclusive of said capacitor, for maintaining the amplitude envelope of an oscillatory current flowing therethrough at a predetermined level.

Claim 15

The oscillator circuit in accordance with claim 7 in which said regenerative feedback path comprises a current amplifier and a phase shifter serially connected therein.

Claim 16

The oscillator circuit in accordance with claim 8 in which said phase shifter includes means for shifting the phase of a signal flowing therethrough by 90*; and said current amplifier includes means for shifting the phase of a signal flowing therethrough by 180*.

Claim 17

A field drive circuit for providing a magnetic field rotating in a plane including: first and second oscillator circuits, each of said oscillator circuits including a first serial conduction path comprising a current source, first and second terminals of an electronic switch which operates in response to a first binary control signal, and a point of reference potential serially connected in that order therein, a second conduction path including a diode shunting said terminals of said switch, and a third conduction path connecting between said point of reference potential and said first terminal, including at least one coil and a capacitor connected therein in an inductive-capacitive circuit; the magnetic axis of said coil in said first oscillator circuit intersecting at a substantially right angle with the magnetic axis of said coil in said second oscillator circuit, thereby defining said plane; control means for coupling said first control signal to said switch in said first oscillator circuit and for delaying said first control signal by a predetermined amount and thereafter coupling the delayed first signal to said switch of said second oscillator circuit; a first synchronizing path connecting between a first point in said third conduction path of said first oscillator circuit and a second point in said third conduction path of said second oscillator circuit, said first path including means for maintaining an oscillatory current in said third conduction path of said second oscillator circuit which has a substantially constant amplitude envelope level and a predetermined phase difference with respect to an oscillatory current flowing in said third conduction path of said first oscillator circuit.

Claim 18

A field drive circuit for providing a magnetic field rotating in a plane including: first and second oscillator circuits, each of said oscillator circuits including a first serial conduction path comprising a current source, first and second terminals of an electronic switch which operates in response to a first binary control signal, and a point of reference potential serially connected in that order therein, a second conduction path including a diode shunting said terminals of said switch, and a third conduction path connecting between said point of reference potential and said first terminal, including at least one coil and a capacitor connected therein in an inductive-capacitive circuit; the magnetic axis of said coil in said first oscillator circuit intersecting at a substantially right angle with the magnetic axis of said coil in said second oscillator circuit, thereby defining said plane; control means for coupling said first control signal to said switch in said first oscillator circuit and for delaying said first control signal by a predetermined amount and thereafter coupling the delayed first signal to said switch of said second oscillator circuit; a first synchronizing path connecting between a first point in said third conduction path of said first oscillator circuit and a second point in said third conduction path of said second oscillator circuit, said first path including means for maintaining an oscillatory current in said third conduction path of said second oscillator circuit which has a substantially constant amplitude envelope level and a predetermined phase difference with respect to an oscillatory current flowing in said third conduction path of said first oscillator circuit.