Transistor oscillator with diode in feedback circuit providing amplitude stabilization

Claim 2

An oscillator comprising: a resonant circuit including at least an inductance element and a capacitance element; an amplifying device having first, second and third electrodes; biasing means coupled between said second and third electrodes for conditioning said amplifying device for conduction; means for coupling said resonant circuit to said first electrode; and rectifier means coupling said resonant circuit to said third electrode of said amplifying device for sustaining oscillations in said resonant circuit, said rectifier means further providing charging of said capacitance element and reducing of the amplitude of oscillations fed back to said third electrode upon an increase of a first polarity portion of said oscillations beyond a predetermined level.

Claim 3

An oscillator as defined in claim 1 wherein said oscillator further includes a resistor coupled to said capacitance element to dissipate a portion of said charge.

Claim 4

An oscillator as defined in claim 1 Wherein said means for coupling said resonant circuit to said first electrode comprises a capacitor.

Claim 5

An oscillator as defined in claim 1 and further comprising a source of potential and a source of reference potential wherein said biasing means comprises a first resistor and a second resistor connected in series combination between said source of potential and said reference potential, and having a common connection of said first and second resistors coupled to said second electrode of said amplifying device thereby establishing a relatively constant potential on said third electrode.

Claim 6

An oscillator as defined in claim 4 wherein said biasing means further comprises a bypass capacitor coupled between said second electrode of said amplifying device and said source of reference potential.

Claim 7

An oscillator as defined in claim 1 wherein said amplifying device is a transistor wherein said first electrode is a collector and said second electrode is a base and said third electrode is an emitter.

Claim 8

An oscillator as defined in claim 1 wherein said resonant circuit includes a voltage-dependent capacitor and means for coupling a tuning potential to said voltage-dependent capacitor.

Claim 9

An oscillator as defined in claim 1 and further comprising a pickup coil coupled to said inductance element for providing an output signal from said oscillator.

Claim 10

An oscillator comprising: a resonant circuit comprising an inductance element, a capacitance element and a voltage-dependent capacitance; a transistor having collector, base and emitter electrodes; biasing means coupled between said base electrode and said emitter electrode to provide a relatively constant potential on said emitter electrode; means for coupling said collector electrode to said resonant circuit; a rectifier for coupling said resonant circuit to said emitter electrode of said transistor to sustain oscillations in said resonant circuit, said rectifier further providing charging of said capacitance element and reducing of the amplitude of oscillations fed back to said emitter electrode upon an increase of a first polarity portion of said oscillations beyond a predetermined level; and, a bleeder resistor coupled to said capacitance element to dissipate a portion of said charge.

Claim 11

An oscillator comprising: a resonant circuit comprising an inductance element, a capacitance element and a voltage-dependent capacitance; a transistor having collector, base and emitter electrodes; biasing means coupled between said base electrode and said emitter electrode to provide a relatively constant potential on said emitter electrode; means for coupling said collector electrode to said resonant circuit; a rectifier for coupling said resonant circuit to said emitter electrode of said transistor to sustain oscillations in said resonant circuit, said rectifier further providing charging of said capacitance element and reducing of the amplitude of oscillations fed back to said emitter electrode upon an increase of a first polarity portion of said oscillations beyond a predetermined level; and, a bleeder resistor coupled to said capacitance element to dissipate a portion of said charge.

Claim 12

An oscillator as defined in claim 9 and further comprising a source of potential and a source of reference potential wherein said biasing means comprises a first resistor and a second resistor connected in series combination between said source of potential and said source of reference potential and having a common connection of said first and second resistors coupled to said base of said transistor.

Claim 13

An oscillator as defined in claim 10 wherein said biasing means further comprises a bypass capacitor coupled between said base electrode of said transistor and said source of reference potential.

Claim 14

An oscillator as defined in claim 11 and further comprising an oscillator signal output coil coupled to said inductance element for providing an output signal from said oscillator.