Temperature compensating circuit for an oscillator

Claim 2

An automatic frequency control for a reactance tuned oscillator, comprising: a source of direct voltage having positive and negative terminals for providing a voltage of reference magnitude; temperature sensitive means connected to said source positive and negative terminals and energized by said source voltage for producing a positive polarity output voltage having said reference magnitude and a further magnitude increasing thereabove in response to environmental temperature increases; first reactance tuning means included in said oscillator and activated by said temperature means positive polarity output voltage having said reference magnitude for providing a corresponding amount of reactance to set the frequency of said oscillator at a predetermined value; and second reactance tuning means connected to said temperature means and first tuning means and including a plurality of semiconductor diodes, each connected in series with a reactorresistor network; said diodes negative biased to different amounts above said source positive voltage reference magnitude to OFF states by said source voltage of negative polarity applied from said source negative terminal through said temperature means and network resistors to said diodes to disconnect said network reactors from said first tuning means as said temperature means positive polarity output voltage of said certain magnitude is applied to said first tuning means; said diodes turned ON in turn as said temperature means positive output voltage magnitude increases above said reference magnitude for overcoming said respective different amounts of biasing voltage in turn to connect said respective network reactors in turn in circuit with said first tuning means to provide respective step-amounts of reactance in turn to supplement said first tuning means reactance to further control the frequency of said oscillator to maintain the frequency deviation thereof at substantially zero value relative to said predetermined frequency value in response to said environmental temperature increases.

Claim 3

The automatic frequency control according to claim 1 in which said network reactors include discrete capacitors disconnected from said first tuning means as said diodes are in said OFF states and thereby rendered ineffective for supplementing said first tuning means reactance when said temperature means positive output voltage has said certain magnitude; said capacitors connected in turn in circuit with said first tuning means as said diodes are in said ON states in turn and thereby supplementing said first tuning means reactance as the magnitude of said temperature means positive output voltage increases above said certain magnitude to overcome said diode different amounts of biasing voltage in turn.

Claim 4

The automatic frequency control according to Claim 1 in which said network reactors include discrete inductors disconnected from said first tuning means as said diodes are in said OFF states and thereby rendered ineffective for supplementing said first tuning means reactance when said temperature means positive output voltage has said certain magnitude; said inductors connected in turn in circuit with said first tuning means as said diodes are in said ON states in turn and thereby supplementing said first tuning means reactance as the magnitude of said temperature means positive output voltage increases above said certain magnitude to overcome said diode different amounts of biasing voltage in turn.

Claim 5

The automatic frequency control according to claim 1 in which said respective diodes have first corresponding terminals connected in circuit with said source positive terminal and said first tuning means and also having other corresponding terminals connected to first corresponding terminals of said respective reactor-resistor networks whose other terminals are connected in circuit with said oscillator means and said source negative terminal.

Claim 6

The automatic frequency control according to claim 4 in which said reactors of said reactor-resistor networks are capacitors.

Claim 7

The automatic frequency control according to claim 4 in which said reactors of said reactor-resistor-resistor networks are inductors.

Claim 8

The automatic frequency control according to claim 4 in which said diodes are a zener type.

Claim 9

The automatic frequency control according to claim 4 in which said first tuning means includes a crystal; said diodes and network reactors being connected in circuit with said crystal.

Claim 10

An automatic frequency control for a reactance tuned oscillator, comprising: a source of direct voltage having positive and negative terminals for providing a voltage of reference magnitude; temperature sensitive means connected to said source positive and negative terminals and energized by said source voltage for producing a positive polarity output voltage having said reference magnitude and a further magnitude increasing thereabove in response to environmental temperature increases; a reactance tuning crystal included in said oscillator and activated by said temperature means positive output voltage having said reference magnitude for causing said crystal to produce a corresponding amount of reactance to set the frequency of said oscillator at a predetermined value; and Zener diode-capacitor-resistor tuning means for said oscillator, including a plurality of Zener diodes and parallel capacitor-resistor networks, each diode connected in series with one network; said respective diodes having first corresponding terminals connected in circuit with said source positive terminal and said crystal and also having other corresponding terminals connected to first corresponding terminals of said respective networks whose other terminals are connected to circuit with said source negative terminal and said oscillator for negative biasing of said diodes from said source negative terminal through said respective network resistors by different amounts of voltage above said source positive voltage reference magnitude to OFF states to disconnect said capacitors from said crystal when said temperature means positive output voltage of said certain magnitude is applied to said crystal and said diode first corresponding terminals; said diodes activated to ON states in turn as said temperature means positive output voltage magnitude increases above said reference magnitude to overcome said respective different amounts of biasing voltage in turn for connecting said respective capacitors in turn in circuit with said crystal to supplement said crystal reactance to vary the reactance tuning of said oscillator to maintain oscillator frequency deviation at a substantially zero value relative to said predetermined frequency value in response to said environmental temperature increases.

Claim 11

An automatic frequency control for a reactance tuned oscillator, comprising: a source of direct voltage having positive and negative terminals for providing a voltage of reference magnitude; temperature sensitive means connected to said source positive and negative terminals and energized by said source voltage for producing a positive polarity output voltage having said reference magnitude and a further magnitude increasing thereabove in response to environmental temperature increases; a reactance tuning crystal included in said oscillator and activated by said temperature means positive output voltage having said reference magnitude for causing said crystal to produce a corresponding amount of reactance to set the frequency of said oscillator at a predetermined value; and Zener diode-capacitor-resistor tuning means for said oscillator, including a plurality of Zener diodes and parallel capacitor-resistor networks, each diode connected in series with one network; said respective diodes having first corresponding terminals connected in circuit with said source positive terminal and said crystal and also having other corresponding terminals connected to first corresponding terminals of said respective networks whose other terminals are connected to circuit with said source negative terminal and said oscillator for negative biasing of said diodes from said source negative terminal through said respective network resistors by different amounts of voltage above said source positive voltage reference magnitude to OFF states to disconnect said capacitors from said crystal when said temperature means positive output voltage of said certain magnitude is applied to said crystal and said diode first corresponding terminals; said diodes activated to ON states in turn as said temperature means positive output voltage magnitude increases above said reference magnitude to overcome said respective different amounts of biasing voltage in turn for connecting said respective capacitors in turn in circuit with said crystal to supplement said crystal reactance to vary the reactance tuning of said oscillator to maintain oscillator frequency deviation at a substantially zero value relative to said predetermined frequency value in response to said environmental temperature increases.

Claim 12

An automatic frequency control for a reactance tuned oscillator, comprising: a source of direct voltage having positive and negative terminals for producing a voltage of reference magnitude; temperature sensitive means connected to said source positive and negative terminals and energized by said source voltage for producing a positive polarity output voltage having said reference magnitude and a further magnitude increasing thereabove in response to environmental temperature increases; a reactance tuning crystal included in said oscillator and activated by said temperature means positive output voltage having said reference magnitude for causing said crystal to produce a corresponding amount of reactance to set the frequency of said oscillator at a predetermined value; and Zener diode-inductor-resistor tuning means for said oscillator, including a plurality of Zener diodes, inductors and resistors, each diode, inductor and resistor connected in series; said respective diodes having first corresponding terminals connected in circuit with said source positive terminal and said crystal and also haviNg other corresponding terminals connected through associated inductors and resistors in circuit with said source negative terminal and said oscillator for negative biasing of said diodes by different amounts of voltage above said source positive voltage reference magnitude to OFF states to disconnect said inductors from said crystal when said temperature means positive output voltage of said certain magnitude is applied to said crystal and said diode first corresponding terminals; said diodes activated to ON states in turn as said temperature means positive output voltage magnitude increases above said reference magnitude to overcome said respective different amounts of biasing voltage in turn for connecting said respective inductors in turn in circuit with said crystal to supplement said crystal reactance to vary the reactance tuning of said oscillator to maintain oscillator frequency deviation at a substantially zero value relative to said predetermined frequency value in response to said environmental temperature increases.

Claim 13

An automatic frequency control for a reactance tuned oscillator, comprising: a source of direct voltage having positive and negative terminals for producing a voltage of reference magnitude; temperature sensitive means connected to said source positive and negative terminals and energized by said source voltage for producing a positive polarity output voltage having said reference magnitude and a further magnitude increasing thereabove in response to environmental temperature increases; a reactance tuning crystal included in said oscillator and activated by said temperature means positive output voltage having said reference magnitude for causing said crystal to produce a corresponding amount of reactance to set the frequency of said oscillator at a predetermined value; and Zener diode-inductor-resistor tuning means for said oscillator, including a plurality of Zener diodes, inductors and resistors, each diode, inductor and resistor connected in series; said respective diodes having first corresponding terminals connected in circuit with said source positive terminal and said crystal and also haviNg other corresponding terminals connected through associated inductors and resistors in circuit with said source negative terminal and said oscillator for negative biasing of said diodes by different amounts of voltage above said source positive voltage reference magnitude to OFF states to disconnect said inductors from said crystal when said temperature means positive output voltage of said certain magnitude is applied to said crystal and said diode first corresponding terminals; said diodes activated to ON states in turn as said temperature means positive output voltage magnitude increases above said reference magnitude to overcome said respective different amounts of biasing voltage in turn for connecting said respective inductors in turn in circuit with said crystal to supplement said crystal reactance to vary the reactance tuning of said oscillator to maintain oscillator frequency deviation at a substantially zero value relative to said predetermined frequency value in response to said environmental temperature increases.