Crystal oscillator with stepped variable capacitor

Claim 2

A stepped variable capacitor comprising a substrate; a plurality of capacitor elements deposited on said substrate, each of said capacitor elements consisting of a common electrode, an output electrode, and a dielectric sandwiched between said common and output electrodes; a contact member having a plurality of flexible contact fingers, one of said contact fingers being positioned in registration with the output electrode of each of said capacitor elements for displacement into and out of electrical engagement therewith; and means for selectively positioning each of said contact fingers either in or out of engagement with its respective output electrode, whereby the capacitance of said stepped variable capacitor may be varied step by step by selecting combinations of said capacitor elements by the selective operation of said means for positioning said contact fingers.

Claim 3

A stepped variable capacitor as recited in claim 1, wherein said means for selectively positioning each of said contact fingers includes a screw secured to each of said contact fingers and mounted for displacement for carrying said contact fingers into and out of electrical contact with their respective output electrodes

Claim 4

A stepped variable capacitor as recited in claim 1, wherein said contact fingers are formed of a resilient material normally biased to be positioned out of electrical contact with the associated output electrodes.

Claim 5

A stepped variable capacitor as recited in claim 1, wherein the common electrode and dielectric of all of said capacitor elements are formed as a unit deposited on said substrate, each of said output electrodes being spaced from the other of said output electrode.

Claim 6

A stepped variable capacitor as recited in claim 4, wherein said output electrodes are each of a different dimension, whereby each of said capacitor elements have a different capacitance.

Claim 7

A stepped variable capacitor as recited in claim 5, wherein the output electrodes are dimensioned so that the capacitance value of said capacitance elements varies in accordance with a geometric progression.

Claim 8

A stepped variable capacitor as recited in claim 1, wherein said contact member is substantially comb-shaped, said contact fingers projecting from one side thereof.

Claim 9

A quartz crystal oscillator comprising a crystal vibrator; and circuit means for sustaining the vibration of said vibrator including a thermo-compensating element formed of a ferroelectric material and first and second stepped variable capacitor means, said first stepped variable capacitor means being connected in series with said thermo-compensating element and said crystal vibrator for the regulation of the frequency of said oscillator, said second stepped variable capacitor means being connected in parallel with said first stepped variable capacitor means and said thermo-compensating element for the selective adjustment of the rate of temperature compensation by said thermo-compensating element.

Claim 10

A quartz crystal oscillator comprising a crystal vibrator; and circuit means for sustaining the vibration of said vibrator including a thermo-compensating element formed of a ferroelectric material and first and second stepped variable capacitor means, said first stepped variable capacitor means being connected in series with said thermo-compensating element and said crystal vibrator for the regulation of the frequency of said oscillator, said second stepped variable capacitor means being connected in parallel with said first stepped variable capacitor means and said thermo-compensating element for the selective adjustment of the rate of temperature compensation by said thermo-compensating element.

Claim 11

A quartz crystal oscillator as recited in claim 8, wherein each of said first and second stepped variable capacitor means includes a substrate, a plurality of capacitor elements deposited on said substrate, each of said capacitor elements consisting of a common electrode, an output electrode and a dielectric sandwich between said common and output electrodes; a contact member having a plurality of flexible contacts fingers, one of said contact fingers being positioned in registration with the output electrode of each of said capacitor elements for displacement in to and out of electrical engagement therewith, and means for selectively positioning each of said contact fingers either in or out of engagement with its respective output electrode, so that the capacitance of each of said stepped variable capacitors may be varied step by step by selecting combinations of said capacitor elements by the selective operation oF said means for positioning said contact fingers.