Compensated voltage-controlled oscillator particularly for analog to digital converters

Claim 3

The device as claimed in claim 1 wherein said second means includes: a. first transistor means having a base contact, an emitter contact and a collector contact, said capacitor means connected across said collector and emitter contacts of said first transistor means, said collector contact connected to said first means; b. second transistor means having a base contact, an emitter contact and a collector contact, said emitter contact of said second transistor means connected to said first means; c. third transistor means having a base contact an emitter contact and a collector contact, said base contact of said third transistor means connected to said collector contact of said second transistor means, said base contact of said second transistor means connected to said collector contact of said third transistor means, said emitter contact of said third transistor means operatively connected to said base contact of said first transistor means and said fourth means; d. resistor means; e. first diode means; and f. zener diode means; g. said resistor means and said first diode means, in parallel, connected serially between said zener diode means and said base contact of said second transistor means; h. said non-linearity compensating means including said third transistor, said first diode means, said resistor means and said zener diode means, said non-linearity compensating means operating to compensate for the non-zero ratio of the discharge time of said capacitor means to its charging time by decreasing the firing potential at said base contact of said second transistor means as frequency increases; i. said temperature compensating means including said zener diode means and said first and third transistor means, the temperature coefficient of said zener diode means matched by the temperature coefficients characterizing the saturation voltage of said first transistor means and the base to emitter voltage drop of said second transistor means.

Claim 4

The device as claimed in claim 1 wherein said first means includes voltage to current converter means for translating said input signal to a proportional current.

Claim 7

The device as claimed in claim 4 wherein said means for generating said counting pulses is floating analog section means and said means for generating said timing signal is grounded digital section means.

Claim 8

The device as claimed in claim 5 wherein said floating analog section means includes voltage to current converter means for translating said analog input signal into a proportional current.

Claim 9

The device as claimed in claim 5 wherein said grounded digital section means includes timer means and counter means, said timer means generating said timing signal and said counter means gated to respond to only those counting pulses occuring within said gating pulse, said counter means generating said digital output signal.

Claim 10

The device as claimed in claim 4 wherein said means for generating said counting pulses is floating analog section means and said means for generating said timing signal is grounded digital section means, said capacitor means controlling the rate at which said counting pulses occur, said grounded digital second means including timer means for generating said timing signal and counter means for generating said digital output signal defined by the number of counting pulses occuring within said gating pulse, said timer means having fourth means for controlling the width of said gating pulse, changes in the rate at which said counting pulses occur due to the effects of temperature counteracted by a compensating change in the width of said gating pulse.

Claim 11

The device as claimed in claim 8 wherein said third means is coupling transformer means establishing a common path for said pulsed signal and said timing signal.

Claim 12

The device as claimed in claim 8 wherein said means for generating said counting pulses includes voltage to current converter means for translating said analog input signal to a porportional current and current to count converter means for converting said proportional current to said counting pulses, said current to count converter means including said first means, said capacitor means, and said third means.

Claim 13

The device as claimed in claim 8 wherein said capacitor means is a first capacitor and said fourth means is a second capacitor, said first and second capacitors having tracking temperature coefficients.

Claim 14

The device as claimed in claim 4 wherein said second means includes: a. first transistor means having a base contact, an emitter contact and a collector contact, said capacitor means connected across said collector and emitter contacts of said first transistor means, said collector contact connected to said first means; b. second transistor means having a base contact, an emitter contact and a collector contact, said emitter contact of said second transistor means connected to said first means; c. third transistor means having a base contact, an emitter contact and a collector contact, said base contact of said third transistor means connected to said collector contact of said second transistor means, said base contact of said second transistor means connected to said collector contact of said third transistor means, said emitter contact of said third transistor means operatively connected to said base contact of said first Transistor means and said third means; d. resistor means; e. first diode means; and f. zener diode means; g. said resistor means and said first diode means, in parallel, connected serially between said zener diode means and said base contact of said second transistor means; h. said non-linearity compensating means including said third transistor, said first diode means, said resistor means and said zener diode means, said non-linearity compensating means operating to compensate for the non-zero ratio of the discharge time of said capacitor means to its charging time by decreasing the firing potential at said base contact of said second transistor means as frequency increases; i. said temperature compensating means including said zener diode means and said first and third transistor means, the temperature coefficient of said zener diode means matched by the temperature coefficients characterizing the saturation voltage of said first transistor means and the base to emitter voltage drop of said second transistor means.

Claim 15

A digital meter for presenting an analog input signal in digital form, said digital meter comprising: a. analog means for receiving said analog input signal and for generating a pulsed signal having counting pulses occurring at a rate functionally related to a characteristic of said analog input signal, said analog means including i. first means through which said analog input signal is applied; ii. capacitor means operatively connected to said first means, said capacitor means having charged and discharged states; iii. second means operatively connected to said first means and said capacitor means, said second means having first and second conditions, said second means including non-linearity compensating means and temperature compensating means; and iv. third means including a transformer operatively connected to said second means; v. said capacitor means in its discharged state and said second means in its first condition, said input signal applied to said capacitor means through said first means and second capacitor means dynamically changing into its charged state, said second means changing to its second condition in response to said capacitor means dynamically changing into its charged state, said capacitor means dynamically changing into its discharged state in response to said second means changing to its second condition, said non-linearity compensating means operating to compensate for non-linearity caused by the non-zero ratio of the discharge time of said capacitor means to its minimum changing time, a counting pulse generated by said second means coupled through said third means for each negative going transistion of said capacitor means, successive counting pulses occurring at a frequency functionally related to a characteristic of said analog input signal being coupled through said third means; b. digital means for generating a timing signal having a gating pulse occurring at selected intervals and for generating an intermediate signal functionally related to the number of counting pulses occurring within said gating pulse; c. said third means operatively connected to said digital means, said third means establishing a common path for coupling said pulsed signal to said digital means and for coupling said timing signal to said analog means, said coupled timing signals synchronizing said analog means and said digital means; and d. display means operatively connected to said digital means for visually presenting said intermediate signal in digital form.

Claim 16

A digital meter for presenting an analog input signal in digital form, said digital meter comprising: a. analog means for receiving said analog input signal and for generating a pulsed signal having counting pulses occurring at a rate functionally related to a characteristic of said analog input signal, said analog means including i. first means through which said analog input signal is applied; ii. capacitor means operatively connected to said first means, said capacitor means having charged and discharged states; iii. second means operatively connected to said first means and said capacitor means, said second means having first and second conditions, said second means including non-linearity compensating means and temperature compensating means; and iv. third means including a transformer operatively connected to said second means; v. said capacitor means in its discharged state and said second means in its first condition, said input signal applied to said capacitor means through said first means and second capacitor means dynamically changing into its charged state, said second means changing to its second condition in response to said capacitor means dynamically changing into its charged state, said capacitor means dynamically changing into its discharged state in response to said second means changing to its second condition, said non-linearity compensating means operating to compensate for non-linearity caused by the non-zero ratio of the discharge time of said capacitor means to its minimum changing time, a counting pulse generated by said second means coupled through said third means for each negative going transistion of said capacitor means, successive counting pulses occurring at a frequency functionally related to a characteristic of said analog input signal being coupled through said third means; b. digital means for generating a timing signal having a gating pulse occurring at selected intervals and for generating an intermediate signal functionally related to the number of counting pulses occurring within said gating pulse; c. said third means operatively connected to said digital means, said third means establishing a common path for coupling said pulsed signal to said digital means and for coupling said timing signal to said analog means, said coupled timing signals synchronizing said analog means and said digital means; and d. display means operatively connected to said digital means for visually presenting said intermediate signal in digital form.

Claim 17

The digital meter as claimed in claim 13 wherein said analog means is floating analog means and said digital means is grounded digital means.

Claim 18

The digital meter as claimed in claim 14 wherein said floating analog means includes voltage to current converter means for generating a proportional current functionally related to a characteristic of said analog input signal and current to converter means fOr converting said proportional current to said counting pulses, said current to converter means including said first means, said capacitor means and said third means.

Claim 19

The digital meter as claimed in claim 15 wherein said grounded digital means includes timer means and counter means, said timer means generating said timing signal and said counter means gated to respond to only those pulses occuring within aid gating pulse, said counter means generating said intermediate signal.

Claim 20

The digital meter as claimed in claim 13 wherein said analog means is floating analog means and said digital means is grounded digital means, said capacitor means controlling the rate at which said counting pulses occur, said grounded digital means including timer means for generating said timing signal and counter means for generating said intermediate signal defining the number of counting pulses occurring within said gating pulse, said timer means having fourth means for controlling the width of said gating pulse, changes in the rate at which said counting pulses occur due to the effects of temperature counteracted by a compensating change in the width of said gating pulse.

Claim 21

The digital meter as claimed in claim 17 wherein said capacitor means is a first capacitor and said fourth means is a second capacitor, said first and second capacitors having tracking temperature coefficients.

Claim 22

A digital panel meter comprising: a. floating analog section means including voltage to current converter means and current to count converter means; b. grounded digital means including timer means, counter means and display means; and c. transformer coupling means operatively connecting said floating analog section means and said grounded digital section means, said coupling means establishing a common path between said floating analog section means and said grounded digital section means; d. said voltage to current converter means receiving an analog input signal and generating a current functionally related to a characteristic of said analog input signal; e. said current to count converter means receiving said current and generating a pulsed signal having repetitive counting pulses occurring at a frequency functionally related to said current; f. said timer means generating a timing signal having a gating pulse occuring at selected intervals; g. said couting signal coupled to said grounded digital section means via said coupling means and added to said timing signal, said timing signal coupled to said grounded digital section means via said coupling means for synchronizing said floating analog section means and said grounded digital section means; h. said counter means responsive to only those counting pulses occuring within said gating pulse, said counter means generating a digital signal related to a characteristic of said analog input signal; i. said digital signal applied to said display means, said analog input signal presented by said display means in digital form.

Claim 23

A digital panel meter comprising: a. floating analog section means including voltage to current converter means and current to count converter means; b. grounded digital means including timer means, counter means and display means; and c. transformer coupling means operatively connecting said floating analog section means and said grounded digital section means, said coupling means establishing a common path between said floating analog section means and said grounded digital section means; d. said voltage to current converter means receiving an analog input signal and generating a current functionally related to a characteristic of said analog input signal; e. said current to count converter means receiving said current and generating a pulsed signal having repetitive counting pulses occurring at a frequency functionally related to said current; f. said timer means generating a timing signal having a gating pulse occuring at selected intervals; g. said couting signal coupled to said grounded digital section means via said coupling means and added to said timing signal, said timing signal coupled to said grounded digital section means via said coupling means for synchronizing said floating analog section means and said grounded digital section means; h. said counter means responsive to only those counting pulses occuring within said gating pulse, said counter means generating a digital signal related to a characteristic of said analog input signal; i. said digital signal applied to said display means, said analog input signal presented by said display means in digital form.

Claim 24

The digital panel meter as claimed in claim 19 wherein said grounded digital section means includes multiplier means operatively connected to said counter means, said digital signal defining said analog signal in engineering units.

Claim 25

The digital panel meter as claimed in claim 19 wherein said current to count converter means includes first compensating means and wherein said timer means includes second compensating means, a characteristic change of said first compensating means due to the effects of temperature varying the frequency of said counting pulses, a characteristic change of said second compensating means due to the effect of temperature varying the width of said gating pulse, variation in the frequency of said counting pulses due to the effects of temperature compensated by a counteracting variation in the width of said gating pulse due to the effects of temperature.