Digital measuring apparatus

Claim 2

Apparatus for measuring a physical quantity and providing a decimal digital display of said measured quantity comprising: transducer means for converting said physical quantity into an analog signal having a substantially constant slope of a magnitude which varies directly with the magnitude of said physical quantity in accordance with a predetermined function; and means for translating said analog signal into displayed decimal numbers, decimal point location, and other range information representing said magnitude comprising: means operative during a range finding period for storing a differential level of said analog signal proportional to said magnitude and simultaneously producing and registering a particular number of ranging pulses indicative of the decimal range of magnitudes in which said slope of said analog signal lies; means operative during a subsequent measuring period for producing and registering a number of measuring pulses proportional to said stored differential level of said analog signal such that said number of registered measuring pulses comprises said measured quantity in decimal digital form; and means for producing a decimal number display of said number of measuring pulses and a decimal point display located in accordance with said number of ranging pulses.

Claim 3

Apparatus for measuring a physical quantity and providing a decimal digital display of said measured quantity comprising: transducer means for converting said physical quantity into a linear analog signal having a substantially constant slope of a magnitude which varies directly with the magnitude of said physical quantity in accordance with a predetermined function; storing means for storing said analog signal; inhibitable gating means for gating said analog signal into said storing means; discharging means for discharging said stored analog signal from said storing means at a preselected constant rate when said gating means is inhibited; first and second sensing means operative to sense the level of said stored analog signal and to supply first and second level signals, respectively, having first values when said stored analog signal is below preselected first and second levels, respectively, and second values when said stored analog signal is at or above said first and second levels, respectively; programmable pulsing means operative in response to a first level signal of a second value to produce periodic pulses having one of first and second periodicities; resettable register means for accumulating said periodic pulses from said pulsing means; decoding means for translating said accumulated periodic pulses into displayed decimal digits corresponding to the sum of said accumulated pulses and for providing output pulses as preselected sums of accumulated pulses occur; coincidence means for signaling the coincidence of one of said output pulses with a second levEl signal of a second value; inhibitable ranging means for accumulating said output pulses and for translating the sum of said accumulated output pulses into display range information; control circuit means responsive to said coincidence signal to change from a first stable state to a second stable state and being operative in said first stable state to program said programmable pulsing means to produce periodic pulses having said first periodicity, being operative in changing from said first stable state to said second stable state to reset said resettable register means, and being operative in said second state to inhibit said inhibitable gating means and said inhibitable ranging means and to program said programmable pulsing means to produce periodic pulses having said second periodicity.

Claim 4

Apparatus for measuring a physical quantity and providing a decimal digital display of said measured quantity comprising: transducer means for converting said physical quantity into a linear analog signal having a substantially constant slope of a magnitude which varies directly with the magnitude of said physical quantity in accordance with a predetermined function; storing means for storing said analog signal; inhibitable gating means for gating said analog signal into said storing means; discharging means for discharging said stored analog signal from said storing means at a preselected constant rate when said gating means is inhibited; first and second sensing means operative to sense the level of said stored analog signal and to supply first and second level signals, respectively, having first values when said stored analog signal is below preselected first and second levels, respectively, and second values when said stored analog signal is at or above said first and second levels, respectively; programmable pulsing means operative in response to a first level signal of a second value to produce periodic pulses having one of first and second periodicities; resettable register means for accumulating said periodic pulses from said pulsing means; decoding means for translating said accumulated periodic pulses into displayed decimal digits corresponding to the sum of said accumulated pulses and for providing output pulses as preselected sums of accumulated pulses occur; coincidence means for signaling the coincidence of one of said output pulses with a second levEl signal of a second value; inhibitable ranging means for accumulating said output pulses and for translating the sum of said accumulated output pulses into display range information; control circuit means responsive to said coincidence signal to change from a first stable state to a second stable state and being operative in said first stable state to program said programmable pulsing means to produce periodic pulses having said first periodicity, being operative in changing from said first stable state to said second stable state to reset said resettable register means, and being operative in said second state to inhibit said inhibitable gating means and said inhibitable ranging means and to program said programmable pulsing means to produce periodic pulses having said second periodicity.

Claim 5

Apparatus for converting an analog signal having a substantially constant slope of a magnitude which varies directly with the magnitude of a measured quantity in accordance with a predetermined function into a decimal digital display of said measured quantity comprising: storing means for storing said analog signal; gating means for gating said analog signal into said storing means; first and second sensing means operative to sense the level of said stored analog signal and to supply first and second level signals, respectively, having first values when said stored analog signal is below preselected first and second levels, respectively, and second values when said stored analog signal is at or above said first and second levels, respectively; ranging pulse means operative in response to a change in said first level signal from said first to said second value to produce a ranging pulse at ranging intervals which are predetermined in accordance with said predetermined function and the difference between said first and second levels; coincidence circuit means for producing a coincidence signal when one of said ranging pulses coincides with said second level signal having a second value; first inhibit means operative in response to said coincidence signal to inhibit said gating means and said range pulsing means so that a particular level of said analog signal is stored by said storing means; discharging means operative in response to the inhibiting of said gating means to discharge said stored analog signal at a preselected constant rate; measuring pulse means operative in response to said coincidence signal to produce periodic measuring pulses having a periodicity which is preselected in accordance with said preselected constant rate of discharge; second inhibit means operative in response to a change in said first level signal from said second to said first value to inhibit said measuring pulse means; means for counting said ranging pulses and for translating said count into displayed range information, and means for counting said measuring pulses and for displaying the sum thereof in digital form.

Claim 6

Apparatus for converting an analog signal having a substantially constant slope of a magnitude which varies directly with the magnitude of a measured quantity in accordance with a predetermined function into a decimal digital display of said measured quantity comprising: storing means for storing said analog signal; gating means for gating said analog signal into said storing means; first and second sensing means operative to sense the level of said stored analog signal and to supply first and second level signals, respectively, having first values when said stored analog signal is below preselected first and second levels, respectively, and second values when said stored analog signal is at or above said first and second levels, respectively; ranging pulse means operative in response to a change in said first level signal from said first to said second value to produce a ranging pulse at ranging intervals which are predetermined in accordance with said predetermined function and the difference between said first and second levels; coincidence circuit means for producing a coincidence signal when one of said ranging pulses coincides with said second level signal having a second value; first inhibit means operative in response to said coincidence signal to inhibit said gating means and said range pulsing means so that a particular level of said analog signal is stored by said storing means; discharging means operative in response to the inhibiting of said gating means to discharge said stored analog signal at a preselected constant rate; measuring pulse means operative in response to said coincidence signal to produce periodic measuring pulses having a periodicity which is preselected in accordance with said preselected constant rate of discharge; second inhibit means operative in response to a change in said first level signal from said second to said first value to inhibit said measuring pulse means; means for counting said ranging pulses and for translating said count into displayed range information, and means for counting said measuring pulses and for displaying the sum thereof in digital form.

Claim 7

Apparatus as claimed in claim 3, further comprising third sensing means operative to sense the level of said stored analog signal and to supply a third level signal having a first value when said stored analog signal is below a preselected third level, said third level being greater the highest measurable level of said stored analog signal; and circuit means operative in response to a change in said third level signal from said first to said second value to provide an above range signal to said coincidence circuit means; said coincidence circuit means producing a coincidence signal in response thereto.

Claim 8

Apparatus as claimed in claim 3, wherein said range-pulsing means comprises a source of periodic pulses having a periodicity predetermined in accordance with said predetermined function and the difference between said first and second levels; a binary register for accumulating said periodic pulses; and decoding means for supplying output pulses when preselected numbers of said periodic pulSes are accumulated in said binary register.

Claim 9

Apparatus as claimed in claim 5, wherein said source of periodic pulses comprises a clock circuit programmable to supply clock pulses with preselected periodicity; and measuring pulse means includes said clock circuit; and said means for counting said measuring pulses includes said binary register.

Claim 10

Apparatus as claimed in claim 3, wherein said analog signal is a voltage signal; said storing means is a storage capacitor; said gating means is a linear gating circuit coupling said voltage signal into said storage capacitor; said first and second sensing means are first and second voltage level detectors coupled to said storage capacitor, said first and second level signals being TRUE when said stored voltage signal is below preselected first and second voltage levels, respectively, and being FALSE when said stored voltage signal is at or above said first and second levels, respectively; said preselected first voltage level being sufficiently greater than a zero level to eliminate substantially the effects of noise on said apparatus.

Claim 11

Apparatus as claimed in claim 7, wherein said discharging means is a constant current source connected to said storage capacitor; and said ranging pulse means, said measuring pulse means, and said means for counting said measuring pulses together comprise: a clock circuit programmable to produce periodic pulses with preselected first and second periodicity and having an input coupled to said first voltage level detector so that said periodic pulses are produced only when said first level signal is FALSE: a binary register coupled to said clock circuit to accumulate said periodic pulses and having a reset input; and a decoding circuit coupled to said binary register to convert said accumulated periodic pulses to a decimal count and to decode an output pulse at preselected individual decimal count magnitudes; said clock circuit, said binary register, and said decoding circuit functioning as said ranging pulse means when said clock circuit is programmed to produce periodic pulses with preselected second periodicity so that said periodic pulses are said measuring pulses.

Claim 12

Apparatus as claimed in claim 8, wherein said decimal digital display comprises n decimal digits; said decoding circuit decodes said output pulses at decimal count magnitudes corresponding to decimal numbers 10i, where i 0, 1,- n-1, and decimal number 10n-1; said first periodicity being preselected in accordance with the difference in magnitude between said first and second voltage levels and said predetermined function such that said output pulses define n+ 1 measurable ranges of said measured quantity.

Claim 13

Apparatus for converting an analog signal having a substantially constant slope of a magnitude which varies directly with the magnitude of a measured quantity into a decimal digital display of said measured quantity comprising: means for defining a plurality of ranging intervals of ascending decimal orders of magnitude; means for accumulating a differential level of said analog signal proportional to said magnitude during one or more of said ranging intervals; means for producing and registering a number of measuring pulses proportional to said stored differential level such that said number of registered pulses comprises said measured quantity in decimal digital form; and means for producing a decimal number display of said number of measuring pulses and a decimal point display located in accordance with the number of ranging intervals during which said analog signal is accumulated.

Claim 14

Apparatus for converting an analog signal having a substantially constant slope of a magnitude which varies directly with the magnitude of a measured quantity into a decimal digital display of said measured quantity comprising: means for defining a plurality of ranging intervals of ascending decimal orders of magnitude; means for accumulating a differential level of said analog signal proportional to said magnitude during one or more of said ranging intervals; means for producing and registering a number of measuring pulses proportional to said stored differential level such that said number of registered pulses comprises said measured quantity in decimal digital form; and means for producing a decimal number display of said number of measuring pulses and a decimal point display located in accordance with the number of ranging intervals during which said analog signal is accumulated.