Digital thermometer

Claim 1

An apparatus for measuring temperature within a preselected range of temperatures, comprising: means for generating a first electrical signal having a time duration responsive to and indicative of the value of said temperature, means for generating a second electrical signal having a constant, preselected time duration; means for generating an electrical clock signal comprised of a plurality of discrete pulses occurring at a preselected frequency, wherein each pulse is representative of a preselected increment of temperature; means connected to the output of said clock for counting said pulses; and means connected to the outputs of said means for generating said first electrical signal and said means for generating said second electrical signal and connected to said clock for comparing said first and second electrical signals and for gating said clock signal to said counting means responsive to the time durations of said first and second electrical signals.

Claim 2

An apparatus for measuring temperature within a preselected range of temperatures, comprising: means for generating a first electrical signal having a time duration responsive to and indicative of the value of said temperature, means for generating a second electrical signal having a constant, preselected time duration; means for generating an electrical clock signal comprised of a plurality of discrete pulses occurring at a preselected frequency, wherein each pulse is representative of a preselected increment of temperature; means connected to the output of said clock for counting said pulses; and means connected to the outputs of said means for generating said first electrical signal and said means for generating said second electrical signal and connected to said clock for comparing said first and second electrical signals and for gating said clock signal to said counting means responsive to the time durations of said first and second electrical signals.

Claim 12

An apparatus for measuring temperature within a preselected range of temperatures, comprising: means for transducing said temperature into an electrical signal having a magnitude proportional thereto; means for generating a triggering signal; means connected to the outputs of said transducing means and said triggering means for generating a first electrical signal having an absolute magnitude which, from the instant of time said triggering signal is sensed, continuously is either in excess of or less than a preselected threshold magnitude for a time duration responsive and proportional to said transduced electrical signal and then, upon expiration of said time duration, changes substantially instantaneously to a magnitude which is the other of in excess of or less than said threshold magnitude; means connected to the output of said triggering means for generating a second electrical signal having an absolute magnitude which, from the instant of time said triggering signal is sensed, continuously is one of in excess of or less than said preselected threshold magnitude for a preselected time duration and then, upon expiration of said constant time duration, changes substantially instantaneously to a magnitude which is the other of in excess of or less than said threshold magnitude; said means for generating said first electrical signal and said means for generating said second electrical signal each being adapted to function repetitively responsive to said triggering signal supplied thereto; a clock for emitting repetitively pulses at a preselected constant frequency, each of said pulses being representative of a preselected increment of temperature; a counter connected to the output of said clock; means coNnected to the outputs of said first and second electrical signal generating means and connected to the input of said clock for comparing said first and second electrical signals and for selectively gating responsive thereto said clock pulses to the input of said counter; said clock pulses being gated during the period of time that said time duration of said first electrical signal exceeds said time duration of said second electrical signal; and the output of said clock being connected to the input of said triggering means and said clock and said triggering means being adapted so that said triggering means triggers said means for generating said first electrical signal and said means for generating said second electrical signal repetitively responsive to a preselected number of pulses being counted by said counter.

Claim 13

An apparatus for measuring temperature within a preselected range of temperatures, comprising: means for transducing said temperature into an electrical signal having a magnitude proportional thereto; means for generating a triggering signal; means connected to the outputs of said transducing means and said triggering means for generating a first electrical signal having an absolute magnitude which, from the instant of time said triggering signal is sensed, continuously is either in excess of or less than a preselected threshold magnitude for a time duration responsive and proportional to said transduced electrical signal and then, upon expiration of said time duration, changes substantially instantaneously to a magnitude which is the other of in excess of or less than said threshold magnitude; means connected to the output of said triggering means for generating a second electrical signal having an absolute magnitude which, from the instant of time said triggering signal is sensed, continuously is one of in excess of or less than said preselected threshold magnitude for a preselected time duration and then, upon expiration of said constant time duration, changes substantially instantaneously to a magnitude which is the other of in excess of or less than said threshold magnitude; said means for generating said first electrical signal and said means for generating said second electrical signal each being adapted to function repetitively responsive to said triggering signal supplied thereto; a clock for emitting repetitively pulses at a preselected constant frequency, each of said pulses being representative of a preselected increment of temperature; a counter connected to the output of said clock; means coNnected to the outputs of said first and second electrical signal generating means and connected to the input of said clock for comparing said first and second electrical signals and for selectively gating responsive thereto said clock pulses to the input of said counter; said clock pulses being gated during the period of time that said time duration of said first electrical signal exceeds said time duration of said second electrical signal; and the output of said clock being connected to the input of said triggering means and said clock and said triggering means being adapted so that said triggering means triggers said means for generating said first electrical signal and said means for generating said second electrical signal repetitively responsive to a preselected number of pulses being counted by said counter.

Claim 17

An apparatus for measuring temperature within a preselected range of temperatures, including: a clock for emitting repetitively pulses at a preselected constant frequency, each of said pulses being representative of a preselected increment of temperature; means for transducing said temperature into a first electrical logic signal which, from a first selected instant of time, is one of a first and second binary states and remains at said state for a time duration responsive and proportional to said temperature and then switches states to the other of said first and second states; a counter connected to the output of said clock; means for generating a second electrical logic signal which, from a second selected instant of time, is one of a first and second binary states and remains at said state until a first preselected number of clock pulses are counted by said counter and then switches states to the other of said first and second states, said first preselected number of pulses being indicative of said preselected range of temperatures; said means for generating said first electrical signal at said first selected instant of time and said means for generating said second electrical signal at said second selected instant of time each being adapted to function repetitively responsive to triggering signals applied thereto; means connected to the output of said counter and to the input of said means for generating said first electrical signal and to the input of said means for generating said second electrical signal for determining when said first preselected number of pulses and a second and third preselected number of pulses have been counted by said counter and emitting triggering signals responsive thereto, said first selected instant of time and said second selected instant of time occurring when said second and third preselected number of pulses, respectively, have Been emitted by said clock means and counted by said counter; said means for generating said first electrical signal and said means for generating said second electrical signal being responsive to said second and third preselected number of pulses having been counted by said counter whereby if said temperature being measured is within said preselected range of temperatures, the termination of said time duration of said logic component of said first electrical signal will occur during the period of time that said logic component of said second electrical signal remains at said one of a first and second binary states awaiting a triggering signal indicating that said counter has counted said first preselected number of pulses; and means connected to the output of said first and second electrical signal generating means and to the input of said clock for comparing said first and second electrical signals and for selectively gating responsive thereto said clock pulses to the input of said counter; said clock pulses being gated to said counter during the interval of time that said second electrical signal becomes one of a first and second binary states responsive to a triggering signal being applied thereto at said first selected instant of time and said first electrical signal switching binary states responsive to the termination of said time duration which is proportional to the temperature being measured.

Claim 18

An apparatus for measuring temperature within a preselected range of temperatures, including: a clock for emitting repetitively pulses at a preselected constant frequency, each of said pulses being representative of a preselected increment of temperature; means for transducing said temperature into a first electrical logic signal which, from a first selected instant of time, is one of a first and second binary states and remains at said state for a time duration responsive and proportional to said temperature and then switches states to the other of said first and second states; a counter connected to the output of said clock; means for generating a second electrical logic signal which, from a second selected instant of time, is one of a first and second binary states and remains at said state until a first preselected number of clock pulses are counted by said counter and then switches states to the other of said first and second states, said first preselected number of pulses being indicative of said preselected range of temperatures; said means for generating said first electrical signal at said first selected instant of time and said means for generating said second electrical signal at said second selected instant of time each being adapted to function repetitively responsive to triggering signals applied thereto; means connected to the output of said counter and to the input of said means for generating said first electrical signal and to the input of said means for generating said second electrical signal for determining when said first preselected number of pulses and a second and third preselected number of pulses have been counted by said counter and emitting triggering signals responsive thereto, said first selected instant of time and said second selected instant of time occurring when said second and third preselected number of pulses, respectively, have Been emitted by said clock means and counted by said counter; said means for generating said first electrical signal and said means for generating said second electrical signal being responsive to said second and third preselected number of pulses having been counted by said counter whereby if said temperature being measured is within said preselected range of temperatures, the termination of said time duration of said logic component of said first electrical signal will occur during the period of time that said logic component of said second electrical signal remains at said one of a first and second binary states awaiting a triggering signal indicating that said counter has counted said first preselected number of pulses; and means connected to the output of said first and second electrical signal generating means and to the input of said clock for comparing said first and second electrical signals and for selectively gating responsive thereto said clock pulses to the input of said counter; said clock pulses being gated to said counter during the interval of time that said second electrical signal becomes one of a first and second binary states responsive to a triggering signal being applied thereto at said first selected instant of time and said first electrical signal switching binary states responsive to the termination of said time duration which is proportional to the temperature being measured.

Claim 21

A method of measuring temperature within a preselected range of temperatures, including the steps of: generating a first electrical signal having a time duration responsive to and indicative of the value of said temperature; generating a second electrical signal having a constant, preselected time duration; generating an electrical clock signal comprised of a plurality of discrete pulses occurring at a preselected frequency, wherein each pulse is representative of a preselected increment of temperature; counting said pulses; comparing said first and second electrical signals and gating said clock signal to said counting means responsive to the time durations of said first and second electrical signals; and determining from said gated pulse signals counted by said counter said temperature being measured.

Claim 22

A method of measuring temperature within a preselected range of temperatures, including the steps of: generating a first electrical signal having a time duration responsive to and indicative of the value of said temperature; generating a second electrical signal having a constant, preselected time duration; generating an electrical clock signal comprised of a plurality of discrete pulses occurring at a preselected frequency, wherein each pulse is representative of a preselected increment of temperature; counting said pulses; comparing said first and second electrical signals and gating said clock signal to said counting means responsive to the time durations of said first and second electrical signals; and determining from said gated pulse signals counted by said counter said temperature being measured.

Claim 23

A method of measuring temperature within a preselected range of temperatures, including the steps of: transducing said temperature into a first electrical logic signal which, from a selected instant of time, is a preselected one of a first and second state for a time duration indicative of said temperature; producing a second electrical logic signal which, from said selected instant of time, is a preselected one of a first and second state for a preselected time duration; generating pulses repetitively at a preselected frequency, each pulse being representative of a preselected increment of temperature; comparing said first electrical signal with said second electrical signal and gating said pulses for the interval of time equal to said duration of said logic component of said first electrical signal less said time duration of said logic component of said second electrical signal; counting said gating pulses; determining from said number of gated pulses counted the temperature being measured; and displaying said temperature.

Claim 24

A method of measuring temperature within a preselected range of temperatures, including the steps of: transducing said temperature into a first electrical logic signal which, from a selected instant of time, is a preselected one of a first and second state for a time duration indicative of said temperature; producing a second electrical logic signal which, from said selected instant of time, is a preselected one of a first and second state for a preselected time duration; generating pulses repetitively at a preselected frequency, each pulse being representative of a preselected increment of temperature; comparing said first electrical signal with said second electrical signal and gating said pulses for the interval of time equal to said duration of said logic component of said first electrical signal less said time duration of said logic component of said second electrical signal; counting said gating pulses; determining from said number of gated pulses counted the temperature being measured; and displaying said temperature.