US3851528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic thermometer
Assignee: Individual
•
Filing: 1972-10-06
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Granted: 1974-12-03
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Expires: 1992-10-06
Abstract
Abstract A fool proof and pocket size electronic thermometer is described that is particularly useful for obtaining oral or rectal body temperatures. The thermometer includes a casing on which is mounted a scale for visually indicating temperature readings. A simplified plug-in connector is used to connect a miniature electrical cord to the casing. Such cord terminates in a disposable semiconductor junction through which a constant current is made to flow so that the voltage developed across it is dependent upon its temperature in a straight line function. The casing encloses small operating batteries and low power consumption circuitry for providing the constant current flow through the semiconductor junction and translating voltage changes developed across it into temperature readings. Circuitry is provided for disabling the measuring circuit and driving the indicator off scale to indicate battery voltage below a predetermined level.
Inventors
- 👤 H Nichols
- 👤 J Bauman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:43
CPC Classifications
G; G01; G01K; G01K13/00; G01K13/20; G01K7/00; G01K7/01
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
324 words
An electronic thermometer especially useful for measuring man and animal body temperatures comprising a temperature probe of a material in which a voltage develops when a constant current flows therethrough, which voltage changes generally proportionately to changes in the temperature of said material; circuit means for translating variations in the voltage in said material indicative of temperature changes into temperature readings, said circuit means including a feedback operational amplifier having its feedback connection from its output terminal to a first inverting one of its primary input terminals for maintaining the potential at said first primary input terminal at essentially the same potential as the second non-inverting primary input terminal of said amplifier, said feedback connection passing through said material to provide current flow therethrough, means for applying an essentially constant potential to said second primary input terminal of said amplifier, resistance means connected between a generally constant potential source and said first primary input terminal to thereby provide a source of constant current flow through said temperature probe material and said feedback connection, said material being connected to said output terminal of said amplifier in said feedback connection through a first one of a pair of resistances, the second one of which is connected between the amplifier output terminal side of said material and a generally constant potential source to cause current variations in said first resistance which are proportional to potential variations at the amplifier output terminal side of said material and any voltage changes at the output terminal of said amplifier are proportional to but greater than voltage changes at the output terminal side of said material both constant current flow through said material and voltage amplification is obtained with a single operational amplifier; indicating means connected with said circuit means for displaying said temperature readings; and a probe cord electrically connected between said probe and said circuit means for conveying variations in said voltage across said material to said circuit means.
Claim 2
Dependent Claim
324 words
An electronic thermometer especially useful for measuring man and animal body temperatures comprising a temperature probe of a material in which a voltage develops when a constant current flows therethrough, which voltage changes generally proportionately to changes in the temperature of said material; circuit means for translating variations in the voltage in said material indicative of temperature changes into temperature readings, said circuit means including a feedback operational amplifier having its feedback connection from its output terminal to a first inverting one of its primary input terminals for maintaining the potential at said first primary input terminal at essentially the same potential as the second non-inverting primary input terminal of said amplifier, said feedback connection passing through said material to provide current flow therethrough, means for applying an essentially constant potential to said second primary input terminal of said amplifier, resistance means connected between a generally constant potential source and said first primary input terminal to thereby provide a source of constant current flow through said temperature probe material and said feedback connection, said material being connected to said output terminal of said amplifier in said feedback connection through a first one of a pair of resistances, the second one of which is connected between the amplifier output terminal side of said material and a generally constant potential source to cause current variations in said first resistance which are proportional to potential variations at the amplifier output terminal side of said material and any voltage changes at the output terminal of said amplifier are proportional to but greater than voltage changes at the output terminal side of said material both constant current flow through said material and voltage amplification is obtained with a single operational amplifier; indicating means connected with said circuit means for displaying said temperature readings; and a probe cord electrically connected between said probe and said circuit means for conveying variations in said voltage across said material to said circuit means.
Claim 3
Dependent Claim
229 words
An electronic theremometer especially useful for measuring man and animal body temperatures comprising a temperature probe of a material having an electrical characteristic which depends in a predetermined manner on the temperature of said material; circuit means for translating variations in said electrical characteristic of said material indicative of temperature changes into temperature readings; indicating means connected with said circuit means for displaying said temperature readings; a probe cord electrically connected between said probe and said circuit means for conveying variations in said electrical characteristic across said material to said circuit means; a source of two dc potentials of opposite polarity for electrically energizing said material and said circuit means; and switching means for simultaneously connecting the separate terminals of said differing potentials to said material and said circuit means with a single pole of a switch, said switching means including a pair of oppositely polarized transistors, each of which is respectively connected between said circuit means and an associated one of said differing potential terminals in the direction of normal current flow through said transistor, the bases of said transistors being connected to one another through a resistance and a single pole of a switch whereby the closing of said switch results in simultaneous current flow tHrough said bases to a simultaneously turn said transistors on to saturation for the application of said potentials to said circuit means.
Claim 4
Dependent Claim
229 words
An electronic theremometer especially useful for measuring man and animal body temperatures comprising a temperature probe of a material having an electrical characteristic which depends in a predetermined manner on the temperature of said material; circuit means for translating variations in said electrical characteristic of said material indicative of temperature changes into temperature readings; indicating means connected with said circuit means for displaying said temperature readings; a probe cord electrically connected between said probe and said circuit means for conveying variations in said electrical characteristic across said material to said circuit means; a source of two dc potentials of opposite polarity for electrically energizing said material and said circuit means; and switching means for simultaneously connecting the separate terminals of said differing potentials to said material and said circuit means with a single pole of a switch, said switching means including a pair of oppositely polarized transistors, each of which is respectively connected between said circuit means and an associated one of said differing potential terminals in the direction of normal current flow through said transistor, the bases of said transistors being connected to one another through a resistance and a single pole of a switch whereby the closing of said switch results in simultaneous current flow tHrough said bases to a simultaneously turn said transistors on to saturation for the application of said potentials to said circuit means.
Claim 5
Dependent Claim
305 words
An electronic thermometer especially useful for measuring man and animal body temperatures comprising a temperature probe of a material having an electrical characteristic which depends in a predetermined manner on the temperature of said material; circuit means for translating variations in said electrical characteristic of said material indicative of temperature changes into temperature readings; indicating means connected with said circuit means for displaying said temperature readings; a probe cord electrically connected between said probe and said circuit means for conveying variations in said electrical characteristic across said material to said circuit means; a casing within which said circuit means and battery power source means for electrically energizing said material are housed; said circuit means including means for detecting when the output potential of said battery power source reaches a reduced, predetermined level, and means responsive to said detection by immediately supplying a predetermined potential to said indicating means for visually displaying thereon said reduced potential condition of said battery power source means; said means for detecting when the output potential of said battery reaches a reduced, predetermined level including an operational amplifier having the output potential of said battery applied to one of its primary input terminals and a constant reference voltage applied to the other one thereof, and a diode serially connected in a feedback connection between the output terminal of said amplifier and the input terminal thereof to which said battery voltage is applied, said diode being electrically oriented in said feedback connection in a direction which isolates the output terminal of said amplifier from said input terminal until such time as the application by said battery to said input terminal of said reduced, predetermined level of potential causes the potential difference across said diode to close said feedback path and thereby cause said amplifier to apply said predetermined voltage to said instrument.
Claim 6
Dependent Claim
305 words
An electronic thermometer especially useful for measuring man and animal body temperatures comprising a temperature probe of a material having an electrical characteristic which depends in a predetermined manner on the temperature of said material; circuit means for translating variations in said electrical characteristic of said material indicative of temperature changes into temperature readings; indicating means connected with said circuit means for displaying said temperature readings; a probe cord electrically connected between said probe and said circuit means for conveying variations in said electrical characteristic across said material to said circuit means; a casing within which said circuit means and battery power source means for electrically energizing said material are housed; said circuit means including means for detecting when the output potential of said battery power source reaches a reduced, predetermined level, and means responsive to said detection by immediately supplying a predetermined potential to said indicating means for visually displaying thereon said reduced potential condition of said battery power source means; said means for detecting when the output potential of said battery reaches a reduced, predetermined level including an operational amplifier having the output potential of said battery applied to one of its primary input terminals and a constant reference voltage applied to the other one thereof, and a diode serially connected in a feedback connection between the output terminal of said amplifier and the input terminal thereof to which said battery voltage is applied, said diode being electrically oriented in said feedback connection in a direction which isolates the output terminal of said amplifier from said input terminal until such time as the application by said battery to said input terminal of said reduced, predetermined level of potential causes the potential difference across said diode to close said feedback path and thereby cause said amplifier to apply said predetermined voltage to said instrument.
Claim 7
Dependent Claim
46 words
The electronic thermometer of claim 3 wherein a second diode is connected between the output terminal of said operational amplifier and said instrument to isolate said amplifier from said instrument until the output terminal of said amplifier provides said predetermined voltage indicative of a weak battery.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |