US3834238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic thermometer
Assignee: Royal Medical Corp
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Filing: 1971-08-19
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Granted: 1974-09-10
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Expires: 1991-08-19
Abstract
Abstract An electronic thermometer having: a temperature-sensitive probe and one of two optional electronic circuits, each of which has means for changing a basic comparison voltage in steps or increments through a series of stair-stepped voltages toward the amplified small voltage from the thermistor until the stabilized thermistor voltage and the comparison voltage are equal, and indicating the result in degrees. One of these circuits comprises a stairstep generator, and the other a set of resistors of different values.
Inventors
- 👤 F Mueller
- 👤 B Stricklin
- 👤 R Weeks
- 👤 B Martin
- 👤 R Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:36
CPC Classifications
G; G01; G01K; G01K13/00; G01K13/20; H; H03; H03M; H03M1/00; H03M1/12; H03M1/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
318 words
An electronic thermometer, comprising: a probe, having a temperature-measuring thermistor; an indicator, for indicating the temperature of an object in contact with the said probe; and electronic circuitry, connected to said thermistor and indicator, comprising: an electric battery, supplying a relatively small voltage; a power switch connected to said battery; a D.C.-D.C. transistor inverter, connected to said battery, converting said relatively small voltage to a higher voltage; a thermistor-voltage amplifier, connected to said thermistor and transistor inverter, receiving a portion of said higher voltage; a voltage comparator, connected to said amplifier and to said inverter, receiving a portion of said higher voltage; a regulator, receiving a portion of said higher voltage and regulating it to provide a basic output voltage having a value between said small voltage and higher voltage; means electrically connecting said regulator and thermistor, comprising resistance means; an oscillator, connected to said power switch; a counter, connected to said power switch and to said oscillator; means electrically connecting said oscillator and counter, comprising a gate; a decoder driver, connected to said power switch, counter and indicator; means, connected to said oscillator, voltage comparator and regulator, for supplying summed, incrementally varying voltages, varying in one direction from said basic voltage, comprising a first transistor and a second transistor that alternately receive voltage pulses from said oscillator, a capacitor connected to said first transistor having a capacity of less than a microfarad, a second capacitor having a capacity well above that of said first-named capacitor, capable of being charged to a plurality of volts, connected to said first-named capacitor and receiving increments of voltage from it, and conductors connecting said oscillator, transistors, capacitors and voltage comparator; a flip-flop, connected to said comprator and said gate, receiving triggering voltage from the comparator when the voltages from said second capacitor and said thermistor-voltage amplifier are equal, supplying voltage to said gate, for disconnecting the said counter from said oscillator.
Claim 2
Dependent Claim
318 words
An electronic thermometer, comprising: a probe, having a temperature-measuring thermistor; an indicator, for indicating the temperature of an object in contact with the said probe; and electronic circuitry, connected to said thermistor and indicator, comprising: an electric battery, supplying a relatively small voltage; a power switch connected to said battery; a D.C.-D.C. transistor inverter, connected to said battery, converting said relatively small voltage to a higher voltage; a thermistor-voltage amplifier, connected to said thermistor and transistor inverter, receiving a portion of said higher voltage; a voltage comparator, connected to said amplifier and to said inverter, receiving a portion of said higher voltage; a regulator, receiving a portion of said higher voltage and regulating it to provide a basic output voltage having a value between said small voltage and higher voltage; means electrically connecting said regulator and thermistor, comprising resistance means; an oscillator, connected to said power switch; a counter, connected to said power switch and to said oscillator; means electrically connecting said oscillator and counter, comprising a gate; a decoder driver, connected to said power switch, counter and indicator; means, connected to said oscillator, voltage comparator and regulator, for supplying summed, incrementally varying voltages, varying in one direction from said basic voltage, comprising a first transistor and a second transistor that alternately receive voltage pulses from said oscillator, a capacitor connected to said first transistor having a capacity of less than a microfarad, a second capacitor having a capacity well above that of said first-named capacitor, capable of being charged to a plurality of volts, connected to said first-named capacitor and receiving increments of voltage from it, and conductors connecting said oscillator, transistors, capacitors and voltage comparator; a flip-flop, connected to said comprator and said gate, receiving triggering voltage from the comparator when the voltages from said second capacitor and said thermistor-voltage amplifier are equal, supplying voltage to said gate, for disconnecting the said counter from said oscillator.
Claim 3
Dependent Claim
23 words
A thermometer as set forth in claim 1, comprising a reset switch, connected to said regulator and said means for supplying summed voltages.
Claim 4
Dependent Claim
38 words
A thermometer as set forth in claim 2, in which: said thermistor-voltage amplifier is in inverted mode; and said reset switch is electrically connected to said first-named transistor, applyiNg positive voltage from said regulator to said first-named transistor.
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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) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |