Patent US1681082A successfully refreshed from Google Patents.
Patent US4881057A successfully refreshed from Google Patents.
US4881057A
Expired / Lapsed
US
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Temperature sensing apparatus and method of making same
Assignee: Ranco Inc of Delaware
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Filing: 1987-09-28
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Granted: 1989-11-14
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Expires: 2007-09-28
Abstract
Abstract A temperature sensor. Two thick film resistor elements are mounted to a substrate and then a thermistor coupled to those elments to form a voltage divider. The resistance of the thermistor is determined at a reference temperature and the thick film resistor elements are precisely trimmed using a laser trimming system to produce a precision voltage divider. To sense temperatures the voltage divider is energized and its resistance ratio is sensed utilizing a bridge circuit.
Inventors
- 👤 Richard R. Garcia
- 👤 Royal H. Sites
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:40
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/02; G01K15/00; G01K7/16; G01K7/22; G01K7/24
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
94 words
A method of manufacturing a temperature sensor comprising the steps of: forming a voltage divider having first and second connected segments wherein forming said first segment comprises mounting a thermistor element having a resistance that varies with temperature on a substrate and forming said second segment comprises depositing a monolithic resistor element onto the substrate; measuring the resistance of the thermistor element at a reference temperature and recording the measured resistance; and precisely trimming the monolithic resistor element to produce a precise resistance ratio between the first and second segments at said reference temperature.
Claim 2
Independent Claim
94 words
A method of manufacturing a temperature sensor comprising the steps of: forming a voltage divider having first and second connected segments wherein forming said first segment comprises mounting a thermistor element having a resistance that varies with temperature on a substrate and forming said second segment comprises depositing a monolithic resistor element onto the substrate; measuring the resistance of the thermistor element at a reference temperature and recording the measured resistance; and precisely trimming the monolithic resistor element to produce a precise resistance ratio between the first and second segments at said reference temperature.
Claim 3
Dependent Claim
41 words
The sensor manufacturing method of claim 1 wherein the first segment is formed by connecting a parallel monolithic resistor element in parallel to the thermistor and both the series coupled and parallel monolithic resistor elements are trimmed to precise resistance values.
Claim 4
Dependent Claim
15 words
The method claimed in claim 1 further including encapsulating said sensor in an elastomeric material.
Claim 5
Dependent Claim
29 words
The method claimed in claim 1 further including depositing said second segment on a substrate, connecting said thermistor to said substrate and supporting said substrate in a sensor housing.
Claim 6
Dependent Claim
112 words
A temperature probe comprising: (a) a temperature sensor comprising, (i) a substrate; (ii) a thermistor connected to the substrate; (iii) a resistor element deposited on the substrate and electrically coupled to the thermistor to form a voltage divider; (iv) at least one conductor for supplying power to the voltage divider; and (v) an output signal conductor connected to an output junction between said resistor and said thermistor; (b) a probe housing at least partially surrounding said sensor with said substrate disposed within but spaced from said housing; and (c) a resiliently deformable body of material surrounding said temperature sensor for isolating said temperature sensor from mechanical stress applied to said probe housing.
Claim 7
Dependent Claim
112 words
A temperature probe comprising: (a) a temperature sensor comprising, (i) a substrate; (ii) a thermistor connected to the substrate; (iii) a resistor element deposited on the substrate and electrically coupled to the thermistor to form a voltage divider; (iv) at least one conductor for supplying power to the voltage divider; and (v) an output signal conductor connected to an output junction between said resistor and said thermistor; (b) a probe housing at least partially surrounding said sensor with said substrate disposed within but spaced from said housing; and (c) a resiliently deformable body of material surrounding said temperature sensor for isolating said temperature sensor from mechanical stress applied to said probe housing.
Claim 8
Dependent Claim
48 words
A temperature probe as defined in claim 5 wherein said probe housing comprises a wall member defining a slot, said conductors supported by an insulating conduit engaged in said slot with said conduit and conductors supporting said sensor cantilever fashion in said housing during assembly of said probe.
Claim 9
Dependent Claim
23 words
The probe claimed in claim 5 further including a resiliently deformable grommet-like member engaged in said slot and firmly engaging said insulating conduit.
Claim 10
Dependent Claim
28 words
The sensor claimed in claim 5 further including a second resistance element deposited on said substrate and electrically coupled to said voltage divider in parallel with said thermistor.
Claim 11
Independent Claim
132 words
A method of making precision temperature sensors comprising: (a) forming electrically conductive circuit portions on a plurality of individual substrate regions; (b) forming at least a resistor element in each of said substrate regions in electrically conductive engagement with respective circuit portions; (c) attaching a discrete thermistor to each substrate region, each thermistor electrically coupled to a respective resistor element to form a voltage divider with an output junction between said resistance element and said thermistor; (d) maintaining said substrate regions precisely known stable temperature; (e) measuring the resistance of each thermistor at said temperature and recording the measured resistance; and (f) measuring the resistance of each resistor element and trimming each resistor element to alter the resistance thereof to a resistance value dictated by the measured thermistor resistance at said temperature.
Claim 12
Independent Claim
132 words
A method of making precision temperature sensors comprising: (a) forming electrically conductive circuit portions on a plurality of individual substrate regions; (b) forming at least a resistor element in each of said substrate regions in electrically conductive engagement with respective circuit portions; (c) attaching a discrete thermistor to each substrate region, each thermistor electrically coupled to a respective resistor element to form a voltage divider with an output junction between said resistance element and said thermistor; (d) maintaining said substrate regions precisely known stable temperature; (e) measuring the resistance of each thermistor at said temperature and recording the measured resistance; and (f) measuring the resistance of each resistor element and trimming each resistor element to alter the resistance thereof to a resistance value dictated by the measured thermistor resistance at said temperature.
Claim 13
Dependent Claim
13 words
The method claimed in claim 9 further including attaching conductors to said substrate.
Claim 14
Dependent Claim
26 words
The method claimed in claim 10 further including encapsulating said substrate in a resiliently flexible body of elastomeric material with said conductors extending from said body.
Claim 15
Independent Claim
140 words
A method of making a temperature sensor comprising the steps of: forming a voltage divider network comprising first and second series connected resistive segments and an interposed output junction; the first segment comprising a thermistor element whose resistance changes as the temperature of the thermistor element changes and the second segment comprising a resistor element; forming said second segment comprising forming said resistor element by depositing resistive material on a substrate to produce a monolithic resistor having a predetermined nominal resistance value; transferring heat between said thermistor and a medium to establish and maintain an accurately determinable thermistor temperature; measuring the resistance of the thermistor while at the accurately determinable temperature; and trimming the resistance of the deposited resistor to change the resistance value from said nominal value to a predetermined value dependent upon the measured resistance of said thermistor.
Claim 16
Independent Claim
140 words
A method of making a temperature sensor comprising the steps of: forming a voltage divider network comprising first and second series connected resistive segments and an interposed output junction; the first segment comprising a thermistor element whose resistance changes as the temperature of the thermistor element changes and the second segment comprising a resistor element; forming said second segment comprising forming said resistor element by depositing resistive material on a substrate to produce a monolithic resistor having a predetermined nominal resistance value; transferring heat between said thermistor and a medium to establish and maintain an accurately determinable thermistor temperature; measuring the resistance of the thermistor while at the accurately determinable temperature; and trimming the resistance of the deposited resistor to change the resistance value from said nominal value to a predetermined value dependent upon the measured resistance of said thermistor.
Claim 17
Dependent Claim
23 words
The method of claim 12 where the trimming step is performed by laser trimming the monolithic resistor to achieve the predetermined resistance value.
Claim 18
Dependent Claim
21 words
The method of claim 13 further comprising the step of encapsulating the voltage divider network in a moisture protective potting material.
Claim 19
Dependent Claim
21 words
The method of claim 14 wherein prior to encapsulating the substrate and voltage divider are positioned within a heat conductive housing.
Claim 20
Dependent Claim
17 words
The method of claim 12 where the thermistor and resistive material are mounted to a single substrate.
Claim 21
Dependent Claim
24 words
The method of claim 12 where the transferring step is performed by immersing the thermistor in a liquid bath having an accurately controlled temperature.
Claim 22
Dependent Claim
107 words
A temperature probe for monitoring temperature comprising substrate means, precision trimmed monolithic resistor means mounted on the substrate means, thermistor means electrically coupled to said monolithic resistor means to form a voltage divider, energizing means connected across the voltage divider for energizing the probe with a voltage and sensor means coupled to a junction between the monolithic resistor means and the thermistor means for monitoring a voltage at said junction related to the temperature of the thermistor means; said precision trimmed monolithic resistor means and said thermistor means having a precise resistance ratio at a reference temperature at which the resistance of the thermistor is precisely known.
Claim 23
Dependent Claim
107 words
A temperature probe for monitoring temperature comprising substrate means, precision trimmed monolithic resistor means mounted on the substrate means, thermistor means electrically coupled to said monolithic resistor means to form a voltage divider, energizing means connected across the voltage divider for energizing the probe with a voltage and sensor means coupled to a junction between the monolithic resistor means and the thermistor means for monitoring a voltage at said junction related to the temperature of the thermistor means; said precision trimmed monolithic resistor means and said thermistor means having a precise resistance ratio at a reference temperature at which the resistance of the thermistor is precisely known.
Claim 24
Dependent Claim
21 words
The temperature sensor of claim 18 additionally comprising a thermally conductive enclosure for mounting the thermistor means and monolithic resistor means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-13 | 1993-05-15 | 1993-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-13 | 1997-05-15 | 1997-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-13 | 2001-05-15 | 2001-11-14 | $7700.00 | Window Closed / Lapsed |