US5073758A
Expired / Lapsed
US
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Resistance measurement in an active and high temperature environment
Assignee: Apex Brands Inc
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Filing: 1990-03-30
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Granted: 1991-12-17
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Expires: 2010-03-30
Abstract
Abstract A circuit and method for measuring resistance in an active and high temperature environment is provided using a low frequency square wave as an input. The square wave input is fed through the unit under test into a full-wave rectifier and RMS circuit. The full-wave rectifier and averaging circuit cancel out errors caused by the Seebeck effect and noise. The resulting d.c. signal is proportional to the resistance of the unit under test and can be displayed.
Inventors
- 👤 Lester B. Postlewait
- 👤 Charles M. Newton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:14
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
80 words
A method for measuring the resistance of a part of a powered soldering iron, comprising: providing an a.c. signal; passing the a.c. signal through said part of the soldering iron to modify said a.c. signal; transmitting the modified a.c. signal through a full-wave rectifier to obtain a full-wave rectified signal; and averaging the full-wave rectified signal over time to generate a direct current signal having an amplitude which is proportional to the resistance of said part of the soldering iron.
Claim 2
Independent Claim
80 words
A method for measuring the resistance of a part of a powered soldering iron, comprising: providing an a.c. signal; passing the a.c. signal through said part of the soldering iron to modify said a.c. signal; transmitting the modified a.c. signal through a full-wave rectifier to obtain a full-wave rectified signal; and averaging the full-wave rectified signal over time to generate a direct current signal having an amplitude which is proportional to the resistance of said part of the soldering iron.
Claim 3
Dependent Claim
54 words
The method of claim 1, wherein said providing step includes generating a square wave signal, said passing step includes passing the square wave signal through said conductor to modify said square wave signal, and said transmitting step includes transmitting the modified square wave signal through a full-wave rectifier to obtain a full-wave rectified signal.
Claim 4
Dependent Claim
20 words
The method of claim 1, wherein said providing step includes generating an a.c. signal by alternating between two d.c. signals.
Claim 5
Dependent Claim
20 words
The method of claim 3, wherein said generating an a.c. signal is done by electronically alternating between two d.c. signals.
Claim 6
Dependent Claim
63 words
The method of claim 1, wherein said providing step includes generating a current signal by forming an oscillating control signal, controlling a switch with said oscillating control signal, alternating the output of said switch between a first and a second d.c. voltage signal to form a square wave voltage signal, and converting said square wave voltage signal into said square wave current signal.
Claim 7
Dependent Claim
32 words
The method of claim 5, wherein said first d.c. voltage signal has an amplitude which is equal in magnitude and opposite in sign of the amplitude of the second d.c. voltage signal.
Claim 8
Dependent Claim
21 words
The method of claim 1, wherein said passing step includes passing the a.c. signal through an energized and hot soldering tip.
Claim 9
Dependent Claim
38 words
The method of claim 7, wherein said providing step includes generating a square wave current signal, and said passing step includes passing the square wave current signal through said soldering tip to form a square wave voltage signal.
Claim 10
Dependent Claim
15 words
The method of claim 1, further comprising: sending said direct current signal to a display.
Claim 11
Dependent Claim
37 words
The method of claim 1, wherein said soldering gun comprises a tip, a heating element, and a ground connection, and said part of the soldering iron is the connection between said tip, heating element, and ground connection.
Claim 12
Dependent Claim
16 words
The method of claim 1, wherein said rectifying and averaging steps compensate for the Seebeck effect.
Claim 13
Independent Claim
75 words
A method for measuring the resistance of an energized and hot soldering tip, comprising: providing a square wave signal; passing the square wave signal through said soldering tip to modify said square wave signal; transmitting the modified square wave signal through a full-wave rectifier to obtain a full-wave rectified signal; and averaging the full-wave rectified signal over time to generate a d.c. signal having an amplitude which is proportional to resistance of said soldering tip.
Claim 14
Independent Claim
75 words
A method for measuring the resistance of an energized and hot soldering tip, comprising: providing a square wave signal; passing the square wave signal through said soldering tip to modify said square wave signal; transmitting the modified square wave signal through a full-wave rectifier to obtain a full-wave rectified signal; and averaging the full-wave rectified signal over time to generate a d.c. signal having an amplitude which is proportional to resistance of said soldering tip.
Claim 15
Independent Claim
107 words
A device for measuring the resistance of a part of a powered soldering iron environment, comprising: a generating circuit for generating an a.c. signal, said generating circuit being coupled to said part of the soldering iron for passing said a.c. signal therethrough; a full-wave rectifier for full-wave rectifying a modified a.c. signal, said full-wave rectifier being coupled to said part of the soldering iron; and an averaging circuit for averaging a full-wave rectified signal over time and generating a direct voltage signal having an amplitude which is proportional to the resistance of said part of the soldering iron, said averaging circuit being coupled to said full-wave rectifier.
Claim 16
Independent Claim
107 words
A device for measuring the resistance of a part of a powered soldering iron environment, comprising: a generating circuit for generating an a.c. signal, said generating circuit being coupled to said part of the soldering iron for passing said a.c. signal therethrough; a full-wave rectifier for full-wave rectifying a modified a.c. signal, said full-wave rectifier being coupled to said part of the soldering iron; and an averaging circuit for averaging a full-wave rectified signal over time and generating a direct voltage signal having an amplitude which is proportional to the resistance of said part of the soldering iron, said averaging circuit being coupled to said full-wave rectifier.
Claim 17
Dependent Claim
14 words
The device of claim 13, wherein said generating circuit generates a square wave signal.
Claim 18
Dependent Claim
15 words
The device of claim 14, wherein said generating circuit generates a square wave current signal.
Claim 19
Dependent Claim
123 words
The device of claim 13, wherein said generating circuit comprises: an oscillator circuit for forming an oscillating control signal; a first d.c. voltage supply; a second d.c. voltage supply; a switch having at least three inputs, a first input is coupled to the first d.c. voltage supply, a second input is coupled to the second d.c. voltage supply, a third input which controls the output of said switch, said third input is coupled to said oscillator circuit, and said oscillation signal causes the output of said switch to alternate between said first and second inputs of said switch forming a square wave voltage signal; and a bipolar current source circuit for converting said square wave voltage signal into a square wave current signal.
Claim 20
Dependent Claim
32 words
The device of claim 16, wherein said first d.c. voltage supply has an amplitude which is equal in magnitude and opposite in sign to the amplitude of said second d.c. voltage supply.
Claim 21
Independent Claim
13 words
The device 13, wherein said conductor is an energized and hot soldering tip.
Claim 22
Independent Claim
13 words
The device 13, wherein said conductor is an energized and hot soldering tip.
Claim 23
Dependent Claim
39 words
The device of claim 13, further comprising: a display device for displaying a value which is proportional to the amplitude of said direct current voltage signal, said value being equal to the amplitude of the resistance of said conductor.
Claim 24
Dependent Claim
37 words
The device of claim 13, wherein said soldering gun comprises a tip, a heating element, and a ground connection, and said part of the soldering iron is the connection between said tip, heating element, and ground connection.
Claim 25
Dependent Claim
16 words
The device of claim 13, wherein said rectifying and averaging steps compensate for the Seebeck effect.
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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) | 1994-12-16 | 1995-06-17 | 1995-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-16 | 1999-06-17 | 1999-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-16 | 2003-06-17 | 2003-12-17 | $7700.00 | Window Closed / Lapsed |