US3906391A
Expired / Lapsed
US
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Linear period thermistor temperature oscillator
Assignee: Westinghouse Electric Corp
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Filing: 1974-06-14
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Granted: 1975-09-16
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Expires: 1994-06-14
Abstract
Abstract An oscillator circuit which converts the resistance variation with temperature of a non-linear thermistor into a variation in the period of an oscillator which is linear with temperature.
Inventors
- 👤 Lawrence C Murdock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:19
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/16; G01K7/22; G01K7/24; G01K7/245; H; H03; H03K; H03K3/00; H03K3/02; H03K3/023; H03K3/0231; H03K7/00; H03K7/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
129 words
A linear period thermistor oscillator comprising: a. an amplifier including first and second inputs and an output and being of the type which provides an output signal which switches between relatively positive and negative output values depending upon the relative magnitude of signals applied to said first and second inputs; b. first and second feedback paths respectively connecting said output with said first and second inputs; c. said first feedback path including a circuit of the type which, in response to said output signal, provides a non-linear output signal, said non-linear output signal being applied to said first input; d. said second feedback path including a voltage divider network; e. a thermistor having a resistance which varies non-linearly with temperature, connected as an element in said voltage divider network.
Claim 2
Dependent Claim
129 words
A linear period thermistor oscillator comprising: a. an amplifier including first and second inputs and an output and being of the type which provides an output signal which switches between relatively positive and negative output values depending upon the relative magnitude of signals applied to said first and second inputs; b. first and second feedback paths respectively connecting said output with said first and second inputs; c. said first feedback path including a circuit of the type which, in response to said output signal, provides a non-linear output signal, said non-linear output signal being applied to said first input; d. said second feedback path including a voltage divider network; e. a thermistor having a resistance which varies non-linearly with temperature, connected as an element in said voltage divider network.
Claim 3
Dependent Claim
39 words
Apparatus according to claim 1 wherein: a. said voltage divider network is connected between said output and a point of reference potential; b. said thermistor is connected in circuit between said point of reference potential and said second input.
Claim 4
Dependent Claim
22 words
Apparatus according to claim 2 wherein: a. the voltage across said thermistor is applied as the input signal to said second input.
Claim 5
Dependent Claim
19 words
Apparatus according to claim 1 which includes: a. a fixed resistance connected in parallel circuit configuration with said thermistor.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |