US3603147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulsed anemometer circuit
Assignee: THERMO SYSTEMS Inc
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Filing: 1969-11-05
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Granted: 1971-09-07
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Expires: 1989-11-05
Abstract
Abstract An electronic circuit for operating resistance sensors at a constant temperature to obtain measurements of velocity and direction in fluids. The circuit has a balancing bridge including a sensor and amplifier producing a pulsed output voltage directly proportional to the electrical power input to the sensor and proportional to the heat transfer rate between the sensor and fluid. The output voltage of the amplifier triggers an electronic switch operable to control the voltage supplied to the bridge. One form of the circuit has a dummy load coupled to the switch to take the power supplied to the switch when the bridge is cut off from the voltage supply. The circuit can have a plurality of bridges and sensors coupled to a single amplifier.
Inventors
- 👤 Frank D Dorman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:38
CPC Classifications
G; G01; G01P; G01P5/00; G01P5/10; G01P5/12
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
100 words
A pulsed anemometer circuit comprising: bridge means including a resistance sensor and an amplifier; switch means connected to the resistance sensor, the amplifier, and an external voltage supply, said switch means operable to supply a pulsed voltage signal to the bridge means; means to sequentially operate the switch means to connect the bridge means with said voltage supply, said amplifier operative to turn off said switch means during the time the bridge means is balanced and to turn on said switch means during the time said bridge means is unbalanced, whereby the sensor is maintained at a substantially constant temperature.
Claim 2
Dependent Claim
100 words
A pulsed anemometer circuit comprising: bridge means including a resistance sensor and an amplifier; switch means connected to the resistance sensor, the amplifier, and an external voltage supply, said switch means operable to supply a pulsed voltage signal to the bridge means; means to sequentially operate the switch means to connect the bridge means with said voltage supply, said amplifier operative to turn off said switch means during the time the bridge means is balanced and to turn on said switch means during the time said bridge means is unbalanced, whereby the sensor is maintained at a substantially constant temperature.
Claim 3
Dependent Claim
15 words
The circuit of claim 1 wherein: said amplifier is connected to a negative reference voltage.
Claim 4
Dependent Claim
25 words
The circuit of claim 1 wherein: said means to operate the switch means is an oscillator imparting a square wave signal to the switch means.
Claim 5
Dependent Claim
33 words
The circuit of claim 1 including: a dummy load connected to the switch means, said switch means operative to connect the voltage supply to the dummy load when the bridge means is balanced.
Claim 6
Dependent Claim
15 words
The circuit of claim 4 wherein: said amplifier is connected to a negative reference voltage.
Claim 7
Dependent Claim
144 words
A pulsed anemometer circuit comprising: first bridge means having a first resistance sensor; second bridge means having a second resistance sensor; an amplifier connected to the first bridge means and the second bridge means operable to produce output signals in accordance with the current required to balance the bridge means; switch means connected to a voltage supply, the first bridge means, second bridge means and amplifier; means to trigger the switch means to sequentially operate the switch means to provide separate sequential-pulsed voltages for the first bridge means and second bridge means, said amplifier operative to actuate the switch means in sequence during the times the first bridge means and second bridge means are unbalanced to supply the pulsed voltage sequentially to the first bridge means and second bridge means, whereby the first sensor and second sensor are separately maintained at substantially constant temperatures.
Claim 8
Dependent Claim
144 words
A pulsed anemometer circuit comprising: first bridge means having a first resistance sensor; second bridge means having a second resistance sensor; an amplifier connected to the first bridge means and the second bridge means operable to produce output signals in accordance with the current required to balance the bridge means; switch means connected to a voltage supply, the first bridge means, second bridge means and amplifier; means to trigger the switch means to sequentially operate the switch means to provide separate sequential-pulsed voltages for the first bridge means and second bridge means, said amplifier operative to actuate the switch means in sequence during the times the first bridge means and second bridge means are unbalanced to supply the pulsed voltage sequentially to the first bridge means and second bridge means, whereby the first sensor and second sensor are separately maintained at substantially constant temperatures.
Claim 9
Dependent Claim
22 words
The circuit of claim 6 wherein: the first resistance sensor and second resistance sensor are separate resistance films on a common support.
Claim 10
Dependent Claim
26 words
The circuit of claim 6 wherein: said means to trigger the switch means is an oscillator imparting a square wave voltage signal to the switch means.
Claim 11
Dependent Claim
33 words
The circuit of claim 6 including: a dummy load connected to the switch means, said switch means operative to connect the voltage supply to the dummy load when both bridge means are balanced.
Claim 12
Dependent Claim
15 words
The circuit of claim 9 wherein: said amplifier is connected to a negative reference voltage.
Claim 13
Dependent Claim
15 words
The circuit of claim 6 wherein: said amplifier is connected to a negative reference voltage.
Claim 14
Dependent Claim
17 words
The circuit of claim 6 wherein: said switch means is connected to an external constant voltage supply.
Claim 15
Dependent Claim
120 words
A pulsed anemometer circuit comprising: a plurality of bridge means, each bridge means having a resistance sensor; an amplifier connected to each bridge means operable to produce output signals in accordance with current required to balance each bridge means; switch means connected to a voltage supply, the plurality of bridge means, and the amplifier; means to trigger the switch means to sequentially operate the switch means to provide separate sequential pulse voltages for the plurality of bridge means, said amplifier operative to actuate the switch means in sequence during the times the plurality of bridge means are unbalanced to supply the pulsed voltage sequentially to the plurality of bridge means, whereby the sensors are separately maintained at substantially constant temperatures.
Claim 16
Dependent Claim
120 words
A pulsed anemometer circuit comprising: a plurality of bridge means, each bridge means having a resistance sensor; an amplifier connected to each bridge means operable to produce output signals in accordance with current required to balance each bridge means; switch means connected to a voltage supply, the plurality of bridge means, and the amplifier; means to trigger the switch means to sequentially operate the switch means to provide separate sequential pulse voltages for the plurality of bridge means, said amplifier operative to actuate the switch means in sequence during the times the plurality of bridge means are unbalanced to supply the pulsed voltage sequentially to the plurality of bridge means, whereby the sensors are separately maintained at substantially constant temperatures.
Claim 17
Dependent Claim
13 words
The circuit of claim 13 wherein: the resistance sensors comprise separate resistance films.
Claim 18
Dependent Claim
26 words
The circuit of claim 14 wherein: said means to trigger the switch means is an oscillator imparting a square wave voltage signal to the switch means.
Claim 19
Dependent Claim
35 words
The circuit of claim 13 including: a dummy load connected to the switch means, said switch means operative to connect the voltage supply to the dummy load when said plurality of bridge means are balanced.
Claim 20
Dependent Claim
15 words
The circuit of claim 13 wherein: said amplifier is connected to a negative reference voltage.
Claim 21
Dependent Claim
17 words
The circuit of claim 13 wherein: said switch means is connected to an external constant voltage supply.
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) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |