EP0128601A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Temperature monitoring device
Assignee: KU Leuven
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Filing: 1984-05-08
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Granted: —
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Expires: 2004-05-08
Abstract
Abstract Device for warning against the passing of a temperature value, e.g. in case of fire, overheating or undercooling. The temperature sensor is a wire (15), made of shape memory alloy, which can be laid in a tortuous shape along the room to be watched, and this wire is coupled to a circuit responsive to the rate of change of the electrical resistance of the wire above a threshold value to generate the warning signal. This circuit includes a Wheatstone bridge (9) connected to an amplifier (4) with an integrating feedback circuit (20) with limited integrating speed. The amplifier (4) is further connected to a comparator (12) having its output connected to an alarm relay (13).
Inventors
- 👤 John Vandorpe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 21:24
CPC Classifications
G; G08; G08B; G08B17/00; G08B17/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
53 words
A temperature monitoring device comprising a wire made of shape memory alloy, and a circuit having an input coupled to said wire and being responsive to a rate of change of the electrical resistance of the wire above a threshold value to generate a warning indication of the passing of a temperature value.
Claim 2
Dependent Claim
53 words
A temperature monitoring device comprising a wire made of shape memory alloy, and a circuit having an input coupled to said wire and being responsive to a rate of change of the electrical resistance of the wire above a threshold value to generate a warning indication of the passing of a temperature value.
Claim 3
Dependent Claim
80 words
A device according to claim 1, in which said circuit responsive to a rate of change of resistance above a threshold value comprises a passive electrical network in which said wire is included, a differentiator circuit of which the input is connected to two points of said network adapted to deliver a voltage changing in response to a change of resistance of said wire, and a threshold circuit of which the input is connected to the output of said differentiator.
Claim 4
Dependent Claim
84 words
A device according to claim 1, in which said circuit responsive to a rate of change of resistance above a threshold value comprises a passive electrical network in which said wire is included, an amplifier of which the input is connected by resistive means to two points of said network adapted to deliver a voltage changing in response to a resistance change of said wire, the output of said amplifier being fed back towards the input via an integrator having a limited integrating speed.
Claim 5
Dependent Claim
62 words
A device according to claim 3, in which said integrator with limited integrating speed comprises a generator of clock pulses, an up-down counter for counting the clock pulses at one input up or down according as the voltage at a second input is positive or negative, and a digital-to-analog converter of which the input is connected to the output of said counter.
Claim 6
Independent Claim
22 words
A device according to any one of the preceding claims, in which said shape memory alloy is a Cu-Al-Zn shape memory alloy.
Claim 7
Independent Claim
34 words
A device for monitoring overheating according to any one of the preceding claims, in which said circuit responsive to a rate of change of resistance is responsive to a rate of drop of resistance.
Claim 8
Independent Claim
25 words
A device according to any one of the preceding claims, in which said alloy has an Mg temperature in the range between 30°C and 150°C.
Claim 9
Independent Claim
41 words
A device according to any one of the preceding claims, in which the wire has a circular cross-section of a diameter in the range between 0.1 mm and 3 mm and a length in the range from 0.5 to 100 metres.
References Cited (Backward Citations)
FR1230121A
Cited
US3044050A
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US3516082A
Cited
US3643245A
Cited
GB1589870A
Cited
US4356478A
Cited
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