Patent US4157977A successfully refreshed from Google Patents.
Patent US3831003A successfully refreshed from Google Patents.
US3831003A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for the steady temperature control
Assignee: Siemens AG
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Filing: 1973-03-08
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Granted: 1974-08-20
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Expires: 1993-03-08
Abstract
Abstract A circuit arrangement for effecting a uniform temperature control, utilizing a resistance bridge having a temperaturedependent resistance as a temperature sensor and an operational amplifier in whose output circuit a heating resistance is disposed, the two difference inputs of the operational amplifier being connected in the zero branch of the resistance bridge, and the heating resistance being operatively connected to the output of the operational amplifier by a transistor, circuited for common-emitter operation, the heating resistance being connected to the collector electrode of the transistor, a voltage divider being connected in parallel with the heating resistance, with a part of the resistance of such voltage divider being disposed in a branch of the resistance bridge, and the resistance values of the respective bridge branches or legs, at the normal operating temperature, being substantially equal.
Inventors
- 👤 H Foerster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:21
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/1906; G05D23/1909
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
141 words
In a circuit arrangement for effecting a uniform temperature control, utilizing a resistance bridge having a temperaturedependent resistance as a temperature sensor, and a transistor amplifier in whose output circuit a heating resistance is disposed, the combination of a resistance bridge, a transistor amplifier in the form of an operational amplifier constructed in integrated technique, the two difference inputs of which are connected in the zero branch of the resistance bridge, a transistor operatively connected to the output of the operational amplifier for common-emitter operation, a heat resistance connected to the oscillator electrode of the transistor, and a voltage divider connected in parallel with the heat resistance, a part of the resistance of the voltage divider being disposed in a branch of the resistance bridge, the resistance values of the respective bridge branches, at the normal operative temperature, being substantially equal.
Claim 2
Dependent Claim
141 words
In a circuit arrangement for effecting a uniform temperature control, utilizing a resistance bridge having a temperaturedependent resistance as a temperature sensor, and a transistor amplifier in whose output circuit a heating resistance is disposed, the combination of a resistance bridge, a transistor amplifier in the form of an operational amplifier constructed in integrated technique, the two difference inputs of which are connected in the zero branch of the resistance bridge, a transistor operatively connected to the output of the operational amplifier for common-emitter operation, a heat resistance connected to the oscillator electrode of the transistor, and a voltage divider connected in parallel with the heat resistance, a part of the resistance of the voltage divider being disposed in a branch of the resistance bridge, the resistance values of the respective bridge branches, at the normal operative temperature, being substantially equal.
Claim 3
Dependent Claim
44 words
A circuit arrangement according to claim 1, wherein the value of the portion of the resistance, of the voltage divider which forms a part of the resistance bridge, is small as compared with the remaining resistance in series therewith forming the associated bridge branch.
Claim 4
Dependent Claim
41 words
A circuit arrangement according to claim 1, comprising in further combination, a Zener diode, the cathode of which is connected to the output of the operational amplifier and the anode of which is operatively connected to the base of the transistor.
Claim 5
Dependent Claim
20 words
A circuit arrangement according to claim 3, wherein said diode anode is connected to the transistor base over a resistance.
Claim 6
Dependent Claim
70 words
A circuit arrangement according to claim 1, comprising in further combination, a first capacitor connected in the zero branch of the resistance bridge, having a capacitance value such that undesired high-frequency stray-effects are substantially weakened, and a second capacitor, connecting the output of the differential amplifier with its inverted input, having a capacitance value such that the previously weakened high-frequency stray-effects reaching the amplifier input will receive no material amplification.
Claim 7
Dependent Claim
20 words
A circuit arrangement according to claim 5, wherein said first and second capacitors have equal capacity values of approximately 1nF.
Claim 8
Dependent Claim
68 words
A circuit arrangement according to claim 2, comprising in further combination, a first capacitor connected in the zero branch of the resistance bridge, having a capacitance value such that undesired high-frequency are substantially weakened, and a second capacitor, connecting the output of the differential amplifier with its inverted input, having a capacitance value such that the previously weakened hiGh-frequency reaching the amplifier intput will receive no material amplification.
Claim 9
Dependent Claim
41 words
A circuit arrangement according to claim 7, comprising in further combination, a Zener diode, the cathode of which is connected to the output of the operational amplifier and the anode of which is operatively connected to the base of the transistor.
Claim 10
Dependent Claim
20 words
A circuit arrangement according to claim 8, wherein said diode anode is connected to the transistor base over a resistance.
Claim 11
Dependent Claim
20 words
A circuit arrangement according to claim 9, wherein said first and second capacitors have equal capacity values of approximately 1nF.
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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |