Patent US3578754A successfully refreshed from Google Patents.
US3578754A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Deforsting controller for electric refrigerator
Assignee: Panasonic Holdings Corp
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Filing: 1969-02-25
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Granted: 1971-05-18
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Expires: 1989-02-25
Abstract
Abstract A defrosting controller for electric refrigerators which is operated under control of a first transistor adapted for triggering a silicon-controlled rectifier depending upon the result detected by a temperature detector in the freezer of the refrigerator and under control of a second transistor for keeping the first transistor in one state during the defrosting operation so that the defrosting operation is automatically stopped as soon as the temperature within the freezer reaches a predetermined temperature after starting the defrosting operation. Thus, frost accumulated within the freezing compartment can completely be removed and an unnecessary temperature rise within the freezing and provisions compartments can be prevented.
Inventors
- 👤 Zenji Kusuda
- 👤 Takeji Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:07
CPC Classifications
F; F25; F25D; F25D21/00; F25D21/002; F25D21/006; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1906; G05D23/1909; G05D23/20; G05D23/24; F25D2700/00; F25D2700/12; F25D2700/122
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
182 words
A defrosting controller for an electric refrigerator having a defrosting heater means, a silicon-controlled rectifier for controlling the operation of said defrosting heater, and control means for triggering said silicon-controlled rectifier, said control means being urged to its conducTive state and to its cutoff state when said silicon-controlled rectifier is in its conductive state and cutoff state, respectively, said control means comprising a transistor the collector of which is connected with the gate of said silicon-controlled rectifier, a charging means composed of a diode and a capacitor which is connected in parallel with said silicon-controlled rectifier, a voltage dividing means which divides the voltage obtained by said charging means sand applies the divided voltage to the base of said transistor and DC bias supplying means for supplying a DC bias voltage to said transistor, wherein a temperature detector thermally coupled to the freezer is connected with the base of said transistor as a base bias dividing resistor and a switch adapted to be closed to start the defrosting operation is connected between the base of said transistor and an AC power line.
Claim 2
Dependent Claim
182 words
A defrosting controller for an electric refrigerator having a defrosting heater means, a silicon-controlled rectifier for controlling the operation of said defrosting heater, and control means for triggering said silicon-controlled rectifier, said control means being urged to its conducTive state and to its cutoff state when said silicon-controlled rectifier is in its conductive state and cutoff state, respectively, said control means comprising a transistor the collector of which is connected with the gate of said silicon-controlled rectifier, a charging means composed of a diode and a capacitor which is connected in parallel with said silicon-controlled rectifier, a voltage dividing means which divides the voltage obtained by said charging means sand applies the divided voltage to the base of said transistor and DC bias supplying means for supplying a DC bias voltage to said transistor, wherein a temperature detector thermally coupled to the freezer is connected with the base of said transistor as a base bias dividing resistor and a switch adapted to be closed to start the defrosting operation is connected between the base of said transistor and an AC power line.
Claim 3
Dependent Claim
15 words
A defrosting controller according to claim 1, in which said temperature detector is a thermistor.
Claim 4
Dependent Claim
18 words
A defrosting controller according to claim 1, in which said voltage dividing means comprises resistors connected in series.
Claim 5
Dependent Claim
189 words
A defrosting controller for an electric refrigerator having a defrosting relay means for controlling a hot gas flow, a silicon-controlled rectifier for controlling the operation of said defrosting relay means, and control means for triggering said silicon-controlled rectifier, said control means being urged to its conductive state and to its cutoff state when said silicon-controlled rectifier is in its conductive state and cutoff state, respectively, said control means comprising a transistor the collector of which is connected with the gate of said silicon-controlled rectifier, a charging means composed of a diode and a capacitor which is connected in parallel with said silicon-controlled rectifier, a voltage dividing means which divides the voltage obtained by said charging means and applies the divided voltage to the base of said transistor, and DC bias supplying means for supplying a DC bias voltage to said transistor, wherein a temperature detector thermally coupled to the freezer is connected with the base of said transistor as a base bias dividing resistor and a switch adapted to be closed to start the defrosting operation is connected between the base of said transistor and an AC power line.
Claim 6
Dependent Claim
189 words
A defrosting controller for an electric refrigerator having a defrosting relay means for controlling a hot gas flow, a silicon-controlled rectifier for controlling the operation of said defrosting relay means, and control means for triggering said silicon-controlled rectifier, said control means being urged to its conductive state and to its cutoff state when said silicon-controlled rectifier is in its conductive state and cutoff state, respectively, said control means comprising a transistor the collector of which is connected with the gate of said silicon-controlled rectifier, a charging means composed of a diode and a capacitor which is connected in parallel with said silicon-controlled rectifier, a voltage dividing means which divides the voltage obtained by said charging means and applies the divided voltage to the base of said transistor, and DC bias supplying means for supplying a DC bias voltage to said transistor, wherein a temperature detector thermally coupled to the freezer is connected with the base of said transistor as a base bias dividing resistor and a switch adapted to be closed to start the defrosting operation is connected between the base of said transistor and an AC power line.
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) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |