US5454230A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refrigeration control circuit with self-test mode
Assignee: Whirlpool Corp
•
Filing: 1994-09-26
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Granted: 1995-10-03
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Expires: 2014-09-26
Abstract
Abstract A defrost controller for a refrigerator/freezer including one or more of the following features: (1) a timer module that can serve as a real time, cumulative time or variable time defrost timer; (2) an algorithm to control defrosting in view of frequent power outages; (3) a power up defrost cycle; (4) a default reaction to loss of compressor run information; (5) a simple manufacturing test initiator; (6) a test initialization via thermostat actuation; (7) a relay power supply which supplies two different energization voltages; (8) a relay energization signal which decays rapidly from a voltage in excess of the relay rated voltage to a voltage within the relay rated voltage; and (9) respective relay energization sequence to overcome light contact welding.
Inventors
- 👤 Donald E. Janke
- 👤 Joseph M. Szynal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:05
CPC Classifications
F; F25; F25D; F25D21/00; F25D21/002; F25D21/008; H; H01; H01H; H01H47/00; H01H47/002; F25B; F25B2600/00; F25B2600/23; H01H2047/003; H01H3/00; H01H3/001; H01H47/02; H01H47/04; H01H47/043; H01H47/10; H01H47/22; H01H47/223
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
107 words
A freezer defrost cycle control circuit, comprising: a timer module operatively configured to interconnect to a compressor, a defrost heater, a power supply, a relay via which the compressor and defrost heater are actuated, and a compressor thermostat switch coupled in series with the compressor, the timer module including a programmable microcontroller configured and programmed to receive and process signals, including a designated signal, and to perform a test routine whenever the designated signal is turned on or off a predetermined number of times within a predetermined interval, the designated signal being a feedback signal from the compressor providing operational status about the compressor to the micro-controller.
Claim 2
Dependent Claim
107 words
A freezer defrost cycle control circuit, comprising: a timer module operatively configured to interconnect to a compressor, a defrost heater, a power supply, a relay via which the compressor and defrost heater are actuated, and a compressor thermostat switch coupled in series with the compressor, the timer module including a programmable microcontroller configured and programmed to receive and process signals, including a designated signal, and to perform a test routine whenever the designated signal is turned on or off a predetermined number of times within a predetermined interval, the designated signal being a feedback signal from the compressor providing operational status about the compressor to the micro-controller.
Claim 3
Dependent Claim
46 words
The freezer defrost cycle control circuit of claim 1, wherein the designated signal is coupled to the micro-controller via the compressor thermostat switch, the micro-controller performing a test routine whenever the compressor is turned on or off the predetermined number of times within the predetermined interval.
Claim 4
Dependent Claim
32 words
The freezer defrost cycle control circuit of claim 1, wherein the programmable micro-controller is configured to perform said test routine whenever the test signal is turned on 3 times within 30 seconds.
Claim 5
Independent Claim
111 words
An apparatus including a freezer defrost cycle control circuit, comprising: a timer module operatively configured to interconnect to a compressor, a defrost heater, a power supply, a relay via which the compressor and defrost heater are actuated, and a compressor thermostat switch coupled in series with the compressor, the timer module including a programmable micro-controller configured and programmed to receive and process signals, including a designated signal, and to perform a test routine whenever the designated signal is turned on or off a predetermined number of times within a predetermined interval, wherein the designated signal is a feedback signal from the compressor providing operational status about the compressor to the micro-controller.
Claim 6
Independent Claim
111 words
An apparatus including a freezer defrost cycle control circuit, comprising: a timer module operatively configured to interconnect to a compressor, a defrost heater, a power supply, a relay via which the compressor and defrost heater are actuated, and a compressor thermostat switch coupled in series with the compressor, the timer module including a programmable micro-controller configured and programmed to receive and process signals, including a designated signal, and to perform a test routine whenever the designated signal is turned on or off a predetermined number of times within a predetermined interval, wherein the designated signal is a feedback signal from the compressor providing operational status about the compressor to the micro-controller.
Claim 7
Dependent Claim
46 words
The freezer defrost cycle control circuit of claim 4, wherein the designated signal is coupled to the micro-controller via the compressor thermostat switch, the micro-controller performing a test routine whenever the compressor is turned on or off the predetermined number of times within the predetermined interval.
Claim 8
Dependent Claim
32 words
The freezer defrost cycle control circuit of claim 4, wherein the programmable micro-controller is configured to perform said test routine whenever the test signal is turned on 3 times within 30 seconds.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-02 | 1999-04-03 | 1999-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-02 | 2003-04-03 | 2003-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-02 | 2007-04-03 | 2007-10-03 | $7700.00 | Window Closed / Lapsed |