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US5454230A Expired / Lapsed US ⏱️ 0.0 years remaining

Refrigeration control circuit with self-test mode

Assignee: Whirlpool Corp
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Filing: 1994-09-26
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Granted: 1995-10-03
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Expires: 2014-09-26
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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 09:53
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.

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

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