US 5,280,227 A · Electronic control for an appliance

Abstract

An electronic control for a motor which eliminates the motor centrifugal switch and more particularly a control for a domestic refuse compactor which permits the user to control the approximate full trash bag weight and obtain more compaction from a split phase induction drive motor. A ferrite core sensor on the main winding of the drive motor samples the lagging phase angle of the motor main winding current during a compaction stroke. A low force cycle is achieved by terminating the stroke as soon as phase samples fall below a threshold defined at the start of each cycle by a locked motor main winding phase sample acquired prior to starting the motor. A medium force cycle terminates the stroke when compaction forces exceed the main winding breakdown torque. A high force cycle is achieved by re-activating a motor start winding when compaction forces exceed the main winding breakdown torque and terminating the stroke as soon as the phase samples exceed a threshold defined at the start of each cycle during motor starting. The control uses programmed referencing techniques to eliminate factory pre-calibration.

Claims65

Dependent claims

A motor control for a refuse compact having a refuse receptacle, a ram reciprocable into and out of said refuse receptacle, a split phase induction drive motor with a start winding and a run winding, an AC power supply selectively supplying said drive motor with a line voltage alternating at a line frequency, and a drive assembly interconnecting said motor with said ram such that said ram is effectively driven into and out of said refuse receptacle by operation of said motor, said control comprising:

detection means for detecting the onset of stall in said motor indicative of the onset of compaction of refuse in said refuse receptacle;
wherein said detection means further comprises means for periodically measuring the phase angle of said run winding during energization of said run winding;
and
means for controlling the operation of said refuse compactor in response to said detection of the onset of stall in said motor, said means for controlling the operation of said refuse compactor comprising means for energizing said start winding in response to a predetermined change in said phase angle measurement indicative of the compaction of refuse in said refuse receptacle.

1 more element

A motor control for a refuse compactor having a refuse receptacle, a ram reciprocable into and out of said refuse receptacle, a split phase induction drive motor with a start winding and a run winding, an AC power supply selectively supplying said drive motor with a line voltage alternating at a line frequency, and a drive assembly interconnecting said motor with said ram such that said ram is effectively driven into and out of said refuse receptacle by operation of said motor, said control comprising:

detection means for detecting the onset of stall in said motor indicative of the onset of compaction of refuse in said refuse receptacle;
wherein said detection means further comprises means for periodically measuring the phase angle of said run winding during energization of said run winding;
and
means for controlling the operation of said refuse compactor in response to said detection of the onset of stall in said motor, said means for controlling the operation of said refuse compactor further comprises:
first calculator means, responsive to said phase angle measurements from said means for measuring, said first calculator means further comprising means for comparing at least two of said phase angle measurements and selectively generating a first motor control signal upon detection of a predetermined change in said measurement characteristic of the onset of stall in said motor;
second calculator means, responsive to said phase angle measurements, for comparing the most recent phase angle measurement with a locked rotor phase angle measurement and selectively generating a second motor control signal upon detection of a current phase angle measurement approximately equal to said locked rotor phase angle measurement;
first power switching means for discontinuing the supplying of power to said run winding in response to said first motor control signal;
second power switching means for initiating the supplying of power to said start winding in response to said second motor control signal;
and
selector means for selecting said first or said second calculator means.

7 more elements

detection means for detecting the onset of stall in said motor indicative of the onset of compaction of refuse in said refuse receptacle;
wherein said detection means further comprises means for periodically measuring the phase angle of said run winding during energization of said run winding;
and
means for controlling the operation of said refuse compactor in response to said detection of the onset of stall in said motor;
and further wherein said motor has a run winding having a characteristic speed-torque curve and wherein the phase angle of said run winding is dynamically indicative of the location of the motor along said speed-torque curve during operation of said motor, and further wherein said means for detecting the onset of compaction comprises:
means for storing said phase angle measurements;
and
means for comparing said stored phase angle measurements to detect a predetermined change in said phase angle indicative of the onset of stall of said motor.

5 more elements

A refuse compactor comprising:

a refuse receptacle;
ram means reciprocable into and out of said refuse receptacle;
a motor having a run winding;
drive means interconnecting said motor with said ram means such that said ram means is selectively driven into and out of said refuse receptacle by operation of said motor;
means for detecting the onset of stall of said motor indicative of the onset of compaction of refuse in said refuse receptacle wherein said means for detecting the onset of compacting further comprises:
means for measuring the phase angle of said run winding during energization of said run winding;
and
means for storing said measurements of said phase angle;
and
means for comparing two or more of said stored phase angle measurements;
and
means for controlling the operation of said motor in response to the detection of the onset of compaction;
and further wherein said means for measuring the phase angle of said run winding during energization of said run winding further comprises:
transformer means comprising a transformer winding having at least one turn of said run winding of said motor, said transformer providing a voltage signal;
a current pulse circuit responsive to said voltage signal and providing a current pulse output in response to zero crossings of said run winding;
a volt pulse circuit responsive to the line voltage to provide a volt pulse output corresponding to the line frequency;
voltage regulator means for supplying an unregulated DC bias voltage to said current pulse circuit and for supplying a full wave rectified voltage to said volt pulse circuit, said unregulated DC bias voltage adjusting the sensitivity of said current pulse circuit for the effect of line voltage variation on said run winding;
and
first calculator means responsive to said current pulse output and said volt pulse output to calculate the lagging phase angle therebetween;
and still further wherein said means for controlling the operation of said motor further comprises:
second calculator means, responsive to said phase angle measurements from said first calculator means, for comparing at least two of said phase angle measurements and generating a motor control signal upon detection of a predetermined change in said measurement characteristic of the onset of stall in said motor;
and
power switching means for controlling the supply of power to at least one of said motor windings in response to said motor control signal.

20 more elements

A diagnostic apparatus for a refuse compactor having a refuse receptacle, a ram reciprocable into and out of said refuse receptacle, a motor with a start winding and a run winding, and a drive assembly interconnecting said motor with said ram such that said ram is effectively driven into and out of said refuse receptacle by operation of said motor, said diagnostic apparatus comprising:

detection means for detecting the onset of stall in said motor indicative of the onset of compaction of refuse in said refuse receptacle;
and
timing means for measuring the duration of operation of said motor prior to the onset of stall;
and
load measuring means responsive to said timing means for estimating the volume of refuse in said refuse receptacle;
said detection means further comprises:
means for measuring motor phase angle;
means for temporarily storing phase angle measurements during each cycle of operation of said refuse compactor;
means for comparing said stored phase angle measurements;
and
means for detecting a characteristic increase in motor phase angle above the minimum phase angle measured during the current operational cycle of said refuse compactor.

8 more elements

A control for a refuse compactor having a refuse receptacle, a ram reciprocable into and out of said refuse receptacle, a split phase induction drive motor with a start winding and a run winding, an AC power supply selectively supplying said drive motor with a line voltage alternating at a line frequency, and a drive assembly interconnecting said motor with said ram such that said ram is effectively driven into and out of said refuse receptacle by operation of said motor, said control comprising:

detection means for detecting the onset of stall in said motor indicative of the onset of compaction of refuse in said refuse receptacle, wherein said detection means further comprises means for periodically measuring the phase angle of said run winding during energization of said run winding;
and
means for controlling the operation of said refuse compactor in response to said detection of the onset of stall in said motor, wherein said means for controlling the operation of said motor further comprises:
first calculator means, responsive to said phase angle measurements from said means for measuring,
first power switching means for controlling the supplying of power to at least one of said motor windings in response to said first motor control signal.

2 more elements

Dependencies are inferred from the claim text.

Electronic control for an appliance

Life of this patent

Electronic control for an appliance

Life of this patent

Abstract

Claims65