US4972134A
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US
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Motor control circuit for automatic washer
Assignee: Whirlpool Corp
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Filing: 1988-05-02
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Granted: 1990-11-20
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Expires: 2008-05-02
Abstract
Abstract A motor control circuit for operating a permanent split capacitor motor from an ac source. The motor control circuit causes the motor to accelerate and decelerate according to a velocity profile. A driver circuit connects the motor to the ac source. The driver circuit receives a pulse signal at a predetermined time point after a zero crossing of the ac source and connects the ac line current to the motor at the predetermined time point, then the driver circuit disconnects the ac source from the motor at the next zero crossing of the ac source. A ramp wave signal is generated, each ramp thereof beginning at a zero crossing of the ac source and a dc voltage representative of the speed of the motor is also generated. A velocity profile having a predetermined period is provided on an output of a velocity profile generator. A first comparator circuit has a first input for receiving the dc voltage and a second input for receiving the velocity profile. An error signal is provided on an output thereof. A second comparator has a first input receiving the ramp wave signal and a second input receiving the error signal. An output signal is provided on an output thereof to a monostable circuit which has an input ac coupled to the output of the second comparator and which has an output for providing the pulse signal.
Inventors
- 👤 Edward H. Getz
- 👤 Joseph A. Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:07
CPC Classifications
H; H02; H02P; H02P25/00; H02P25/02; H02P25/04
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
203 words
A motor control circuit for operating a permanent split capacitor motor from an ac source, comprising: means for driving said motor from the ac source, said means for driving receiving a pulse signal at a predetermined time after a zero crossing of the voltage of the ac source, said means for driving connecting the ac source to said motor at said predetermined time and then disconnecting the ac source from said motor at a next zero crossing of ac current in said motor; first means for providing a first signal indicative of the speed of said motor; means for generating a velocity profile having means for generating a square wave signal and means for converting said square wave signal to said velocity profile; means for providing said pulse signal receiving said first signal and said velocity profile signal to produce said pulse signal therefrom; means for generating said square wave signal having a predetermined time period; means for generating a triangular wave signal from said square wave signal; means for clipping said triangular wave signal to produce a trapezoid wave signal; and means for adjusting a dc offset of said trapezoidal signal to produce aid velocity profile signal having said predetermined time period.
Claim 2
Dependent Claim
203 words
A motor control circuit for operating a permanent split capacitor motor from an ac source, comprising: means for driving said motor from the ac source, said means for driving receiving a pulse signal at a predetermined time after a zero crossing of the voltage of the ac source, said means for driving connecting the ac source to said motor at said predetermined time and then disconnecting the ac source from said motor at a next zero crossing of ac current in said motor; first means for providing a first signal indicative of the speed of said motor; means for generating a velocity profile having means for generating a square wave signal and means for converting said square wave signal to said velocity profile; means for providing said pulse signal receiving said first signal and said velocity profile signal to produce said pulse signal therefrom; means for generating said square wave signal having a predetermined time period; means for generating a triangular wave signal from said square wave signal; means for clipping said triangular wave signal to produce a trapezoid wave signal; and means for adjusting a dc offset of said trapezoidal signal to produce aid velocity profile signal having said predetermined time period.
Claim 3
Dependent Claim
28 words
The motor control circuit according to claim 1, wherein said predetermined time period of said square wave is substantially longer than a time period of the ac source.
Claim 4
Dependent Claim
27 words
The motor control circuit according to claim 2, wherein said means for providing said pulse signal produces a pulse signal every half cycle of the ac source.
Claim 5
Dependent Claim
75 words
The motor control circuit according to claim 2, wherein said velocity profile has a predetermined time period and said means for driving is reversible to drive said motor in one direction during a first time period of said velocity profile and in an opposite direction during a next second time period of said velocity profile, said means for driving receiving a direction signal for reversing said motor from said means for generating a velocity profile.
Claim 6
Dependent Claim
52 words
The motor control circuit according to claim 4, wherein said velocity profile has value of substantially zero at a time point between said first and second time periods of said velocity profile so that said motor is substantially stopped when the means for driving receives said direction signal for reversing said motor.
Claim 7
Dependent Claim
71 words
The motor control circuit according to claim 5, wherein said means for driving said motor has a means for switching receiving said direction signal from said means for generating a velocity profile, said means for switching alternately activating two driver circuits for periodically changing the direction of rotation of said motor, said direction signal causing said means for switching to reverse said motor when said velocity profile signal is substantially zero.
Claim 8
Dependent Claim
48 words
The motor control circuit according to claim 2, wherein said pulse signal has a pulse having a predetermined time width which is greater than any time difference between a zero crossing of the voltage of the ac source and a zero crossing of the current in said motor.
Claim 9
Dependent Claim
35 words
The motor control circuit according to claim 2, wherein said zero crossing signal is substantially a ramp wave signal, each ramp thereof beginning at substantially a zero crossing of the voltage of the ac source.
Claim 10
Dependent Claim
96 words
The motor control circuit according to claim 2, wherein said zero crossing signal is a ramp wave signal, each ramp thereof beginning at substantially a zero crossing of the voltage of said ac source and wherein said means for controlling comprises: means for comparing said error signal to each of said ramps of said ramp wave signal and producing an output signal when a level of said ramp signal is greater than said error signal; and means for forming said pulse signal of a predetermined width when a leading edge of said output signal is received.
Claim 11
Dependent Claim
47 words
The motor control circuit according to claim 2, wherein said means for controlling provides said direction signal having a predetermined time period to said means for driving and wherein said velocity profile has a predetermined time period substantially equal to said time period of said direction signal.
Claim 12
Dependent Claim
42 words
The motor control circuit according to claim 2, including second means for producing a second signal indicative of the zero crossing of the voltagE of the ac line source and said means for providing said pulse signal also receiving said second signal.
Claim 13
Dependent Claim
60 words
The motor control according to claim 2, wherein said first means comprises means for determining a substantially instantaneous speed of said motor and outputting a tach signal indicative thereof, means for generating a dc voltage having a voltage level representative of said tach signal, and means for comparing said velocity profile to said dc voltage to produce an error signal.
Claim 14
Dependent Claim
32 words
The motor control circuit according to claim 11, wherein said second means comprises means for detecting a zero voltage crossing of the ac source and outputting a zero crossing signal indicative thereof.
Claim 15
Dependent Claim
109 words
The motor control circuit according to claim 2, wherein said motor first and second windings and said means for driving selectively connects the ac source to one of said first and second windings as a run winding and to the other of said first and second windings as an auxiliary winding in response to a direction signal, said means for driving connecting the ac source to said first and second windings at a first time after a zero crossing of the voltage of the ac source and then disconnecting the ac source from said first and second windings at a next zero crossing of ac current in the motor.
Claim 16
Independent Claim
219 words
A method of operating a permanent split capacitor motor from an ac line source, comprising, the steps of: driving said motor from the ac source by receiving a pulse signal at a predetermined time after a zero crossing of the voltage of the ac source, connecting the ac source to said motor at said predetermined time and then disconnecting the ac source from said motor at a next zero crossing of the current in said motor; detecting a zero voltage crossing of the ac source and providing a zero crossing signal indicative thereof; determining a substantially instantaneous speed of said motor and providing a tach signal indicative thereof; generating a dc voltage having a voltage level representative of said tach signal; generating a velocity profile signal by generating a square wave signal and converting said square wave signal to said velocity profile; comparing said velocity profile signal to said dc voltage to produce an error signal; producing said pulse signal from said error signal and said zero crossing signal; generating a square wave signal having a predetermined time period; generating a triangular wave signal from said square wave signal; clipping said triangular wave signal to produce a trapezoidal wave signal; and adjusting a dc offset of said trapezoidal signal to produce said velocity profile having said predetermined time period.
Claim 17
Independent Claim
219 words
A method of operating a permanent split capacitor motor from an ac line source, comprising, the steps of: driving said motor from the ac source by receiving a pulse signal at a predetermined time after a zero crossing of the voltage of the ac source, connecting the ac source to said motor at said predetermined time and then disconnecting the ac source from said motor at a next zero crossing of the current in said motor; detecting a zero voltage crossing of the ac source and providing a zero crossing signal indicative thereof; determining a substantially instantaneous speed of said motor and providing a tach signal indicative thereof; generating a dc voltage having a voltage level representative of said tach signal; generating a velocity profile signal by generating a square wave signal and converting said square wave signal to said velocity profile; comparing said velocity profile signal to said dc voltage to produce an error signal; producing said pulse signal from said error signal and said zero crossing signal; generating a square wave signal having a predetermined time period; generating a triangular wave signal from said square wave signal; clipping said triangular wave signal to produce a trapezoidal wave signal; and adjusting a dc offset of said trapezoidal signal to produce said velocity profile having said predetermined time period.
Claim 18
Dependent Claim
26 words
The method according to claim 15, wherein said predetermined time period of said square wave is substantially longer than the time period of the ac source.
Claim 19
Dependent Claim
20 words
The method according to claim 15, wherein a pulse signal is produced for every half cycle of the ac source.
Claim 20
Dependent Claim
56 words
The method according to claim 15, wherein said velocity profile has a predetermined time period and wherein said method further comprises: producing a direction signal to drive said motor in one direction during a first time period of said velocity profile and in an opposite direction during a next second time period of said velocity profile.
Claim 21
Dependent Claim
47 words
The method according to claim 18, wherein said velocity profile has a value of substantially zero at a time point between said first and second time periods of said velocity profile so that said motor is substantially stopped when said direction signal causes said motor to reverse.
Claim 22
Dependent Claim
46 words
The method according to claim 15, wherein said pulse signal has a pulse having a predetermined time width which is greater than any time difference between a zero crossing of the voltage of the ac source and a zero crossing of the current in said motor.
Claim 23
Dependent Claim
34 words
The control circuit according to claim 15, wherein said zero crossing signal is substantially a ramp wave signal, each ramp thereof beginning at substantially a zero crossing of the voltage of said ac source.
Claim 24
Dependent Claim
189 words
The motor control circuit for operating a permanent split capacitor motor from an ac source, comprising means for driving said motor from the ac source, said means for driving receiving a pulse signal at a predetermined time after a zero crossing of the voltage of the ac source, said means for driving connecting the ac source to said motor as said predetermined time and then disconnecting the ac source from said motor at a next zero crossing of ac current in said motor; first means for providing a first signal indicative of the speed of said motor; means for generating a velocity profile; means for providing said pulse signal receiving said first signal and said velocity profile signal to produce said pusle signal therefrom every half cycle of the ac source; means for generating said square wave signal having a predetermined time period; means for generating a triangular wave signal from said square wave signal; means for clipping said triangular wave signal to produce a trapezoidal wave signal; and means for adjusting a dc offset of said trapezoidal signal to produce said velocity profile having said predetermined time period.
Claim 25
Dependent Claim
189 words
The motor control circuit for operating a permanent split capacitor motor from an ac source, comprising means for driving said motor from the ac source, said means for driving receiving a pulse signal at a predetermined time after a zero crossing of the voltage of the ac source, said means for driving connecting the ac source to said motor as said predetermined time and then disconnecting the ac source from said motor at a next zero crossing of ac current in said motor; first means for providing a first signal indicative of the speed of said motor; means for generating a velocity profile; means for providing said pulse signal receiving said first signal and said velocity profile signal to produce said pusle signal therefrom every half cycle of the ac source; means for generating said square wave signal having a predetermined time period; means for generating a triangular wave signal from said square wave signal; means for clipping said triangular wave signal to produce a trapezoidal wave signal; and means for adjusting a dc offset of said trapezoidal signal to produce said velocity profile having said predetermined time period.
Claim 26
Dependent Claim
28 words
The motor control circuit according to claim 22, wherein said predetermined time period of said square wave is substantially longer than a time period of the ac source.
Claim 27
Dependent Claim
75 words
The motor control circuit according to claim 22, wherein said velocity profile has a predetermined time period and said means for driving is reversible to drive said motor in one direction during a first time period of said velocity profile and in an opposite direction during a next second time period of said velocity profile, said means for driving receiving a direction signal for reversing said motor from said means for generating a velocity profile.
Claim 28
Independent Claim
206 words
A method of operating a permanent split capacitor motor from an ac source, comprising the steps of: driving said motor from the ac source by receiving a pulse signal at a predetermined time after a zero crossing of the voltage of the ac source, connecting the ac source to said motor at said predetermined time and then disconnecting the ac source from said motor at a next zero crossing of the current in said motor; detecting a zero voltage crossing of the ac source and providing a zero crossing signal indicative thereof; determining a substantially instantaneous speed of said motor and providing a tach signal indicative thereof; generating a dc voltage having a voltage level representative of said tach signal; generating a velocity profile; comparing said velocity to said dc voltage to produce an error signal; producing said pulse signal from said error signal and said zero crossing signal every half cycle of the ac source; generating a square wave signal having a predetermined time period; generating a triangular wave signal from said square wave signal; clipping said triangular wave signal to produce a trapezoidal wave signal; and adjusting a dc offset of said trapezoidal signal to produce said velocity profile having said predetermined time period.
Claim 29
Independent Claim
206 words
A method of operating a permanent split capacitor motor from an ac source, comprising the steps of: driving said motor from the ac source by receiving a pulse signal at a predetermined time after a zero crossing of the voltage of the ac source, connecting the ac source to said motor at said predetermined time and then disconnecting the ac source from said motor at a next zero crossing of the current in said motor; detecting a zero voltage crossing of the ac source and providing a zero crossing signal indicative thereof; determining a substantially instantaneous speed of said motor and providing a tach signal indicative thereof; generating a dc voltage having a voltage level representative of said tach signal; generating a velocity profile; comparing said velocity to said dc voltage to produce an error signal; producing said pulse signal from said error signal and said zero crossing signal every half cycle of the ac source; generating a square wave signal having a predetermined time period; generating a triangular wave signal from said square wave signal; clipping said triangular wave signal to produce a trapezoidal wave signal; and adjusting a dc offset of said trapezoidal signal to produce said velocity profile having said predetermined time period.
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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) | 1993-11-19 | 1994-05-21 | 1994-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-19 | 1998-05-21 | 1998-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-19 | 2002-05-21 | 2002-11-20 | $7700.00 | Window Closed / Lapsed |