US5444359A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Load sensitive variable voltage motor controller
Assignee: ELCOTEC Inc
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Filing: 1992-06-26
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Granted: 1995-08-22
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Expires: 2012-06-26
Abstract
Abstract An apparatus and method for controlling the voltage applied to an induction motor is taught. Load sensing is incorporated by monitoring the current through the motor, and combining that signal with a signal derived from the AC line voltage and AC voltage across the motor. This composite signal is averaged, with the resulting averaged signal being utilized to control a device for modulating voltage applied to the motor such as a phase control integrated circuit device.
Inventors
- 👤 Chris A. Riggio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:39
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/66; G05F1/10; G05F1/12; G05F1/40; G05F1/44; G05F1/45; G05F1/455
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
109 words
A method for controlling the voltage applied to a load, comprising the steps of: receiving an AC line voltage; generating an operating AC voltage from the AC line voltage; applying said operating AC voltage across the load; generating a first signal which is a function of the magnitude of said operating AC voltage; generating a second signal representative of the magnitude of the AC current through the load; generating a composite signal representative of a combination of said first and said second signals; generating an average signal representative of the average value of said composite signal; modifying said operating AC voltage in response to changes in said average signal.
Claim 2
Independent Claim
109 words
A method for controlling the voltage applied to a load, comprising the steps of: receiving an AC line voltage; generating an operating AC voltage from the AC line voltage; applying said operating AC voltage across the load; generating a first signal which is a function of the magnitude of said operating AC voltage; generating a second signal representative of the magnitude of the AC current through the load; generating a composite signal representative of a combination of said first and said second signals; generating an average signal representative of the average value of said composite signal; modifying said operating AC voltage in response to changes in said average signal.
Claim 3
Dependent Claim
44 words
The method of claim 1 wherein said step of modifying said operating AC voltage comprises reducing the magnitude of said operating AC voltage below the line voltage for a portion of each cycle, the length of said portion being determined by said average signal.
Claim 4
Dependent Claim
52 words
The method of claim 2 wherein said step of reducing said load voltage comprises inputting said average signal into a phase control integrated circuit device, said phase control integrated circuit device generating a control signal operative to interrupt transmission of the line voltage to the load for said portion of each cycle.
Claim 5
Dependent Claim
51 words
The method of claim 1 wherein the step of generating said average signal comprises inputting said composite signal into a rectifier circuit and rectifying said composite signal, and further comprising inputting the output of said rectifier circuit into an integrator circuit, thereby integrating said composite signal to generate said average signal.
Claim 6
Independent Claim
175 words
A method for controlling the voltage applied to a load, comprising the steps of: receiving an AC line voltage; generating an operating AC voltage from the AC line voltage by switching off the AC line voltage to be applied to the load for a portion of each cycle such that the R.M.S. value of the operating AC voltage is below the R.M.S. value of the line voltage; applying the operating AC voltage across the load; generating a first signal which is a function of the instantaneous magnitude of said operating AC voltage applied to the load; generating a second signal representative of the instantaneous magnitude of the AC current through the Load; generating a composite signal representative of a combination of said first and said second signals; integrating said composite signal to generate an average signal; modifying the operating AC voltage by changing the portion of the AC line voltage cycle during which in the applied voltage is switched off in response to said average signal representative of the average value of said composite signal.
Claim 7
Independent Claim
175 words
A method for controlling the voltage applied to a load, comprising the steps of: receiving an AC line voltage; generating an operating AC voltage from the AC line voltage by switching off the AC line voltage to be applied to the load for a portion of each cycle such that the R.M.S. value of the operating AC voltage is below the R.M.S. value of the line voltage; applying the operating AC voltage across the load; generating a first signal which is a function of the instantaneous magnitude of said operating AC voltage applied to the load; generating a second signal representative of the instantaneous magnitude of the AC current through the Load; generating a composite signal representative of a combination of said first and said second signals; integrating said composite signal to generate an average signal; modifying the operating AC voltage by changing the portion of the AC line voltage cycle during which in the applied voltage is switched off in response to said average signal representative of the average value of said composite signal.
Claim 8
Independent Claim
133 words
An apparatus for controlling the voltage applied to a load comprising: terminal means for receiving an AC line voltage; means for generating an operating AC voltage from the AC line voltage; connector means for applying said operating AC voltage across the load; voltage detection means for generating a first signal which is a function of the magnitude of said operating AC voltage; current sensing means for generating a second signal representative of the magnitude of the AC current through the load; signal combining means for generating a composite signal representative of a combination of said first and said second signals; signal averaging means for generating an average signal representative of the average value of said composite signal; AC voltage modulation means for adjusting the operating AC voltage in response to said average signal.
Claim 9
Independent Claim
133 words
An apparatus for controlling the voltage applied to a load comprising: terminal means for receiving an AC line voltage; means for generating an operating AC voltage from the AC line voltage; connector means for applying said operating AC voltage across the load; voltage detection means for generating a first signal which is a function of the magnitude of said operating AC voltage; current sensing means for generating a second signal representative of the magnitude of the AC current through the load; signal combining means for generating a composite signal representative of a combination of said first and said second signals; signal averaging means for generating an average signal representative of the average value of said composite signal; AC voltage modulation means for adjusting the operating AC voltage in response to said average signal.
Claim 10
Dependent Claim
35 words
The apparatus of claim 6 wherein said AC voltage modulation means comprises voltage reduction means for switching off the line voltage for a portion of each cycle, said portion being determined by said average signal.
Claim 11
Dependent Claim
52 words
The apparatus of claim 7 wherein said voltage reduction means comprises a phase control integrated circuit device, said phase control integrated circuit device being responsive to said average signal to generate a control signal operative to switch off transmission of the line voltage to the load for said portion of each cycle.
Claim 12
Dependent Claim
36 words
The apparatus of claim 8 wherein said signal averaging means comprises a rectifying circuit connected to said signal combining means and an integrator circuit connected to said rectifying circuit and to said AC voltage modulation means.
Claim 13
Independent Claim
167 words
An apparatus for controlling the voltage applied to a load comprising: means for receiving an AC line voltage; means for generating an operating AC voltage from the AC line voltage by reducing the AC line voltage to be applied to the load for a portion of each cycle; means for applying said operating AC voltage across the load; voltage detection means for generating a first signal which is a function of the magnitude of said operating AC voltage; current sensing means for generating a second signal representative of the magnitude of the AC current through the load; signal combining means for generating a composite signal representative of a combination of said first and said second signals; signal averaging means for generating an average signal representative of the average value of said composite signal; AC voltage modulation means for modifying said generation of said operating AC voltage by changing said portion of the cycle during which in the applied voltage is reduced in response to said average signal.
Claim 14
Independent Claim
167 words
An apparatus for controlling the voltage applied to a load comprising: means for receiving an AC line voltage; means for generating an operating AC voltage from the AC line voltage by reducing the AC line voltage to be applied to the load for a portion of each cycle; means for applying said operating AC voltage across the load; voltage detection means for generating a first signal which is a function of the magnitude of said operating AC voltage; current sensing means for generating a second signal representative of the magnitude of the AC current through the load; signal combining means for generating a composite signal representative of a combination of said first and said second signals; signal averaging means for generating an average signal representative of the average value of said composite signal; AC voltage modulation means for modifying said generation of said operating AC voltage by changing said portion of the cycle during which in the applied voltage is reduced in response to said average signal.
References Cited (Backward Citations)
US3441823A
Cited
US3506852A
Cited
US3633094A
Cited
US3821634A
Cited
US3859591A
Cited
US3997825A
Cited
US4011489A
Cited
US4048550A
Cited
US3961236A
Cited
US4078393A
Cited
US4158164A
Cited
US4052648A
Cited
US4194145A
Cited
US4190793A
Cited
US4176307A
Cited
US4255695A
Cited
US4185575A
Cited
US4237531A
Cited
US4242625A
Cited
US4266177A
Cited
US4333046A
Cited
US4271386A
Cited
US4287464A
Cited
US4302717A
Cited
US4323835A
Cited
US4298831A
Cited
GB2073921A
Cited
US4379258A
Cited
GB2079500A
Cited
JPS5768694A
Cited
US4433276A
Cited
US4404511A
Cited
US4417190A
Cited
US4380730A
Cited
US4439718A
Cited
US4426614A
Cited
JPS58144597A
Cited
US4459528A
Cited
US4469998A
Cited
US4567425A
Cited
JPS61142981A
Cited
US4689548A
Cited
JPS62285691A
Cited
US4766363A
Cited
US4870340A
Cited
US5087870A
Cited
US5006973A
Cited
US5239255A
Cited
US5191278A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-08-21 | 1999-02-20 | 1999-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-21 | 2003-02-20 | 2003-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-21 | 2007-02-20 | 2007-08-22 | $7700.00 | Window Closed / Lapsed |