Patent US3600657A successfully refreshed from Google Patents.
US3600657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for electronic sensing of motor torque
Assignee: Individual
•
Filing: 1970-06-17
•
Granted: 1971-08-17
•
Expires: 1990-06-17
Abstract
Abstract A circuit is provided for connection to an AC line and a reactive load which extracts a voltage wave form from the line, the phase of which is adjustable. A pickup to the load extracts a current wave form from the load on the line to the load and converts the current wave form to pulses which are synchronized with the zero crossing or points where the current goes to zero. A phase detector is connected to the voltage wave source and the current zero crossing pulse source and converts the signals to a DC analog output of the phase relationship between the voltage and current wave and this current is used to control by means of a voltage level operated switch, and an external circuit.
Inventors
- 👤 Ernest H Pfaff
- 👤 Thomas F Mills Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:58
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/34; G01R31/343; H; H02; H02P; H02P29/00; H02P29/40
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
110 words
In combination with an AC line and a reactive load connected thereto, means for controlling the current to the load comprising means for obtaining an AC voltage signal from the line and for controlling the phase thereof, means for obtaining an AC current signal from the load, phase detector Means connected to said phase control means and to said current signal means arranged to provide a direct current output voltage which is the DC analog of the phase angle relationship of said two signals, and means operated by said detector means connected to the load circuit to control the load circuit in the presence of the voltage from said detector.
Claim 2
Dependent Claim
110 words
In combination with an AC line and a reactive load connected thereto, means for controlling the current to the load comprising means for obtaining an AC voltage signal from the line and for controlling the phase thereof, means for obtaining an AC current signal from the load, phase detector Means connected to said phase control means and to said current signal means arranged to provide a direct current output voltage which is the DC analog of the phase angle relationship of said two signals, and means operated by said detector means connected to the load circuit to control the load circuit in the presence of the voltage from said detector.
Claim 3
Dependent Claim
26 words
An apparatus as described in claim 1, herein an AC current signal detector is arranged to detect the points where the current wave goes to zero.
Claim 4
Dependent Claim
29 words
An apparatus as described in claim 2, wherein means for generating pulses synchronized with said current zero points is provided and is connected to said AC current detector means.
Claim 5
Dependent Claim
58 words
An apparatus as described in claim 3, wherein said means for detecting the points where the current wave goes to zero comprises, an amplifier and a feedback means to cause the amplifier to operate at open loop gain at the zero points with heavy negative feed back at the other points to provide a substantially square wave output.
Claim 6
Dependent Claim
24 words
An apparatus as described in claim 4, wherein a differentiator circuit is connected to said output and converts the square wave output to pulses.
Claim 7
Dependent Claim
53 words
An apparatus as described in claim 3, wherein said phase detector has a first transistor (Q6) connected (as an impedance changer) with its base emitter to the phase adjuster and a second transistor (Q7) with its emitter connected to the emitter of the first transistor and its base connected to the pulse generator.
Claim 8
Dependent Claim
28 words
An apparatus as described in claim 6, wherein filter storage means is connected across the collector and ground of the second transistor and provides said DC analog voltage.
Claim 9
Dependent Claim
24 words
An apparatus as described in claim 7, wherein said filter storage means has a time constant sufficient to store the voltage between pulse intervals.
Claim 10
Dependent Claim
29 words
An apparatus as described in claim 8, wherein the means to control the load is a voltage level operated switch connected between the load and said filter storage means.
Claim 11
Independent Claim
101 words
The method of controlling the AC current from a line to a reactive load which comprises extracting a voltage wave from the line and adjusting the phase thereof, extracting a current wave from the load and converting the current wave to pulses that coincide with the points where the current wave passes through the zero current points, and utilizing the phase controlled voltage wave and said pulses to generate an output which is the direct current analog of the phase angle between the applied voltage and the load current, and then utilizing said output to control the current to the load.
Claim 12
Independent Claim
101 words
The method of controlling the AC current from a line to a reactive load which comprises extracting a voltage wave from the line and adjusting the phase thereof, extracting a current wave from the load and converting the current wave to pulses that coincide with the points where the current wave passes through the zero current points, and utilizing the phase controlled voltage wave and said pulses to generate an output which is the direct current analog of the phase angle between the applied voltage and the load current, and then utilizing said output to control the current to the load.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-16 | 1975-02-15 | 1975-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-16 | 1979-02-15 | 1979-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-16 | 1983-02-15 | 1983-08-17 | $7700.00 | Window Closed / Lapsed |