Patent US4489263A successfully refreshed from Google Patents.
US4489263A
Expired / Lapsed
US
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Electronic speed control circuits
Assignee: Technical Components Pty Ltd
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Filing: 1983-10-17
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Granted: 1984-12-18
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Expires: 2003-10-17
Abstract
Abstract Circuit arrangements to improve the performance of motor speed control circuits using electronic switching on an AC waveform where it is desired to remotely control the electronic switch without either load current or the load waveforms being present at the controlling element. The voltage across the switching device, during the time it is off, is rectified, and used as the charging voltage for the phase firing circuit, with a resistor capacitor timing network determining the firing of the switching device when the capacitor voltage reaches a predetermined value.
Inventors
- 👤 Mark A. Potter
- 👤 John S. Crawford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:30
CPC Classifications
H; H02; H02P; H02P25/00; H02P25/02; H02P25/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
116 words
A circuit arrangement wherein the speed of an induction motor is controlled by varying the phase angle at which the alternating supply waveform is switched using an electronic switching device and where the voltage across the switching device during the time it is off is rectified and used as the charging voltage for the phase firing circuit; the phase at which the switching device is fired being determined by the rectified voltage and a resistor - capacitor timing network in which the capacitor is discharged at a fixed time relative to each half cycle and the firing point is set such that the switching device is switched on whenever the capacitor voltage reaches a certain value.
Claim 2
Dependent Claim
116 words
A circuit arrangement wherein the speed of an induction motor is controlled by varying the phase angle at which the alternating supply waveform is switched using an electronic switching device and where the voltage across the switching device during the time it is off is rectified and used as the charging voltage for the phase firing circuit; the phase at which the switching device is fired being determined by the rectified voltage and a resistor - capacitor timing network in which the capacitor is discharged at a fixed time relative to each half cycle and the firing point is set such that the switching device is switched on whenever the capacitor voltage reaches a certain value.
Claim 3
Dependent Claim
34 words
A circuit arrangement as claimed in claim 1 wherein the voltage across the switching device is rectified and the resulting DC voltage is used as the timing aiming voltage in resistance capacitance timing circuit.
Claim 4
Dependent Claim
23 words
A circuit arrangement as claimed in claim 2 where the resistive path of the resistive capacitance timing network contains a non-liner resistance element.
Claim 5
Dependent Claim
35 words
A circuit arrangement as claimed in claim 3 where the non-linear resistance element is made up by the addition of a zener diode in series and or in parallel with part of the timing resistor.
Claim 6
Dependent Claim
16 words
A circuit arrangement as claimed in claim 4 above where the switching device is a triac.
References Cited (Backward Citations)
US3757184A
Cited
US4323835A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-18 | 1988-06-18 | 1988-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-18 | 1992-06-18 | 1992-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-18 | 1996-06-18 | 1996-12-18 | $7700.00 | Window Closed / Lapsed |