US3689808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for an electromagnet
Assignee: Parker Hannifin Manufacturing Switzerland SA
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Filing: 1970-10-01
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Granted: 1972-09-05
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Expires: 1990-10-01
Abstract
Abstract A control system for an electromagnet provided with a power winding controlling the motion of the movable core and with a maintenance winding holding the core in its attracted condition. The power winding is first energized through a first thyristor (a silicon controlled rectifier, generally designated SCR) or transistor by a closing of a rough rectified A.C. circuit and, after a short delay, a condenser discharges through a component provided with a threshold for voltage conduction into an electrode controlling another thyristor or transistor or the like means which energizes then the maintenance winding and provides for the release or the first thyristor or transistor so as to deenergize the power winding. The maintenance winding remains then energized until the rectified circuit is switched off.
Inventors
- 👤 Harald Stampfli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:18
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/18; H01F7/1805
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
266 words
In combination with an electromagnet including a power winding and a core-maintaining winding, the provision of a control circuit comprising first and second feed lines, a main switching means in one of said lines, said power winding and said core-maintaining winding being connected each by one of their extremities to said first feed line, each winding being inserted in series with a semi-conductive element the conductivity of which is controlled by a control electrode with the two windings and cooperating semi-conductive elements being connected in parallel between said first and second feed lines, means including a resistor in series with the core-maintaining winding and directly connected to the other extremity of said coremaintaining winding at one end and to the control electrode for the power winding at the other end, said means controlling the conductivity of the semi-conductive element inserted in series with the power winding, and controlled by the energization of the core-maintaining winding so as to be de-energized when the latter is energized and conversely, and delaying means inserted across the two lines and adapted to control the conductivity of the semi-conductive element inserted in series with the coremaintaining winding to energize the latter at a predetermined moment following the closing of the main switching means, whereby the power winding is first energized with the relatively high power necessary to move the magnet core to an operative position, and after a time delay the core-maintaining winding is energized, causing de-energization of the power winding so that the magnet core is maintained in operative position by the relatively low power required by the core-maintaining winding.
Claim 2
Dependent Claim
266 words
In combination with an electromagnet including a power winding and a core-maintaining winding, the provision of a control circuit comprising first and second feed lines, a main switching means in one of said lines, said power winding and said core-maintaining winding being connected each by one of their extremities to said first feed line, each winding being inserted in series with a semi-conductive element the conductivity of which is controlled by a control electrode with the two windings and cooperating semi-conductive elements being connected in parallel between said first and second feed lines, means including a resistor in series with the core-maintaining winding and directly connected to the other extremity of said coremaintaining winding at one end and to the control electrode for the power winding at the other end, said means controlling the conductivity of the semi-conductive element inserted in series with the power winding, and controlled by the energization of the core-maintaining winding so as to be de-energized when the latter is energized and conversely, and delaying means inserted across the two lines and adapted to control the conductivity of the semi-conductive element inserted in series with the coremaintaining winding to energize the latter at a predetermined moment following the closing of the main switching means, whereby the power winding is first energized with the relatively high power necessary to move the magnet core to an operative position, and after a time delay the core-maintaining winding is energized, causing de-energization of the power winding so that the magnet core is maintained in operative position by the relatively low power required by the core-maintaining winding.
Claim 3
Dependent Claim
40 words
A control circuit as claimed in claim 1, comprising a supply of A.C. and means rectifying the current from said supply to feed a rough rectified current through said feed lines, and wherein said semi-conductive elements are silicon controlled rectifiers.
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) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |