Electricity: electrical systems and devices – Control circuits for electromagnetic devices – Systems for magnetizing – demagnetizing – or controlling the...
Reexamination Certificate
2010-04-08
2011-11-15
Leja, Ronald W (Department: 2836)
Electricity: electrical systems and devices
Control circuits for electromagnetic devices
Systems for magnetizing, demagnetizing, or controlling the...
Reexamination Certificate
active
08059381
ABSTRACT:
A magnet controller supplied by a DC generator controls a lifting magnet. Four transistors, forming an H bridge, allow DC current to flow in both directions in the lifting magnet. During “Lift”, full voltage is applied to the lifting magnet. During “Drop”, reverse voltage is applied briefly to demagnetize the lifting magnet. At the end of the “Lift” and the “Drop”, most of the lifting magnet energy is returned to the DC generator. A transient voltage suppressor protects against voltage spike generated when current reverses in the generator.
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Knobbe Martens Olson & Bear LLP
Leja Ronald W
The Electric Controller & Manufacturing Company, LLC
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