Electricity: electrical systems and devices – Control circuits for electromagnetic devices – Systems for magnetizing – demagnetizing – or controlling the...
Patent
1993-12-14
1995-11-28
Pellinen, A. D.
Electricity: electrical systems and devices
Control circuits for electromagnetic devices
Systems for magnetizing, demagnetizing, or controlling the...
H01H 4702
Patent
active
054713609
ABSTRACT:
A DC electromagnet apparatus that can prevent an excessive making coil current caused by changes in a power supply voltage. The electromagnet has an operation coil, a switching device, and a current detecting resistor connected in series. A one-shot pulse generating circuit produces a one-shot pulse having a pulse width corresponding to the duration of the making coil current flowing through the operation coil to close the electromagnet. A Miller circuit generates, based on the one-shot pulse, a trapezoidal pulse having a predetermined rising rate, a predetermined peak value, and a pulse width substantially equal to that of the one-shot pulse. A comparator produces an ON control signal that controls the switching device in such a manner that the making coil current becomes proportional to the trapezoidal pulse.
REFERENCES:
patent: 4511945 (1985-04-01), Nielsen
patent: 4978865 (1990-12-01), Hartmann et al.
patent: 5214561 (1993-05-01), Morita
Ishikawa Kimitada
Ishikawa Minoru
Fleming Fritz M.
Fuji Electric & Co., Ltd.
Pellinen A. D.
LandOfFree
DC electromagnet apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with DC electromagnet apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and DC electromagnet apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2017634