Protective circuit for intrinsically safe electro-magnetic...

Details Protective circuit for intrinsically safe electro-magnetic... Protective circuit for intrinsically safe electro-magnetic...

2011-01-18

2011-01-18

Jackson, Stephen W (Department: 2836)

Electricity: electrical systems and devices

Control circuits for electromagnetic devices

For relays or solenoids

C361S160000, C361S167000, C307S130000

Reexamination Certificate

active

07872846

ABSTRACT:
A protective circuit (30) for intrinsically safe electromagnetic actuators operating at the voltage of a power supply approved for underground mining, for switching electrohydraulic valves in underground mining, comprising a coil (11) connected to a first potential (2) and a second potential (3) of the power supply and associated with at least two spaced apart short-circuit means (12) connected in parallel with the electromagnetic actuator coil (11) for short-circuiting ting the coil in the event of a reversal of the potential of the coil voltage. In accordance with the present invention the protective circuit comprises a semiconductor switch (T3) which is inserted between the coil (11) and the second potential (3) and, in the event of a voltage reduction or potential reversal, isolates the coil (11) from the second potential, so that the discharge from the coil (11) has no adverse effect on the energy supply system or the intrinsic safety.

REFERENCES:
patent: 4178619 (1979-12-01), Seiler et al.
patent: 4503480 (1985-03-01), Pickard et al.
patent: 4706158 (1987-11-01), Todaro et al.
patent: 4740202 (1988-04-01), Stacey et al.
patent: 5508874 (1996-04-01), Williams et al.
patent: 5806522 (1998-09-01), Katims
patent: 6105192 (2000-08-01), Deiterman et al.
patent: 6137192 (2000-10-01), Staffiere
patent: 6693411 (2004-02-01), Bub et al.
patent: 6996389 (2006-02-01), Fitzpatrick et al.
patent: 2002/0154524 (2002-10-01), Yamanaka et al.
patent: 2003/0160200 (2003-08-01), Suilmann et al.
patent: 63003689 (1988-01-01), None
Paul Horowitz, The Art of Electronics, 2006, The Press Syndicate of the University of Cambridge, Second Edition, 229-230.

Affiliated with

Also associated with

Rating

Protective circuit for intrinsically safe electro-magnetic... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Protective circuit for intrinsically safe electro-magnetic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Protective circuit for intrinsically safe electro-magnetic... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2717917