Non-incendive shut-down system for engine magnetos

Abstract

Abstract A shut-down system for an internal combustion engine having a magneto circuit which when grounded causes the engine to shut down. A normally open sensor switch responsive to some malfunction of the engine grounds the magneto circuit through an "indicator" circuit when the sensor switch closes. To avoid arcing with sufficient energy release to ignite flammable mixtures of gases or dust which might occur when ordinary switch contacts are operated, non-arcing solid state switches are used in those parts of the system which handle ignition levels of electrical energy and means are provided for reducing to non-ignition levels the electrical energy that is handled by ordinary switch contacts in the system. In addition, means may be provided to remove magneto primary voltage from the system for a short period of time while the engine is being started up so that the magneto circuit is not grounded by operation of the sensor switch before the engine reaches running conditions. The system can be extended to accommodate any number of indicator circuits and sensor switches. A "test without kill" feature may be added in order to test the integrity of the sensor switch wiring and the proper functioning of the overall system without killing the engine. Further, a hard-ground feature may be included in the event the impedance of a coil in the indicator circuit through which the magneto circuit is grounded is too high to effectively ground the magneto circuit. Also, a manual shut-down or "kill" switch may be included. In addition, a matrix arrangement for connecting various sensor switches and indicator circuits may be employed to reduce the number of indicator circuits required to identify uniquely four or more primary sensor points and to provide a redundant shut-down path should one of the indicator circuits fail.

Inventors

• 👤 Glenn G. Van Burkleo

Bibliographic Details