Patent ID: 8378836

Claim:
A magnetic field strength threshold alarm including: a sensor responsive to a magnetic field and actuating in response to a strength of the magnetic field above a predetermined threshold, the sensor including: a housing including a seat support and an electrical contact; a movable member supported by the support of the housing for movement through a 360° range of directions, the movable member including a magnet responsive to the magnetic field to cause movement of the movable member irrespective of direction of incidence of the magnetic field, the movable member and the magnet thereof being configured to be operational such that the magnet responds to the magnetic field to move the moveable member without consumption of energy, the movable member also including an electrical conductor, movement of the movable member responsive the magnetic field of strength above the predetermined threshold causes the electrical conductor of the movable member to electrically engage the electrical contact of the housing so that electrical energy may flow through the electrical conductor of the movable member; and a bias member is connected between the movable member and the housing to bias the movable member away from an engagement of the electrical conductor of the movable member to the electrical contact of the housing; wherein the movable member includes a single sphere as a pivot point, located coincident with a center of mass of the movable member, the single sphere supported by the housing seat support, and the bias member biases the single sphere into engagement with the seat support; and an alarm device operatively connected to the sensor and outputting an alarm, via consumption of electrical energy, responsive to the sensor actuation via receipt of electrical energy proceeding through the electrical conductor of the movable member and the electrical contact of the housing responsive the magnetic field of strength above the predetermined threshold, the sensor and alarm device being configured such that the alarm device is only powered via the sensor actuation so that the alarm device does not to consume energy without the sensor actuation.