Abstract: An improved electronic magnetometer has a flux-concentrating core making grazing contact with a magnetically conductive element which is preferably part of a piezoelectric transducer. The core and transducer are mounted so as to make non-coherent, chattering contact when the transducer is caused to vibrate. A pickup coil attached to a signalling device enables a user to find a null in a field of magnetic flux with novel accuracy.

Abstract: A two-terminal device for connection by its two terminals into an electrical circuit having a power source or signal connected to an electrical load or signal receiver and a means for causing selected brief interruptions of the circuit, comprising an electronic reflex element connected to receive power or a signal from the source via the two terminals and to change from a first state to a second state in response to the interruptions, the state change being dependent on the brevity of the interruptions, the reflex element including a control element connected to prevent power or a signal from reaching the load or signal receiver when the reflex element is in a particular one of the states and the circuit is not being interrupted.

Abstract: An electric blanket control effective to deactivate power to the blanket's resistance wire heating circuit, the control having a capacitance detector constructed and adapted to respond to differences in the capacitance of the heating circuit attributable to the presence or absence of the user under the heating wire of the blanket, and a switch responsive to the detector adapted to interrupt power to the heating circuit when the capacitance value of the heating circuit indicates the absence of the user.

Abstract: An audible alarm device comprising a transducer which resonates at its natural frequency in an alarm mode to produce an alarm tone, this same transducer being driven, e.g. in a "ready" mode, by a non-resonant background signal generator in the manner to produce background sound of relatively low intensity which can indicate that the alarm circuit is functioning but is not in its alarm mode.

Abstract: An emergency flashlight for illumination or signalling comprising an abrasive member and a pyrophoric member. The abrasive and pyrophoric members are mounted for predetermined relative movement against each other to produce and project a stream of self-igniting particles of pyrophoric material abraded from the pyrophoric member. The position of the members and the direction of their relative movement is aligned to present the stream of particles to a light-transmitting combustion zone. As a flashlight, the device includes a reflector having a reflection or focal zone coincident with this combustion zone and constructed to beam the emitted light to the region to be illuminated. The reflector shields the eyes of the operator from the emitted light and from burning particles and, in preferred embodiments, is a uniform surface of revolution to provide a concentrated light beam.