Abstract: A magnetic proximity switch comprises an elongated, substantially cylindrical body which houses a switching circuit, said switching circuit closing when a magnetic target passes within a certain range of the switch. This switching circuit preferably comprises two leaf portions hermetically sealed in a glass enclosure within the switch body, a biasing magnet being positioned adjacent one leaf portion for generating a flux that is shared with the one leaf portion, extending the magnetic field toward the end of the switch body and effectively increasing the sensing range of the switch. The switch also is equipped with a plurality of visual indicators, preferably light-emitting diodes, which are illuminated when the switch is closed to provide immediate visual indication as to the position of the switch, regardless of the rotational orientation of the switch.

Abstract: A telephone subscriber line interface circuit includes a first circuit portion and a second circuit portion, a first battery voltage and a second battery input for receiving a second battery voltage. The second circuit portion is coupled to the second battery input. The telephone subscriber line interface circuit further includes a switch for coupling the first circuit portion to one of the first battery input and the second battery input.