Abstract: A self testing fault detector having a line side and a load side and a conductive path there between, said apparatus is provided. The self testing fault detector includes a controller, adapted to perform periodic status tests on a protection circuit of the self testing fault detector without interrupting power to the load.

Abstract: A protection circuit for an HID dimming circuit is provided. A resistive component limits the initial current after a relay closes and current flows from a charged capacitor to a second capacitor. An inductive component limits the rate of change of current through the circuit. A voltage limited device limits voltage across the contacts of a solid state relay. The circuit is preferably formed in a small module that is adapted to be plugged into an HID lighting device.

Abstract: A network switch and method of switching are provided, in which first and second signal converters convert electrical signals to optical signals and vice versa. The network switch monitors alarm contacts and power drawn by the first and second signal converters, and switches from one to the other in the case of an alarm condition or power loss. In order to force a corresponding switch at the remote end, power is removed from one of the signal converters in order to force an alarm in the corresponding signal converter at the remote end.

Abstract: A starter circuit is provided for starting an HID lamp. The circuit de-couples the high voltage starting pulse from the input lines (ballast output lines) so that the starter can function properly regardless of the distance between the ballast and the lamp.

Abstract: An apparatus and method for controlling a motion sensor switch which is adapted to control a lighting circuit in an area monitored by the motion sensor switch. The apparatus and method employs a setting adjustment device, such as a potentiometer, having a setting range which sets the duration of a delay period during which the motion sensor switch delays deactivating the lighting circuit after sensing that the monitored area has become vacant. The setting adjustment device further includes a first setting position, a second setting position, or both. The apparatus and method further employs a bypass controller, such as a comparator circuit or software-implemented comparator, which, when the setting adjustment device is set to the first or second bypass setting position, controls the motion sensor switch to maintain the lighting circuit activated or deactivated, regardless of whether the motion sensor senses motion in the monitored area.

Abstract: An apparatus and method for detecting the presence of a battery in a battery charging circuit is provided. An inductor is placed in series with a charging circuit and the battery connection leads. A switching device and a capacitive device are connected in parallel to one another and in series with a gated device to form an indicator circuit. The indicator circuit is connected in parallel with the battery connection terminals. A series of pulses is applied to the gated device, allowing current to flow into the capacitive device during each pulse and energize the switching device when a battery is present. When no battery is present, the inductor prevents sufficient current from the charging circuit from energizing the capacitive device and the switching device.

Abstract: A communications station for use in a distributed audio system having two Hall-effect integrated circuits mounted on a printed circuit hook switch board, the hook switch board mounted within a handset cradle of the communications station. The Hall-effect integrated circuits place the communications station on-hook or off-hook, depending on the amount of ambient magnetic flux. The ambient magnetic flux varies with the presence or absence of a handset in the cradle. Thus, if a handset containing a magnet is in the cradle, and the applied magnetic flux is greater than the predetermined flux necessary to affect the Hall-effect integrated circuit, the communications station will go on-hook. When the handset and the resultant flux is removed from the cradle, the Hall-effect integrated circuit will change state and the communications station will go off-hook.