Abstract: In an exit sign, an insertable battery pack module is designed to fit in the lower portion of the exit sign housing. This battery pack module incorporates a pair of lamps as well as a battery, battery charger and transfer circuitry. The module incorporates a pair of reflective surfaces so that light from lamp filaments tangentially hit at least a portion of the exit sign stenciled area along the bottom portion of the letters forming the word EXIT. If an exit sign is only to have utility AC power, then the module need not be installed within the exit sign. In this configuration, the bottom portion of the exit sign can incorporate a slidable panel which is removed if the battery pack module is later inserted. The battery pack module incorporates the indicator light and test button which then would show through the area where the panel formerly resided.

Abstract: In an exit sign, a plurality of rugged low voltage incandescent lamps are mounted on a printed circuit board to provide proper illumination. The lamps are positioned to provide indirect illumination to the "EXIT" stencilling of the exit sign. The exit sign can be adapted for use with both low voltage alternating current and low voltage emergency direct current. Because the lamps are driven at low voltage and are resistant to failure due to vibration, etc., they can be expected to attain a long life in service.

Abstract: An emergency lighting supervisory system monitors utility power so as to automatically connect emergency lights to a battery source when utility power fails. The system continuously monitors selected parameters and, automatically, periodically tests the system under simulated full-load emergency conditions and annunciates the results of these tests. Such periodic tests also enhance battery capacity. The system also provides a closed loop three-mode battery charging control circuit. It can optionally communicate its status as well as receive commands from an external computer or other source by means of a data communication interface.

Abstract: A fail-safe relay system for use in infrared security barriers or other apparatus producing a sensing signal so as to control the de-activation and permit the re-activation of an interconnected device; such as a machine press. The relay system uses two relays with contacts in series in conjunction with electronic circuitry. Safe-start operation for preventing reactivation of the interconnected device if any unsafe condition exists, including failure of either pair of relay contacts to open when an unsafe condition is sensed, is also accomplished.

Abstract: A high frequency self-contained emergency lighting fluorescent pack is exteriorally mountable to a fluorescent fixture either in line with a fluorescent lamp having a length shorter than that normally installed in the fluorescent fixture or in a side-by-side relationship near the fluorescent lamp. In either configuration, the emergency lighting fluorescent pack de-energizes all electrical connections when the interconnected fluorescent lamp is not properly in place, and only energizes the electrical connections when the fluorescent lamp is properly installed.The emergency lighting fluorescent pack incorporates a battery pack, a battery charger for maintaining the batteries in the battery pack at full charge, a high frequency emergency power generating inverter module for igniting and maintaining the fluorescent lamp in the illuminated state by energy supplied by the battery pack, and transfer circuitry for causing the energization of the emergency power module by the battery pack when utility AC power fails.