Abstract: A two terminal control switch having a main switch and a saturable current transformer whose primary winding is series connected with the main switch. A center tapped full wave rectifier has a capacitor connected between its DC sides, such capacitor also being connected to a junction between the primary winding and the main switch.

Abstract: A lighting system for supplying AC power normally, and DC power on an emergency basis selectively, to electron discharge devices, particularly fluorescent lamps; thus, the AC or DC power is furnished over common lines to a high frequency inverter associated with each lamp or lamp fixture; the arrangement is such that substantially no extra wire or wiring is required for the emergency lighting, whether the installation be a new one or retrofitted. In the latter case, new style electronic ballasts replace the old or core type ballasts in those fixtures that are to provide the emergency lighting; such electronic ballasts including the aforesaid inverter capabilities.

Abstract: A self-contained maintenance-free emergency lighting system involving a housing including a tough plastic cover so as to protect the system from vandalism; in order to test the system to determine whether it is operating properly, i.e., such that the emergency battery supply will furnish power to the emergency lamp, a magnetically operated test switch is included within the housing. By such feature, no external projection of a switch or the like is required. An arrangement is also provided for allowing the emergency lamp or bulb to float; that is to say, to preclude any kind of shock to the dome or cover from causing breakage of such lamp. Also, the plastic dome is extremely difficult to remove in that a tamper-proof screw is provided which is not readily visible nor is it readily accessible. An electrical circuit arrangement is also provided which includes a transfer relay which is normally open.