Abstract: An emergency lighting system powers all the luminaires of a lighting system during normal use, and switches from utility power to an emergency power source to drive some of the luminaires during a power outage. The typical on/off wall switch control for regular use carries out an automatic system test routine every time it is switched off. First, the non-emergency luminaires are extinguished, the emergency luminaires are activated for a time-limited period, and the system reverts to regular utility power and on/off control by the wall switch.

Abstract: Apparatus for sensing occupancy of a room detects the infrared energy that is radiated by persons and may be used actuate any of a variety of devices such as electric lights, heating systems, air conditioners or alarms. Detection of persons throughout a broad area is made possible by a dome shaped lens assembly having an array of Fresnel lens segments which face in different directions and which focus intercepted infrared towards one or more infrared sensing components. Economical fabrication of the lens is realized by forming the Fresnel lens grooves in a sheet of material while it is in a flat condition and then sandwiching the material between nested dome shaped frameworks. In the preferred form, the sensor includes an adapter which can support different numbers of infrared sensors in any of a plurality of different orientations to accommodate to the configurations of different rooms.

Abstract: A low power switching circuit for delivering electrical power to a load includes a rectifier network connected between the hot leg of the AC utility supply and the earth ground of the utility supply. A neon lamp interposed in the rectifier supply limits the current drawn through the rectifier to less than the 500 .mu.a code limit for current flow to ground. A high sensitivity, dual coil, bistable relay is connected between the hot leg of the AC supply and the load, which is connected to the neutral leg of the same supply. A capacitor network is connected to the DC output of the rectifier to store sufficient power to operate the relay, and a transistor switching network is connected to deliver the power from the capacitor network to the relay upon receipt of a trigger signal. A "smart" switch such as an area occupancy sensor may be connected to the transistor switching network to provide the trigger signal to cause the relay to switch AC power to the load.

Abstract: A defensive personnel barrier and method for fabrication thereof includes an elongated metal strip having a longitudinally extending bend therein to form a spine extending therealong with laterally opposed flanges extending obliquely from the spine. Each flange is stamped or die cut to provide a plurality of cuts spaced therealong and extending diagonally from the spine to the outer edge of the flange. The diagonally cut portions are bent upwardly from the plane of the flange to form a plurality of barbs spaced longitudinally in the metal strip. The barbs of the opposed flanges are staggered longitudinally, and the edges of the barbs are sufficiently sharp to discourage manual grasping of the strip. One or more strips may be secured atop a fence or similar barrier to discourage climbing thereon. The barrier strips may also be secured to existing linear barbed wire strands by means of a saddle block and J bracket assembly provided by the invention.

Abstract: A burglar alarm employs ultrasonic sound to protect a plurality of rooms. Each protected room contains a transmitter which emits an ultrasonic signal in a controlled wave pattern. The signal is received, filtered, and detected to determine if a doppler shift in the ultrasonic signal of a particular amplitude and frequency characteristic of human movement is present. If so, an alarm is given.