Abstract: A kit retrofits a conventional exit sign, which normally uses internally mounted incandescent or fluorescent lamps, to operate using multiple LED sources in a group or assembly on a board. Indicia lighting is accomplished substantially indirectly through reflection of light from the LED sources. The LED source is electrically powered through an adapter that fits into the socket of the original incandescent lamp or fluorescent lamp, which is removed in the retrofit process. Metalized plastic light reflective panels are provided in the kit for adhesively connecting to inner surfaces of the enclosure for improved lighting efficiency of the indicia. Reduction of energy consumption by 10 or 20 times is coupled with virtually zero maintenance costs over long periods of time.

Abstract: An emergency lighting system utilizing standard nonemergency circuitry to provide power to all of the light fixtures in a facility during a power failure. This emergency lighting system uses an electronic inverter to convert d.c. power stored in batteries to either a high or low frequency a.c. power which is supplied to the facility's standard light circuitry. The high or low frequency a.c. power generated by the inverter causes the output voltage of the ballast within each of the facility's fluorescent and/or HID lamps to decrease, thereby reducing the illumination intensity of each of these lamps and saving battery power. Since the incandescent, electroluminescent or L.E.D. exit signs of the facility are generally insensitive to a change in the frequency of the a.c. power, each of these lights continues to operate at full brilliance. Alternatively, a chopper regulator may be used to lower the average voltage level of the power provided to the facility's light circuitry.

Abstract: A telephone activated power controller comprised of an electrical power inlet and a number of power outlets for supplying power to the devices of a computer or other system. A detection circuit detects telephone rings and off-hook conditions and powers up the system. A remote control circuit allows the computer to keep the power on after hang-up or manual power-off. A status sensor circuit tells the computer if the device has been turned on manually or remotely. An inhibit circuit prevents the device from responding to a telephone ring or off-hook condition if it is engaged. The controller also has a surge protection circuit to prevent large voltages or current from reaching the power outlets.

Abstract: A circuit containing a pair of spaced leads and first, second and third current paths across the leads. The first path defines a first stage containing a first zener diode in series with a first resistor. A second zener diode can be placed in parallel across the first resistor to prevent excessive buildup of voltage across the first resistor. The second path defines a second stage containing a varistor which acts to relieve the first stage with a higher power dissipation but at a slower reaction time. The third path defines a third stage containing a gas discharge tube in series with a second resistor. A varistor is in parallel with the second resistor of the third stage to limit the voltage across the second resistor due to impulse current. The circuit combine the zener diodes, the varistor and the gas discharge tube in a manner to ensure rapid response and high energy dissipation to incoming transient impulses.

Abstract: An interruptible power supply can supplant a primary power source with a secondary power source such as a battery when the primary power source fails. The supply has a switching device, an inverter and a pair of output terminals. The inverter is coupled to the output terminals. The inverter can couple electrical energy from the battery to the pair of output terminals. The switching device is responsive to the presence of electrical potential at the primary power source for coupling and decoupling the primary power source or the secondary power source to the output terminals. The switching device can also provide a current path from the primary source to the output terminals, which bypasses the inverter. A force commutation device responds to the voltage at the primary power source for driving the switching device, causing it to decouple the primary power source from the output terminals.

Abstract: A high-efficiency, low-cost D.C. to A.C. electronic inverter generates sinusoidal ouptut voltage(s) by utilization of an oscillator and divider circuitry that generates extremely precise symmetrical control signals. These control signals cause a push-pull amplifier comprising power switch drive transistors to periodically alternately energize power switches comprising two banks of matched output transistors, that in turn generate high current inputs to a ferro-resonant transformer. The transformer is tuned to provide the desired output sinusoidal voltage.The inverter incorporates unique overload and short-circuit protection electronics that prevent catastrophic destruction of the power switch drive transistors as well as the power switch transistors. Furthermore, to maximize the inverter's efficiency, the power switch driving circuit receives electrical energy from the ferro-resonant transformer in order to insure deep saturation of the power switch transistors.