Abstract: A directional enhancement system for quadrophonic sound systems wherein the improvement comprises an automatic dimension control. The automatic dimension control utilizes a plurality of limiting devices, each of which has an input terminal, an output terminal and a control terminal and is operative to limit the voltage at its output terminal to the lesser of the voltages appearing at its input terminal and its control terminal. The dimension control can also be operative to limit the maximum values of the directional control signals generated and their sums to a voltage controlled by the user of the system thereby limiting the amount of directional enhancement provided by the system.

Abstract: The disclosed invention relates to directional enhancement systems and provides apparatus for enhancing the directional content of information contained in a plurality of composite signals derived from preceding decoding apparatus of the system. The apparatus of this invention includes a plurality of limiting devices equal in number to the number of control signals provided in the processor of the directional enhancement system. Each one of the plurality of limiting devices has an input terminal connected to a different one of the control signal outputs of the processor, a control terminal and a control device having an input coupled to a variable control voltage source and an output coupled in common to all of the control terminals of said limiting device. The apparatus of this invention limits any control signal which may be developed in the processor to a value less than or equal to that which would obtain in the absence of the dimension control apparatus of this invention.

Abstract: Constant power balance control systems for stereophonic and quadraphonic sound systems are disclosed. Three different embodiments of the invention are disclosed. The first embodiment is a resistive network having a plurality of fixed resistors and a linear potentiometer. The second embodiment is a solid state circuit having four pairs of transistors. The transistors of each transistor pair are chosen to have characteristics such that for the same base-to-emitter voltage, the collector currents of the transistors of each pair satisfy a given ratio. The third embodiment is a combination of the first two embodiments. The third embodiment provides a comprehensive quadraphonic gain and balance control system.

Abstract: A system which will provide emergency lighting as desired when the normal power supply such as the utility power is interrupted or otherwise not available. The system provides the emergency power by means of the same wiring that is used to provide the utility power to the lights. In addition, the "on-off" switch or switches used to control the turning on and off of the lights when the utility power is available also provides control of the lights when the emergency supply is being utilized.

Abstract: Electrochemical energy cells are disclosed. The energy cells are basically reserve-type batteries in which the electrolyte is separated from the electrodes until the battery is ready for use. In a first embodiment, the battery is a cylindrical battery in which the electrolyte is stored in a frangible envelope inside the battery case and above the electrode structure. Means are provided to break the envelope holding the electrolyte to permit the electrolyte to flow into the electrode cavity. The anode and cathode are designed to permit free flow of the electrolyte. In a second embodiment, the battery is also cylindrically shaped but is formed in a very thin or short cylinder. In this second embodiment the electrolyte is stored in a frangible envelope in the center of the battery casing. Again, means are provided to break the frangible envelope so that the electrolyte can flow into the electrode cavity and activate the battery.

Abstract: Method and apparatus for enhancing the directional content of information recorded or transmitted as four separate channels on a medium having only two independent tracks or channels and subsequently decoded into four signals each of which contains predominantly information pertaining to one of the four original channels but also information pertaining to others, in such a way that the resultant output signals when amplified and presented to four separate loudspeakers give the listener the illusion of four separate sources of sound.