Abstract: An arrangement for use in connection with an air handling unit includes a controller and a processing circuit. The controller is configured to control a device within an air handler unit, which includes at least a first coil. The processing circuit is configured to receive first information representative of a maximum liquid flow rate through the first coil and second information representative of a maximum air flow rate of the first coil. The processing circuit is further configured to generate a time constant estimate, based on the first information and second information, for use in the controller in performing control of the device.

Abstract: An apparatus and method is disclosed for solving optimization problems without the need to build mathematical models or rules. The inventive method combines the structure of a single-loop feedback control system and optimization search engine mechanisms. Running in real-time, a Model-Free Adaptive (MFA) optimizer can automatically search for the optimal operating point for a dynamic system when a parabolic relationship exists between the input and output. The MFA optimizer comprises a user-selected Min/Max setter to define the searching objective, a process acting-mode search engine to determine if the process is running in direct-acting or reverse-acting mode, a maximum search engine and a minimum search engine to find the maximum or minimum. This apparatus and method is useful in fuel-and-air ratio optimization for combustion processes, yield optimization for chemical or biological reactors, and operating efficiency optimization for coal or ore ball mills.

Abstract: An apparatus and method is disclosed for automatically controlling single-input-multi-output (SIMO) systems or processes. The control output signals of a plurality of single-input-single-output (SISO) automatic controllers are combined by a combined output setter so that these SISO controllers are converted to a multi-input-single-output (MISO) automatic controller based on certain criteria; and its resulting controller output signal is able to manipulate only one actuator to control a plurality of continuous process variables or attempt to minimize a plurality of error signals between the setpoints and their corresponding process variables.

Abstract: An apparatus and method is disclosed for automatically controlling multi-input-single-output (MISO) systems or processes. The control output signal of a single-input-single-output (SISO) automatic controller is converted by a reverse, sequential or combined split-range setter into a plurality of ranges of signals so that the SISO controller is converted to a single-input-multi-output (SIMO) automatic controller based on certain criteria; and the resulting controller output signals are able to manipulate a plurality of actuators to control one continuous process variable in different operating conditions. Without the need of building process mathematical models, this inventive apparatus and method is useful for automatically controlling unevenly paired multivariable systems or processes where there are more system inputs than outputs including but not limited to pH processes, chemical reactors, and air handling units.

Abstract: The present invention provides a DTMF decoder that combines software and hardware and the method of operating the same. The DTMF decoder that combines software and hardware comprises an amplifier, an analog to digital convert, and a CPU or a digital logic circuit. The amplified DTMF signal is converted from analog to digital via the analog to digital converter according to the present invention. Since the digital DTMF signal converted from analog to digital integrally preserves the spectrum message of the DTMF signal, the digital DTMF signal can be further decoded by the CPU or the digital logic circuit. Therefore, the decoding error problem due to the software decoding method can be solved. In addition, when compared with the DTMF decoder with the hardware decoding method, the DTMF decoder that combines software with hardware of the present invention significantly reduces the cost, and even provides better performance and more flexibility in application when compared with the hardware decoding method.

Abstract: A packaging assembly for semiconductor memory modules using synchronous clocking signals distributed to each module within a package. The clock distribution network on the assembly is characterized by including a transmission line termination means, preferably a resistor, coupled immediately adjacent to one of the assembly input pins.

Abstract: A low profile ceramic choke for global positioning antenna systems having a ceramic ring with a plurality of concentric segments arranged in coaxial relationship about a center occupied by a circular antenna. The segments are spaced apart from each other and may be housed in a metal enclosure. The top surface of the ceramic ring and the enclosure are of frustro-conical configuration to provide for moisture elimination. The choke is less bulky and is smaller in size and the use of ceramic as a high dielectric constant material promotes fabrication by molding and mass production techniques.

Abstract: A low cost quadrifilar helix antenna having a molded body providing an elongated hollow radome supporting at least one radiating elements and a feed network within the body. In one form, the body is molded in two identical half sections so as to be joined together into a unitary construction with the feed network and radiating elements being applied to the internal surface by a plating procedure. In another form, the molded body is a thick walled cylinder having at least one spiral passageway occupied by inserted wires constituting the radiating elements.

Abstract: In the fabrication of integrated circuits, a method is provided for forming recessed silicon dioxide isolation in which the "bird's beak" problem associated with conventional silicon dioxide-silicon nitride composite masking structures is minimized. A conventional composite mask comprising a bottom layer of silicon dioxide and an upper layer of silicon nitride having a plurality of openings defining the regions in the silicon substrate which are to be thermally oxidized is formed on the substrate. Recesses are then etched in the silicon substrate in registration with the openings in the composite mask. The silicon dioxide layer should be, in effect, over-etched to extend the openings in the silicon dioxide to greater lateral dimensions than the openings in the silicon nitride layer whereby the silicon nitride layer at the periphery of the openings is undercut.