Abstract: A valve apparatus used in heating and cooling systems in which a valve housing, a valve element, a drive mechanism, and a torque limiting mechanism operate to open and close the valve element between different ports to allow fluid flow through the flow passage within the valve. A torque limiting mechanism comprising a spring limits the amount of torque required by the motor by using energy stored in the spring to assist in maintaining the valve element in a closed position, or to maintain the valve element in an intermediate position for the regulation of flow through the valve flow passage in both mixing and diverting applications. The valve mechanism includes a motor driven mechanism with a de-energizing circuit to stop the rotation of the motor upon the motor driven mechanism applying a predetermined amount of compression to the spring. The compressed spring exerting a substantially equal force to the valve element for closing the different ports.

Abstract: A positioning actuator for positioning at least a part of a movable load at selected positions in a range of available positions in response to corresponding provisions of electrical energy of selected polarities between a pair of power terminals connected through limit switches to an electrical motor which switches limit that range. Energy storage is used to force the motor to further separate the contacts in those switches after they have been initially opened.

Abstract: In a process for fabricating a printed circuit board assembly carrying a chip on board type microcircuit package, aluminum wires are bonded to the aluminum pads on the microcircuit and to bare copper connector pads on the printed circuit board to form the electrical connection between them. The microcircuit, aluminum wires, and copper connection pads are then encapsulated with a material such as low stress liquid encapsulant having a thermal expansion coefficient approximately equal to that of the printed circuit board substrate material. Preferably the process includes steps of mounting the microcircuit and forming the copper connector pads on a printed circuit board laminate comprising cellulose epoxy mat such as CEM-1.

Abstract: A nozzle assembly for the water distribution tray of a humidifier has at least one arm which cooperates with a feature such as a slot on a tray wall, to hold the nozzle assembly in a desired position above a water distribution area of the tray. In a preferred embodiment, the nozzle assembly has two pairs of arms for mounting the nozzle assembly to the tray. Each pair of arms together form a wishbone shape. The arm ends of each pair can be deflected toward each other to permit the ends to enter a slot on the tray wall. When the arm ends are released within the slot, they latch with the slot to hold the nozzle assembly in the desired position.

Abstract: A frame supports a deep filter element to allow the filter element to be installed in a duct's conventional air intake opening as a replacement for a conventional shallow filter element. The frame has a flange to mate with a surface of the intake opening's interior flange. In one embodiment, two identical side panels are assembled with the relatively stiff end panels of a particular filter element to form the frame.

Abstract: A thermostat employing a lever for selecting the temperature setting has a detent mechanism for creating individual detent positions associated with temperature setting values. In a preferred embodiment the detent mechanism comprises ridges and valleys in the surface of the baseplate on which the thermostat elements are mounted. A projection on the setting lever engages the individual valleys to create the detent effect, and a edge of the cover cooperates with resiliency of the lever to deflect the lever so as to cause the projection on the lever to continually engage the ridges and valleys. Another embodiment has ridges and valleys on the edge of the cover which engage a first projection on the lever. A second projection slides along the baseplate surface and cooperates with resiliency of the lever to deflect the lever creating force urging the first projection into continual engagement with the ridges and valleys.

Abstract: A process for forming a UV sensitive gallium nitride layer includes a step of depositing a layer of aluminum nitride on which the gallium nitride layer is deposited. Two tests, sheet resistance and photoluminescent response of the gallium nitride layer, allow one to determine that a particular gallium nitride layer produced by the process will have the required response to UV radiation. Either a careful calibration which determines a required length of the aluminum nitride deposition time, or the introduction of silicon into the gallium nitride layer during its deposition, has been found to result in deposit of a gallium nitride layer which has superior UV sensing characteristics.

Abstract: An in-duct humidifier has a permeable rectangular pad to be placed in a heated air stream. Water dripping onto the top of the pad is evaporated by the air stream which is passing through the pad to thereby increase its humidity. The pad is held in a frame and the frame is mounted in the humidifier's housing. The frame holds the pad by an arrangement of sloped surfaces and narrow projections to minimize the area of the frame in direct contact with the pad. By minimizing the contact area between the pad and the frame, the amount of water flowing onto the frame and evaporating from the frame is minimized, thereby reducing the rate and amount of minerals dissolved in the water which are deposited on the frame surfaces.

Abstract: A space comfort system controls humidity in a space by applying heat to air recirculated to the space when the humidity is excessive and cooling of the air is not required. In a preferred embodiment, the call for heat occurs from the time the humidity increases to a level above a differential band within which is the humidity set point until humidity falls to below the differential band. Heat is applied to the air only when there is no demand for cooling of the air.

Abstract: An in-duct humidifier has an evaporative pad onto the top of which water is dripped. Air passing through the pad evaporates the water to thereby increase the air's humidity. An improved tray for dripping the water onto the top of the pad has a sloped floor in which are a number of holes. A nozzle assembly which is mounted directly on the top of the tray and an improved arrangement of walls on the tray floor assists in delivering equal amounts of water to all of the holes, resulting in even distribution of water throughout the pad and more efficient operation of the humidifier.

Abstract: A filter assembly has a cylindrical filter element immersed in the fluid to be filtered, and which fluid normally flows radially inwards through the filter element and is thereby filtered. When the filter element is to be cleaned by backflushing, fluid flowing inwardly through the filter element is impelled by a rotating pump vane which directs fluid within the filter element outwardly at relatively high through the filter element thereby dislodging debris which may have adhered to the exterior of the filter element.

Abstract: A sensor provides a status signal indicating a condition of an operating system to the operating system's control system. The sensor has an inherent variable quantity such as resistance whose magnitude indicates the operating system status. The control system includes a user-operable switch which when actuated signals the microprocessor to determine the approximate value of the sensor's variable quantity. The magnitude of the variable quantity is then indicated by a signal comprising one or more beeps of sound or flashes of light. The number of beeps or flashes indicates the approximate present magnitude of the sensor's variable quantity. In a preferred embodiment, the control system comprises a microprocessor programmed to control the operating system and to perform most of the functions of the invention.

Abstract: A computer system receives a number of different dependent variable data sets, all varying with respect to a single independent variable such as time, and displays a plot of each data set on a different one of a set of graphs, all of the graphs having conforming and preferably identical, aligned scales of the independent variable. The identical scales for the common independent variable are preferably in precise vertical alignment, which allows the viewer to more easily see relationships in the changes of the dependent variable data sets as the independent variable changes.

Abstract: A printed circuit board carries a microcircuit package electrically connected to bare copper connector pads on the printed circuit board microcircuit package by aluminum wires. The copper connection pads are encapsulated by a material such as low stress liquid encapsulant having a thermal expansion coefficient approximately equal to that of the printed circuit board substrate material. Preferably the printed circuit board laminate comprises cellulose epoxy mat such as CEM-1.

Abstract: An actuator uses an AC motor assembly having a random chance of rotating in either direction upon stalling or first receiving power, to provide torque for operating its output member. The output member operates from one extreme position to another. Limit stops prevent the output member from moving past each extreme position. There is a limit switch which removes power from the motor assembly while the output member is at an extreme position. A startup switch supplies power to the motor assembly at each extreme position when the output member is to be driven to the other extreme position.

Abstract: A burner controller for safe operation of a furnace has a an electromechanical latch for holding first and second fuel valves open responsive to an enable signal. The latch comprises an armature attached to the second valve and an electromagnet assembly attached to the first valve. When the electromagnet assembly receives the enable signal and the armature is attracted to the electromagnet assembly, the magnetic force opposes force of a spring urging the first and second valve simultaneously closed. When the enable signal is not present, the spring forces both valves into their closed position. An auxiliary valve in series flow arrangement with the second valve opposes flow of fuel passing through the second valve in certain situations.