Abstract: An enclosure comprises a housing defining an opening, and a cover movable between a closed position, a slide open position, and a hinge open position. The hinge open position is rotationally displaced about a hinge axis from the closed position, and the slide open position is translationally displaced from the closed position along a slide path that is perpendicular to the hinge axis. There is a position between the closed position and the slide open position in which rotation of the cover is inhibited.

Abstract: A fan assembly includes a drive housing having a shaft opening, a drive mechanism (e.g., an electric motor) positioned in the drive housing and including a fan shaft positioned through the shaft opening, and a fan rotor mounted for rotation with the fan shaft. The fan rotor includes cooling vanes and a cooling plate positioned between the cooling vanes and the shaft opening. Preferably, the cooling plate includes a flat portion adjacent the cooling vanes and a substantially curved portion radially inward of the flat portion to guide air from the drive housing to the cooling vanes. The fan rotor can further include exhaust blades and a back plate between the exhaust blades and the cooling vanes. An air inlet shroud guides air to the exhaust blades, and the fan rotor can further include an inlet venturi plate positioned between the exhaust blades and the air inlet shroud.

Abstract: A vibration detection circuit. The circuit includes an accelerometer, a combining filter, an amplifier, and an analog to digital converter. The accelerometer generates one or more signals indicative of movement along an axis. The combining filter filters a component of the one or more signals not associated with movement and combines the components of the one or more signals indicative of movement to create a combined signal. The amplifier amplifies the combined signal and creates an amplified signal. The analog to digital converter converts the amplified signal into a digital value.

Abstract: A balancing circuit for a metal detector. The metal detector includes an oscillating power source, a transmit coil connected to the oscillating power source, first and second receive coils inductively coupled to the transmit coil, a first amplitude balancing circuit connected to the first receive coil, and a first phase balancing circuit connected to the first receive coil. The first phase balancing circuit includes a capacitor and a variable resistor.

Abstract: A vibration detection circuit. The circuit includes an accelerometer, a combining filter, an amplifier, and an analog to digital converter. The accelerometer generates one or more signals indicative of movement along an axis. The combining filter filters a component of the one or more signals not associated with movement and combines the components of the one or more signals indicative of movement to create a combined signal. The amplifier amplifies the combined signal and creates an amplified signal. The analog to digital converter converts the amplified signal into a digital value.

Abstract: A balancing circuit for a metal detector. The metal detector includes an oscillating power source, a transmit coil connected to the oscillating power source, first and second receive coils inductively coupled to the transmit coil, a first amplitude balancing circuit connected to the first receive coil, and a first phase balancing circuit connected to the first receive coil. The first phase balancing circuit includes a capacitor and a variable resistor.

Abstract: A vibration canceling circuit for a metal detector. The metal detector includes a transmit coil, first and second receive coils, a differential circuit coupled to the first and second receive coils, a controller coupled to the differential circuit, and a vibration canceling circuit coupled to the controller. The controller uses a signal provided by the vibration canceling circuit to remove a vibration component from a metal detection signal.

Abstract: An environmental sensor including an inlet and an outlet such that a flow of fluid moves from the inlet to the outlet, a particle detection portion to detect particles in the fluid, and a controller connected to the particle detection portion. The environmental sensor can be in communication with a data acquisition system (e.g., via a wireless access point) to form a particle counting system. Also disclosed are methods of operating the environmental sensor and methods of operating the particle detection system.

Abstract: An environmental sensor including an inlet and an outlet such that a flow of fluid moves from the inlet to the outlet, a particle detection portion to detect particles in the fluid, and a controller connected to the particle detection portion. The environmental sensor can be in communication with a data acquisition system (e.g., via a wireless access point) to form a particle counting system. Also disclosed are methods of operating the environmental sensor and methods of operating the particle detection system.

Abstract: Disclosed is an air-flow-directing grille assembly of the type having two frame members and a grille bar supported by such frame members for pivoting movement about a grille bar axis. In the improvement, each frame member has a hole, the bar has an axle extending through the holes and each hole and the axle are cooperatively sized to provide a friction fit between such hole and axle. The grille bar is thereby frictionally retained in a position. A new method for making a grille assembly includes providing a pair of frame members, each having a hole therethrough of a first diameter. A grille bar is provided to have an axle with a second diameter at least equal to the first diameter. The axle and the frame member holes are urged into frictional engagement with one another and the grille bars will thereby hold a selected air-flow-directing position.

Abstract: A safety spring lock for locking an air pattern control in a diffuser includes a normally bowed strip carrying a retainer clip. The strip is flattened to engage the clip with a fixed part of the diffuser, the clip engages the diffuser and that engagement and the inherent bias of strip hold the spring lock in place in the diffuser. The safety lock includes a U-shaped portion spaced from the retainer clip and connected to the retainer carrying portion by a normally bowed strip which is flexed to a flattened position to locate the U-shaped portion adjacent to portion of the movable air pattern conrol when it part of the diffuser. The U-shaped portion is urged into engagement with a portion of the air pattern control to prevent movement thereof in the diffuser which would otherwise be sufficient to remove the air pattern control from the diffuser.

Abstract: A system is disclosed for the automated pricing and ordering of custom manufactured parts, as for the air handling equipment industry. The system includes software for personal computers of the sales representatives which assists the sales representative in creating product identification codes which specify the specifications of the product to be made. A completed order of such items is deposited in an electronic mail system addressed to the manufacturer. A host computer at the manufacturer periodically polls the electronic mail system for communications and then either prices the quote or processes the order.

Abstract: A rooftop ventilator includes a fan arranged for rotation about a generally vertical axis. The fan is on a rooftop curb through which air is drawn by the fan from the building interior. A housing extends over the fan and the fan terminates above and spaced from a curb to define a discharge opening for air drawn through the curb. A scroll arrangement is located above the curb and arranged around the periphery of the fan to receive air discharged by the fan and direct it toward the discharge opening. The scroll arrangement is made up of a plurality of scroll elements equally spaced around the periphery of the fan. Each of the scroll elements includes a first elongated element having one end generally adjacent the fan periphery and extending away from the fan periphery; a second elongated element, connected to the first elements to provide a generally continuous extension from the fan periphery. Each of the first and second scroll elements are linear.

Abstract: An air distribution device system includes an air distribution device of rectangular configuration and an auxiliary frame adapted to flush-mount the air distribution device within a ceiling of the type wherein ceiling material is directly fastened to overlying structural members such as joists or rafters. The auxiliary frame is substantially rectangular in form and is fashioned from elongate frame members of T-shaped cross section. The vertical portions of the T-shaped frame members are fastened to the structural members so that the horizontal portions of the frame members are substantially coplanar with the ceiling. Thereafter, the air distribution device rests upon, and is supported by, the horizontal portions of the frame members. When desired, the air distribution device can be raised off the auxiliary frame to obtain access to the interior of the ceiling.

Abstract: An opposed blade balanced damper includes three sector-shaped damper blades individually mounted to a frame for pivotal movement around a pair of pivot tabs integrally formed on each damper blade. A user-actuable control assembly simultaneously controls the relative rotational position of each damper blade so as to selectively regulate airflow through a duct. The damper blades and control assembly function to direct airflow toward the center of the duct and thereby maintain symmetrical airflow through the duct. This is achieved by rotating the damper blades so that the inner ends of the damper blades move downstream, and the outer ends of the damper blades move upstream, as the damper blades are rotated from a closed to an open position.

Abstract: A controller, for controlling an electrode boiler steam humidifier includes a plurality of current loop transformers, coupled to the boiler electrodes, for sensing the current drawn by the electrode boiler. A current level detector provides a control voltage to a solenoid controlled valve, associated with the boiler, to drain a predetermined quantity of water from the boiler and thereby reduce the electrode current, when the electrode current exceeds a predetermined upper current limit. A resettable counter is provided for limiting the number of automatic attempts which can be made to reduce the electrode current. Normal periodic actuation of the humidistat resets the counter to avoid reaching the predetermined count through long-term acquisition of isolated over-current occurrences.