Abstract: A method and apparatus for controlling a ventilation damper unit utilizing a direct coupled two-position rotary damper actuator with a DC solenoid is disclosed. The actuator acts to rotate the output coupling, and in turn, the damper shaft to open the damper. After approximately 95 degrees +/−3 degrees of output coupling rotation, a limit switch is activated and a DC solenoid equipped with a full way bridge rectifier extends to a brake rotor to lock the damper into position. Simultaneously power is shut-off to the actuator motor assembly to reduce electrical consumption. Upon complete power failure to the actuator unit, such as during a fire and smoke emergency, the DC solenoid is spring returned allowing the damper to be spring returned to a closed position, thus preventing flow of air and smoke through a building and starving a fire of oxygen.

Abstract: A throttle valve includes a one-piece valve body defining a transverse flow passage and an actuation device cavity. The throttle valve includes a valve assembly having a shaft which extends through the flow passage and which is mounted to the valve body via a pair of aligned passages formed in the walls of the valve body defining the flow passage. One of the aligned passages establishes communication with the actuation device so as to enable the valve shaft to be assembled to the valve body through the actuation device cavity. A pole carrier is mounted to the valve shaft and a pair of pole members are secured to the pole carrier. An electromagnetic actuation device is mounted within the actuation device cavity and is operable on the pole members in a contactless manner to impart rotation to the valve shaft through the pole members and the pole carrier upon energization of a coil assembly associated with theelectromagnetic actuation device.

Abstract: A brushless DC motor is controlled by determining a speed of the motor and a line voltage supplying drivers of the motor. Based upon these determined values and predetermined motor performance data, a maximum PWM on-time is determined for drive signals supplied to windings of the motor. This maximum PWM on-time thereby limits motor torque output to a predetermined maximum. Stopping the motor is performed in sequential phases including a loaded generator phase, an active braking phase and a holding phase. During holding, the amount of energy supplied to the motor is reduced to the point just before slippage such that holding energy is minimized. Upon power failure, the motor is driven toward a spring return home position overcoming static friction that may prevent the spring return mechanism from functioning properly. These techniques are applied to a motor in an actuator.

Abstract: An adaptive controller is provided for controlling the velocity of a ram in an injection molding apparatus during the injection stage of the molding cycle. The controller includes two sets of parameters. The first set define an open-loop control equation for controlling the ram velocity. The second set of parameters define a closed-loop control equation for controlling the ram velocity. Control of the ram, during the injection stage, is partitioned into discrete segments, wherein the open-loop control equation governs during the first portion of each segment, and the closed-loop equation governs during the latter portion of each segment. Both control equations are designed to drive the ram at a set, target velocity. At the end of each segment, a processor evaluates the actual ram velocity with the set, target velocity. Based upon this evaluation, the first and second set of parameters are modified to improve the ram performance and efficiency on the subsequent injection cycle.

Abstract: A switched reluctance generator that can be used in an air cycle machine, where the generator uses the energy from the shaft of the air cycle machine to provide a back-up power supply to the magnetic bearings supporting the shaft. The generator includes circuitry for comparing the non-commutated excitation current with a command signal to regulate the excitation current, thereby regulating the generator output voltage.

Abstract: A backup bearing for use with magnetic bearings to support a rotating shaft in the event that the magnetic bearings fail due to the loss of electric power. The backup bearing includes a housing and a fluid film bearing element which is adapted to passively float in the housing and with the shaft during normal operation of the magnetic bearings and which is adapted to support the rotating shaft on a film of fluid if the magnetic bearings fail.

Abstract: An adaptive controller is provided for controlling the transition, in an injection molding apparatus, from the injection stage to the packing stage. The controller operates by controlling the velocity of the ram during the injection stage, and controlling the ram pressure during the packing stage. The controller anticipates the transition from the injection stage to the packing stage by monitoring the ratio of pressure to velocity. The divergence of this ratio forecasts the onset of the packing stage. At this time, a pressure relief valve is preset in anticipation of the packing stage, to prevent a pressure spike during the transition period. The flow control valve is held constant during the transition.

Abstract: A plurality of electromagnetics in an array surround a shaft, with current controlled in the coils of the electromagnets to support the shaft at a desired position approximately centered between the electromagnets. Shaft position sensors provide feedback to a control system for modulating the current to the electromagnet coils, which are arranged in pairs on opposite sides of the shaft. A drive circuit for each coil includes first and second switching transistors which connect the coil to the power supply to transfer a current pulse to the coil. A pair of circulating diodes begin conducting when the transistors turn off, and return power to the supply. A control circuit for the drive circuits interleaves on and off intervals for the coils in the electromagnet pairs so that one coil of the pair is being switched off at about the same time as the other coil of the pair is being switched on.

Abstract: A position sensor includes a coil of small diameter litz wire wound around a ferrite rod. The rod is secured in the end of a ceramic support and an end cap is secured on the other end of the rod to form a bobbin section on which the coil is wound. Two palladium silver strips are formed axially along the length of the support extending from the bobbin section to near the base of the support. Two free ends of the coil are formed into strain relief loops and soldered to the strips. Lead wires of comparatively larger diameter are also soldered to the strips but near the base of the support. The strips establish electrical continuity between the coil and the lead wires while separating the end portions of the coil from the lead wires so as to prevent the lead wires from inducing stress into the relatively fragile coil wires.

Abstract: A control circuit for a gearmotor is located internal to a plastic gearbox to reduce handling damage and damage resulting from exposure to the environment. The control circuit includes a metal track which provides an electrical conductive path for input power to an electric motor and electrical components and thereby eliminates the need for a printed circuit board. The metal track includes a plurality of alternative control circuits paths, the appropriate circuit being chosen during assembly of the gearmotor by selectively piercing knock-out tabs in the metal track. The metal track includes locking receptacles for receiving switch and d.c. motor electrical terminals and further includes crimping receptacles for receiving electrical component lead wires. The metal track is located on the internal surface of the plastic gearbox cover by integrally molded posts and is secured to the cover by ultrasonically or heat staking the posts.

Abstract: The rotor of a shaded-pole motor carries a braking ring with a radially projecting stop lug adapted to coact with a pivoted pawl to brake the rotor to a stop when the motor is de-energized. The pawl carries a pole piece which, upon energization of the motor, is magnetically attracted toward the stator thereof to cause the pawl to pivot to a released position clear of the stop lug. The braking mechanism requires relatively few components, and those components may be used universally either with a motor with a clockwise rotatable rotor or a motor in which the rotor rotates in a counterclockwise direction.

Abstract: An electric motor acts through a gear train to rotate an output shaft in one direction while a torsion spring rotates the shaft in the opposite direction when the motor is de-energized. When the output shaft stops abruptly at a limit position after being rotated by the spring, a lost-motion drive connection permits the output gear of the drive train to rotate relative to the shaft in order to dissipate kinetic energy through the gear train and to avoid impact loading of the gear train and the motor.

Abstract: An air cycle machine for producing a supply of cooled air and including a compressor rotor fixed to a shaft which is driven by a turbine rotor, the turbine serving to expand air which is pressurized by the compressor. Magnetic bearings support the shaft radially in a housing for rotation about a precisely established axis while a magnetic thrust bearing keeps the shaft in a precisely fixed axial position. The housing and the bearings are constructed as two split sections to permit the housing and the bearings to be separated radially and facilitate repair and/or replacement of the shaft and other internal components.

Abstract: An elongate resistive sensor useful as an element of a pneumatic manifold failure detecting and locating system. A sensing loop is based on a coaxial cable having a core of known resistance per unit length. A eutectic salt impregnated insulant separates the core and sheath but has a temperature breakdown characteristic which provides the sensing function. Upon a pneumatic manifold failure, the sensing cable is heated, the eutectic salt insulator breaks down, a core-to-sheath short occurs, and currents in the sensing cable are substantially altered as a result. The cable is connected as a loop, and differential currents into the ends of the loop are detected and processed to determine the position of the short. Terminating resistors are associated with connectors which connect multiple cable sections into a single loop, and the terminating impedance is further sensed to determine an open circuit condition at any connector.

Abstract: A quick-calibrate control module for use in a heating and cooling system is provided which responds to setpoint signals from a control potentiometer to drive a remote actuator to corresponding positions. The control module comprises a motor coupled to the actuator and a feedback potentiometer coupled to the motor for producing a feedback signal relating to the actuator position. Operational amplifiers combine the setpoint signal and the feedback signal to produce an error signal, and a comparator responds to the error signal and drives the motor to minimize the error signal. A reference supply is connected to the control potentiometer, the reference supply having a zero setting potentiometer which calibrates the closed position of the actuator to a corresponding zero setting of the control potentiometer. A stroke adjustment potentiometer scales the feedback signal to calibrate a desired open position of the actuator with a corresponding setting of the control potentiometer.

Abstract: A non-contact caliper-type gauge particularly suited for measuring the thickness of a running web. In its preferred form, the system includes a pair of opposed scanning heads defining a gap through which the running web passes, the heads being adapted to transverse across the width of the running web. Each of the heads includes and ultrasonic transducer for directing energy at the web, detecting energy reflected from the face of the web nearest the respective transducer and determining the distance between a reference in the head and the facing surface of the web. One of the heads also includes a transducer, preferably an eddy current transducer, which operates on energy to which the web is transparent. The second transducer senses the distance between the heads thereby to determine any variations in the distance between the heads during traverse.

Abstract: The piston of a reciprocating hydraulic actuator carries a pump which is driven by an electric motor and which supplies oil from the low pressure chamber of a cylinder to the high pressure chamber thereof in order to advance the piston. An exhaust valve in the piston is normally held in a closed position by magnetic force created by energizing a coil and, when closed, enables pressurization of the high pressure chamber of the cylinder. When a second coil is energized, the magnetic field of the first coil is negated and the valve is opened by a spring to permit oil to exhaust from the high pressure chamber to the low pressure chamber and permit a second spring to retract the piston. If both the pump motor and the second coil are de-energized, the first coil keeps the valve closed and causes the piston to remain in a commanded position.

Abstract: A system and method for reporting of alarms (or other conditions) to a remote location, in a building automation system. The alarm is reported in graphical format which shows not only the information related directly to the alarm, but also additional information, including graphical information, intended to put the alarm in context. The system provides the user the ability to specify a transmittable alarm, and to define a graphical message for that alarm which includes fixed or static building parameters associated with real time building operating parameters. Upon occurrence of an alarm condition, the system assembles a graphical display for transmission which includes the specified fixed parameters and measured data for the real time operating parameters. The system assures that data is collected and assembled into the graphic display for all specified real time operating parameters, then initiates a facsimile transmission of the graphic display to a remote location.

Abstract: An air cycle machine for producing a supply of cooled air and including a compressor rotor fixed to a shaft which is driven by a turbine rotor, the turbine serving to expand air which is pressurized by the compressor. Magnetic bearings support the shaft radially in a housing for rotation about a precisely established axis while a magnetic thrust bearing keeps the shaft in a precisely fixed axial position. The housing and the bearings are constructed as two split sections to permit the housing and the bearings to be separated radially and facilitate repair and/or replacement of the shaft and other internal components.