Abstract: An elevator group supervisory control system for allocating elevator hall calls to elevator cars depending upon estimates given by processing of data indicative of travels of said cars, including a probability processor for determining an estimated future response probability based on predetermined travel data and an estimation processor for allocating hall calls to respective elevator cars based at least in part on the estimated future response probability.
Abstract: A simple combinational technique is disclosed using one or more H-switches for start-up control and frequency conversion in an AC motor. A coordinating logic system provides H-switch toggling timing patterns yielding phase shifted voltage waveforms in the motor windings to afford a rotating field during start-up, and provides irregular switching times yielding a chopped sinusoid output waveform of converted frequency for variable speed operation.
July 29, 1982
Date of Patent:
July 10, 1984
Herman P. Schutten, Robert W. Sackett, Jan K. Sedivy, Michael E. Taken
Abstract: Analyzer apparatus for evaluating the performance of an elevator type transportation system that has a plurality of transport vehicles that serve a plurality of common stations includes a plurality of interface circuits each for connection to a system component to be monitored such as an elevator hall call button or a car relay, and each providing an output signal indicative of the current status of its monitored system component. Associated with each interface circuit is one or more event accumulator devices, and logic interconnects each interface circuit and its corresponding event accumulator device or devices. The analyzer also includes a signal generator for repetitively generating signals at periodic time intervals, and circuitry for applying each time interval signal to the logic for causing an accumulator device to accumulate event duration counts as a function of the monitored component current status signals from its interface circuit.
Abstract: In the disclosed camera exposure control, data recording and film winding are performed sequentially and the system is protected from battery voltage drop arising from the effective increase in consumption of electrical energy necessary to make each exposure as compared with the ordinary camera, by detecting the battery level upon occurrence of a prescribed phase of the operating cycle. In one embodiment, the battery is also checked at a subsequent step of the cycle (for example, film winding operation is permitted only when the battery level is above the predetermined level). According to an embodiment of the invention, a sequence control circuit controls the photographic operation sequentially.
Abstract: An electrical switching circuit for a multi-phase a.c. supply uses semiconductor rectifier switches SCR1 to 5 to reversibly switch power to a multi-phase electric motor so that the motor can be run in a forward or a reverse direction. The SCRs are provided in two sets, one for switching power to forward run the motor, and the other set for reverse running of the motor. Inductor elements .DELTA.L are connected in series with the SCRs. The inductor elements comprise coils which include a non-linear permeability core, for example of ferrite or permalloy, which are operative to suppress voltage transients at switch on of the motor. These transients would otherwise produce spurious firing of the SCRs and could produce a short circuit across the input phases of the a.c. supply. The circuit is used in a valve actuator. Improved torque limit switches and position limit switches are disclosed, which operate a low voltage and which use Reed and Hall effect switches.
Abstract: A digital input signal is fed through an interface to a logic phase control which decodes the signal to provide a plurality of phase signals in a predetermined relationship for driving a sychronous DC stepper motor. The phase signals are fed to corresponding phase drivers which amplify the pulses of the phase signals before they are applied to the corresponding phase windings of the stepper motor. Each phase driver includes an operational amplifier and a power transistor connected in a closed loop to provide a current pulse having a constant predetermined peak amplitude to the corresponding phase winding during acceleration of the motor. The inductive time constant of the motor phase windings is thus overcome so that an applied mechanical load can be rapidly accelerated without stalling and the absence of dropping resistors minimizes power dissipation and heat generation.
Abstract: A phase-detector (16, 18, 20) is provided for use in a power factor controller for a three-phase induction motor. The power factor controller includes switching thyristors (10, 12 14) for each motor phase winding and the phase detector for each phase includes an operational amplifier (36) which senses the current phase angle for that phase by sensing the voltage across the phase thyristor. Common mode rejection is achieved by providing positive feedback between the input and output of the voltage sensing operational amplifier.
December 16, 1982
Date of Patent:
July 10, 1984
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: In this control box, a first switching device (R-1) is actuated when the operator acts on a selector (1) whereby he can choose, on one hand, the direction of the driving of the motor (9) and, on the other hand, by means of a brief or prolonged action, the driving speed of this motor. If the action is prolonged, the switching device (R-1) is inhibited by a second switching device (R-2) controlled by a timing circuit (27) which was initiated at the start of the action. This second switching device then supplies power to the motor (9) through a series resistor (18) so long as the selector (1) is actuated. Application in an electric window raiser of an automobile vehicle.
Abstract: A "mode switch" is used for smoothly switching a servovalve controlled device such as an SMC press, in particular, from control under one parameter to control by another. The mode switch provides a very smooth transfer of control from displacement control between two relatively movable parts to force control to provide for controlling the force exerted by actuators acting between the two parts. The mode switch electronically tracks the signals so that when the switching is made the signals are precisely equal to prevent abrupt changes in the control signals. This smooth transfer is achieved even under active control, that is when both control signals are changing in value.
Abstract: To reduce battery drain by a DC electric motor (e.g. in the case of an ambulatory monitoring tape recorder) the motor is fed with pulses of current derived from a pulse circuit that includes a differential amplifier monitoring the voltage difference between a first reference voltage that is related to torque load on the motor and a second reference voltage that is derived by adding a sawtooth waveform to a base signal that is proportional to the voltage across the motor.
October 15, 1982
Date of Patent:
July 3, 1984
The University Court of the University of Edinburgh
Abstract: Vending machine control and diagnostic apparatus for a vending apparatus having product delivery means comprising an electrically operated actuator for delivery of products, an impedance element and a circuit opening switch. The impedance element and the switch are connected electrically in series with each other and in a parallel circuit with the actuator, and the opening and closing of the switch is controlled by the operation of the actuator. The control and diagnostic apparatus detects changes in impedance of the parallel circuit.
Abstract: A brushless DC motor has a rotor which is partially magnetized. The magnetized portion of the rotor extends in a circumferential arc of approximately 180.degree. and has a first magnetic polarity (either north or south polarity). The stator of the brushless DC motor has two pairs of asymmetrically positioned poles. The first pair of poles are circumferentially spaced from one another by an angle which is greater than 180.degree.. Similarly, the second pair of poles are circumferentially spaced from one another at an angle greater than 180.degree.. First and second windings are wound on the first and second pairs of poles, respectively. A magnetic sensor senses the angular position of the magnetized portion of the rotor and provides a signal to a control circuit, which alternately energizes the first and second windings in synchronism with the sensed angular position of the rotor. The torque generated is greater than the 180.degree. angle, and no point of zero torque exists.
Abstract: A charge-discharge switching circuit for use in a cordless telephone which automatically connects and disconnects the receiver and transmitter circuits from a rechargeable storage battery in the handset in response to the base unit charger signal so that the transmitter and receiver circuits are disconnected from the storage battery when it is being charged by the charger in the base unit of the cordless telephone.
Abstract: An elevator system is battery powered. The battery is charged by a battery charger and also regenerated by a polyphase motor which drives the car and which is inverter operated. The charge on the battery is controlled by sensing the battery voltage and, if the voltage is excessive for an interval of time, applying a load to the battery for an interval of time. The battery voltage may also be sensed by controlling the battery discharge in proportion to the excess voltage.
Abstract: A clamping tracer control system which performs a tracing feed and a pick feed alternately and effects a clamping feed at a preset clamp level and in which, between the pick feed position where the clamping feed is carried out first and the pick feed position where the clamping feed has been completed, tracer control is repeated while changing the clamp level sequentially, and when the clamping feed has been completed in the repeated tracer control, the clamp level is restored to its area of initial value to resume tracer control of the tracing feed and the pick feed alternately in the next area.
Abstract: A waterproof pouch to house a personal stereo cassette tape player or radio electrically connected by means of a retractile cable to a pair of waterproof headphones. The waterproof pouch has a closure enabling the pouch to repeatedly be hermetically sealed and reopened. A tubular belt loop is attached to one side of the pouch and secures a belt and buckle combination which fastens around the user's waist. A connector permanently and hermetically secures the electrical cable extending from the exterior to the interior of the pouch. The electrical cable in a coiled retractile form extends from the connector and splits into a Y-shape with both legs electrically attached to the waterproof headphones. Both waterproof headphones consist of a rigid disc with a waterproof earphone mounted on one side and a bracket mounted on the opposite side such that an elastic headband extends through the bracket. The headband is adjustable in length and secures the headphones to the user's head.
Abstract: Disclosed is a rotary machine powered by magnetic fields and comprises at least one fixed and at least one movable permanent magnetic member which have a curvilinear surface adapted to provide mutually eccentric magnetic fields and which operate to rotate the movable member with respect to the fixed member until a magnetic equilibrium position is reached, at which time means are included to rotate the movable member away from the equilibrium position, whereupon the eccentric fields again interact to cause rotation. The curvilinear surfaces are in the form of a spiral which expand in an arithmetic or geometric progression and are poled to provide alternatively either attractive or repulsive forces between opposing faces of the magnetic members.
Abstract: The invention is an electric starting system for starting aircraft jet engines (32), (34) and (36) using an APU (10) free turbine driven generator (12). The operating power factor of the starter-generator (12) is controlled during start mode operation of the APU (10) by monitoring the line current via a current transformer (58). Contactors (14) and (16) connect the generator (12) into the aircraft's ac power system and ac starting system, respectively. A master start relay (22) is provided, and is closed in the `start` mode such that a power electronics inverter (24) may be powered from external power via contactors (18). The variable-voltage/variable-frequency output of inverter (24) is controlled via a logic controller (26) and can be applied sequentially to the three engine driven generators (32), (34) and (36) via start relays (42), (44) and (46) to start the engines (32), (34) and (36) respectively.
Abstract: A method for slaving a stepping motor proposes several levels of width of the control pulses U in order to adapt the torque provided by the motor to the load imposed thereon. The method includes measurement of the induced voltage Ui during a time interval T.sub.Ui situated immediately before the end of the control pulse U if the duration of such pulse does not exceed a predetermined duration T.sub.n (FIG. 8) or within a gap T.sub.x opened in the control pulse U if such pulse does exceed said predetermined duration T.sub.n (FIG. 11).The method may be applied to slaving stepping motors wherein the stator exhibits air gaps or saturable zones.
Abstract: An apparatus for controlling an AC powered elevator by rectifying a commercial AC power source into a direct current through a rectifier, converting the direct current into a variable frequency AC power through a main inverter, driving the AC motor by the thus converted AC power to operate the cage of the elevator, and sending the regenerated electric power back to the commercial AC power source via a regeneration inverter connected to the DC side of the main inverter when regeneration braking is applied to the electric motor. If the main inverter becomes defective, the main inverter is separated from the electric motor, the AC side of the regeneration inverter is connected to the motor, and the motor is operated by relying upon the regeneration inverter.