Abstract:
A communication system comprising a base station and two or more terminals configured for communicating with the base station by means of a communications protocol, wherein: the communications protocol operates in a frequency band to which unlicensed access is permitted; and the terminals are configured for unattended operation with the base station.
Abstract:
A communications system includes a first and second device capable of transmitting and receiving RF communications; a controller for the first device capable of receiving or transmitting a code via a non-RF communication; a controller for the second device capable of receiving the code via a non-RF communication; and a processor for authenticating the first device for RF communication with the second device using the received code.
Abstract:
A method for implementing control signal linearization for an electric motor is disclosed. In an exemplary embodiment, the method includes receiving a desired voltage command to be applied to the motor and determining whether the magnitude of the desired voltage command falls between a first value and a second value. If the magnitude of the desired voltage command falls between the first value and the second value, then modulating a voltage command between the first and the second value over a determined sample period, thereby resulting in the application of a modulated voltage command to the motor.
Abstract:
A signal representative of a rectified current supplied by a current sensor is applied to the input of a correction circuit. The form of the input signal of the correction circuit, deformed with respect to the form of a theoretical signal, is corrected so as to reduce the errors of the rms or mean current values. The output signal of the correction circuit is equal to the input signal if the difference between the output signal and the input signal is lower than a limiting value. In the opposite case, the output signal is equal to a variation signal equal to the limiting value. Application to measuring devices and trip relays.
Abstract:
A communication system comprising a base station and two or more terminals configured for communicating with the base station by means of a communications protocol, wherein: the communications protocol operates in a frequency band to which unlicensed access is permitted; and the terminals are configured for unattended operation with the base station.
Abstract:
The present disclosure provides engineered ketoreductase enzymes having improved properties as compared to a naturally occurring wild-type ketoreductase enzyme. Also provided are polynucleotides encoding the engineered ketoreductase enzymes, host cells capable of expressing the engineered ketoreductase enzymes, and methods of using the engineered ketoreductase enzymes to synthesize a variety of chiral compounds. The engineered ketoreductase polypeptides are optimized for catalyzing the conversion of N,N-dimethyl-3-keto-3-(2-thienyl)-1-ketopropanamine to (S)—N,N-dimethyl-3-hydroxy-3-(2- thienyl)-1-propanamine.
Abstract:
A method for controlling a voltage mode controlled electric machine comprising: receiving a torque value representative of a desired torque; obtaining a speed value indicative of a rotational velocity of the electric machine; acquiring a phase advance value indicative of a desired phase advance angle; generating a voltage command responsive to the torque value, the position value; the generating is responsive to the torque value, the speed value, and the phase advance value.
Abstract:
A method for estimating the distance between a transmitter and a receiver, the transmitter being arranged to transmit a signal as a series of bursts, and the carrier frequency of each burst being set according to a predetermined sequence, the method comprising: forming a first series comprising the measured differences between the phases of successive bursts as received at the receiver; forming a second series comprising estimated differences between the phases of successive bursts as received at a supposed time difference between the transmitter and the receiver; and determining the quality of fit between the first series and the second series.
Abstract:
A brushless DC motor modifies motor commutation events to reduce noise by providing overlapping activation of the switch being deactivated with the switch being newly activated so that three switches are temporarily activated. The newly activated switch is pulse width modulated with a motor torque controlling duty cycle, and the switch being deactivated is pulse width modulated synchronously with the newly activated switch but with a duty cycle decreasing from the torque controlling duty cycle. The decreasing modulation of the switch being deactivated allows a slower current decrease in the phase turning off to reduce or eliminate the disturbances, and thus the noise. The decreasing modulation is preferably exponential in manner, with a time constant varying inversely with motor speed so that the duty cycle reaches a predetermined minimum in a predetermined maximum number of motor electrical degrees. The decreasing modulation may be switched on at low motor speeds where its noise reduction is required and switched off at higher motor speeds where the potential for interference with commutation is greater. The decreasing modulation is applicable in a dual switching mode in which each activated switch, except for the switch being deactivated in commutation, is pulse width modulated at the torque controlling duty cycle, or in a modified single switching mode in which the activated switch of one of the upper or lower groups is always closed continuously during its activation, except for commutation, during which the switch remaining on, which alternates between the groups, is closed continuously. Each mode of operation is applied in the motor speed/torque region to which it is best suited.