Patent application number | Description | Published |
20110102041 | METHOD AND DEVICE FOR GENERATING PWM SIGNALS - A PWM signal for driving power transistors of a half-bridge of a converter is generated with the aid of a digital circuit, in which an internal reference value is compared to the counter content of a counting ramp. In this context, a logic state of the PWM signal depends upon whether the internal reference value is greater than the counter content of the counting ramp. After each comparison between the internal reference value and the counter content, an n-bit long data word dependent on the result of this comparison is output serially as PWM signal, n being greater than or equal to 2. The resolution of the PWM signal is thereby improved by the factor n in comparison to conventional systems, without markedly increasing the circuit expenditure. | 05-05-2011 |
20110279183 | Electronic Circuit with a Linear Amplifier Assisted by a Switch-Mode Amplifier - An electronic circuit includes a linear amplifier unit having a first current feedback loop, assisted by a switched-mode amplification unit having a second current feedback loop. The inputs of the two units are connected so that they receive, at the same time, a current setpoint in an operating mode in order to generate a fixed current across a load connected to the output of the units. The first feedback loop includes a first sensor to measure the current in the load, a first subtractor element to subtract the first measured current from the current setpoint, a first controller connected to the output of the first subtractor element and controlling a linear amplifier, which supplies the first output current to the load. The second feedback loop includes a second current sensor to measure a second current supplied to the load, between a connecting node of two switches connected in series to a supply voltage source and an inductor whose output is connected to the load. The second loop further includes a second subtractor element to subtract the second measured current from the current setpoint, a second controller connected to the output of the second subtractor element and controlling a pulse-width modulator that controls the activation of the switches to alternately connect the inductor either to the high potential or to the low potential of the supply voltage source. | 11-17-2011 |
20110304294 | Method for Controlling Three Single-Phase Motors and Moving a Platform in a Direction of the Normal, as Well as a Platform Suitable for That Purpose - In a method for controlling three single-phase motors and moving a platform in a direction of the normal, the motors are controlled by one three-phase converter, so that a first motor is operated between a first phase and a second phase of the converter, and a series connection or parallel connection of a second and third motor is operated between a second phase and a third phase of the converter. A platform is adapted to perform this method. | 12-15-2011 |
20130181652 | Control Circuit for an Electric Motor Having a Power-Supply Control Device - The control circuit of an electric motor, which has at least one phase supplied with high voltage and has a defined high-voltage zone, is provided with a control for the supply current of the phase with a setpoint-value current, and has devices for measuring the supply current which generate a first analog signal whose value corresponds to the measured current, an electronic control unit being disposed in a low-voltage zone, and having an analog-to-digital converter for converting the first analog signal or another analog signal acting as the first analog signal, into a corresponding digital signal which is supplied to the electronic control unit. The measuring devices are formed by a bleeder resistor, which is disposed in series with the phase, as well as by a differential amplifier whose two inputs, respectively, are connected to two contacts of the bleeder resistor. The analog-to-digital converter is located in the high-voltage zone a galvanic separating element is situated between the analog-to-digital converter and the electronic control unit. The control circuit has, inter alia, a voltage converter which, within the high-voltage zone, provides a floating low voltage which supplies the analog-to-digital converter. | 07-18-2013 |
Patent application number | Description | Published |
20140068911 | METHOD FOR REMOVING AN INNER CASING FROM A MACHINE - The method for removing an inner casing from a machine includes removing a top part of the outer casing, removing a top part of the inner casing, removing the bottom part of the inner casing, before removing the bottom part of the inner casing connecting the bottom part of the inner casing to the rotor, such that the bottom part of the inner casing is supported by the rotor, then rotating the rotor around the longitudinal axis to make the bottom part of the inner casing accessible. | 03-13-2014 |
20140072422 | METHOD AND GUIDE FOR REMOVING AN INNER CASING FROM A TURBOMACHINE - The method for removing an inner casing from a machine such as a turbine or compressor includes providing supports between the outer casing and the inner casing of the machine, removing a top part of the outer casing, then removing a top part of the inner casing, then connecting a ring sector to a bottom part of the inner casing to replace the removed top part of the inner casing, then rotating the reciprocally connected ring sector and bottom part of the inner casing around the longitudinal axis to make the bottom part of the inner casing accessible, then removing the bottom part of the inner casing, guiding the reciprocally connected ring sector and bottom part of the inner casing during rotation, to prevent movement along the longitudinal axis. | 03-13-2014 |