Abstract:
Controlling an H-bridge of switches, characterized in that during a cycle, the current takes a peak value of constant sign during a continuous portion corresponding to a cycle fraction equal to .vertline. /U.vertline., where is the mean voltage applied to the load and U is the voltage of the DC voltage source, said portion being preceded by a cycle portion corresponding to a cycle fraction equal to 1/2(1-.vertline. /U.vertline.) during which the two switches (I1, I2) of the H-bridge which are connected to ground are closed (or open as the case may be), and followed by a cycle portion likewise corresponding to a cycle fraction equal to 1/2(1-.vertline. /U.vertline.) during which the two switches (I1, I2) of the H-bridge which are connected to ground are open (or closed as the case may be).
Abstract translation:控制开关的H桥,其特征在于,在一个周期期间,电流在对应于等于| V / U |的周期分数的连续部分期间获得恒定符号的峰值,其中V是平均值 施加到负载的电压,U是DC电压源的电压,所述部分之前是对应于等于+ E的周期分数的周期部分,f 1/2 + EE(1 | V / U | ),其中连接到地的H桥的两个开关(I1,I2)是闭合的(或者视情况而定),并且后面是同样对应于等于+ E的周期分数的周期部分, 其中连接到地面的H桥的两个开关(I1,I2)打开(或视情况而定)闭合的1/2 + EE(1 | V / U |)。
Abstract:
A method of balancing voltages in a group of capacitors of a power electronic device, such as a multilevel power inverter, includes making a balancing determination regarding whether to (i) inject energy into the selected one of the capacitors from an energy storage element, or (ii) extract energy from the selected one of the capacitors into the energy storage element based on the voltage of a selected one of the capacitors, and either injecting energy into the selected one of the capacitors from the energy storage element, or extracting energy from the selected one of the capacitors into the energy storage element based on the balancing determination. Also, a voltage balancing circuit that implements the method. In one particular implementation, a spatial second derivative algorithm is used. In another particular implementation, a comparison to an average capacitor voltage is used.
Abstract:
A method of driving a number of series connected active power semiconductor groups, wherein each of the active power semiconductor groups includes one or more gate oxide-isolated active power semiconductor devices. The method includes generating a current pulse, providing the current pulse to a primary portion of a transformer unit and in response thereto causing a number of reflected current pulses to be reflected at a secondary portion of the transformer unit, and transferring and latching each of the reflected current pulses to create a respective latched gate drive signal, and providing each respective latched gate drive signal to an associated one of the active power semiconductor groups for driving the one or more gate oxide-isolated active power semiconductor devices of the associated one of the active power semiconductor groups. Also, a gate drive circuit that implements the method.
Abstract:
A density and viscosity sensor 1 for measuring density and viscosity of fluid F, the sensor 1 comprising: a resonating element 3, 3A, 3B, 3C, 3D, 3E, 3F, 3G arranged to be immersed in the fluid F, an actuating/detecting element 4, 4A, 4B coupled to the resonating element, a connector 7 for coupling to the actuating/detecting element 4, 4A, 4B, a housing 2 defining a chamber 8A isolated from the fluid F, the housing 2 comprising an area of reduced thickness defining a membrane 9 separating the chamber 8A from the fluid F, the membrane 9 having a thickness enabling transfer of mechanical vibration between the actuating/detecting element 4, 4A, 4B and the resonating element 3, 3A, 3B, 3C, 3D, 3E, 3F, 3G, the actuating/detecting element 4, 4A, 4B is positioned within the chamber so as to be isolated from the fluid F and mechanically coupled to the membrane 9, the resonating element 3, 3A, 3B, 3C, 3D, 3E, 3F, 3G arranged to be immersed in the fluid F is mechanically coupled to the membrane 9, wherein the resonating element 3, 3A, 3B, 3C, 3D, 3E, 3F, 3G has a shape defining a first resonance mode and a second resonance mode characterized by different resonant frequencies F1, F2 and different quality factors Q1, Q2, the first resonance mode moving a volume of fluid, the second mode shearing a surrounding fluid.
Abstract:
A density and viscosity sensor 1 for measuring density and viscosity of fluid F, the sensor 1 comprising a resonating element 3, 3A, 3B, 3C, 3D arranged to be immersed in the fluid F, an actuating/detecting element 4A, 4B coupled to the resonating element, and a connector 7 for coupling to the actuating/detecting element 4A, 4B. The sensor 1 further comprises a housing 2 defining a chamber 8A isolated from the fluid F, the housing 2 comprising an area of reduced thickness defining a membrane 9 separating the chamber 8A from the fluid F. The actuating/detecting element 4A, 4B is positioned within the chamber so as to be isolated from the fluid F and mechanically coupled to the membrane 9. The resonating element 3, 3A, 3B, 3C, 3D arranged to be immersed in the fluid F is mechanically coupled to the membrane 9. The membrane 9 has a thickness enabling transfer of mechanical vibration between the actuating/detecting element 4A, 4B and the resonating element 3, 3A, 3B, 3C, 3D.
Abstract:
In an electric motor which includes an electronic control device and an armature within a closed motor casing, the electronic control device is arranged within the casing, in a position offset axially from but close to the armature. The motor includes a thermal screen which is interposed axially between the armature and the control device, and the screen includes means for dissipating heat outside the casing.
Abstract:
A three-phase synchronous electric motor, especially a motor of a motorized fan unit for a motor vehicle, includes a synchronizing device in which the energizing signal for the three phases of the motor is synchronized with the rotational position of the rotor. The energizing signals are synchronized with a single position signal representing the rotational position of the rotor, and, in order to start the motor, its three phases are supplied with three energizing signals out of phase one with another by 2.pi./3; if the motor then fails to start, the energizing signals are phase shifted by 2.pi./3.
Abstract translation:三相同步电动机,特别是用于机动车辆的电动风扇单元的电动机包括同步装置,其中电动机的三相的激励信号与转子的旋转位置同步。 激励信号与表示转子的旋转位置的单个位置信号同步,为了起动电动机,其三相被提供三个不同相位的激励信号,另一个由2π/ 3提供; 如果电机无法启动,则激励信号相移2 pi / 3。
Abstract:
A method of protecting an adjustable impedance element such as a transistor controlling the power supplied to an electric motor, in particular in a motor vehicle, wherein the control of said adjustable impedance element is modified when the current passing through it exceeds a given threshold, characterized in that said current threshold is an increasing function of the voltage U.sub.M across the terminals of the motor.
Abstract:
Location of a firearm firing projectiles is accomplished by using an acoustic detection antenna that includes at least three microphones spaced apart from one another to detect and record signals and time offsets of the signals which are representative of the muzzle noise of the firearm and/or the soundwave emitted by the mach cone generated by a projectile that has supersonic muzzle velocity, and processing the signals and their time offsets in such a manner as to determine at least the direction in which the firearm is located.
Abstract:
A system for converting a first voltage into a second voltage includes input terminals and output terminals, switching members disposed between the terminals which can convert voltage, and a device for controlling the switching members. The device includes a cell for controlling a switching member, and a member for managing and supplying the control cell. The member is connected to the control cell by a link allowing the simultaneous transmission of a control signal and electrical energy. The member includes a device for generating a pulse, and which includes at least two different control intervals.