摘要:
A system and method for determining electric motor efficiency includes a monitoring system having a processor programmed to determine efficiency of an electric motor under load while the electric motor is online. The determination of motor efficiency is independent of a rotor speed measurement. Further, the efficiency is based on a determination of stator winding resistance, an input voltage, and an input current. The determination of the stator winding resistance occurs while the electric motor under load is online.
摘要:
A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.
摘要:
A system and method for a motor management system includes a computer readable storage medium and a processing unit. The processing unit configured to determine a voltage value of a voltage input to an alternating current (AC) motor, determine a frequency value of at least one of a voltage input and a current input to the AC motor, determine a load value from the AC motor, and access a set of motor nameplate data, where the set of motor nameplate data includes a rated power, a rated speed, a rated frequency, and a rated voltage of the AC motor. The processing unit is also configured to estimate a motor speed based on the voltage value, the frequency value, the load value, and the set of nameplate data and also store the motor speed on the computer readable storage medium.
摘要:
Metal alloy heatsink films for magnetic recording media are disclosed. The metal alloy heatsink films possess both high thermal conductivity and improved mechanical properties such as relatively high hardness. The metal alloy heatsink films also have controlled microstructures which are compatible with subsequently deposited crystalline magnetic recording layers. The films may comprise single phase CuZr or AgPd alloys having a selected crystal structure and orientation. The combination of high thermal conductivity, good mechanical properties and controlled microstructures makes the metal alloy heatsink films suitable for various applications including heat assisted magnetic recording systems.
摘要:
A thin film structure including a plurality of grains of a first magnetic material having a first Curie temperature embedded in a matrix of a second material having a second Curie temperature, wherein the second Curie temperature is lower than the first Curie temperature and the second material comprises one or more of an oxide, a sulfide, a nitride, and a boride.
摘要:
A cable slack handling device including a base portion with a first lobe and a second lobe each joined with the base portion. The first and second lobes each have an arcuate exterior wall portion to accommodate cable slack around a perimeter of the cable slack handling device. A connection device holder is located between a portion of the first and second lobes. The connection device holder is adapted to contain cable connection devices. The connection device holder has two opposite ends each adapted to receive cables.
摘要:
A thin film structure having a magnetic layer and a seed layer positioned adjacent to the magnetic layer is provided. The seed layer includes a L10 structure.
摘要:
A system and method for nonintrusively determining electric motor efficiency includes a processor programmed to, while the motor is in operation, determine a plurality of stator input currents, electrical input data, a rotor speed, a value of stator resistance, and an efficiency of the motor based on the determined rotor speed, the value of stator resistance, the plurality of stator input currents, and the electrical input data. The determination of the rotor speed is based on one of the input power and the plurality of stator input currents. The determination of the value of the stator resistance is based on at least one of a horsepower rating and a combination of the plurality of stator input currents and the electrical input data. The electrical input data includes at least one of an input power and a plurality of stator input voltages.
摘要:
A method for providing CMP slurries for copper CMP that have improved pot life by ameliorating hydrogen peroxide degradation in slurries. The method comprises a composition that has a transition metal content of less than about 5 parts per million (ppm), preferably less than about 2 ppm. Preferably the method comprises a composition containing less than about 2 ppm of yttrium, zirconium, and/or iron.
摘要:
A circuit and method for improving EMI noise performance in a bridgeless PFC boost converter. Such a converter comprises a boost inductor having a first end connected to a first AC input terminal and a second end connected to a first junction defined between the anode of a first diode and a first terminal of a first switch; a second terminal of the first switch connected to a common line; a parallel circuit of a capacitance and a load connected between the cathode of the first diode and the common line; a series circuit of a second diode and a second switch connected between the cathode of the first diode and the common line; and a second AC input terminal connected to a second junction defined between the anode of the second diode and the second switch. High-frequency EMI noise is bypassed by placing a first filter capacitor between the first AC terminal and the common line. A second boost inductor may be connected between the second AC input terminal and the second junction, and a second filter capacitor may be connected between the second AC terminal and the common line. The first and/or second filter capacitor has a lower impedance in a high frequency range than the corresponding first or second boost inductor. Preferably the first and second capacitors have substantially the same capacitance.