Highly accurate average current controller using charge sharing method for LED lamp driver

2018 ◽  
Vol 54 (7) ◽  
pp. 439-441
Author(s):  
H.‐A Ahn ◽  
S.‐K. Hong ◽  
O.‐K. Kwon
Keyword(s):  
Charge Sharing ◽  
Current Controller ◽  
Average Current

Electrolytic Isolation of Twin-Type Shock Deformation Structures

1967 ◽  
Vol 25 ◽  
pp. 318-319
Author(s):  
F. I. Grace ◽  
L. E. Murr
Keyword(s):  
Grain Boundaries ◽  
Thin Foil ◽  
Electrolyte Composition ◽  
Experimental Conditions ◽  
Average Current Density ◽  
Electron Transmission ◽  
Deformation Structures ◽  
The Matrix ◽  
Average Current ◽  
Specimen Edge

During the course of electron transmission investigations of the deformation structures associated with shock-loaded thin foil specimens of 70/30 brass, it was observed that in a number of instances preferential etching occurred along grain boundaries; and that the degree of etching appeared to depend upon the various experimental conditions prevailing during electropolishing. These included the electrolyte composition, the average current density, and the temperature in the vicinity of the specimen. In the specific case of 70/30 brass shock-loaded at pressures in the range 200-400 kilobars, the predominant mode of deformation was observed to be twin-type faults which in several cases exhibited preferential etching similar to that observed along grain boundaries. A novel feature of this particular phenomenon was that in certain cases, especially for twins located in the vicinity of the specimen edge, the etching or preferential electropolishing literally isolated these structures from the matrix.

Direct Current Deadbeat Predictive Controller for BLDC Motor Using Single DC-Link Current Sensor

2020 ◽  
Vol 38 (8A) ◽  
pp. 1187-1199
Author(s):  
Qaed M. Ali ◽  
Mohammed M. Ezzalden
Keyword(s):  
Control System ◽  
High Speed ◽  
Fast Response ◽  
Bldc Motor ◽  
Current Controller ◽  
Three Phase ◽  
Predictive Controller ◽  
Two Phases ◽  
Dc Current ◽  
Three Phase Inverter

BLDC motors are characterized by electronic commutation, which is performed by using an electric three-phase inverter. The direct control system of the BLDC motor consists of double loops; including the inner-loop for current regulating and outer-loop for speed control. The operation of the current controller requires feedback of motor currents; the conventional current controller uses two current sensors on the ac side of the inverter to measure the currents of two phases, while the third current would be accordingly calculated. These two sensors should have the same characteristics, to achieve balanced current measurements. It should be noted that the sensitivity of these sensors changes with time. In the case of one sensor fails, both of them must be replaced. To overcome this problem, it is preferable to use one sensor instead of two. The proposed control system is based on a deadbeat predictive controller, which is used to regulate the DC current of the BLDC motor. Such a controller can be considered as digital controller mode, which has fast response, high precision and can be easily implemented with microprocessor. The proposed control system has been simulated using Matlab software, and the system is tested at a different operating condition such as low speed and high speed.

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