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The sensorless motor drive of Brushless Direct Current (BLDC) motors with wye-connected windings, now becomes accepted in many practical applications because it can solve the drawbacks of Hall sensors based motor drive. One of the most popular sensorless control schemes is based on the phase Back Electromotive Force (BEMF) or terminal phase voltage from the floated phase. Sensorless commutation signals are obtained from the detection of zero crossing points of the phase BEMF. However, it is impossible to adopt this technique for the delta-connected BLDC motors. Therefore, a sensorless motor drive with sensorless circuit based on the line-to-line terminal voltages for a delta-connected BLDC motor is proposed in this paper. Moreover, a low-pass filter with variable cut-off frequencies was designed successfully with a simple algorithm in this paper. Furthermore, the performance of the proposed sensorless control scheme was also compared to that of the Hall based control. Finally, the experimental results demonstrated that the sensorless motor drive was successfully developed for the delta-connected BLDC motor. The feasibility of the complete system was also validated.

The brushless DC motors (BLDC) have been widely applied to the motion control over a wide range of industrial applications because of its superior characteristics of high efficiency, high power density, easy control and maintenance, in recent years. However high performance motor drives require fast and quick speed response caused from system disturbance and parameter variations. In order to obtain the dynamic speed response due to these problems, a PID control method based on a radial basis function neural network (RBFNN) is proposed in this paper. The gain parameters of PID controller are tuned by performing the RBFNN according to the variations of parameters. A prototype of RBFNN based motor drive is designed and implemented in this paper. The experimental results demonstrate the feasibility of the complete designed system

Type I invariant NKT cells (iNKT cells) are a subset of alphabeta T cells characterized by the expression of an invariant alpha-chain variable region 14-alpha-chain joining region 18 (V(alpha)14J(alpha)18) T cell antigen receptor (TCR) alpha-chain. The iNKT cells derive from CD4(+)CD8(+) double-positive (DP) thymocytes, and their generation requires a long half-life of DP thymocytes to allow V(alpha)14-J(alpha)18 rearrangements, expression of glycolipid-loaded CD1d on DP thymocytes, and signaling through the signaling-activation molecule SLAM-adaptor SAP pathway. Here we show that the transcription factor c-Myb has a central role in priming DP thymocytes to enter the iNKT lineage by simultaneously regulating CD1d expression, the half-life of DP cells and expression of SLAMF1, SLAMF6 and SAP.

The aim of this paper is to design and implement arm strength training machine with electromyographic (EMG) biofeedback based on a microcontroller system. The hardware design based on a microcontroller is analyzed and discussed. The software programming is developed in MPLAB integrated development environment from the Microchip Technology Inc. and the friendly user interface is created as well. Finally, an arm strength training machine with electromyographic biofeedback is realized and demonstrated. The experimental results show the feasibility and fidelity of the complete designed system.

To improve the drawback of inconvenient and bulk weight of exercise machine, an arm strength training machine based on PMSM drive controller which has the advantages of user friendly, light weight, movable, and convenient, is designed and implemented in this paper. The hardware design based on a microcontroller is analyzed and discussed. The software programming is developed in MPLAB integrated development environment from the Microchip Technology Inc. and the friendly user interface is created as well. Finally, a prototype of PMSM drive for arm strength training machine is realized and demonstrated. The experimental results show the feasibility and fidelity of the complete designed system.

The establishment of interactive communication between arm strength training machine (ASTM) and the people will make the exercise and rehabilitation therapies become more friendly. This paper presents a friendly human interface for ASTM, in such a way to reduce the occurrence for improper operation of exercise machine. The system hardware consists of a universal asynchronous receiver/transmitter (UART) communication, analog and digital converter (ADC) converter, Personal Computer (PC), and a permanent magnet synchronous motor (PMSM) drive which is basically realized by a microcontroller for simulating the weight stack. The system software for human interface is developed under PC and written in C language. The firmware of motor drive is programming basically on the MPLAB development tool by Microchip technology incorporated. Finally, a prototype of human interface arm strength training machine is realized and demonstrated. The experimental results show the feasibility and fidelity of the complete designed system.

In order to cultivate talents and raise the design ability for power converters at engineering education on campus, the design methodology of a flyback dc/dc converter is introduced step by step in this paper. First of all, the fundamental of switching power converters is analyzed and described in this paper. Later, the power converter is modeled and simulated. The open and closed loop controls of the power converter are then compared each other. Finally, a power converter is realized and implemented based on the simulation results. Following the procedure of design methodology in sequence, it can predict that students can obtain the basic design skill of a power dc/dc converter from the college education. Though only the design methodology of the flyback converter is considered in this paper, it can be extended to any type of the dc/dc converter design.