Analytical expressions for the vector magnetic fields and Fourier transforms associated with thin film heads are presented. These results are derived from accurate, approximate expressions for the surface field of an asymmetric thin film head determi

半导体激光器矢量光场分布研究,作者：QQ 64134703 ，电子毕业设计，欢迎咨询 -Semiconductor laser optical field distribution of vector, the authors: QQ 64134703, e-graduate design, please consult

空间电压矢量控制PWM(SVPWM）也叫磁通正弦PWM法.它以三相波形整体生成效果为前提，以逼近电机气隙的理想圆形旋转磁场轨迹为目的，用逆变器不同的开关模式所产生的实际磁通去逼近基准圆磁通，由它们的比较结果决定逆变器的开关，形成PWM波形.此法从电动机的角度出发，把逆变器和电机看作一个整体,以内切多边形逼近圆的方式进行控制，使电机获得幅值恒定的圆形磁场（正弦磁通）.-Space voltage vector control PWM (SVPWM), also known as magnetic