| 摘要 |
PROBLEM TO BE SOLVED: To secure a steep filter characteristic with narrow band width by extracting only a fundamental wave angular frequency component having a time change from an orthogonal biaxial voltage signal that is converted into two phases from three phases and eliminating other components to convert them into three phases. SOLUTION: Two outputs of a conversion circuit 17 is represented as a complex variable U=Ux+jUy of input signals Ux and Uy of the orthogonal (x) and y axes and then supplied to an orthogonal biaxial filter circuit 25. Then, the transfer coefficients of low and high pass filters of real coefficients are referred to as F(s), the desired center angular frequency to be transmitted (band width 2a) or blocked (band width 2b) as ω, the imaginary unit as (j), and the complex coefficient therefor function in which the Laplacian operator (s) of the transfer coefficient F(s) is replaced by (s-jω) is referred to as F(s-jω), respectively. Under such conditions, the transfer expression U.F (s-jω)=V which is the result of the variable U passed through the function F(s-jω) represented in terms of a complex variable V=Vx+jVy of the output signals Vx and Vy is multiplied by the denominator of F(s-jω) to make the real and imaginary parts equal to each other. |
