| 摘要 |
<P>PROBLEM TO BE SOLVED: To compensate the on delay time with accuracy when the output of a current amplifier is compared with a triangular wave and converted into PWM. <P>SOLUTION: With respect to the output of a current amplifier, the on-delay time is compensated with the following timing: it is assumed that the relation between the outputs in phases U, V, and W of the current amplifier can be expressed as U>V>W, as illustrated in FIG. 2. Further, the amount of compensation equivalent to the on-delay time is let to be ΔV. In the direction in which the triangular wave rises (the range of the triangular wave marked with T<SB>1</SB>), the compensation is made as follows: for phase U, point a is unchanged, and compensation is not made; for phase V, point c is compensated by an amount equivalent to a time of -(1/2)ΔV; and for phase W, point e is compensated by an amount equivalent to a time of -ΔV. In the direction in which the triangular wave falls (the range of the triangular wave marked with T<SB>2</SB>), the compensation is made as follows: for phase U, point b is compensated by an amount equivalent to a time of +ΔV; for phase V, point d is compensated by an amount equivalent to a time of +(1/2)ΔV; and for phase W, point f is unchanged, and compensation is not made. <P>COPYRIGHT: (C)2004,JPO |
