| 摘要 |
PURPOSE: To obtain an accurate speed signal for a motor and to enhance accuracy of speed control by shortening the time interval of correction. CONSTITUTION: A counter circuit 6 begins to count the clock of a clock generator 4 based on the rise edge of encoder pulse outputted from an encoder 200. The clock is counted over three periods of the encoder clock, for example, and a speed signal for a motor 100 is generated. An error operating circuit 9 compares the speed signal with a reference speed signal from a reference signal generation circuit 8 to operate an error. A PWM circuit 11 outputs a drive signal having PWM modulation factor corresponding to the error which is amplified through an amplifier 400 before it is fed to a motor 100. |
