| 摘要 |
PURPOSE:To contrive to facilitate integration and to enhance performance of speed control of a speed control device of electric motor by a method wherein converting means to convert a rotating frequency signal into a DC signal are constituted of digital-analog converting circuits consisted of digital switches and resistors. CONSTITUTION:The converting means D, E, I to convert the rotating frequency signal of the electric motor A are constituted of the digital-analog converting circuit consisted of a network of the digital switches S1-Sn being enabled to be changed over in accordance with the rotating frequency signal and the resistors R, 2R1-2Rn. The rotating frequency signal corresponding to the rated speed of the motor is set up at the point deviated from the center of control range of the converting circuit. Accordingly integration of the converting means is facilitated. and enhancement of controlling performance of speed control can be attained. |
