| 摘要 |
PURPOSE:To eliminate heating in a stationary position of a servo-motor by providing a blind sector and a circuit for applying an offset voltage, on a differential amplifier circuit for fetching an output difference of a position setting circuit and a position detecting circuit of the servo-motor. CONSTITUTION:A voltage is impressed to both ends of potentiometers 11, (setting) and potentiometer 21 (detecting) and a voltage is fetched from its sliding piece. This divided voltage becomes an input of a differentials amplifier circuit 3. A blind sector circuit 6 consisting of + and - blind sector circuits 61, 62 consists of an analog comparator, and provides no output, when an input voltage is below a prescribed voltage corresponding to the blind sector. Accordingly, until the input voltage becomes the prescribed voltage, the output voltage becomes '0'. Also, an analog adding circuit is used for an offset voltage circuit 7 consisting of + and - offset voltage circuits 71, 72, and when an output of the circuit 3 is + or -, a prescribed + or - voltage is added. An analog switch 8 selects and switches an output of the circuits 61, 62, 71 and 72 by an output voltage of the circuit 3, which is inputted to its control terminal 81.
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