| 摘要 |
PURPOSE:To simplify the circuit construction of the entire copying device such as an automatic gas cutting off machine, by providing two sine-cosine potentiometers while shifting the rotary shaft of one of said potentiometers by 90 deg. against that of the other potentiometer and by controlling the central position of an optical detecting part. CONSTITUTION:The output signal of an optical detecting element is supplied to the input terminals 18a, 18b of a CD comparing operation circuit 18, and the output terminal of said optical detecting element is connected to a relay 13. Namely, said output terminal is connected to a connecting point between the normally closed contact 13b of the relay 13 and the normally closed contact of a relay 15, and a movable contact 15c is connected to the input terminal of a DC amplifier 24. The DC amplifier 24 amplifies a supplied signal, and the resultant voltage E2 is supplied to a sine-cosine potentiometer 31. The rotary shaft of the sine-cosine potentiometer 31 is provided, while being shifted by 90 deg. against the rotary shaft 28 of a sine-cosine potentiometer, so that driving of an optical detecting part 4 in the persuing direction is controlled by the output signal of the one sine-cosine potentiometer, and the central position of the optical detecting part 4 by the other sine-cosine potentiometer. |
