| 摘要 |
A first position sensor for fireproof shutter of self-generation electromotive force detection type is provided to reduce cost and time of installation and manufacture by performing second fireproof shutter system by adding an simple electronic circuit to first fireproof shutter system. A first position sensor(1) for fireproof shutter of self-generation electromotive force detection type comprises a signal detection circuit(1-1), an amplifier circuit(1-2), and a shaping circuit(1-3). The signal detection circuit detects a minute current in an anode of an electric motor. The amplifier circuit amplifies a detected minute self-generation electromotive force signal to a fixed size. The shaping circuit changes a self-generation electromotive force signal of an amplified sine wave form to a signal of a square wave form. |
