直流モーター制御装置（DC Motor Controller)

古い旋盤の駆動モーターは誘導電動機（単相100V）なので回転数や回転方向の変更ができません。そこで直流電動機DC90V　1/2馬力を使って回転数や方向が可変出来るようにします。PWM制御でIGBTを使って制御します。IGBTは比較的最近開発されたパワー制御素子で絶縁型ゲートでコレクタとエミッター間の電圧降下が小さいので効率が良く発熱損失がちいさい。まだ製作を始めたばかりで配線は途中の段階ですがケースを小さくしすぎたようで配線が非常にやりにくい状態です。電流計は1ｍAですが、これに分流器と倍率器を付けてスイッチで切り替えて電流と電圧を表示します。これは途中の製作段階での報告です。

The drive motor of my old lathe is an induction motor driven by 100V AC so rotation speed and direction can not change. I will replace this motor with with DC 90V 1/2 HP motor to be able to adjust the rotation speed and direction. This controll can be done by using a power semi-conductor element called IGBT in PWM circuit. IGBT is a newly developed element. The voltage drop between collector and emitter is very small then the efficiency is very high and power loss is very small. The wiring work is not easy because I made a verysmall alminum box for my old lathe. The meter is a 1mA current meter but can be used both for current and voltage by switching the brunch wire and multiply resister. This controll device is not completed yet. This is a short report on the way of making the device.