ELECTROMAGNETIC DRIVING SHUTTER

PURPOSE:To reduce electric energy consumed by shutter control by rotating a permanent magnet from the 1st rotational position to the 2nd rotational position and then reversely rotating it by supplying a pulse current to an electromagnet to open/close the shutter. CONSTITUTION:The shutter is usually closed, and under the closed status, no current is supplied to an electromagnet 14 and a core 15 is not excited. The N pole of a permanent magnet 3 out of permanent magnets 3, 4 fitted to a driving lever 1 is opposed to the end face of one outer leg of the core 15 with a slight shift and the S pole of the permanent magnet 4 is separated from the end face of the other outer leg of the core 15 and approached to the end face of the center leg. Under said status, suction force is applied from the N pole of the magnet 3 to the end face of the leg of the core 15 so that the N pole is just opposed to the end face of the leg, so that week counterclockwise torque is applied to a driving lever 1 and the lever 1 is abutted upon an adjusting screw 9 so as to be mechanically stabilized. In case of releasing shutter, a positive pulse current is supplied to the electromagnet 14 and then a negative pulse current is supplied.