A device that applies a pulsating voltage obtained by half-wave rectification of an alternating current to a coil, and causes the movable iron core to vibrate by the electromagnetic force thereof is called an electromagnetic vibrator. The movable iron core is supported by a spring such as rubber, glass steel, or steel to resonate the entire vibration system. The electromagnetic vibrator can be mounted on the side wall of the bucket or the feed chute to prevent the material from arching or adhering to the side wall, and can also be used to place the material evenly into the container by vibration. The vibration mechanism of the electromagnetic feeder is also the same principle.