A coil with a very long compared to the Diameter field. Magnetic fields generated by solenoid side similar to a bar magnet. Depending on the position of the pole of current .
As the coils are very long, powerful compared to the diameter Middle ศูย์ pitch. Magnet caused so little noi is similar to the magnetic bars. The position of the terminal block, depending on the direction of electricity .
There is a winding very long when compared to the past, ศูย์ magnet that is caused by a magnetic bar ลินอยด์ similar to position of the connector is dependent on the direction of electrical current