What the difference between AC & DC solenoid?
There are two other differences between an AC and DC solenoid:
1) The iron core of the coil, the electromagnet, is solid for DC and layered for AC to avoid loss in iron due to eddy current.
2)The AC solenoid has a “split pole” – a part of the layered pole (around 30% of cross sectional area) has a copper ring as short circuit so that in this part of the magnet the maximum and minimum of magnetic intensity is phase shifted by 90° in respect to the main part of the pole, and therefore avoiding chattering of the solenoid by having a total magnetic force that is always well above zero when actuated.
