Difference between ac , dc magnetic coil?

Difference between ac , dc magnetic coil?

any one explain the logic of ac dc magnetic coil

Mike:

Thank you for the clarification to my response. You are correct there are AC magnetic coils used in solenoids and relays.

Niel

Imran:

From a structural and physical standpoint there is no difference between an AC and a DC electro-magnetic coil. They both are made by wrapping of wires around a core. For DC electro-magnets the core is usually made of iron or steel. For AC electro-magnetic coils the “core” could be air.

The differences are their function and purpose. There is a good description on wikipedia [1] that describes the difference functions for electro-magnetic coils. DC electro-magnetic coils can be used for electro-magnets, solenoids and relays. All the other forms of electro-magnet coils can be used in AC applications.

Niel

Both AC and DC coils are available for use in control relays. The DC coil draws in the former to close the relay. The AC coil also does this, but the polarity switches 60 times per second. This is not generaly a problem because the soft iron former is equally attracted to a south pole as a north pole, but it does mean that the magnetising current passes through the zero value 120 times per second, which might conceivably cause a bit of chattering of the relay. To overcome this a remanence washer is used to slow down the rate of the magnetic field collapse. With both types available, the choice for a designer would be whichever is most convenient to suit the available supply.