A dumb question about inductors

[Jerry James]

Can an inductor work with DC? in my experience I have to connect the an inductor to an AC source than taking another inductor hooked up to my scope and I am supposed to see a wave from the "second coil" I have a 120VAC to 7VAC for my experiment so far I am not getting much reading on the scope triangle waves that are really dirty!!

[Jerry]

I have to say you are right, it is a dumb question....just kidding :-).  I'm feeling like a little fun today.

You can use DC or AC with an Inductor, it just depends on want you want the inductor to do.  If you want the inductor to create a constant magnetic field, then use DC.  If you want the magnetic field to be stronger then use an iron core.  I'm sure you have seen these in use before.  They are commonly used in junkyards where they process scrap metal.

 

Take a look at the image to the right.  The crane drops this into a pile of scrap metal, turns on the juice and the scrap metal sticks to it.  It's DC juice that we are giving it.  Then the crane lifts it up, moves to some other location and turns the juice off causing all the scrap metal to fall.  This is just a large scale electromagnet.  It can also be done on a small scale if you want.

So now what happens when we apply an AC voltage to our electromagnet?  Since DC means Direct Current and AC means Alternating Current, with AC the current would be alternating.  This would mean that our electromagnet would be turning on and off everytime the current alternates.  That would not be very useful for our junkyard magnet but it is very useful in other electronic circuits where you need some form of filtering or storage of energy in the form of a magnetic field.

Please let me know if you have further questions.