Ok i hope this doesnt seem like too stupid a question but in transformer windings, is the wire used insulated? I mean as it is coiled tightly into a solenoid what stops the current/voltage from going through the the many rings as if the wire was just laid adjacent to the core? in pictures i have never seen individual strand insulation or is there insulation and i just have to take a better look?

cheers

 

Take an iron core and wrap an uninsulated wire around it to form a winding, what do you get? The windings will short out rendering the arrangement useless.

The idea is to pass a current through the wound wire which induces a magnetic field which propagates into the iron core. This magnetic field induces eddy currents within the iron core, which would induce a current in a second winding positioned somewhere around the iron core. Look at Ampere's Law, Faraday's Law, and if you can brave it Maxwell's Equations for information.

Dave

 

i think you might be talking about the enameling of the wire.that does the work of insulation.

 

i think you might be talking about the enameling of the wire.that does the work of insulation.

Yeah, the important point being that for the transformer arrangement to work, the winding has to be insulated from the core otherwise on a fundamental level it doesn't work.

Dave

 

like mr dave said it is important to insulate the wire from core and themselves
so that the current travels in circular path. in shell type winding as far as i know primary and sec winding are shared on the core sides such that half of the windings are on both sides hence again insulation might be req.

 

Mentaaal,

Can I bring your attention to our article on Transformers, particularly Voume II - Chapter 9.1 which explicitly states at the start:

Suppose we were to wrap a coil of insulated wire around a loop of ferromagnetic material and energize this coil with an AC voltage source

Further reading of this section of the e-book may help your understanding of the subject. Feel free to question further.

Dave

 

once again thank you guys for swiftly resolving my query. i have to say i have ready the entire dc and ac sections but it has been a while and i am sure i didnt take it all in. i guess i already new the answer i just needed confirmation particularly as the windings on a transformer dont look insulated at all, it just looks like plain wire.
cheers!

 

They are enamelled copper wires, like recca02 mentioned above. The plain ones do sometime look like bare copper, except they are a bit more shiny. There are also coloured ones, like green, red, blue, etc.