I'm seeing some chokes with the 2 coils on opposite sides of the core, and others with both windings combined or overlapping. What's the difference?

 

one is laying down/horizontal and the others stand up vertical?

 

One is a one handed coil and the other is a two handed coil.

Just guessing.....can't really see it.

 

The one with the green core is intended for something like AC mains use where there must be adequate insulation between the windings. Some add an insulating barrier between the windings. The others look like coupled inductors for a switcher, probably custom made. The color of the core suggests to me that it is probably a Chinese counterfeit of Micrometals type 26 powdered iron, which has a permeability of 75 if I recall correctly.

 

The one with the green core is intended for something like AC mains use where there must be adequate insulation between the windings.

Isn't inductor wire already insulated?

Assume the 2nd has just 2 windings, identical wire size, core, and number of turns as the first example.

Only difference is the windings each turn go together, around the core, instead of opposite sides.

Will the functionality be identical?

Thx