Series toroids

[technogeek]

As I understand toroids, most of the magnetic flux is contained within the core. (unlike a cylindrical core with field lines coming out both ends)

So when you need to place two toroids in series to make a larger inductance, is it "safe" to put them close to each other? Assuming a horizontal & vertical configuration option isn't available....... Is mutual inductance a concern with the same current flowing through each?

 

[Zed]

I've seen toroidal inductors stacked on top of each other so I'm assuming there would be no problem but I'm not 100% sure to be honest.

 

[technogeek]

I'll take the one yes and deafening silence as a "resounding yes!"

 

[stevez]

I'd encourage you to interpret "deafening silence" as a resounding "not sure" ....

My understanding of toroids is limited and like yours, suggests that most of the magnetic field is confined - most of suggests that some of the field is not contained. If your application is not critical it would seem harmless enought to try it.

I'd suggest some kind of experiment. If you have an L meter you might measure the inductance in series while stacked as you intend as well as in other arrangements with some separation. If you do that -share the results with us. If I had no other choice I might stack the toroids the apply some AC current (controlled, small amount) and look to see if any voltage at all appears across the other toroid's leads.

 

[mneary]

Since the consequence of mutual inductance is a slightly higher series total, even if it existed your circuit would have to be really sensitive in order to care.

Insulate to avoid shorting one to the other.