Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

"wet" type transformer DC pass (?!?!) are they exist?

Status
Not open for further replies.

plouf

Junior Member level 3
Joined
Feb 9, 2012
Messages
31
Helped
1
Reputation
2
Reaction score
3
Trophy points
1,288
Location
Athens,Greece
Activity points
1,597
Hi

while searching for some telphone circuits i come across this article -> https://en.wikipedia.org/wiki/Line_isolation_transformer
it claims that "wet" type transformer can pass DC, therefore you can detect on/off hook ?

since i never come across this, is this true ? if yes does anyone knows ANY "wet" transformer type to buy from anywhere that can DC pass ? (without extra components)
 

You misunderstood the Wikipedia article. No transformer can "pass" DC current between primary and secondary. The article talks about a transformer that doesn't saturate with DC current flowing in the primary winding.
 

The wikipedia article is badly written: I do not understand what is wet or dry refers to in this context.

Certainly no isolation transformer will be designed to pass DC; not even with a gapped core.

A core with a gap will have a higher magnetic reluctance and will need greater mmf to saturate. But that also comes at a price.
 

The wikipedia article is badly written: I do not understand what is wet or dry refers to in this context.

Certainly no isolation transformer will be designed to pass DC; not even with a gapped core.

A core with a gap will have a higher magnetic reluctance and will need greater mmf to saturate. But that also comes at a price.

As far as wet or dry goes the only thing that comes to mind is whether it's and oil filled transformer or not.
 

The term "wet" means that a DC current is flowing into the circuit. In this case the current is made flowing through the primary winding. Of course there is no DC transfer from the primary to the secondary windings,
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top