# Question on transformer core saturation

Discussion in 'Homework Help' started by Pompey, Aug 26, 2010.

1. ### Pompey Thread Starter New Member

Aug 23, 2010
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Hello everyone. I work in train control. In this industry we use impedance bonds to pass 750v dc and block the track circuit ac signal thereby achieving track circuit separation. There is an unwanted condition that may occur ( unbalanced current) that can lead to core saturation and signal leakage through the impedance bond. I'm pretty sure how that condition is related to the formula reluctance equals length divide by permisivity times area but could someone verify how core saturation is related to this formula.

2. ### hgmjr Moderator

Jan 28, 2005
9,030
214
Greetings Pompey,

I have moved your post from its location within another existing post to a thread of its own. Here at AAC we urge our members to create their own threads rather than tack their question onto the end of an existing and perhaps related post. This avoids confusion and insures that the unique aspects of your question are addressed specifically.

hgmjr

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3. ### Pompey Thread Starter New Member

Aug 23, 2010
4
0
Hello everyone. I work in train control. In this industry, we use impedance bonds to pass 750v dc (for propulsion power) and blocks the track circuit ac signal, thereby, achieving track circuit separation for the purpose of train detection.
There is an undesired condition that may occur ( unbalance current) that can lead to the core of the impedance bond being saturated which causes signal leakage through the impedance bond. A false occupancy is the result ( system indicates a train is there that really isn't).
I'm pretty sure how core saturation is related to the formula Reluctance equals length divide by the product of permissivity times area but could someone verify how core saturation is related to this formula.

Last edited by a moderator: Aug 29, 2010
4. ### hgmjr Moderator

Jan 28, 2005
9,030
214
Your post is interesting. Do you have a link to a document that provides more information on the train detection scheme?

hgmjr

5. ### Pompey Thread Starter New Member

Aug 23, 2010
4
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Hello hgmjr. May i have your e-mail address so that i can send you a PDF file on train control.

Mar 6, 2009
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7. ### Pompey Thread Starter New Member

Aug 23, 2010
4
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Yes! this is the topic under discussion! These are not the same impedance bond that we use but the theory is the same. Three tuned circuits ( cab, transmitter and rcvr signals). It passes dc but attenuates the ac signals.

Last edited: Sep 6, 2010