# In & Out Of Phase Inductors

By: Christophe Campain

# Introduction To Inductor Phasing

<p class="callout info">With the traditional way of representing a transformer, it’s pretty easy to figure out the dot convention meaning.</p>

![Screenshot from 2022-06-20 01-30-54.png](https://stanslegacy.com/uploads/images/gallery/2022-06/scaled-1680-/uuztmumjPAwwrhgj-screenshot-from-2022-06-20-01-30-54.png)

In the case of inductors **in series** AND **magnetically coupled**, it is not always easy to figure out if the  
inductors are in phase or out of phase because they are not always represented side by side in the  
traditional way of transformers.

<p class="callout info">To help us, simply “connect” the bottom of a usual transformer to follow the current and figure out what would mean in series.</p>

![Screenshot from 2022-06-20 01-31-06.png](https://stanslegacy.com/uploads/images/gallery/2022-06/scaled-1680-/QdbVh2HA8hNiMfLd-screenshot-from-2022-06-20-01-31-06.png)

<p class="callout success">**In phase** : Current flows in the same direction.  
</p>

<p class="callout warning">**Out of phase**: Current flows in an opposing direction.</p>

So for 2 inductors **that are magnetically coupled** to each other and **in series**, if their input or output  
currents goes in the same direction, they are **in phase** and if their currents oppose to each other,  
they are 180° **out of phase**.

![Screenshot from 2022-06-20 01-31-12.png](https://stanslegacy.com/uploads/images/gallery/2022-06/scaled-1680-/ZFYQDajtN9W30Ka9-screenshot-from-2022-06-20-01-31-12.png)

PDF Version: [In phase or out of phase.pdf](https://stanslegacy.com/attachments/1)