I have created the following circuit in Partsim. When I run the DC Bias analysis, the circuit on the left side of the coupled inductor behaves as expected. However, I do not see any voltage appearing on the right side of the coupled inductor. Shouldn't this inductor induce the same voltage to the right side of the circuit?

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I set the coupled inductor to have a "Coefficient of Coupling" of 1, an "Inductor 1 Value" of 1, and an "Inductor 2 Value" of 1.

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    \$\begingroup\$ Never used partsim, but ain't your source DC? (The label says so, despite the somewhat misleading symbol.) Transformers need AC. \$\endgroup\$
    – Fizz
    Oct 9, 2015 at 19:41
  • \$\begingroup\$ Yes source is DC. I was thinking that might be the problem but couldn't seem to find out for sure. So I need an AC source for the voltage to get induced on the other side of the circuit? \$\endgroup\$
    – flyingL123
    Oct 9, 2015 at 19:42
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    \$\begingroup\$ Yes, you need AC. \$\endgroup\$
    – Fizz
    Oct 9, 2015 at 19:43
  • \$\begingroup\$ By the way, if you wonder why I changed the tag to transformer: electronics.stackexchange.com/questions/96648/… \$\endgroup\$
    – Fizz
    Oct 9, 2015 at 21:20

1 Answer 1


If you wrap a coil around a magnet do you get a battery and free power for life? No you don't. For exactly the same reason you don't get anything out of a transformer with just DC applied. In simple terms, with dc applied to a lossless transformer, the voltage across the primary is zero volts. That means it takes no power therfore it can't deliver any power to the secondary.

In slightly more complicated terms, the primary is still an inductor and that acts as a perfect short under DC conditions.


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