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Superposition theorem fails when you have two ideal (identical) voltage sources in parallel. Under which specific constraints can I apply it?

I have read that, in DC Circuits, superposition requires that ideal voltage sources are never placed in parallel, and ideal current sources are never placed in series. Is this true?

I have tried to apply it to the following circuit, with R1 = 0.25 ohms, R2 = 0.32 ohms and V1 = V2 = 1.5V, but I'm getting absurd results:

enter image description here

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    \$\begingroup\$ So can you show us your work? \$\endgroup\$ – dirac16 Feb 21 at 21:47
  • \$\begingroup\$ Also, your result. One version of the circuit should be with the V1 = 0V (turned off and thus replaced by a short-circuit). The other version is with V2 turned off and should yield an identical circuit since V1 = V2, except the polarities are in the opposite direction. Therefore, the currents in each version are identical but opposing and therefore when superimposed cancel out and equal zero. \$\endgroup\$ – DKNguyen Feb 21 at 21:51
  • \$\begingroup\$ Superposition will work for this circuit...the circuit you provided as a schematic is not the same as what you described originally. Show us your work. \$\endgroup\$ – Elliot Alderson Feb 21 at 22:36
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The superposition theorem works for any linear circuit.

The problem with two voltage sources in parallel is that if their voltages are not identical then you have a nonsense circuit. Two different voltage sources in parallel will violate either or definition of parallel or our definition of an ideal voltage source.

EDIT after OP provides a schematic: The circuit you provided does not have ideal voltage sources in parallel. Superposition will work.

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    \$\begingroup\$ To add, connecting two ideal voltage sources together is analogous to writing "3 = 5". It's nonsense within the framework of schematics like "3 = 5" is nonsense within the framework of arithmetic expressions. \$\endgroup\$ – Shamtam Feb 21 at 21:39
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    \$\begingroup\$ This is correct, superposition applies to any linear system. Unfortunately this is a tautology, since the definition of a linear system boils down to "a system where superposition applies". \$\endgroup\$ – The Photon Feb 21 at 22:41

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