• BME 210
  • Handout 3: Superposition and Source Transform

    Superposition

    1. Select one of the independent sources. Set all other independent sources to zero.
    2. Relabel voltages and currents using suitable notation.
    3. Analyze the simplified circuit to find the desired currents and/or voltages.
    4. Repeat steps 1–3 until each independent source has been considered.
    5. Add the partial currents and/or voltages obtained from the separate analyses.
    6. Do not add power quantities (they are non-linear).

    Source Transformation

    1. A common goal in source transformation is to end up with either all current sources or all voltage sources in the circuit.
    2. Repeated source transformations can be used to simplify a circuit by allowing resistors and sources to eventually be combined.
    3. The resistor value does not change during a source transformation, but it is not the same resistor (i.e., currents and voltages are lost).
    4. If the voltage or current associated with a particular resistor is used as a controlling variable for a dependent source, it should not be included in any source transformation.
    5. If the voltage or current associated with a particular element is of interest, that element should not be included in any source transformation.
    6. In a source transformation, the head of the current source arrow corresponds to the “+” terminal of the voltage source.
    7. A source transformation on a current source and resistor requires that the two elements be in parallel.
    8. A source transformation on a voltage source and resistor requires that the two elements be in series.




    Last updated:
    January 6, 2018