  Magnetic fields of order $10^1-10^2$ gauss that are present in the envelopes
of red giant stars are ejected in common envelope scenarios. These fields could
be responsible for the launching of magnetically driven winds in
proto-planetary nebulae. Using 2D simulations of magnetized winds interacting
with an envelope drawn from a 3D simulation of the common envelope phase, we
study the confinement, heating, and magnetic field development of post-common
envelope winds. We find that the ejected magnetic field can be enhanced via
compression by factors up to $\sim 10^4$ in circumbinary disks during the
self-regulated phases. We find values for the kinetic energy of the order of
$10^{46}$ erg that explain the large values inferred in proto-planetary nebula
outflows. We show that the interaction of the formed circumbinary disk with a
spherical, stellar wind produces a "tapered" flow that is almost
indistinguishable from an imposed tapered flow. This increases the uncertainty
of the origin of proto-planetary nebula winds, which could be either stellar,
circumstellar (stellar accretion disk), circumbinary (circumbinary accretion
disk), or a combination of all three.
  Within this framework, a scenario for self-collimation of weakly magnetized
winds is discussed, which can explain the two objects where the collimation
process is observationally resolved, HD 101584 and Hen 3-1475. An explanation
for the equatorial, molecular hydrogen emission in CRL 2688 is also presented.
