  We give an updated version of the analytical equation of state used in the
Cambridge stellar evolution code (STARS) as a free to use open-source package
that we have used to model cool white dwarfs down to temperatures
$\log_{10}(T_\mathrm{eff}/\mathrm{K})\:=\;3$. With this update in the STARS
code we model the secular evolution of cataclysmic variable (CV) stars using a
double dynamo model wherein there is an interplay between two $\alpha-\Omega$
dynamos, one in the convective envelope and the other at the boundary of a
slowly rotating shrinking radiative core and the growing convective envelope.
We confirm that this model provides a physical formalism for the interrupted
magnetic braking paradigm. In addition, our model also provides a mechanism for
extra angular momentum loss below the period gap. We construct the relative
probability distribution of orbital periods $P_\mathrm{orb}$ using the {mass}
distribution of white dwarfs in cataclysmic variables and find that our model
excellently reproduces the period gap and the observed period minimum spike in
CV distribution. We also compare the evolutionary trajectories from our model
with those of other empirical models and find agreement between the two. We
also report good agreement between our modelled systems and observational data.
