[Jarvamundo (Alex)]

the model is this:

Scott says: “As I see it, [variable] binaries operate generally as follows: Each of the stars has an electrical capacitance. These two capacitances are permanently connected by a plasma (cloud). This plasma exhibits (as do all plasmas) a nonlinear resistance. If one of the stars charges up to a high enough voltage ... , then the plasma will go into the arc mode and emit brilliant light, perhaps x-rays and gamma-rays. Electrical energy will be transferred from the first capacitor (star) to the other. It doesn't make any difference which star is bigger.
“The "bridge" between the two stars probably doesn't go away. After the arc discharge is over (the voltage difference between the two capacitors is dissipated), the plasma bridge goes back into its normal glow or dark current mode and waits for the next discharge.”

now is this oscillation linked to mechanics... interesting question bojan, i feel capacities of the bodies and distance and available plasma to be the dominant variables.