  A dielectric elastomer generator (DEG) can be used for converting mechanical
energy from natural motion sources such as walking, waves, trees etc, into
electrical energy. A DEG is comprised of a soft and flexible Dielectric
Elastomer capacitor (DE), a Priming Circuit (PC), which transfers high
potential charge onto/off the DE electrodes, and a power extraction circuit
which harvests the generated power. To generate power, the PC must charge and
discharge the DE in synchronization with the DE's capacitance change. A simple
circuit to do this exists: the self-priming circuit (SPC). The SPC consists of
diodes and capacitors which passively switch between charge delivery and charge
receiving states in synchronization with the DE's capacitance change. Until now
there has been no understanding of how to design a SPC in order to maximize
harvested energy from the dielectric elastomer (DE). A new mathematical model
for a SPC is presented, leading to design and optimization. An accuracy of 0.1%
between model, simulation and experiment is obtained once losses are taken into
consideration. The behavior of the SPC is shown to be related to the maximum
and minimum capacitance's of the DE, but is largley unaffected by the exact
capacitance waveform
