A Modified Electret Microelectromechanical Generator with Autostabilization Mode

This work is devoted to theoretical and experimental study of the modified conditioning circuit of electrostatic microgenerator based on the Bennet doubler and allowing to operate with any capacitance modulation depth of the variable capacitor. A mathematical model of the generator enabling to find the charge variation for each circuit element depending on the circuit parameters is developed. It has been established that depending on capacitance modulation depth of the variable capacitor the circuit is able to operate in two different modes. When capacitance modulation depth is less than 2 one can observe an autostabilization of the storage capacitor voltage and charge, but when capacitance modulation depth is more than 2 a monotonous growth of the storage capacitor voltage and charge is observed. Analytical expressions allowing evaluate capacitors stabilized voltages in case when capacitance modulation depth is less than 2 have been derived. It has been found that an increase of the variable capacitor capacitance results in increase of the energy accumulation rate in the power source and therefore to increase the microgenerator power.