The Bennet Doubler Circuit with a Transistor Voltage Divider for Kinetic Energy Harvesters

Operation features of the modified Bennet doubler circuit combined with a transistor voltage divider for kinetic energy harvesters are studied. The output parameters of the Bennet doubler circuit as well as the transformerless voltage divider with transistor-diode commutation of switchable capacitors are obtained using numerical simulation. It is shown that the joint circuit of the Bennet doubler and the transistor divider can be effectively used for kinetic energy harvesters. This circuit enables to reduce the high output voltages, and it can prevent the unlimited growth of charge and voltage, which is typical for the Bennet doubler circuit. It is demonstrated that the value of the saturation voltage $U$L on the load resistance $R$L strongly depends on the resistances R1, R2 in the transistor base circuit, and when the resistance of the limiting resistors increases the saturation voltage increases too. Moreover as the load resistance $R$L increases the value of the saturation voltage also increases even for fixed R1 and R2. It should be noted that at higher resistances and higher values of the load capacitance $C$L in steady-state mode the load voltage fluctuates weaker. The division coefficient of the transistor divider connected to the Bennet doubler depends on the circuit parameters. The analysis shows that as the resistances R1, R2, RL, and the value of η increase the division coefficient will tend to an ideal value.