Energy harvesting device

An energy harvesting device, comprising:

• an electric generator for charging an electric storage;
• and
• an power management circuit configured to operate with power from the electric storage, and to charge the electric storage with power from the electric generator,
• the electric generator including two or more electric generation portions each configured to generate AC power when vibrated,
• the power management circuit including
• a first power extraction circuit,
• a second power extraction circuit, and
• a switch circuit,
• the first power extraction circuit including a first input unit, a first output unit, and a rectification circuit between the first input unit and the first output unit,
• the rectification circuit being configured to convert AC power received by the first input unit into DC power and provide the converted DC power to the first output unit,
• the second power extraction circuit including a second input unit, a second output unit, and a switching circuit which is between the second input unit and the second output unit and is configured to operate with power supplied from the electric storage,
• the switching circuit being configured to generate DC power by use of AC power received by the second input unit and provide the generated DC power to the second output unit,
• the switch circuit having a first connection mode of connecting the electric generator and the electric storage to the first input unit and the first output unit, respectively, and a second connection mode of connecting the electric generator and the electric storage to the second input unit and the second output unit, respectively,
• the switch circuit being configured to, in the first connection mode, connect the two or more electric generation portions to the first input unit such that an effective value of an AC voltage to be provided to the first input unit in the first connection mode is greater than an effective value of an AC voltage to be provided to the second input unit in the second connection mode, and
• the switch circuit being configured to, in the second connection mode, connect the two or more electric generation portions to the second input unit such that the effective value of the AC voltage to be provided to the second input unit in the second connection mode is greater than the effective value of the AC voltage to be provided to the first input unit in the first connection mode.