A novel piezoelectric energy harvesting circuit is proposed. This circuit consists of a piezoelectric element, synchronized switch harvesting on capacitors (SSHC) circuit, two sampling resistors, control circuit, full-bridge rectifier, and load. The control circuit is composed of a zero-crossing detection circuit and a pulse generation circuit. The zero-crossing detection circuit adopts sampling resistance method, which is more accurate and easier to implement than the traditional voltage comparison method. The control signal for controlling switches in the SSHC circuit is generated by pulse generation circuit and its width is dynamically adjusted according to the state of the flipping process. Compared with circuit that uses capacitors to control the width of the control signal, this circuit is easier to implement and has a higher output efficiency. Experiment results show that the circuit proposed can accurately detect the zero-crossing time and automatically adjust the pulse width of the control signal according to the state of the circuit. The output power of the proposed circuit is 1.80 ​mW with 10 ​kΩ load resistance, which is four times that of the traditional SSHC circuit.

提出了一种新颖的压电能量收集电路。该电路由压电元件，电容器上的同步开关收集（SSHC）电路，两个采样电阻器，控制电路，全桥整流器和负载组成。控制电路由过零检测电路和脉冲发生电路组成。过零检测电路采用采样电阻法，比传统的电压比较法更准确，更容易实现。用于控制SSHC电路中的开关的控制信号由脉冲生成电路生成，并且其宽度根据翻转过程的状态而动态地调整。与使用电容器控制控制信号宽度的电路相比，该电路易于实现，并且具有较高的输出效率。实验结果表明，所提出的电路能够准确地检测出过零时间，并根据电路的状态自动调节控制信号的脉冲宽度。拟议电路的输出功率为1.80 mW，负载电阻为10kΩ，是传统SSHC电路的四倍。