Study on the power storage and management circuit of a magnetoelectric self-powered harvester

Since ordinary Fe-Ni/PZT magnetoelectric composite structure has a low output for converting electromagnetic energy into electric energy and its output power is not sufficient for the power requirement of a wireless sensor, an H-type composite structure with higher magnetoelectric voltage coefficient is proposed. The composite structure principle and its performance are introduced in detail. The voltage across a 1.5 F super capacitor can be charged to 0.5 V under the excitation of an AC magnetic intensity of 0.2 Oe. In order to use the output power from the super capacitor efficiently, an instantaneous discharging circuit is designed. Experimental results show that the discharging power of the proposed circuit reaches 120 mW and the discharge time can last for 620 ms for the triggering signal with a frequency of 30 kHz and a duty cycle of 75%. Thus this circuit can meet the wireless sensor power requirement in a transmission cycle time.