Piezotransformers

Research : Smart Devices : Discrete Devices : Piezotransformers

Piezotransformers

Miniaturized piezo transformer prototype.

Objective:

Miniaturized cell-phone battery charger using piezoelectric transformers, and integrated note-book/laptop power adapter.

Approach:

Piezoelectric transformers with drive circuit/charger systems have enormous potential to reduce bulky electromagnetic transformers, increase energy efficiency and reduce the dollar cost per unit.
Exhibit huge power densities, in the order of 40 W/cm³.
96%-98% efficiency range require no heat sinks.
Provide true power isolation and eliminate stray magnetics.

Accomplishments

A multi-layer piezoelectric voltage and power transformer which has one direction poling, operates in a wide-frequency range and delivers both step-up and step-down voltages by inverting the electrical connections has been developed, characterized and implemented.
A complete equivalent circuit model and FEM model for the above design has been developed and used to verify the experimental results.

Publications:

[1]	Ahn CW, Song HC, Nahm S, et al., "Effect of ZnO and CuO on the sintering temperature and piezoelectric properties of a hard piezoelectric ceramic", Journal of the American Ceramic Society 89 (3): 921-925, Mar 2006.
[2]	Priya S, Kim H, Ural S, et al., "High power universal piezoelectric transformer", (vol 53, pg 810, 2006) IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control 53 (4): 810-816, Apr 2006.
[3]	Uchino K, Zheng JH, Chen YH, et al., " Loss mechanisms and high power piezoelectrics", Journal of Materials Science 41 (1): 217-228, Jan 2006.
[4]	Chen CT, Islam RA, Priya S, "Electric energy generator", IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Contol 53 (3): 656-661, Mar 2006.
[5]	Islam RA, Priya S, "Realization of high-energy density polycrystalline piezoelectric ceramics", Applied Physics Letters 88 (3): Art. No. 032903, Jan 16 2006.