Miniaturised battery charger using piezoelectric transformers

Piezoelectric materials are a technology that in recent years have raised enormous interest for their possible use as power transformers. Their main features are high power densities, absence of electromagnetic noise and high voltage isolation capability. This paper presents the results obtained in a prototype of a miniaturized battery charger for mobile phones. Due to the reduced size of the piezoelectric transformers, the charger has been introduced in a plug type case, smaller than a matchbox.