TY - CONF AB - Piezoelectric transformers are well known since the publication of some patent applications at the end of the 1950s. But until today their only business use lies in the field of backlighting systems for LCDs. Due to key features as light-weight, flatness, high step-up at low volume and high efficiency piezoelectric transformers should be usable in a much broader range of applications. This contribution returns to mind their operating principle, shows how to model and to develop such devices as well as give some aspects for development trends that will lead to further applications. AU - Hemsel, Tobias AU - Littmann, Walter AU - Wallaschek, Jörg ID - 8926 IS - vol.1 KW - piezoelectric devices KW - reviews KW - transformers KW - backlighting systems KW - flatness KW - high efficiency piezoelectric transformers KW - high step-up KW - light-weight KW - low volume KW - operating principle KW - piezoelectric transformers KW - Circuits KW - Costs KW - Electromagnetic devices KW - Electromagnetic fields KW - Mechanical energy KW - Piezoelectric materials KW - Power electronics KW - Switching frequency KW - Transformers KW - Vibrations SN - 1051-0117 T2 - Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE TI - Piezoelectric transformers - state of the art and development trends VL - 1 ER - TY - CONF AB - Ultrasonic linear motors have now been investigated for several years. Their key features are high thrust forces related to their volume and good position-accuracy. This contribution consists of two main parts. In the first part we describe the state-of-the-art of linear piezoelectric motors. Characteristics like no-load velocity, maximum thrust force and other technical properties of commercially available devices will be reported as well as those of prototypes. In the second part we report an ongoing research and development project aiming at a linear piezoelectric motor, which is capable of surpassing some of the shortcomings of other piezoelectric motors AU - Hemsel, Tobias AU - Wallaschek, Jörg ID - 8915 KW - linear motors KW - ultrasonic motors KW - linear piezoelectric motor KW - maximum thrust force KW - no-load velocity KW - ultrasonic linear motor KW - Electromagnetic devices KW - Electromagnetic fields KW - Frequency KW - Friction KW - Gears KW - Materials science and technology KW - Piezoelectric materials KW - Research and development KW - Vibrations KW - Wheels SN - 1051-0117 T2 - Ultrasonics Symposium, 2000 IEEE TI - State of the art and development trends of ultrasonic linear motors VL - 1 ER -