Simple Disk Piezo Transformer Based Oscillator

J. P. Sandoz[1], J. M. Kissling[1]
[1]Institute of Applied Microtechnology, La Chaux-de-Fonds, HE‐ARC, Switzerland
Published in 2014

In this contribution we present a COMSOL Multiphysics® example of a disk piezoelectric ceramic transformer (D-PT) coupled with a bipolar NPN transistor to form an auto-oscillator. The comparison between the simulations and the measurements made on our prototype are found to be in good agreement. Having at our disposal a large number of homogenously poled disks, we decided to build and to investigate the performances of D-PT. The results of the simulation validate the fact that with this simple schematic the running frequency is 20% higher than the optimal frequency of the D-PT running alone.In conclusion, the use of COMSOL Multiphysics® turned out to be a very effective way to find good positions for the D-PT clamping points, a particular challenging problem with such a light weight device.