A mechanically controlled oscillator

The theory, realization, characterization, and application of a mechanicall y controlled oscillator is presented in this paper. The control is accompli shed by a mechanical impact, which occurs at stoppers placed at a certain a mplitude of oscillation. In the mechanically controlled operation mode, the oscillation amplitude is defined by these stoppers. With properly designed devices, in spite of the mechanical impact, the oscillation is harmonic an d occurs at the frequency of the driving force. Higher harmonics are not de tectable. The distinguishing marks are that without any electronic control loops, a high stability of the amplitude and phase vs. temperature is achie ved. Since the oscillator is driven with constant amplitude and frequency a nd the detection of the oscillation is necessary only to prove that the osc illator is working, the required electronics is reduced to a minimum. Based on the mechanically controlled oscillator, the micromachined Coriolis Vibr atory Gyroscope DAVED(R) has been developed. It shows a bias stability less than 0.1 degrees/s over the temperature range of 25-100 degrees C. (C) 200 0 Elsevier Science S.A. All rights reserved.