Controlling the primary mode of gyroscopes with a phase-based amplitude regulation

This paper presents the circuit implementation of an amplitude regulation for the primary mode of gyroscopes based on phase-shifting. Instead of regulating the AC or DC value of the driving stage in order to maintain a constant primary oscillation, this concept introduces a tunable phase delay into the driving loop. The high voltages of the driving stage can be set to a constant value and do not have to be adjusted. The driving stage can be realized with a set of simple switches applying two fixed voltages to the gyroscope for actuation. This reduces the complexity of the circuitry enormously. Measurements reveal that the frequency is held constant with a sigma of 1Hz and the amplitude regulation is within 0.6% of the defined value.