Basic Output Generator Excitation and Demodulation Requirements for USD Gyroscopes

This applications note discusses the input signal excitation and output signal conditioning (demodulation) requirements of the transformer type output generator, or pickoff used on the US Dynamics Miniature Rate Integrating Gyroscopes (RIG) and Rate Gyroscopes. In addition, basic transformer type pickoff operation will be presented. The discussions and circuit examples provided in this note are intended to introduce system designers and engineers to the minimum basic requirements for gyroscope pickoff excitation and demodulation.

The US Dynamics miniature gyroscope output generator, also known as a pickoff, generates a user output signal indicating the position of the gyro's gimbal, usually in terms of millivolts per (angular) degree of gimbal rotation. All US Dynamics miniature gyroscope pickoff arrangements are implemented in the form a variable transformer. There are several variations of this basic variable transformer design used in various gyroscope designs. All transformer based pickoffs however, operate in the same fundamental manner. As in all typical transformers, AC voltage, or excitation, is supplied to the pickoff transformer primary winding. From the secondary winding of the pickoff an AC output signal is received.