A low-power-extended-linear-range magnetic levitator

Abstract

In this thesis, I designed and built analog circuits to extend the linear range of a magnetic levitator. Analog Devices AD633 multipliers are used to implement nonlinear terms which compensate for the electromagnet and sensor nonlinearities, which were measured experimentally. Implementing the nonlinear compensation allows the system to be operating point independent. Frequency compensation was done with a lead network since the resulting linearized levitator is essentially a double integrator. Position sensing was done using an OPB732 reflective switch. Nonlinear compensation for the sensor is done with an AD532 multiplier configured as a divider.