Document Type


Date of Award


Degree Name

Master of Science in Electrical Engineering - (M.S.)


Electrical Engineering

First Advisor

William N. Carr

Second Advisor

Durgamadhab Misra

Third Advisor

Kenneth Sohn


A 6-phase bipolarized, high-voltage power supply with rectangular pulse shape has been designed to study the special operational characteristics of various electrostatic-drive micromotors. In particular the design powers the variable-capacitance side-drive micromotor. This power supply provides variable frequency, variable voltage, and variable duty-cycle control. Simulation has been used extensively in the design and design verification.

The bipolarization (dual voltage polarity) of each pair of the phases reduces physical clamping of the rotor to the electrical shield beneath it. Thus, bipolarization of the voltage supplied to the stator nodes reduces charge build-up on the rotor.

The output frequency range varying from 1Hz to 40KHz has been achieved. This supply frequency range corresponds to motor rotational speed range of 5rpm to 200Krpm, for a micromotor with 12 stator poles and 8 rotor poles (3:2 architec-ture). The voltage amplitudes of all six phases can be varied from 20 to 200Volts.

The duty cycle of each phase can be changed by means of a parallel register. The output with variable duty cycle has been obtained, changing from 50% non-overlapping to 33% overlapping.

The power supply with 6-phase bipolarized output, variable frequency, and variable voltage output has been constructed with prototyping wire wrap boards, and assembled in a card cage. The power supply is shown to meet the design specification.



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