Variable Frequency/PWM Driver Circuit

Co-Created with Dr. Soumendra N. Basu, Dr. Mark N Horenstein and Casey Pelkowsky

July 2020

Abstract: 

Professor Basu reached out asking for assistance regarding an electrical component needed for an Electrophoretic Deposition (EPD) experiment. The test required a circuit capable of delivering square waves with variable frequency, PWM and amplitude(±80V). The circuit needed a simple interface to vary these parameters so his research students could preform tests. 

Key Contributions: 

While the primary design of the circuit was delivered by Professor. Horenstein, I worked closely with him to refine the design. After 5 iterative design changes, we were able to significantly reduce the complexity of the circuit and replace some of the analog circuitry with a micro-controller for ease of implementation. After this, I did the physical implementation and debugging of the circuit for Professor Basu. 

Results: 

By applying a high frequency charge across a prepared sample, you can see particles were successfully deposited on the surface of the copper! The final implementation did deviate from the original SPICE design, although the circuit had the same effect. We were unable to get the voltage regulators to properly switch and therefore maintain the required ± voltage. In addition to this, the pulse was replaced with a function generator opposed to the proposed micro-controller.