Design And Build A High Energy Discharge Unit And Camera Triggering Unit

In this project the design and construction of two devices to assist with high speed fluid dynamics experiments involving high energy and high resolution photography were investigated.  Our first device allows for the precise release of thousands of volts stored in an 8µF capacitor, and through a high voltage switch (thyristor).  The resulting current pulse, on the microsecond timescale, has a magnitude on the order of 300 of amps, and gives our lab the capability to test a variety of experimental devices.  A second device, a camera triggering unit, makes it possible to photograph high speed phenomenon with a high resolution, 8 megapixel camera.  The triggering unit remotely senses the magnetic field caused by the current flow from the capacitor, and delivers a manageable voltage signal to a time delay unit. That delay unit allows the user to set a specific time delay, between the voltage signal input and the camera trigger output, determining when a photograph will be taken.  By varying the time delay it is possible to photograph different instances within the evolution of the experiment, therefore creating a high resolution image sequence, similar to a high speed movie.  Our finding showed that, for the first device, we needed to modify our high voltage switch from a Thyristor capable of discharging only 2000V, to an alternate switching device such as a spark gap which is capable of discharging higher voltages.  In addition, we determined that using a proportional, magnetic, Hall Effect sensor is most effective as a time delay trigger.  Though much of our research is complete, there is still testing and construction to be done before both devices are complete.